Side view of the apical third of the root canal of a maxillary lateral incisor with necrotic pulp and chronic periapical lesion adhered to the tooth structure.

 

Courtesy of Ms. Thaís Silva

 

Image Details

Instrument used: Quanta SEM

Magnification: 130X

Horizontal Field Width: 2.30 mm

Voltage: 20 kV

Spot: 4.0

Working Distance: 15.4 mm

Detector: Mix SE+ BSE

 

Hippopotamuses love water, which is why the Greeks named them the "river horse." Hippos spend up to 16 hours a day submerged in rivers and lakes to keep their massive bodies cool under the hot African sun. Hippos are graceful in water, good swimmers, and can hold their breath underwater for up to five minutes. However, they are often large enough to simply walk or stand on the lake floor, or lie in the shallows. Their eyes and nostrils are located high on their heads, which allows them to see and breathe while mostly submerged. Hippos also bask on the shoreline and secrete an oily red substance, which gave rise to the myth that they sweat blood. The liquid is actually a skin moistener and sunblock that may also provide protection against germs. At sunset, hippopotamuses leave the water and travel overland to graze. They may travel 6 miles (10 kilometers) in a night, along single-file pathways, to consume some 80 pounds (35 kilograms) of grass. Considering their enormous size, a hippo's food intake is relatively low. If threatened on land hippos may run for the water—they can match a human's speed for short distances. Hippo calves weigh nearly 100 pounds (45 kilograms) at birth and can suckle on land or underwater by closing their ears and nostrils. Each female has only one calf every two years. Soon after birth, mother and young join schools that provide some protection against crocodiles, lions, and hyenas. Hippos once had a broader distribution but now live in eastern central and southern sub-Saharan Africa, where their populations are in decline. A partially submerged hippopotamus tries to keep cool in the hot African sun. The hippopotamus (Hippopotamus amphibius), or hippo, from the ancient Greek for "river horse" (ἱπποπόταμος), is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae (the other is the Pygmy Hippopotamus.) After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest extant artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, their closest living relatives are cetaceans (whales, porpoises, etc.) from which they diverged about 55 million years ago. The common ancestor of whales and hippos split from other even-toed ungulates around 60 million years ago. The earliest known hippopotamus fossils, belonging to the genus Kenyapotamus in Africa, date to around 16 million years ago.

The hippopotamus is semi-aquatic, inhabiting rivers, lakes and mangrove swamps, where territorial bulls preside over a stretch of river and groups of 5 to 30 females and young. During the day they remain cool by staying in the water or mud; reproduction and childbirth both occur in water. They emerge at dusk to graze on grass. While hippopotamuses rest near each other in the water, grazing is a solitary activity and hippos are not territorial on land. Hippos are recognizable by their barrel-shaped torso, enormous mouth and teeth, nearly hairless body, stubby legs and tremendous size. It is the third largest land mammal by weight (between 1½ and 3 tonnes), behind the white rhinoceros (1½ to 3½ tonnes) and the three species of elephant (3 to 9 tonnes). The hippopotamus is one of the largest quadrupeds and despite its stocky shape and short legs, it can easily outrun a human. Hippos have been clocked at 30 km/h (19 mph) over short distances. The hippopotamus is one of the most aggressive creatures in the world and is often regarded as one of the most dangerous animals in Africa. They are still threatened by habitat loss and poaching for their meat and ivory canine teeth. There is also a colony of non-zoo hippos in Colombia introduced by Pablo Escobar. The most recent theory of the origins of Hippopotamidae suggests that hippos and whales shared a common semi-aquatic ancestor that branched off from other artiodactyls around 60 million years ago.[13][15] This hypothesized ancestral group likely split into two branches around 54 million years ago.[12] One branch would evolve into cetaceans, possibly beginning about 52 million years ago with the proto-whale Pakicetus and other early whale ancestors collectively known as Archaeoceti, which eventually underwent aquatic adaptation into the completely aquatic cetaceans.[17] The other branch became the anthracotheres, a large family of four-legged beasts, the earliest of whom in the late Eocene would have resembled skinny hippopotamuses with comparatively small and narrow heads. All branches of the anthracotheres, except that which evolved into Hippopotamidae, became extinct during the Pliocene without leaving any descendants.[15]

A rough evolutionary lineage can be traced from Eocene and Oligocene species: Anthracotherium and Elomeryx to the Miocene Merycopotamus and Libycosaurus and the very latest anthracotheres in the Pliocene.[18] Merycopotamus, Libycosaurus and all hippopotamids can be considered to form a clade, with Libycosaurus being more closely related to hippos. Their common ancestor would have lived in the Miocene, about 20 million years ago. Hippopotamids are therefore deeply nested within the family Anthracotheriidae. The Hippopotamidae are believed to have evolved in Africa; the oldest known hippopotamid is the genus Kenyapotamus which lived in Africa from 16 to 8 million years ago. While hippopotamid species spread across Asia and Europe, no hippopotamuses have ever been discovered in the Americas, although various anthracothere genera emigrated into North America during the early Oligocene. From 7.5 to 1.8 million years ago an ancestor to the modern hippopotamus, Archaeopotamus, lived in Africa and the Middle East.[19]

While the fossil record of hippos is still poorly understood, the two modern genera, Hippopotamus and Choeropsis (sometimes Hexaprotodon), may have diverged as far back as 8 million years ago. Taxonomists disagree whether or not the modern Pygmy Hippopotamus is a member of Hexaprotodon —an apparently paraphyletic genus also embracing many extinct Asian hippopotamuses that is more closely related to Hippopotamus, or Choeropsis —an older and basal genus.[18][19]

[edit]Extinct species

Three species of Malagasy Hippopotamus became extinct during the Holocene on Madagascar, one of them within the past 1,000 years. The Malagasy Hippos were smaller than the modern hippopotamus, likely through the process of insular dwarfism.[20] There is fossil evidence that many Malagasy Hippos were hunted by humans, a likely factor in their eventual extinction.[20] Isolated members of Malagasy Hippopotamus may have survived in remote pockets; in 1976, villagers described a living animal called the Kilopilopitsofy, which may have been a Malagasy Hippopotamus.[21]

Two species of Hippopotamus, the European Hippopotamus (H. antiquus) and H. gorgops ranged throughout continental Europe and the British Isles. Both species became extinct before the last glaciation. Ancestors of European Hippos found their way to many islands of the Mediterranean during the Pleistocene.[22] Both species were larger than the modern hippopotamus, averaging about 1 meter (3.3 feet) longer. The Pleistocene also saw a number of dwarf species evolve on several Mediterranean islands including Crete (H. creutzburgi), Cyprus (H. minor), Malta (H. melitensis) and Sicily (H. pentlandi). Of these, the Cyprus Dwarf Hippopotamus, survived until the end of the Pleistocene or early Holocene. Evidence from an archaeological site Aetokremnos, continues to cause debate on whether or not the species was encountered, and was driven to extinction, by man. Hippopotamuses are among the largest living mammals; only elephants and some rhinoceroses and whales are heavier. They can live in the water or on land. Their specific gravity allows them to sink and walk or run along the bottom of a river. Hippos are considered megafauna, but unlike all other African megafauna, hippos have adapted for a semi-aquatic life in freshwater lakes and rivers.[9]:3 A hippo's lifespan is typically 40–50 years.[6]:277 Donna the Hippo, 60, was the oldest living hippo in captivity. She lived at the Mesker Park Zoo in Evansville, Indiana, USA[24][25] until her death on August 1, 2012. The oldest hippo ever recorded was called Tanga; she lived in Munich, Germany, and died in 1995 at the age of 61.[26]

Because of their enormous size, hippopotamuses are difficult to weigh in the wild. Most estimates of the weight come from culling operations that were carried out in the 1960s. The average weights for adult males ranged between 1,500–1,800 kg (3,300–4,000 lb). Females are smaller than their male counterparts, with average weights measuring between 1,300–1,500 kg (2,900–3,300 lb).[9]:12 Older males can get much larger, reaching at least 3,200 kg (7,100 lb) with a few exceptional specimens exceeding 3,600 kg (7,900 lb).[27][28] The heaviest known hippopotamus weighed approximately 4,500 kg (9,900 lb).[29] Male hippos appear to continue growing throughout their lives; females reach a maximum weight at around age 25.[30]

Hippos measure 3.3 to 5.2 meters (11 to 17 ft) long, including a tail of about 56 centimeters (22 in) in length and average about 1.5 meters (5 ft) tall at the shoulder.[31][32] The range of hippopotamus sizes overlaps with the range of the white rhinoceros; use of different metrics makes it unclear which is the largest land animal after elephants. Even though they are bulky animals, hippopotamuses can run faster than a human on land. Estimates of their running speed vary from 30 km/h (18 mph) to 40 km/h (25 mph), or even 50 km/h (30 mph). The hippo can maintain these higher speeds for only a few hundred meters. Despite being semi-aquatic and having webbed feet, an adult hippo is not a particularly good swimmer nor can it float. It is rarely found in deep water; when it is, the animal moves by porpoise-like leaps from the bottom. The eyes, ears, and nostrils of hippos are placed high on the roof of the skull. This allows them to be in the water with most of their body submerged in the waters and mud of tropical rivers to stay cool and prevent sunburn. Their skeletal structure is graviportal, adapted to carrying the animals' enormous weight. Hippopotamuses have small legs (relative to other megafauna) because the water in which they live reduces the weight burden. Unlike most other semi-aquatic animals, the hippopotamus has very little hair.[6]:260 The skin is 6 in (15 cm) thick,[33] providing it great protection against conspecifics and predators. The animals's upper parts are purplish-gray to blue-black while the under parts and areas around the eyes and ears can be brownish-pink.[6]:260 The testes of the males descend only partially and a scrotum is not present. In addition, the penis retracts into the body when not erect. The genitals of the female are unusual in that the vagina is ridged and two large diverticula protrude from the vulval vestibule. The function of these is unknown.[9]:28–29

The hippo's jaw is powered by a large masseter and a well developed digastric; the latter loops up behind the former to the hyoid.[6]:259 The jaw hinge is located far back enough to allow the animal to open its mouth at almost 180°.[9]:17 On the National Geographic Channel television program, "Dangerous Encounters with Brady Barr", Dr. Brady Barr measured the bite force of an adult female hippo at 8100 N (1821 lbf); Barr also attempted to measure the bite pressure of an adult male hippo, but had to abandon the attempt due to the male's aggressiveness.[34] Hippopotamus teeth sharpen themselves as they grind together. The lower canines and lower incisors are enlarged, especially in males, and grow continuously. The incisors can reach 40 cm (16 in) while the canines reach up to 50 cm (20 in).[33]

Their skin secretes a natural sunscreen substance which is red-colored. The secretion is sometimes referred to as "blood sweat," but is neither blood nor sweat. This secretion is initially colorless and turns red-orange within minutes, eventually becoming brown. Two distinct pigments have been identified in the secretions, one red (hipposudoric acid) and one orange (norhipposudoric acid). The two pigments are highly acidic compounds. Both pigments inhibit the growth of disease-causing bacteria; as well, the light absorption of both pigments peaks in the ultraviolet range, creating a sunscreen effect. All hippos, even those with different diets, secrete the pigments, so it does not appear that food is the source of the pigments. Instead, the animals may synthesize the pigments from precursors such as the amino acid tyrosine. Hippopotamus amphibius was widespread in North Africa and Europe during the Eemian[36] and late Pleistocene until about 30,000 years ago. The species was common in Egypt's Nile region during antiquity but has since been extirpated. Pliny the Elder writes that, in his time, the best location in Egypt for capturing this animal was in the Saite nome;[37] the animal could still be found along the Damietta branch after the Arab Conquest in 639. Hippos are still found in the rivers and lakes of the northern Democratic Republic of the Congo, Uganda, Tanzania and Kenya, north through to Ethiopia, Somalia and Sudan, west from Ghana to Gambia, and also in Southern Africa (Botswana, Republic of South Africa, Zimbabwe, Zambia, Mozambique). Genetic evidence suggests that common hippos in Africa experienced a marked population expansion during or after the Pleistocene Epoch, attributed to an increase in water bodies at the end of the era. These findings have important conservation implications as hippo populations across the continent are currently threatened by loss of access to fresh water.[10] Hippos are also subject to unregulated hunting and poaching. In May 2006 the hippopotamus was identified as a vulnerable species on the IUCN Red List drawn up by the World Conservation Union (IUCN), with an estimated population of between 125,000 and 150,000 hippos, a decline of between 7% and 20% since the IUCN's 1996 study. Zambia (40,000) and Tanzania (20,000–30,000) possess the largest populations.[1]

The hippo population declined most dramatically in the Democratic Republic of the Congo.[38] The population in Virunga National Park had dropped to 800 or 900 from around 29,000 in the mid 1970s.[39] The decline is attributed to the disruptions caused by the Second Congo War.[39] The poachers are believed to be former Hutu rebels, poorly paid Congolese soldiers, and local militia groups.[39] Reasons for poaching include the belief that hippos are harmful to society, and also for money.[40] The sale of hippo meat is illegal, but black-market sales are difficult for Virunga National Park officers to track. Invasive potential

In the late 1980s, Pablo Escobar kept four hippos in a private menagerie at his residence in Hacienda Napoles, 100 km east of Medellín, Colombia, after buying them in New Orleans. They were deemed too difficult to seize and move after Escobar's fall, and hence left on the untended estate. By 2007, the animals had multiplied to 16 and had taken to roaming the area for food in the nearby Magdalena River.[41] In 2009, two adults and one calf escaped the herd, and after attacking humans and killing cattle, one of the adults (called "Pepe") was killed by hunters under authorization of the local authorities.[42][43] It is unknown what kind of effects the presence of hippos might have on the ecosystem in Colombia. According to experts interviewed by W Radio Colombia, the animals could survive in the Colombian jungles. It is believed that the lack of control from the Colombian government, which is not used to dealing with this species, could result in human fatalities. Hippos spend most of their days wallowing in the water or the mud, with the other members of their pod. The water serves to keep their body temperature down, and to keep their skin from drying out. With the exception of eating, most of hippopotamuses' lives —from childbirth, fighting with other hippos, to reproduction— occur in the water. Hippos leave the water at dusk and travel inland, sometimes up to 8 kilometers (5 mi), to graze on short grass, their main source of food. They spend four to five hours grazing and can consume 68 kilograms (150 lb) of grass each night.[44] Like almost any herbivore, they will consume many other plants if presented with them, but their diet in nature consists almost entirely of grass, with only minimal consumption of aquatic plants.[45] Hippos have (rarely) been filmed eating carrion, usually close to the water. There are other reports of meat-eating, and even cannibalism and predation.[46] The stomach anatomy of a hippo is not suited to carnivory, and meat-eating is likely caused by aberrant behavior or nutritional stress.[9]:84

The diet of hippos consists mostly of terrestrial grasses, even though they spend most of their time in the water. Most of their defecation occurs in the water, creating allochthonous deposits of organic matter along the river beds. These deposits have an unclear ecological function.[45] Because of their size and their habit of taking the same paths to feed, hippos can have a significant impact on the land they walk across, both by keeping the land clear of vegetation and depressing the ground. Over prolonged periods hippos can divert the paths of swamps and channels.[47]

Adult hippos move at speeds up to 8 km/h (5 mph) in water. Adult hippos typically resurface to breathe every three to five minutes. The young have to breathe every two to three minutes.[9]:4 The process of surfacing and breathing is automatic, and even a hippo sleeping underwater will rise and breathe without waking. A hippo closes its nostrils when it submerges into the water. As with fish and turtles on a coral reef, hippo occasionally visit cleaning stations and signal by wide-open mouth their readiness for being cleaned of parasites by certain species of fish. This situation is an example of mutualism in which the hippo benefits from the cleansing while the fish receive food.[ Studying the interaction of male and female hippopotamuses has long been complicated by the fact that hippos are not sexually dimorphic and thus females and young males are almost indistinguishable in the field.[49] Although hippos like to lie close to each other, they do not seem to form social bonds except between mothers and daughters, and are not social animals. The reason they huddle close together is unknown.[9]:49

Hippopotamuses are territorial only in water, where a bull presides over a small stretch of river, on average 250 meters in length, and containing ten females. The largest pods can contain over 100 hippos.[9]:50 Other bachelors are allowed in a bull's stretch, as long as they behave submissively toward the bull. The territories of hippos exist to establish mating rights. Within the pods, the hippos tend to segregate by gender. Bachelors will lounge near other bachelors, females with other females, and the bull on his own. When hippos emerge from the water to graze, they do so individually.[9]:4

Hippopotamuses appear to communicate verbally, through grunts and bellows, and it is thought that they may practice echolocation, but the purpose of these vocalizations is currently unknown. Hippos have the unique ability to hold their head partially above the water and send out a cry that travels through both water and air; hippos above and under water will respond.[ Female hippos reach sexual maturity at five to six years of age and have a gestation period of 8 months. A study of endocrine systems revealed that female hippopotamuses may begin puberty as early as 3 or 4 years of age.[51] Males reach maturity at around 7.5 years. A study of hippopotamus reproductive behavior in Uganda showed that peak conceptions occurred during the end of the wet season in the summer, and peak births occurred toward the beginning of the wet season in late winter. This is because of the female's estrous cycle; as with most large mammals, male hippopotamus spermatozoa is active year round. Studies of hippos in Zambia and South Africa also showed evidence of births occurring at the start of the wet season.[9]:60–61 After becoming pregnant, a female hippopotamus will typically not begin ovulation again for 17 months.[51]

Mating occurs in the water with the female submerged for most of the encounter,[9]:63 her head emerging periodically to draw breath. Baby hippos are born underwater at a weight between 25 and 45 kg (60–110 lb) and an average length of around 127 cm (50 in) and must swim to the surface to take their first breath. A mother typically gives birth to only one hippo, although twins also occur. The young often rest on their mothers' backs when in water that is too deep for them, and they swim underwater to suckle. They also will suckle on land when the mother leaves the water. Weaning starts between six and eight months after birth and most calves are fully weaned after a year.[9]:64 Like many other large mammals, hippos are described as K-strategists, in this case typically producing just one large, well-developed infant every couple of years (rather than large numbers of small, poorly developed young several times per year as is common among small mammals such as rodents. Hippopotamuses are by nature very aggressive animals, especially when young calves are present. Frequent targets of their aggression include crocodiles, which often inhabit the same river habitat as hippos. Nile crocodiles, lions and spotted hyenas are known to prey on young hippos.[53] Hippos are very aggressive towards humans, whom they commonly attack whether in boats or on land with no apparent provocation.[54] They are widely considered to be one of the most dangerous large animals in Africa.[55][56]

To mark territory, hippos spin their tails while defecating to distribute their excrement over a greater area.[57] Likely for the same reason, hippos are retromingent – that is, they urinate backwards.[58] When in combat, male hippos use their incisors to block each others attacks, and their lower canines to inflict damage.[6]:260 Hippos rarely kill each other, even in territorial challenges. Usually a territorial bull and a challenging bachelor will stop fighting when it is clear that one hippo is stronger. When hippos become overpopulated, or when a habitat starts to shrink, bulls will sometimes attempt to kill infants, but this behavior is not common under normal conditions.[52] Some incidents of hippo cannibalism have been documented, but it is believed to be the behavior of distressed or sick hippos, and not healthy behavior. The earliest evidence of human interaction with hippos comes from butchery cut marks upon hippo bones at Bouri Formation dated around 160,000 years ago.[59] Later rock paintings and engravings showing hippos being hunted have been found in the mountains of the central Sahara dated 4,000–5,000 years ago near Djanet in the Tassili n'Ajjer Mountains.[9]:1 The ancient Egyptians recognized the hippo as a ferocious denizen of the Nile.

The hippopotamus was also known to the Greeks and Romans. The Greek historian Herodotus described the hippopotamus in The Histories (written circa 440 BC) and the Roman Historian Pliny the Elder wrote about the hippopotamus in his encyclopedia Naturalis Historia (written circa 77 AD).[37][60] Hippopotamus was one of the many exotic animals brought to fight gladiators in Rome by the emperor Philip I the Arab to commemorate Rome's 1000 years anniversary in 248 AD. Silver coins with hippo's image were minted that year.[citation needed]

Zulu warriors preferred to be as brave as a hippopotamus, since even lions were not considered as brave. "In 1888, Captain Baden-Powell was part of a column searching for the Zulu chief Dinizulu, who was leading the Usutu people in revolt against the British colonists. The column was joined by John Dunn, a white Zulu chief, who led an impi (army) of 2000 Zulu warriors to join the British." [61]

The words of the Zulu anthem sounded like this:

"Een-gonyama Gonyama! "Invooboo! Yah-bo! Yah-bo! Invooboo!"

"John Dunn was at the head of his impi. [Baden Powell] asked him to translate the Zulu anthem his men had been singing. Dunn laughed and replied: "He is a lion. Yes, he is better than a lion—he is a hippopotamus. Hippopotamuses have long been popular zoo animals. The first zoo hippo in modern history was Obaysch who arrived at the London Zoo on May 25, 1850, where he attracted up to 10,000 visitors a day and inspired a popular song, the Hippopotamus Polka.[63] Hippos have remained popular zoo animals since Obaysch, and generally breed well in captivity. Their birth rates are lower than in the wild, but this is attributed to zoos' not wanting to breed as many hippos as possible, since hippos are large and relatively expensive animals to maintain.[9]:129[63]

Like many zoo animals, hippos were traditionally displayed in concrete exhibits. In the case of hippos, they usually had a pool of water and patch of grass. In the 1980s, zoo designers increasingly designed exhibits that reflected the animals' native habitats. The best known of these, the Toledo Zoo Hippoquarium, features a 360,000 gallon pool for hippos.[64] In 1987, researchers were able to tape, for the first time, an underwater birth (as in the wild) at the Toledo Zoo. The exhibit was so popular that the hippos became the logo of the Toledo Zoo. A red hippo represented the Ancient Egyptian god Set; the thigh is the 'phallic leg of set' symbolic of virility. Set's consort Tawaret was also seen as part hippo.[66] The hippopotamus-headed Tawaret was a goddess of protection in pregnancy and childbirth, because ancient Egyptians recognized the protective nature of a female hippopotamus toward her young.[67] The Ijo people wore masks of aquatic animals like the hippo when practicing their water spirit cults.[68] The Behemoth from the Book of Job, 40:15–24 is also thought to be based on a hippo.[69]

Hippos have been the subjects of various African folktales. According to a Bushmen story; when the Creator assigned each animal their place in nature, the hippos wanted to live in the water, but were refused out of fear that they might eat all the fish. After begging and pleading, the hippos were finally allowed to live in the water on the conditions that they would eat grass instead of fish and would fling their dung so that it can be inspected for fish bones.[70] In a Ndebele tale, the hippo originally had long, beautiful hair but was set on fire by a jealous hare and had to jump into a nearby pool. The hippo lost most of his hair and was too embarrassed to leave the water.[70]

Ever since Obaysch inspired the Hippopotamus Polka, hippos have been popular animals in Western culture for their rotund appearance that many consider comical.[63] Stories of hippos like Huberta who became a celebrity in South Africa in the 1930s for trekking across the country;[71] or the tale of Owen and Mzee, a hippo and tortoise who developed an intimate bond; have amused people who have bought hippo books, merchandise, and many a stuffed hippo toy.[72][73] Hippos were mentioned in the novelty Christmas song "I Want a Hippopotamus for Christmas" that became a hit for child star Gayla Peevey in 1953.[74] They also feature in the songs "The Hippopotamus" and "Hippo Encore" by Flanders and Swann, with the famous refrain Mud, Mud, Glorious Mud. They even inspired a popular board game, Hungry Hungry Hippos. Hippos have also been popular cartoon characters, where their rotund frame is used for humorous effect. The Disney film Fantasia featured a ballerina hippopotamus dancing to the opera, La Gioconda.[38] Other cartoon hippos have included Hanna-Barbera's Peter Potamus, the book and TV series George and Martha, Flavio and Marita on the Animaniacs, Pat of the French duo Pat et Stanley, The Backyardigan's Tasha, and Gloria and Moto-Moto from the Madagascar franchise. A Sesame Street cartoon from the early 1970s features a hippo who lives in the country and likes it quiet, while being disturbed when the mouse who likes it loud moves in with her.[citation needed]

The hippopotamus characters "Happy Hippos" were created in 1988 by the French designer Andre Roche [77] based in Munich, to be hidden in the "Kinder Surprise egg" of the Italian chocolate company Ferrero SpA. These characters were not placid like real hippos[contradiction] but rather cute and lively, and had such a success that they reappeared several times in different products of this company in the following years, increasing their popularity worldwide each time.[citation needed] The Nintendo Company published in the years 2001 and 2007 Game Boy adventures of them. In the game of chess, the hippopotamus lends its name to the Hippopotamus Defense, an opening system, which is generally considered weak.The River Horse is a popular outdoor sculpture at George Washington University, Washington, D.C. Botswana, Moremi National Park, Moremi Game reserve, private Reserve, Farm, chobe National park, Chobe Game Reserve, Zambia, Zambezi River, Livingstone, Zimbabwe, Kenya, Tanzania, Wildlife Conservation Project, Maramba River Lodge, South Africa, Krugger National Park. art beach blue bw california canada canon china city concert de england europe family festival film flower flowers food france friends green instagramapp iphoneography italy japan live london music nature new newyork night nikon nyc paris park party people photography portrait red sky snow square squareformat street summer sunset travel trip uk usa vacation water wedding white winter

Antonio Tempesta

Antonio Tempesta detto il Tempestino (Firenze, 1555 – Roma, 5 agosto 1630) è stato un pittore e incisore italiano del primo periodo barocco.

Biografia

Si formò nella cultura del tardo manierismo, con un gusto naturalistico ma anche calligrafico, acquisito dalla frequentazione di Giovanni Stradano, con il quale collaborò alla decorazione di Palazzo Vecchio.

 

Trasferitosi a Roma nel 1573, lavorò per Papa Gregorio XIII affrescando alcune mappe della Sala delle carte geografiche in Vaticano, tra le quali la famosa Mappa di Roma (1593). Nella capitale pontificia lavorò per molte nobili famiglie e per importanti cardinali come Alessandro Farnese e Scipione Borghese. Sono presenti sue opere a San Giovanni dei Fiorentini, alla villa di Caprarola, a Tivoli.

 

Tornò a Firenze per un breve soggiorno, dove collaborò con Alessandro Allori, Ludovico Buti, Giovan Maria Butteri e Ludovico Cigoli alla decorazione dei soffitti della Galleria degli Uffizi nel lato est, eseguita con disegni a grottesche. Ritrasferitosi a Roma si dedicò sempre di più all'incisione, con la quale raggiunse un'ampia fama e diffusione in tutta Europa. Celeberrime le 150 illustrazioni dell'Antico Testamento note come la Bibbia del Tempesta.

 

Fu anche un bravo disegnatore, dotato di una vena particolarmente scenografica, e altri artisti stamparono e diffusero la sua opera nel disegno.

 

L'opera pittorica

"Principiando adunque dalle Pitture diremo che quello Artefice manifestò il suo valore nella Città di Roma, fioritissima sede di tutte le buone Arti, dove erasi portato mentre regnava il Sommo Pontefice Gregorio XIII. Quivi operò varie cose nella Galleria e nelle Logge del Palazzo Papale in Vaticano, tra le quali incontrarono il genio universale alcune vivacissime e spiritose figure a fresco nella storia che rappresenta la traslazione del Corpo di S. Gregorio Nazianzeno, ed i lavori che fece nella Sala dei Tedeschi cioè due belle figure esprimenti la Fama e l'Onore, ed alcune storiette poste sotto le finestre figurate di color giallo".

 

"La buona maniera che fu ravvisata in questi lavori dagli intendenti fece sì che il Cardinale Alessandro Farnese gli ordinasse di ornare coi suoi pennelli i pilastretti della Lumaca nel famoso Palazzo Farnese di Caprarola e che il Cardinal Gambero gli facesse dipingere altre cose nel suo Palazzo di Bagnaia; e perché nell'esecuzione di tali lavori si portò Antonio da valente Maestro, sempre più crebbegli il credito onde gli furono commesse in Roma opere assai più vaste e importanti. Fece pertanto a fresco la Strage degl'Innocenti e la Vergine con i sette dolori, nelle due facciate dell'Altar Maggiore di S. Stefano Rotondo e, nel Palazzo del Marchese Santa Croce sotto il Campidoglio, rappresentò due Battaglie, una terrestre e l'altra marittima, con rara e copiosa invenzione. Dopo aver terminate queste pitture, lavorò molto nel Palazzo Giustiniani, incontro alle antiche Terme di Nerone e nel Palazzo presso a' Cavalli del Monte Quirino, per il Cardinale Scipione Borghese a cui in quel tempo apparteneva: figurò nella Loggia due nobilissime Cavalcate che girano intorno alla medesima a guisa di fregio. In una di esse vedesi il Papa allorché solennemente cavalca con seguito numeroso di uomini a piedi e a cavallo; nell'altra egualmente ricca di figure e di ornamenti è il Gran Turco pure a cavallo accompagnato dalla sua Corte".

 

[...] "Né queste furono le sole produzioni del suo sapere che tanto di nome e di onore fecero acquietargli nella Capitale del Mondo; perocché dipinse ancora in S. Giovanni dei Fiorentini la Cappella di S. Antonio Abate dalla cornice in giù e, sopra la volta, le storie di S. Lorenzo a fresco; in S Pancrazio, per il Cardinale Lodovico de Torres, molti Santi e Sante a fresco ed in S. Giovanni in Fonte, nella Cappella di S. Giovanni Evangelista, alcune eleganti Storiette colorite pure a fresco con eccellente maniera. Non si debbono altresì passare sotto silenzio le vaghissime grottesche e bizzarrie che fece in una Casa incontro ai Signori Gaetani al Corso, architettata da Giovanni Boccalini da Carpi, per essere state sempre universalmente applaudite. Nella nostra Firenze, oltre una sua tavola che vedesi da uno dei lati entro il coro di Santa Felicita rappresentante la gloriosa Resurrezione di Gesù Cristo, fece al celebre Pietro Strozzi alcune sacre Istorie dipinte sopra il Lapislazzuli e altre simili di sua mano espresse sopra vari alabastri, e si trovano nella Raccolta dei Signori Marchesi Niccolini ed in quella del più volte nominato Signore Ignazio Hugford diverse battaglie colorite sul marmo con gusto particolare, adattandosi industriosamente alle macchie dei medesimi marmi che lasciava in gran parte scoperti".

 

L'opera incisoria

"Venendo ora a parlare delle incisioni per lo più ad acqua forte, o eseguite di sua mano o fatte da altri col suo disegno, sarebbe cosa lunga e forse tediosa il descriverle ad una ad una, essendo quasi infinite. Accenneremo pertanto le principali E principiando dalle Sacre Storie son degne di essere ammirate le 220 piccole carte senza titolo che contengono molti fatti dell'antico Testamento dei quali pure rappresentò dodici soggetti in grande. Figurò altresì in 52 piccole carte ovate la vita della Santissima Vergine, di Gesù Cristo e di più Santi servendosi d'un sol contorno senza ombre; in otto carte l'Invenzione della Croce; in sei altre più Santi entro diversi Paesi per eccellenza toccati; in 159 carte i diversi strumenti dei Martiri, le quali stampò in Roma nel 1591; in 14 carte la vita di S. Antonio; in 20, diversi emblemi; per nulla dire della bellissima carta in foglio grande in cui vedesi una Città assediata con S. Jacopo a cavallo che ne da' le chiavi; e del Ritratto del Pontefice Clemente VIII intorno al quale pose varie storiette riguardanti la di lui vita. Disegnò poi quattro storie della Vergine che furono intagliate dal Callot; una Vergine circondata dagli Angioli e da più Santi intagliata da Filippo Tommasini; la Cena di nostro Signore con i 12 Articoli del Credo i quali furono pubblicati dal bulino del Villamena; la Conversion di S. Paolo intaglio di Filippo Tommasini e finalmente la vita ed i miracoli di S. Bernardo di Chiaravalle in foglio, intagliati ottimamente da Cherubino Alberti."

 

"Mostrano altresì quanto valesse nell'invenzione le Metamorfosi d'Ovidio che in 150 carte, in largo, da sé stesso intagliò; le dodici fatiche d'Ercole; le sette Meraviglie del Mondo; le dodici storie d'Alessandro Magno; le 11 Storie del Tasso e le quaranta carte che rappresentano l'intera storia dei sette figliuoli di Lara. Che diremo poi della figura sulle Nuvole con le armi dei Pinelli intagliata da Matteo Greuter che adoprò il suo bulino anche nel pubblicare altre opere dello stesso Autore; dei tre carri sulle nuvole, con figure sopra, col Ritratto di Alberto Arciduca d'Austria che pubblicò in carta grande Valeriano Regnartio; delle diverse invenzioni che vedonsi intagliate da Beniamino Vananglo; della Battaglia nella cui parte superiore sono due putti che reggono le armi Pontificie, intaglio del Villamena; e della carta grande per largo nella quale osservasi un Palazzo ed una Pallade ed in lontananza una battaglia con la Città di Caminiez incisa dallo slesso Tempesta?"

"Fu stimata assai una carta che egli intagliò figurandovi una Città assalita dal nemico con S. Michele Arcangiolo in aria ed incontrarono talmente il genio del pubblico 18 carte che siguravano le principali azioni di Alessandro il Grande che egli s' indusse a pubblicarle ancora in maggior grandezza."

"Resterà però molto più soddissatto chi osserverà la carta grande con la superba Battaglia dei Centauri che intagliò in legno Girolamo Parasoli; l'altra con la Battaglia di Druso coi Germani, intaglio di Matteo Greuter; e quella in cui vedesi in alto il Triregno Pontificio con le Chiavi, intaglio di Francesco Villamena. Sono tenute in grandissima stima la Battaglia di due fogli in largo dove sono incise dal Tempesta le seguenti parole Hebraeorum Victoria; le otto differenti Battaglie per largo esposte alla pubblica luce da Merian; e le altre che vengono dai bulini d'Orazio Brun e di altri. Non ci possiamo dispensare dal far parole della Battaglia delle Amazzoni che intagliò nel 1600; delle otto Battaglie per largo che seguirono tra Carlo V e Francesco I intagliate da Cornelio Boel e delle altre otto seguite fra Scipione ed Annibale perocché sono di particolare eccellenza; come pure ci convien fare menzione delle carte rappresentanti i 13 paraggi di fiumi diversi, quattro di Alessandro Magno, due di Annibale sopra un Elefante, ed uno d'Alessandro Farnese della Schelda."

 

"Infiniti per così dire sono gl'intagli dei diversi Paesi e delle cacce di ogni ispecie di animali che si ammirano di sua mano intagliate o almeno disegnate, ma noi ne rammenteremo soltanto alcune cioè le carte 96 in lungo con vari uccelli dedicate a Massimiliano Bruno; le 39 con cacce dedicate a Gio. Antonio Orsino Duca di S. Gemini; le 71 che compongono un libro d'uccelli del Tempesta e del Villamena di cui è fatta la dedica al Cavaliere del Pozzo; ed infine le carte contenenti una nuova raccolta dei più curiosi Animali. Si vedono di sua mano alcune superbissime Cavalcate che non si possono mai commendare abbastanza tra le quali quella che suol fare il Pontefice nell'andare a prendere il possesso di S. Gio. Laterano e quella del Gran Signore dei Turchi. Recano poi meraviglia le carte dei Cavalli in ogni attitudine disegnati, le quali dedicò a D. Virginio Orsino Duca di Bracciano. Si scorge da queste quanto fosse eccellente nel disegnare i cavalli, impresa ripiena d'infinite difficoltà, ed in vero i Maestri dell'Arte confessano che, avanti a Lui e allo Stradano, rare volte s' incontrano questi animali ad intera perfezione condotti."

 

Da Wikipedia, l'enciclopedia libera.

Raccolta Foto De Alvariis

BIG5. Elephant. Kruger National Park. Kruger Shalati: The Train on the Bridge. South Africa. May/2021

 

Elephant

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are currently recognised: the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.

All elephants have several distinctive features, the most notable of which is a long trunk (also called a proboscis), used for many purposes, particularly breathing, lifting water, and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts, and marshes. They prefer to stay near water. They are considered to be a keystone species due to their impact on their environments. Other animals tend to keep their distance from elephants while predators, such as lions, tigers, hyenas, and any wild dogs, usually target only young elephants (or "calves"). Elephants have a fission–fusion society in which multiple family groups come together to socialise. Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow.

Males ("bulls") leave their family groups when they reach puberty and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell, and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathyfor dying or dead individuals of their kind.

Source: Wikipedia

Elefante

Os elefantes são animais herbívoros, alimentando-se de ervas, gramíneas, frutas e folhas de árvores. Dado o seu tamanho, um elefante adulto pode ingerir entre 70 a 150 kg de alimentos por dia. As fêmeas vivem em manadas de 10 a 15 animais, lideradas por uma matriarca, compostas por várias reprodutoras e crias de variadas idades. O período de gestação das fêmeas é longo (20 a 22 meses), assim como o desenvolvimento do animal que leva anos a atingir a idade adulta. Os filhotes podem nascer com 90 kg. Os machos adolescentes tendem a viver em pequenos bandos e os machos adultos isolados, encontrando-se com as fêmeas apenas no período reprodutivo.

Devido ao seu porte, os elefantes têm poucos predadores. Exercem uma forte influência sobre as savanas, pois mantêm árvores e arbustos sob controle, permitindo que pastagens dominem o ambiente. Eles vivem cerca de 60 anos e morrem quando seus molares caem, impedindo que se alimentem de plantas.

Os elefantes-africanos são maiores que as variedades asiáticas e têm orelhas mais desenvolvidas, uma adaptação que permite libertar calor em condições de altas temperaturas. Outra diferença importante é a ausência de presas de marfim nas fêmeas dos elefantes asiáticos.

Durante a época de acasalamento, o aumento da produção de testosterona deixa os elefantes extremamente agressivos, fazendo-os atacar até humanos. Acidentes com elefantes utilizados em rituais geralmente são causados por esse motivo. Cerca de 400 humanos são mortos por elefantes a cada ano.

Elefante é o termo genérico e popular pelo qual são denominados os membros da família Elephantidae, um grupo de mamíferos proboscídeoselefantídeos, de grande porte, do qual há três espécies no mundo atual, duas africanas (Loxodonta sp.) e uma asiática (Elephas sp.). Há ainda os mamutes (Mammuthus sp.), hoje extintos. Até recentemente, acreditava-se que havia apenas duas espécies vivas de elefantes, o elefante-africano e o elefante-asiático, uma espécie menor. Entretanto, estudos recentes de DNA sugerem que havia, na verdade, duas espécies de elefante-africano: Loxodonta africana, da savana, e Loxodonta cyclotis, que vive nas florestas. Os elefantes são os maiores animais terrestres da actualidade, com a massa entre 4 a 6 toneladas e medindo em média quatro metros de altura, podem levantar até 10.000 kg. As suas características mais distintivas são as presas de marfim

Fonte: Wikipedia

  

Kruger Shalati

Kruger Shalati: The Train on the Bridge. One of the most anticipated and exciting new offerings coming to the iconic Kruger National Park, South Africa. A perfect combination of Africa’s most breathtaking natural splendours with well-deserved luxuries aboard a newly refurbished train that’s reminiscent of African excellence.

Permanently stationed on the historically-rich Selati Bridge above the Sabie River, Kruger Shalati will offer the most unique luxury accommodation in a re-envisioned train which will pay homage to the guests who explored the park nearly 100 years ago while welcoming new explorers from near and far. The train celebrates where the first visits to the iconic park were allowed in the early 1920s, the train would park overnight in the exact spot where Kruger Shalati will be positioned.

Offering 31 rooms, consisting of 24 carriage rooms and 7 Bridge House rooms, all of which will provide a deeply visceral experience, tailored for immersive comfort. Whether you’re looking for a one-of-a-kind adventure, an enthralling break or to simply immerse yourself in earth’s finest creations, Kruger Shalati looks forward to welcoming you on a journey of discovery with nature in the most extraordinary way imaginable.

Source: www.krugershalati.com

Kruger Shalati: O trem na ponte. Uma das novas ofertas mais esperadas e emocionantes que chegam ao icônico Parque Nacional Kruger, na África do Sul. Uma combinação perfeita dos esplendores naturais mais deslumbrantes da África com luxos bem merecidos a bordo de um trem recém-reformado que lembra a excelência africana.

Permanentemente estacionado na histórica Ponte Selati acima do Rio Sabie, Kruger Shalati oferecerá a acomodação de luxo mais exclusiva em um trem reformulado que homenageará os hóspedes que exploraram o parque há quase 100 anos, enquanto recebe novos exploradores. O trem celebra onde as primeiras visitas ao parque icônico foram permitidas no início dos anos 1920, o trem estacionaria durante a noite no local exato onde Kruger Shalati será posicionado.

Oferecendo 31 quartos, consistindo de 24 quartos de carruagem e 7 quartos Bridge House, todos os quais proporcionarão uma experiência profundamente visceral, adaptada para um conforto imersivo. Esteja você procurando por uma aventura única, uma pausa cativante ou simplesmente mergulhar nas melhores criações da terra, Kruger Shalati espera recebê-lo em uma jornada de descoberta com a natureza da maneira mais extraordinária que se possa imaginar.

Fonte: www.krugershalati.com (tradução livre)

 

Kruger National Park

Kruger National Park is one of the largest game reserves in Africa. It covers an area of around 20,000 square kilometres in the provinces of Limpopo and Mpumalanga in northeastern South Africa, and extends 360 kilometres (220 mi) from north to south and 65 kilometres (40 mi) from east to west.

Source: Wikipedia

Parque Nacional Kruger

O Parque Nacional Kruger é a maior área protegida de fauna bravia da África do Sul, cobrindo cerca de 20 000 km2. Está localizado no nordeste do país, nas províncias de Mpumalanga e Limpopo e tem uma extensão de cerca de 360 km de norte a sul e 65 km de leste a oeste.

Os parques nacionais africanos, nas regiões da savana africana são importantes pelo turismo com safári de observação e fotográfico.

O seu nome foi dado em homenagem a Stephanus Johannes Paul Kruger, último presidente da República Sul-Africana bôere. Foi criado em 31 de Maio de 1926

Fonte: Wikipedia

 

Cleavers up, bring 'em here

Femurs all swing on the ceiling like a chandelier

She sittin' there in a white dress, looking like she should get it

Licking the lips of the reddest, should invest in a head clinic

She got a pocket full of incisors and pliers

In a briefcase in case she get inspired, she ain't

She tryin' to suck face off the bone

You should know she is prone to swallow the marrow

 

youtu.be/3ZAPtFRpuu8

Isola Tiberina

 

L'Isola Tiberina (nota anche come Insula Tiberina, Insula Tiberis, Insula Aesculapi, Isola dei Due Ponti, Licaonia, Isola di San Bartolomeo, o semplicemente Insula) è un'isola fluviale nonché l'unica isola urbana del Tevere, nel centro di Roma. Nella Forma Urbis di età severiana viene riportato con la definizione di "inter duos pontes": è infatti collegata alle due rive del Tevere dal Ponte Cestio e dal Ponte Fabricio.

 

Storia

 

La leggenda vuole che l'isola si sia formata nel 510 a.C. dai covoni del grano mietuto a Campo Marzio, di proprietà del re Tarquinio il Superbo, gettati nel Tevere al momento della rivolta che ne causò la cacciata. Alcuni studi moderni, però, proverebbero che l'isola ha origini molto anteriori all'evento. Poco coinvolta nelle vicissitudini della città, per questa ragione ospitò il tempio di Esculapio, dio della medicina, il cui culto fu introdotto nel 292 a.C. in seguito ad una pestilenza.

 

Nella prima metà del I secolo a.C. venne monumentalizzata in opera quadrata, parallelamente alla costruzione dei ponti Fabricio e Cestio, e del Vicus Censorius che li collegava al suo interno, dando all'isola la forma di una nave (di cui oggi è ancora visibile la prua), con blocchi di travertino che rivestono l'interno in peperino, e alcune decorazioni raffiguranti Esculapio con il suo serpente e una testa di toro, forse utile per gli ormeggi.

 

Al centro vi era un obelisco, a raffigurare un albero maestro simbolico, ricordo della nave romana che nel 292 a.C. da Epidauro portò a Roma il simbolo del dio Esculapio. Due anni prima, infatti, alcuni funzionari romani si erano recati nella città greca per visitarne il tempio e consultare la divinità a seguito di una grave pestilenza scoppiata a Roma. Il mito vuole che un serpente - simbolo del dio - si allontanò dal tempio e salì sulla nave romana. Quando la nave tornò a Roma, il rettile scese sull'isola stabilendovisi. Si racconta che la peste svanì miracolosamente dopo la costruzione del tempio dedicato al dio.

 

Monumenti

 

Templi

 

Il Tempio di Esculapio venne inaugurato nel 289 a.C. e sorgeva nella parte meridionale dell'isola, nel luogo oggi occupato dalla chiesa di San Bartolomeo: al suo interno un pozzo prenderebbe la posizione di una fonte collegata al santuario. Ai lati del tempio si trovava un portico per l'accoglienza dei pellegrini e soprattutto dei malati. Nella parte settentrionale si trovavano alcuni piccoli santuari legati a culti particolari, ora situati fra le fondamenta dell'Ospedale Fatebenefratelli. Questi erano: due templi dedicati nel 194 a.C. a Fauno e Veiove; un sacello per Iuppiter Iuralius (ossia "garante dei giuramenti"), oggi sostituito dalla chiesa di San Giovanni Calibita, ma in cui un pavimento musivo mostra una dedica al dio; un altare dedicato al dio Semo Sancus, di origine sabina. Altri culti attestati sull'isola erano rivolti a Tiberino e Gaia, e a Bellona (detta Insulensis).

 

Al posto dell'obelisco, dopo la sua scomparsa, venne eretta una colonna (poi trasferita nel portico della chiesa di San Bartolomeo) dove il 24 agosto di ogni anno si affiggeva l'elenco di chi non aveva seguito il precetto pasquale; la colonna si frantumò nel 1867 a causa dell'urto di un carro. Si racconta che nel 1834 Bartolomeo Pinelli, presente nella lista, si lamentò ufficialmente in sacrestia per essere stato inserito come miniatore, anziché incisore. Oggi sul luogo centrale si trova una piccola edicola reggicroce fatta costruire da papa Pio IX nel 1869 da parte di Ignazio Jacometti, che nelle quattro nicchie raffigurò i santi collegati all'isola: san Bartolomeo, san Paolino da Nola, san Francesco d'Assisi, e san Giovanni di Dio. Nella stessa data del 24 agosto ricorreva la festa dei cocomeri, in cui numerosi venditori esponevano la propria merce sull'isola; nel frattempo alcuni praticavano una gara di nuoto, dal ponte Fabricio a ponte Rotto per afferrare i cocomeri: i giochi sono stati proibiti nel 1870 a seguito degli incidenti dovuti alla corrente del fiume.

 

Basilica di San Bartolomeo

 

Sopra le rovine del tempio di Esculapio l'imperatore Ottone III volle costruire nel X secolo una chiesa dedicata ai santi Adalberto (suo amico, vescovo di Praga e martirizzato nel 998), Paolino e Bartolomeo, e che dopo il restauro di papa Alessandro III nel 1180 mantenne la dedica solamente per l'ultimo santo (allo stesso evento risale un frammento di mosaico oggi presente sulla facciata); in precedenza, nel 1113, era stato aggiunto un campanile da parte di papa Pasquale II. All'interno si trova un antico pozzo con un bassorilievo raffigurante i tre santi (o forse il Salvatore, sant'Adalberto, san Bartolomeo e Ottone III), realizzato con il rocchio di un'antica colonna da Nicola d'Angelo o da Pietro Vassalletto nel XIII secolo: i romani credevano che l'acqua fosse miracolosa, essendovisi trovate le ossa dei martiri romani Esuperanzio e Marcello, e un'iscrizione infatti riporta "Os putei Sci sancti circumdant orbe rotanti"; nel secolo scorso il pozzo è stato chiuso a causa della malsanità dell'acqua.

 

Nella chiesa, nella prima cappella a destra, è conservata l'immagine della Madonna della Lampada, legata all'inondazione del 1557 e alla tradizione del prodigio. L'immagine è una Madonna con Bambino affrescata nella seconda metà del XIII secolo, e posta sopra una mole, per cui era conosciuta anche come Madonna delle Mole. La tradizione vuole che in seguito ad una piena l'immagine fu sovrastata dalle acque, ma una lampada posta lì di fronte si mantenne accesa, e così rimase fino al termine dell'evento. Nella Cappella del Sacramento si trova invece una palla di cannone, di quattordici centimetri di diametro, sparata durante l'assedio di Roma del 1849: le persone che all'interno rimasero incredibilmente illese lasciarono l'oggetto sul luogo a ricordo dell'avvenimento.

 

Nel XVII secolo nacque la tradizione di una cerimonia in suffragio delle vittime del Tevere: ogni 2 novembre, giorno della commemorazione dei defunti, al tramonto dalla chiesa di San Bartolomeo una processione della Confraternita dei Sacconi Rossi di Santa Maria dell'Orto - noti semplicemente come Sacconi Rossi - si recava con alcune torce accese fino alla riva, dove benedicevano le acque e lanciavano una corona di fiori. Dopo anni d'interruzione, la cerimonia è stata ripresa dal 1984 dalla Confraternita dei Sacconi Scuri. Un'altra tradizione vuole che un frate lombardo, un certo Fra Giambattista Orsenigo, fosse un validissimo cavadenti, e che fra il 1867 e il 1903 ebbe come pazienti numerosissime personalità, fra cui il papa Leone XIII.

 

Nell'anno 1999 Giovanni Paolo II decise, in preparazione del Giubileo dell'anno 2000, di istituire una commissione "Nuovi Martiri", che avrebbe dovuto indagare sui martiri cristiani del Ventesimo secolo. La commissione ha lavorato due anni nei locali della Basilica di San Bartolomeo, raccogliendo circa 12.000 dossier di martiri e testimoni della fede giunti da diocesi di tutto il mondo.

 

Passato il Giubileo, Giovanni Paolo II volle che questa memoria dei testimoni della fede del Novecento potesse divenire qualcosa di visibile nella Basilica di San Bartolomeo. Nell'ottobre del 2002, con una solenne celebrazione ecumenica alla presenza dei cardinali Camillo Ruini, Walter Kasper e Francis Eugene George, e del patriarca romeno ortodosso Teoctist, è stata posta sull'altare maggiore una grande icona dedicata ai martiri del Novecento. L'icona rappresenta, con una simbologia presa dall'Apocalisse, le vicende dei martirii di cui si è venuti a conoscenza attraverso i lavori della commissione. Altre memorie di martiri sono collocate nelle cappelline laterali, ognuna dedicata ad una situazione storica particolare.

 

Ospedale Fatebenefratelli

L'ospedale Fatebenefratelli, posto di fronte alla basilica di San Bartolomeo, venne fondato dai seguaci di san Giovanni di Dio nel 1583, e rimodernato in seguito da Cesare Bazzani fra il 1930 ed il 1934. Sulla destra si trova la chiesa di San Giovanni Calibita, edificata sui resti del tempio di Iuppiter Iurarius, e dedicata intorno all'870: la facciata è opera nel 1640 di Luigi Barattoni, completata poi da Romano Carapecchia nel 1711.

 

Ospedale Israelitico

Oltre al già citato Fatebenefratelli, sull'Isola Tiberina è presente anche una delle tre sedi romane dell'Ospedale Israelitico. La sede è operante e si trova a fianco della basilica di San Bartolomeo.

 

L'Isola del Cinema 2009

L'Isola del Cinema è la manifestazione che porta, dal 1995, al centro della Capitale il grande cinema italiano e internazionale, eventi culturali e manifestazioni solidali ospitati nello scenario affascinante dell'Isola Tiberina. Un Salotto Internazionale di Cinema e Cultura sul fiume Tevere: nell'Arena, che ospita un maxischermo, è possibile seguire anteprime e pellicole inedite prestigiose, incontrare registi e attori italiani e internazionali e vedere alcuni tra i più bei film di qualità dell'ultima stagione, mentre nel Cinelab si svolgono rassegne di film d'autore, cortometraggi, rassegne dedicate alla cinematografia internazionale, il Nuovo Cinema Italiano, i migliori film della precedente stagione.

 

Da Wikipedia, l'enciclopedia libera.

Raccolta Foto De Alvariis

 

 

 

 

...le mie statue equestri esprimono il tormento causato dagli avvenimenti di questo secolo. L’inquietudine del mio cavallo aumenta a ogni nuova opera, il cavaliere è sempre più stremato, ha perduto il dominio sulla bestia e le catastrofi alle quali soccombe somigliano a quelle che distrussero Sodoma e Pompei. Io aspiro a rendere visibile l’ultimo stadio della dissoluzione di un mito, del mito dell’individualismo eroico e vittorioso, dell’uomo di virtù degli umanisti. La mia opera degli ultimi anni non vuole essere eroica, ma tragica.

 

Marino Marini, 1972

 

 

 

 

 

These marmosets are gum-feeding specialists. They don't wait for gum-producing trees to exude gum but use their specially adapted chisel-like incisors to make small holes in the bark.This stimulates the flow of gum and enables them to have a year round supply. Their claw-like nails allow them to cling vertically to the trunks as they jump between trees.

 

Information Sourced from Longleat Guidebook.

© Brian E Kushner

Didelphimoarphi (pronounced /daɪˌdɛlfɨˈmɔrfi.ə/) is the order of common opossums of the Western Hemisphere. They are commonly also called possums, though that term is also applied to Australian fauna of the suborder Phalangeriformes. The Virginia Opossum is the original animal named opossum. The word comes from Algonquian wapathemwa. Opossums probably diverged from the basic South American marsupials in the late Cretaceous or early Paleocene. A sister group is Paucituberculata (shrew opossums).

 

Their unspecialized biology, flexible diet and reproductive strategy make them successful colonizers and survivors in diverse locations and conditions. Originally native to the eastern United States, the Virginia Opossum was intentionally introduced into the West during the Great Depression, probably as a source of food.[2] Its range has been expanding steadily northwards, thanks in part to more plentiful, man-made sources of freshwater, increased shelter due to urban encroachment, and milder winters. Its range has extended into Ontario, Canada, and it has been found farther north than Toronto.

 

Characteristics

 

Didelphimorphs are small to medium-sized marsupials, with the largest about the size of a large house cat, and the smallest the size of a mouse. They tend to be semi-arboreal omnivores, although there are many exceptions. Most members of this taxon have long snouts, a narrow braincase, and a prominent sagittal crest. The dental formula is:

Dentition

5.1.3.4

4.1.3.4

 

By mammalian standards, this is a very full jaw. Opossums have more teeth than any other land mammal; only aquatic mammals have more.[citation needed] The incisors are very small, the canines large, and the molars are tricuspid.

 

Didelphimorphs have a plantigrade stance (feet flat on the ground) and the hind feet have an opposable digit with no claw. Like some New World monkeys, opossums have prehensile tails. The stomach is simple, with a small cecum.

 

Opossums have a remarkably robust immune system, and show partial or total immunity to the venom of rattlesnakes, cottonmouths, and other pit vipers.[3][4] Opossums are about eight times less likely to carry rabies than wild dogs, and about one in eight hundred opossums are infected with this virus.[5]

 

[edit] Reproduction and life cycle

Sleeping Virginia opossum with babies in her relaxed pouch

 

As a marsupial, the opossum has a reproductive system that is composed of a placenta and a marsupium, which is the pouch.[6] The young are born at a very early stage, although the gestation period is similar to many other small marsupials, at only 12 to 14 days.[7] Once born, the offspring must find their way into the marsupium to hold onto and nurse from a teat. The species are moderately sexually dimorphic with males usually being slightly larger, much heavier, and having larger canines than females.[8] The largest difference between the opossum and other mammals is the bifurcated penis of the male and bifurcated vagina of the female (the source of the Latin didelphis, meaning double-wombed). Male opossum spermatozoa exhibit cooperative methods of ensuring the survival of genotypically similar sperm by forming conjugate pairs before fertilization[9] . Such measures come into place particularly when females copulate with multiple males. These conjugate pairs increase motility and enhance the likelihood of fertilization. Conjugate pairs dissociate into separate spermatozoa before fertilization. The opossum is one of many species that employs sperm cooperation in its reproductive life cycle.

 

Female opossums often give birth to very large numbers of young, most of which fail to attach to a teat, although as many as thirteen young can attach[8], and therefore survive, depending on species. The young are weaned between 70 and 125 days, when they detach from the teat and leave the pouch. The opossum lifespan is unusually short for a mammal of its size, usually only two to four years. Senescence is rapid.[10]

 

[edit] Diet

 

Didelphimorphs are opportunistic omnivores with a very broad diet. Their diet mainly consists of carrion and many individual opossums are killed on the highway when scavenging for roadkill. They are also known to eat insects, frogs, birds, snakes, small mammals, and earthworms. Some of their favorite foods are fruits, and they are known to eat apples and persimmons. Their broad diet allows them to take advantage of many sources of food provided by human habitation such as unsecured food waste (garbage) and pet food.

Opossum fur is quite soft.

 

[edit] Behavior

 

Opossums are usually solitary and nomadic, staying in one area as long as food and water are easily available. Some families will group together in ready-made burrows or even under houses. Though they will temporarily occupy abandoned burrows, they do not dig or put much effort into building their own. As nocturnal animals, they favor dark, secure areas. These areas may be below ground or above.

Didelphis marsupialis: intrusion in human dwelling (French Guiana)

 

When threatened or harmed, they will play possum, mimicking the appearance and smell of a sick or dead animal. The lips are drawn back, teeth are bared, saliva foams around the mouth, and a foul-smelling fluid is secreted from the anal glands. The physiological response is involuntary, rather than a conscious act. Their stiff, curled form can be prodded, turned over, and even carried away. The animal will regain consciousness after a period of minutes or hours and escape.

 

Adult opossums do not hang from trees by their tails, though babies may dangle temporarily. Their semi-prehensile tails are not strong enough to support a mature adult's weight. Instead, the opossum uses its tail as a brace and a fifth limb when climbing. The tail is occasionally used as a grip to carry bunches of leaves or bedding materials to the nest. A mother will sometimes carry her young upon her back, where they will cling tightly even when she is climbing or running.

 

Threatened opossums (especially males) will growl deeply, raising their pitch as the threat becomes more urgent. Males make a clicking & smack; noise out of the side of their mouths as they wander in search of a mate, and females will sometimes repeat the sound in return. When separated or distressed, baby opossums will make a sneezing noise to signal their mother. If threatened, the baby will open its mouth and quietly hiss until the threat is gone.

The Virginia opposum is the only North American marsupial.

 

Historical references

 

An early description of the opossum comes from explorer John Smith, who wrote in Map of Virginia, with a Description of the Countrey, the Commodities, People, Government and Religion in 1608 that An Opassom hath an head like a Swine, and a taile like a Rat, and is of the bignes of a Cat. Under her belly she hath a bagge, wherein she lodgeth, carrieth, and sucketh her young.[11][12]. The Opossum was more formally described in 1698 in a published letter entitled Carigueya, Seu Marsupiale Americanum Masculum. Or, The Anatomy of a Male Opossum: In a Letter to Dr Edward Tyson, from Mr William Cowper, Chirurgeon, and Fellow of the Royal Society, London, by Edward Tyson, M. D. Fellow of the College of Physicians and of the Royal Society. The letter suggests even earlier descriptions.[13]

 

[edit] Hunting, food and foodways

 

The opossum was once a favorite game animal in the United States, and in particular the southern regions which have a large body of recipes and folklore relating to the opossum. Opossum was once widely consumed in the United States where available, as evidenced by recipes available online[14] and in books such as older editions of The Joy of Cooking. A traditional method of preparation is baking, sometimes in a pie or pasty[1], though at present possum pie & most often refers to a sweet confection containing no meat of any kind. In Dominica and Trinidad opossum or manicou is popular and can only be hunted during certain times of the year owing to over hunting; the meat is traditionally prepared by smoking then stewing. The meat is light and fine-grained, but the musk glands must be removed as part of preparation. The meat can be used in place of rabbit and chicken in recipes. The cousin of the opossum, the possum, found in Australia (and introduced to New Zealand ) is consumed in a similar manner. [15]

 

Historically, hunters in the Caribbean would place a barrel with fresh or rotten fruit to attract opossums who would feed on the fruit or insects. Cubans growing up in the mid-twentieth century tell of brushing the maggots out of the mouths of manicou caught in this manner to prepare them for consumption. It is said also that the gaminess of the meat causes gas.[citation needed]

 

In Mexico, opossums are known as tlacuache or &tlaquatzin. Their tails are eaten as a folk remedy to improve fertility.

 

Opossum oil (Possum grease) is high in essential fatty acids and has been used as a chest rub and a carrier for arthritis remedies given as topical salves.

Surma or Suri are sedentary pastoral people living in south west of Ethiopia, on the western bank of the Omo River, in the Kibish and Tulgit area.

 

These breeders tribal groups have a cattle centred culture. They grow cabbage, beans, yams, tobacco and coffee and breed their cattle, mostly cows, on their traditional lands, located in the Omo Valley. Cows are tremendously important for the Suris. They do not see cattle simply as a material asset but as a life sustaining and meaningful companion. Suri even sing songs for them and make fires to warm them. These cows are not bred for their meat and are usually not killed unless they are needed for ceremonial purposes. They use their milk and their blood, which they both drink. Cows also have a social and symbolic meaning in Suri’s society. Suri men are judged on how much cattle they own. In desperate times, Suri men can risk their lives to steal cattle from other tribes. The average male in the Suri tribe owns 40 cows. Every young male is named after their cattle, which they have to look after since the age of 8. Cows are given to the bride’s family after the wedding ceremony. Usually 20 cows and they offer also a Kalashnikov as wedding gift.

 

This central role of the cow in their way of life accounts for the fierce independence they want to preserve and explains their warlike culture. Indeed, it’s quite common to see men and even women carrying Kalashnikovs, which are part of the daily life. Their remote homeland has always been a place of traditional rivalries with the neighbouring tribes such as the Bume (Nyangatom) or the Toposa from Sudan who regularly team up to raid the Suri’s cattle. These fights, and even sometimes battles, have become quite bloody since automatic firearms have become available from the parties in the Sudanese Civil War. This conflict has pushed neighbouring tribes into Suri’s land and is a constant competition to keep and protect their territory and owns.

 

Like their neighbours, the Surma also paint their bodies. They create a variety of designs on their necked bodies using their fingertips, which helps them to expose their dark skins. The painting could have both a beautifying and opponent frightening purpose. As one studies these body paintings whirls, stripes, flower and star designs are noticeable. Surma men who are generally believed to be expert artists also paint the girls.

 

A ritual chief in the villages known as the Komoru, dressed in colourful robes and wearing a crown of baboon fur leads the Suri. Village life is largely communal, sharing the produce of the cattle (milk and blood). The men in an assembly take decisions of the village.

Although their traditional remoteness and autarky is threatened, only few Surma are familiar with Amharic, the official language of Ethiopia, and their literacy level is very low. Lip plate and Donga stick fight are the two typical distinctive features of these people, which they share with the neighbouring Mursi people.

 

Suri women wear giant lip plate, a sign of beauty, like in Mursi tribe, and also a prime attraction for tourists which help to sustain a view of them, in guidebooks and travel articles, as an untouched people, living in one of the last wildernesses of Africa. When they are ready to marry, teenagers start to make a hole in the lower lip with a wood stick. It will be kept for one night, and is removed to put a bigger one. This is very painful at this time. Few months after, the lip plate has its full size, and the men see the girl as beautiful. The lip plate is made of wood or terracotta. They have to remove the lower incisors to let some space for the disc. Sometimes the pressure of the plate breaks the lip. This is a big problem for the girl because men will consider her as ugly, she won't be able to marry anyone in the tribe apart the old men or the sick people.

 

The Sagenai, called also donga ritual is a combat that brings both wounds and honor to both the winner and loser. The men bodies are decorated with ritual drawings and their heads are protected by a sort of helmet. For the boys participating to the donga, this challenge is a true moment of glory. The combat is taking place in a middle of a circle made by the crowd. The rules are simple and can be summed up as follows: the person who manages to stay on his feet is the winner, and one must absolutely not kill his opponent. The winner will be honored by the entire tribe and can choose girls to date.

The lands of the Suri are stolen by the Ethiopian government to be rented to foreign companies. A Malaysian company, Lim Slow Jin, runs the Koka plantation near Kibish on the east side of the Omo. The lands are confiscated and rented out for 1 euro per hectare for a year.

© Eric Lafforgue

www.ericlafforgue.com

Again, taken through double glazing, so not the sharpest of shots, sorry!

 

Often weighing over half a kilo and measuring about 23cm, without counting the tail. It has a blunt muzzle, small hair-covered ears and a tail that is shorter than its body.

 

Rats have well developed senses of smell taste and touch. They have an acute sense of hearing, frequently using ultrasound to communicate, and are particularly sensitive to any sudden noise.

 

Rats need to gnaw to keep their constantly growing incisor teeth worn down. They damage woodwork, plastic, bricks and lead pipes, and will strip insulation from electrical cables.

 

Brown Rats live in any situation that provides food, water and shelter. In homes, they will live in roof spaces, wall cavities or under floorboards. In gardens, they will burrow into grassy banks or under sheds.

Twenty years ago today, the Smithsonian’s National Zoo welcomed naked mole-rats (Heterocephalus glaber) into its collection. These rodents, which are more closely related to porcupines and guinea pigs than to their namesake, are one of only a handful of mammals that exhibit eusocial behavior. Like insects such as termites and bees, naked mole-rats follow a hierarchical social structure that consists of one breeding female called the queen, up to three breeding males and many non-breeding workers and soldiers. In the wild, a single colony may contain as few as 20 individuals or as many as 300 individuals.

 

Eleven naked mole-rats are currently on exhibit at the Zoo’s Small Mammal House, though two other colonies, each comprised of nine individuals, live off-exhibit. Nearly 300 naked mole-rat pups have been born here and survived to adulthood since 1991. However, no pups have survived in the last 10 years. For unknown reasons, it is common for captive colonies to self-regulate their population. In the wild and in human care, these animals can live upwards of 30 years old.

 

Naked mole-rats are native to the arid-desert and semi-grassy regions of Ethiopia, Kenya and Somalia in Eastern Africa and spend most of their lives navigating through dark underground tunnels. Because they have poor eyesight, they rely on smell, touch and hearing to get around. Measuring only three inches long, these rodents sport very little hair and have bare, wrinkly skin which varies in color from pink to grayish-pink. In addition to hairy feet, they also have hairy mouths that prevent them from swallowing dirt while they dig with their large incisor teeth.

 

Visitors to the Zoo’s website can watch naked mole-rats on the webcam.

 

# # #

 

Photo Credit: Meghan Murphy, Smithsonian’s National Zoo.

 

Per l'Amore del Maestro, 25 artisti affascinati da Piranesi

Il 2020 ha segnato il tricentenario della nascita di Giovanni Battista Piranesi. L'architetto, antiquario, incisore, vedutista, designer e scrittore italiano è stata una delle personalità artistiche di spicco del 18 ° secolo a Roma. La sua interpretazione del mondo classico è diventata di grande importanza non solo nel 18 ° secolo, ma anche molto tempo dopo la sua morte. L'Ufficio dei Lavori Pubblici (OPW) ospiterà la mostra internazionale For the Love of the Master , 25 artisti affascinati da Piranesi per celebrare l'eredità di questo poliedrico artista romano nel 21 ° secolo.A causa della pandemia di COVID-19 la mostra è stata posticipata e si svolgerà nell'estate del 2022.

  

Felt like some delicious sandwiches. So went all out with avocado, tomato sans bacon. Quite refreshing. A good sandwich is an art form. Wrote a post in my blog (here) Am incisor challenged. Ha. So I dice the toms up a bit. man, I just felt like something "fresh." Paid $1.69 for the avocado... just ripe enough.

Guido Reni

Guido Reni (Bologna, 4 novembre 1575 – Bologna, 18 agosto 1642) è stato un pittore e incisore italiano, uno dei massimi esponenti del classicismo seicentesco.

Biografia

Reni nacque a Bologna nell'attuale Palazzo Ariosti di via San Felice 3 da Daniele, musicista e maestro della Cappella di San Petronio e Ginevra Pozzi; venne battezzato il 7 novembre nella chiesa metropolitana di San Pietro. Un'erronea tradizione che risale alla fine del Settecento lo fa nascere a Calvenzano (Vergato), nell'Appennino bolognese.

 

Nel 1584, a dire dello storico Carlo Cesare Malvasia che conobbe il pittore, abbandonò gli studi di musica a cui era stato avviato dal padre per entrare nell'avviata bottega bolognese del pittore fiammingo Denijs Calvaert, amico del padre, che si impegnò a tenerlo per dieci anni. Ebbe per compagni di apprendistato pittori destinati a grande successo come Francesco Albani e il Domenichino e sappiamo che studiò in particolare le incisioni del Dürer e di Raffaello.

 

Morto il padre il 7 gennaio 1594, Guido lasciò la bottega del Calvaert per aderire all'Accademia degli Incamminati, scuola di pittura fondata dai Carracci nel 1582 col nome di Accademia dei Desiderosi (il nome fu cambiato nel 1590). Qui approfondì la pittura ad olio, l'incisione a bulino (riproducendo ad esempio l'Elemosina di San Rocco di Annibale) e copiando a più riprese singole parti dell'Estasi di Santa Cecilia, allora esposta nella chiesa di San Giovanni in Monte.

 

Qui mostrò il suo talento: il Malvasia riferisce l'aneddoto del suggerimento dato da Annibale a Ludovico Carracci, di non gl'insegnar tanto a costui, che un giorno ne saprà più di tutti noi. Non vedi tu come non mai contento, egli cerca cose nuove? Raccordati, Lodovico, che costui un giorno ti vuol far sospirare.

 

Nel 1598, già pittore indipendente, dipinse la Incoronazione della Vergine e quattro santi, oggi nella Pinacoteca di Bologna, per la chiesa di San Bernardo, e vinse la gara, in concorrenza con Ludovico Carracci, per la decorazione della facciata del Palazzo del Reggimento, l'attuale palazzo municipale di Bologna: gli affreschi, commissionati per onorare la visita di papa Clemente VIII (di passaggio in occasione della devoluzione del Ducato di Ferrara allo Stato della Chiesa) e rappresentanti figure allegoriche, si erano già cancellati nell'Ottocento e rappresentarono la rottura con il suo vecchio maestro e con altri allievi dei Carracci. Sono contemporanee le tele della Madonna col Bambino, san Domenico e i Misteri del Rosario della Basilica di San Luca, due affreschi in palazzo Zani a Bologna e, tra diversi altri lavori, l'Assunzione della Vergine nella parrocchiale di Pieve di Cento. Il 5 dicembre 1599 entrò nel Consiglio della Congregazione dei pittori di Bologna.

 

La figura di Guido Reni è stata ripresa anche dallo scrittore tedesco Joseph von Eichendorff nel suo romanzo Aus dem Leben eines Taugenichts, vita di un perdigiorno.

A Roma

Forse già nel 1600 ma certamente nel 1601 era a Roma, dove l'11 ottobre fu pagato dal cardinale Sfondrato per il suo Martirio di santa Cecilia della Basilica di Santa Cecilia in Trastevere: per lo stesso committente e la stessa chiesa eseguì anche l'Incoronazione dei santi Cecilia e Valeriano e una copia - questa volta intera - del dipinto bolognese di Raffaello, l'Estasi di Santa Cecilia con quattro santi, ora nella chiesa di San Luigi dei Francesi e dipinta a Bologna prima della partenza. Nel marzo del 1602 tornò nella città natale per assistere ai funerali del grande Agostino Carracci e fu incaricato di incidere a stampa le decorazioni allestite per il funerale.

 

Viaggiò da Bologna a Roma e di qui a Loreto, per trattare delle eventuali decorazioni della Santa Casa che furono però affidate al Pomarancio.

 

In questo periodo dipinse il Cristo in Pietà adorato dai santi Vittore e Corona, da Santa Tecla e San Diego d'Alcalà, ora nella Cappella della Sacra Spina del Duomo di Osimo (1601 circa) e la Trinità con la Madonna di Loreto (1604) per la Chiesa della Trinità o del Sacramento della stessa cittadina. Entrambe le opere furono richieste dal cardinale Antonio Maria Galli, un creato di Sisto V, noto in ambito storico artistico per le sue commissioni al pittore Cristoforo Roncalli, il Pomarancio.

 

Nel 1605 completò La crocefissione di san Pietro, per la chiesa romana di San Paolo alle Tre Fontane, ora nella Pinacoteca Vaticana, commissionatagli dal cardinale Pietro Aldobrandini. Per il Malvasia sarebbe stato il Cavalier d'Arpino a suggerire l'emulazione del soggetto, derivato dalla tela caravaggesca della basilica di Santa Maria del Popolo, per danneggiare il Caravaggio nei favori dei committenti. Ne riprodusse in parte i contrasti di luce ma tolse il dramma: la sua crocefissione è un tranquillo lavoro di artigiani, che rovesciano un santo rassegnato sulla croce e lo legano e l'inchiodano con gesti lenti e metodici.

 

È la sua ricerca del bello ideale, ricavato dal classicismo raffaellesco nella mediazione dei Carracci che sfiora soltanto la visione naturalistica di Caravaggio ma se ne allontana per la necessità di ammantarla di decoro; di questa esperienza, nel primo decennio del secolo, sono parte il Davide con la testa di Golia del Louvre, il Martirio di santa Caterina per la chiesa di Sant'Alessandro a Conscente, ora al Museo diocesano di Albenga in Liguria, La preghiera nell'orto di Sens e L'incoronazione della Vergine di Londra.

La sua fama è così consolidata che nel 1608 papa Paolo V gli affidò la decorazione di due sale dei Palazzi Vaticani, la Sala delle Nozze Aldobrandine e la Sala delle Dame, e il cardinale Borgherini gli affreschi di San Gregorio al Celio, il Martirio di sant'Andrea e l'Eterno in gloria. L'anno dopo iniziò la decorazione della cappella dell'Annunciata nel palazzo del Quirinale, avvalendosi dell'aiuto di Francesco Albani, Antonio Carracci, Jacopo Cavedone, Tommaso Campana, ma soprattutto Giovanni Lanfranco; l'iscrizione di termine dei lavori reca la data 1610, comprendendo gli affreschi sulle pareti e la tavola dell'Annunciazione sull'altare, "con maggior applauso e meraviglia di tutta la Corte, che vi accorse ad ammirarla come cosa prodigiosa" (Malvasia).

 

Il 25 settembre 1609 ricevette il primo acconto per gli affreschi della cappella Paolina in Santa Maria Maggiore che interruppe alla fine del 1610, sembra per contrasti con l'amministrazione papale. Tornò a Bologna dopo il 1614, anno in cui terminò l'Aurora per il casino Rospigliosi (a Roma). La Strage degli innocenti e il Sansone vittorioso furono probabilmente iniziati a Roma e terminati a Bologna (venti scudi gli erano infatti anticipati a Roma per la commissione della Strage).

 

Se il Sansone è un gigante effeminato che si ristora dopo il massacro, e i morti sembrano dormire placidamente nella serenità albeggiante di una vasta pianura, nell'altra Strage, rappresentata con sei donne, due piccoli morti e due assassini, la tragedia è congelata nella misura e nella simmetria della composizione raffaellesca. Di questo dipinto, suo capolavoro assoluto, si ricordarono Poussin, i pittori neoclassici francesi e persino Picasso, che richiamò la tela di Reni in alcune parti del suo Guernica.

 

Tornò a Roma nel 1612, per terminare in aprile gli affreschi di Santa Maria Maggiore; il cardinale Scipione Borghese gli commissionò, per un Casino nel parco del suo palazzo, ora Palazzo Pallavicini Rospigliosi, l'affresco dell'Aurora, terminato nell'agosto 1614. Il grandioso affresco ebbe grande fortuna fino al Neoclassicismo: il carro di Apollo, circondato dalle figure delle Ore è preceduto dall'Aurora mentre sopra i quattro cavalli vola Fosforo, l'astro del mattino, con una torcia accesa; in basso a destra un paesaggio marino.

 

Dopo un breve soggiorno a Napoli, ancora a Roma ai primi del 1614, tornò definitivamente a Bologna nell'ottobre 1614.

 

Al primo viaggio di ritorno da Roma, e ai dubbi sulla sua pittura, è dedicato il romanzo biografico Il viaggio di Guido Reni, scritto da Manlio Cancogni e vincitore del Premio Grinzane Cavour del 1987 (Lit, Roma, 2013).

 

Da Wikipedia, l'enciclopedia libera.

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Traditionally, two species are recognised, the African elephant (Loxodonta africana) and the Asian elephant (Elephas maximus), although some evidence suggests that African bush elephants and African forest elephants are separate species (L. africana and L. cyclotis respectively). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae are the only surviving family of the order Proboscidea; other, now extinct, families of the order include mammoths and mastodons. Male African elephants are the largest surviving terrestrial animals and can reach a height of 4 m (13 ft) and weigh 7,000 kg (15,000 lb). All elephants have several distinctive features the most notable of which is a long trunk or proboscis, used for many purposes, particularly breathing, lifting water and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

 

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts and marshes. They prefer to stay near water. They are considered to be keystone species due to their impact on their environments. Other animals tend to keep their distance, and predators such as lions, tigers, hyenas and wild dogs usually target only the young elephants (or "calves"). Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow. Elephants have a fission-fusion society in which multiple family groups come together to socialise. Males ("bulls") leave their family groups when they reach puberty, and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathy for dying or dead individuals of their kind.

 

African elephants are listed as vulnerable by the International Union for Conservation of Nature (IUCN), while the Asian elephant is classed as endangered. One of the biggest threats to elephant populations is the ivory trade, as the animals are poached for their ivory tusks. Other threats to wild elephants include habitat destruction and conflicts with local people. Elephants are used as working animals in Asia. In the past they were used in war; today, they are often put on display in zoos and circuses. Elephants are highly recognisable and have been featured in art, folklore, religion, literature and popular culture.

 

(Wikipedia)

 

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We traveled rather long way from Kandy to Haputale during our third day in Sri Lanka and enjoyed local traffic quite heavily - transportation of elephants is really no problem in Sri Lanka :-).

South Africa.

Kruger Park.

Game Drive in open jeep.

 

WATCH THE VIDEO

 

Body stripes are less numerous and broader than that of the Cape Mountain Zebra, whereas body stripes extend around the belly. Leg striping is less prominent. Measures 1.3 to 1.4 metres at the shoulder and weighs 300-320 Kg. They have rounded ears approximately 160-170 mm long. Front portion of mane forms a black tuft between the ears. Diet: Predominantly a grazer, feeding in areas with short grass. Zebra have a strong sensitive upper lip with which it gathers herbage by collecting the grass between the lip and the lower incisors before plucking the harvest.

www.krugerpark.co.za/africa_burchells_zebra.html

While the pandas are very cute, they are bears, with teeth made for ripping and tearing. Note the big incisors for gripping prey.

BIG5 Elephant. Welgevonden Game Reserve. South Africa. Feb/2021

 

Elephant

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are currently recognised: the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.

All elephants have several distinctive features, the most notable of which is a long trunk (also called a proboscis), used for many purposes, particularly breathing, lifting water, and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts, and marshes. They prefer to stay near water. They are considered to be a keystone species due to their impact on their environments. Other animals tend to keep their distance from elephants while predators, such as lions, tigers, hyenas, and any wild dogs, usually target only young elephants (or "calves"). Elephants have a fission–fusion society in which multiple family groups come together to socialise. Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow.

Males ("bulls") leave their family groups when they reach puberty and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell, and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathyfor dying or dead individuals of their kind.

Source: Wikipedia

Elefante

Os elefantes são animais herbívoros, alimentando-se de ervas, gramíneas, frutas e folhas de árvores. Dado o seu tamanho, um elefante adulto pode ingerir entre 70 a 150 kg de alimentos por dia. As fêmeas vivem em manadas de 10 a 15 animais, lideradas por uma matriarca, compostas por várias reprodutoras e crias de variadas idades. O período de gestação das fêmeas é longo (20 a 22 meses), assim como o desenvolvimento do animal que leva anos a atingir a idade adulta. Os filhotes podem nascer com 90 kg. Os machos adolescentes tendem a viver em pequenos bandos e os machos adultos isolados, encontrando-se com as fêmeas apenas no período reprodutivo.

Devido ao seu porte, os elefantes têm poucos predadores. Exercem uma forte influência sobre as savanas, pois mantêm árvores e arbustos sob controle, permitindo que pastagens dominem o ambiente. Eles vivem cerca de 60 anos e morrem quando seus molares caem, impedindo que se alimentem de plantas.

Os elefantes-africanos são maiores que as variedades asiáticas e têm orelhas mais desenvolvidas, uma adaptação que permite libertar calor em condições de altas temperaturas. Outra diferença importante é a ausência de presas de marfim nas fêmeas dos elefantes asiáticos.

Durante a época de acasalamento, o aumento da produção de testosterona deixa os elefantes extremamente agressivos, fazendo-os atacar até humanos. Acidentes com elefantes utilizados em rituais geralmente são causados por esse motivo. Cerca de 400 humanos são mortos por elefantes a cada ano.

Elefante é o termo genérico e popular pelo qual são denominados os membros da família Elephantidae, um grupo de mamíferos proboscídeoselefantídeos, de grande porte, do qual há três espécies no mundo atual, duas africanas (Loxodonta sp.) e uma asiática (Elephas sp.). Há ainda os mamutes (Mammuthus sp.), hoje extintos. Até recentemente, acreditava-se que havia apenas duas espécies vivas de elefantes, o elefante-africano e o elefante-asiático, uma espécie menor. Entretanto, estudos recentes de DNA sugerem que havia, na verdade, duas espécies de elefante-africano: Loxodonta africana, da savana, e Loxodonta cyclotis, que vive nas florestas. Os elefantes são os maiores animais terrestres da actualidade, com a massa entre 4 a 6 toneladas e medindo em média quatro metros de altura, podem levantar até 10.000 kg. As suas características mais distintivas são as presas de marfim

Fonte: Wikipedia

  

Welgevonden Game Reserve

 

Welgevonden Game Reserve, (Dutch for well found), is in the Waterberg District, of the Limpopo, province of South Africa. Welgevonden Game Reserve, (Dutch for "well found"), is a 38,200ha game reserve in the Waterberg District, of the Limpopo Province of South Africa.

It forms part of the Waterberg Biosphere Reserve which was officially declared by UNESCO in 2001 and currently covers an area in excess of 654,033 hectare.

The reserve comprises mountainous terrain that is dissected by deep valleys and kloofs while flat plateaus characterise most hilltops. Altitude varies from 1080 m in the north to ±1800 m in the southern section of the reserve.

Welgevonden is home to over 50 different mammals, including the Big Five. The diversity of habitat leads to a wide range of wildlife with grassy plains abounding with antelope from the largest eland to the diminutive duiker; and cheetah, lion and leopard are regularly seen close by. There are also numerous rare and unusual species such as brown hyena, aardwolf, pangolin and aardvark – all best seen at night. Over 300 bird species can be seen on the reserve, including rare blue cranes which breed in the southern section early in the year.

Source: Wikipedia

Reserva Welgevonden

A Welgevonden Game Reserve, (holandês para bem encontrado), fica no distrito de Waterberg, no Limpopo, província da África do Sul. Welgevonden Game Reserve, (holandês para "bem encontrado"), é uma reserva de safari de 38.200 hectares no distrito de Waterberg, na província de Limpopo da África do Sul.

Faz parte da Reserva da Biosfera de Waterberg que foi oficialmente declarada pela UNESCO em 2001 e atualmente cobre uma área superior a 654.033 hectares.

A reserva compreende terrenos montanhosos que são dissecados por vales profundos e kloofs, enquanto planaltos planos caracterizam a maioria dos topos das colinas. A altitude varia de 1080 m no norte a ± 1800 m na seção sul da reserva.

Welgevonden é o lar de mais de 50 mamíferos diferentes, incluindo os Big Five. A diversidade de habitat leva a uma grande variedade de vida selvagem com planícies gramíneas repletas de antílopes, desde o maior elã até o diminuto duiker; e chita, leão e leopardo são vistos regularmente por perto. Existem também numerosas espécies raras e incomuns, como hiena marrom, aardwolf, pangolin e aardvark - todos melhor vistos à noite. Mais de 300 espécies de pássaros podem ser vistas na reserva, incluindo o Grou-do-paraíso que se reproduzem na seção sul no início do ano.

Fonte: Wikipedia (tradução livre)

 

BIG5. Elephant. Kruger National Park. Kruger Shalati: The Train on the Bridge. South Africa. May/2021

 

Elephant

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are currently recognised: the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.

All elephants have several distinctive features, the most notable of which is a long trunk (also called a proboscis), used for many purposes, particularly breathing, lifting water, and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts, and marshes. They prefer to stay near water. They are considered to be a keystone species due to their impact on their environments. Other animals tend to keep their distance from elephants while predators, such as lions, tigers, hyenas, and any wild dogs, usually target only young elephants (or "calves"). Elephants have a fission–fusion society in which multiple family groups come together to socialise. Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow.

Males ("bulls") leave their family groups when they reach puberty and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell, and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathyfor dying or dead individuals of their kind.

Source: Wikipedia

Elefante

Os elefantes são animais herbívoros, alimentando-se de ervas, gramíneas, frutas e folhas de árvores. Dado o seu tamanho, um elefante adulto pode ingerir entre 70 a 150 kg de alimentos por dia. As fêmeas vivem em manadas de 10 a 15 animais, lideradas por uma matriarca, compostas por várias reprodutoras e crias de variadas idades. O período de gestação das fêmeas é longo (20 a 22 meses), assim como o desenvolvimento do animal que leva anos a atingir a idade adulta. Os filhotes podem nascer com 90 kg. Os machos adolescentes tendem a viver em pequenos bandos e os machos adultos isolados, encontrando-se com as fêmeas apenas no período reprodutivo.

Devido ao seu porte, os elefantes têm poucos predadores. Exercem uma forte influência sobre as savanas, pois mantêm árvores e arbustos sob controle, permitindo que pastagens dominem o ambiente. Eles vivem cerca de 60 anos e morrem quando seus molares caem, impedindo que se alimentem de plantas.

Os elefantes-africanos são maiores que as variedades asiáticas e têm orelhas mais desenvolvidas, uma adaptação que permite libertar calor em condições de altas temperaturas. Outra diferença importante é a ausência de presas de marfim nas fêmeas dos elefantes asiáticos.

Durante a época de acasalamento, o aumento da produção de testosterona deixa os elefantes extremamente agressivos, fazendo-os atacar até humanos. Acidentes com elefantes utilizados em rituais geralmente são causados por esse motivo. Cerca de 400 humanos são mortos por elefantes a cada ano.

Elefante é o termo genérico e popular pelo qual são denominados os membros da família Elephantidae, um grupo de mamíferos proboscídeoselefantídeos, de grande porte, do qual há três espécies no mundo atual, duas africanas (Loxodonta sp.) e uma asiática (Elephas sp.). Há ainda os mamutes (Mammuthus sp.), hoje extintos. Até recentemente, acreditava-se que havia apenas duas espécies vivas de elefantes, o elefante-africano e o elefante-asiático, uma espécie menor. Entretanto, estudos recentes de DNA sugerem que havia, na verdade, duas espécies de elefante-africano: Loxodonta africana, da savana, e Loxodonta cyclotis, que vive nas florestas. Os elefantes são os maiores animais terrestres da actualidade, com a massa entre 4 a 6 toneladas e medindo em média quatro metros de altura, podem levantar até 10.000 kg. As suas características mais distintivas são as presas de marfim

Fonte: Wikipedia

  

Kruger Shalati

Kruger Shalati: The Train on the Bridge. One of the most anticipated and exciting new offerings coming to the iconic Kruger National Park, South Africa. A perfect combination of Africa’s most breathtaking natural splendours with well-deserved luxuries aboard a newly refurbished train that’s reminiscent of African excellence.

Permanently stationed on the historically-rich Selati Bridge above the Sabie River, Kruger Shalati will offer the most unique luxury accommodation in a re-envisioned train which will pay homage to the guests who explored the park nearly 100 years ago while welcoming new explorers from near and far. The train celebrates where the first visits to the iconic park were allowed in the early 1920s, the train would park overnight in the exact spot where Kruger Shalati will be positioned.

Offering 31 rooms, consisting of 24 carriage rooms and 7 Bridge House rooms, all of which will provide a deeply visceral experience, tailored for immersive comfort. Whether you’re looking for a one-of-a-kind adventure, an enthralling break or to simply immerse yourself in earth’s finest creations, Kruger Shalati looks forward to welcoming you on a journey of discovery with nature in the most extraordinary way imaginable.

Source: www.krugershalati.com

Kruger Shalati: O trem na ponte. Uma das novas ofertas mais esperadas e emocionantes que chegam ao icônico Parque Nacional Kruger, na África do Sul. Uma combinação perfeita dos esplendores naturais mais deslumbrantes da África com luxos bem merecidos a bordo de um trem recém-reformado que lembra a excelência africana.

Permanentemente estacionado na histórica Ponte Selati acima do Rio Sabie, Kruger Shalati oferecerá a acomodação de luxo mais exclusiva em um trem reformulado que homenageará os hóspedes que exploraram o parque há quase 100 anos, enquanto recebe novos exploradores. O trem celebra onde as primeiras visitas ao parque icônico foram permitidas no início dos anos 1920, o trem estacionaria durante a noite no local exato onde Kruger Shalati será posicionado.

Oferecendo 31 quartos, consistindo de 24 quartos de carruagem e 7 quartos Bridge House, todos os quais proporcionarão uma experiência profundamente visceral, adaptada para um conforto imersivo. Esteja você procurando por uma aventura única, uma pausa cativante ou simplesmente mergulhar nas melhores criações da terra, Kruger Shalati espera recebê-lo em uma jornada de descoberta com a natureza da maneira mais extraordinária que se possa imaginar.

Fonte: www.krugershalati.com (tradução livre)

 

Kruger National Park

Kruger National Park is one of the largest game reserves in Africa. It covers an area of around 20,000 square kilometres in the provinces of Limpopo and Mpumalanga in northeastern South Africa, and extends 360 kilometres (220 mi) from north to south and 65 kilometres (40 mi) from east to west.

Source: Wikipedia

Parque Nacional Kruger

O Parque Nacional Kruger é a maior área protegida de fauna bravia da África do Sul, cobrindo cerca de 20 000 km2. Está localizado no nordeste do país, nas províncias de Mpumalanga e Limpopo e tem uma extensão de cerca de 360 km de norte a sul e 65 km de leste a oeste.

Os parques nacionais africanos, nas regiões da savana africana são importantes pelo turismo com safári de observação e fotográfico.

O seu nome foi dado em homenagem a Stephanus Johannes Paul Kruger, último presidente da República Sul-Africana bôere. Foi criado em 31 de Maio de 1926

Fonte: Wikipedia

 

Your comments/favs are the highest reward, and very much appreciated.

 

The Red Ruffed Lemur (Varecia rubra) is one of two species in the genus Varecia, the ruffed lemurs; the other is the Black-and-white Ruffed Lemur (Varecia variegata). Like all lemurs, it is native to Madagascar and occurs only in the rainforests of Masoala, in the northeast of the island. It is one of the largest primates of Madagascar with a body length of 53 cm, a tail length of 60 cm and a weight of 3.5–4 kg. Its soft, thick fur is red and black in colour but a few are known to have a white or pink patch on the back of the neck and a ring on the base of the tail in a similar color.

 

There is also another species of ruffed lemur that is similar to the Red Ruffed Lemur; the Black-and-white Ruffed Lemur. They both live in the rainforest along the east coast of Madagascar, but they don't associate with each other.

 

The Red Ruffed Lemur is a very clean animal and spends a lot of time grooming itself and each other. The lower incisors (front teeth) and the claw on the second toe of the hind foot are specially adapted for this behavior. The lower incisors grow forward in line with each other and are slightly spaced. This creates a toothcomb which can be used to groom its long, soft fur. The claw is also used for grooming.

 

The Red Ruffed Lemur lives 15–20 years in the wild. In captivity, 25 years is not uncommon, and one lived to be about 33 years old. It is a diurnal animal, and most active in the morning and evening.

 

[ Source: en.wikipedia.org/wiki/Red_Ruffed_Lemur ]

Near endemic to the South Luangwa valley. The Crawshay's zebra (Equus quagga crawshayi) is a subspecies of the plains zebra. It is native to eastern Zambia, east of the Luangwa River, Malawi, southeastern Tanzania and northern Mozambique south to the Gorongoza District. Crawshay's zebras can be distinguished from other subspecies of plains zebras in that its lower incisors lack an infundibulum. The Crawshay's zebra has very narrow stripes compared to other forms of the Plains zebra.

This youngster, walking across the road to finally join his family who had crossed a few minutes earlier, just looked like a stroppy teenager to us. He looked like he could just have been dragging his feet, with hands stuffed deep in his pockets, huffing as he went along!

 

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Two species are traditionally recognised, the African elephant (Loxodonta africana) and the Asian elephant (Elephas maximus), although some evidence suggests that African bush elephants and African forest elephants are separate species (L. africana and L. cyclotis respectively). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons. Male African elephants are the largest extant terrestrial animals and can reach a height of 4 m (13 ft) and weigh 7,000 kg (15,000 lb). All elephants have several distinctive features the most notable of which is a long trunk or proboscis, used for many purposes, particularly breathing, lifting water and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

 

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts and marshes. They prefer to stay near water. They are considered to be keystone species due to their impact on their environments. Other animals tend to keep their distance where predators such as lions, tigers, hyenas, and wild dogs usually target only the young elephants (or "calves"). Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow. Elephants have a fission–fusion society in which multiple family groups come together to socialise. Males ("bulls") leave their family groups when they reach puberty, and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathy for dying or dead individuals of their kind.

 

Despite their name, the springhare, or the springhaas, is not a hare or lagomorph, but an anomaluromorph rodent in the family Petetidae. Although springhares are highly hystricomorphous, with a greatly englarged infraorbital foramen (large hole anterior to the orbit above, which serves as an attatchment site for the medial masseter muscle), they are more closely related to the strange scaly-tailed squirrels (Anomaluridae) than to Hysticomorpha (which includes the porcupines, capybaras, guinea pigs, chinchillas, among many others). Springhares are highly convergent to rabbits and hares, both superficially with their saltatorial locomotion (jumping behavior), large hind feet, and elongated ears, but also in some of the fine details of the skull, such as a highly reduced temporalis muscle with a small to nonexistent coronoid process on the mandible (blocked by the zygomatic arch here, but you can tell it doesn't extend upward very high, and notice how small the area is for insertion of the temporalis on the skull compared with most mammals). Massively enlarged auditory bullae (the inflated bones in the back of the skull that house the ear bones) are indicators of the jumping lifestyle, and are seen in other rodent jumpers such as jerboas (Dipodidae), kangaroo rats (Heteromyidae), and the vischachas and chinchillas (Chinchillidae).

 

Despite the fact that I cited one of the similarities between true hares and springhares as jumping, the type of saltatorial locomotion they practice is distinctly different. Springhares jump like the previous groups of rodents I mentioned (jerboas, kangaroo rats) and macropods (true kangaroos), in that they hop bipedally consecutively before allowing their forelimbs to touch the ground again, and usually can remain in a bipedal position indefinitely, and are not obligated to stand quadrupedally, like hares and rabbits are (although I'm sure a hare or rabbit could manage stand up right for a while, but then again, so could my pet dashund). Hares and rabbits are more like anurans (frogs, toads, etc.), in that they can jump well, but must land on all fours before jumping again (Pumas are the cat analog of this behavior, in a sense, as they're hind legs are more proportionately longer than their forelegs than any other cat, and they leap rather well).

 

To see their living cuteness (and they are very very cute), see: animaldiversity.ummz.umich.edu/site/resources/lazette_gif...

 

Or to see some beautiful CT cut-aways of one of these skulls, see: www.digimorph.org/specimens/Pedetes_capensis/

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are currently recognised: the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.

 

All elephants have several distinctive features, the most notable of which is a long trunk (also called a proboscis), used for many purposes, particularly breathing, lifting water, and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

 

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts, and marshes. They prefer to stay near water. They are considered to be keystone species due to their impact on their environments. Other animals tend to keep their distance from elephants while predators, such as lions, tigers, hyenas, and any wild dogs, usually target only young elephants (or "calves"). Elephants have a fission–fusion society in which multiple family groups come together to socialise. Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow.

 

Males ("bulls") leave their family groups when they reach puberty and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell, and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathy for dying or dead individuals of their kind.

 

African elephants are listed as vulnerable by the International Union for Conservation of Nature (IUCN) while the Asian elephant is classed as endangered. One of the biggest threats to elephant populations is the ivory trade, as the animals are poached for their ivory tusks. Other threats to wild elephants include habitat destruction and conflicts with local people. Elephants are used as working animals in Asia. In the past, they were used in war; today, they are often controversially put on display in zoos, or exploited for entertainment in circuses. Elephants are highly recognisable and have been featured in art, folklore, religion, literature, and popular culture.

 

ETYMOLOGY

The word "elephant" is based on the Latin elephas (genitive elephantis) ("elephant"), which is the Latinised form of the Greek ἐλέφας (elephas) (genitive ἐλέφαντος (elephantos)), probably from a non-Indo-European language, likely Phoenician. It is attested in Mycenaean Greek as e-re-pa (genitive e-re-pa-to) in Linear B syllabic script. As in Mycenaean Greek, Homer used the Greek word to mean ivory, but after the time of Herodotus, it also referred to the animal. The word "elephant" appears in Middle English as olyfaunt (c.1300) and was borrowed from Old French oliphant (12th century). Loxodonta, the generic name for the African elephants, is Greek for "oblique-sided tooth".

 

TAXONOMY

CLASSIFICATION, SPECIES AND SUBSPECIES

Elephants belong to the family Elephantidae, the sole remaining family within the order Proboscidea which belongs to the superorder Afrotheria. Their closest extant relatives are the sirenians (dugongs and manatees) and the hyraxes, with which they share the clade Paenungulata within the superorder Afrotheria. Elephants and sirenians are further grouped in the clade Tethytheria. Three species of elephants are recognised; the African bush elephant (Loxodonta africana) and forest elephant (Loxodonta cyclotis) of sub-Saharan Africa, and the Asian elephant (Elephas maximus) of South and Southeast Asia. African elephants have larger ears, a concave back, more wrinkled skin, a sloping abdomen, and two finger-like extensions at the tip of the trunk. Asian elephants have smaller ears, a convex or level back, smoother skin, a horizontal abdomen that occasionally sags in the middle and one extension at the tip of the trunk. The looped ridges on the molars are narrower in the Asian elephant while those of the African are more diamond-shaped. The Asian elephant also has dorsal bumps on its head and some patches of depigmentation on its skin. In general, African elephants are larger than their Asian cousins.

 

Swedish zoologist Carl Linnaeus first described the genus Elephas and an elephant from Sri Lanka (then known as Ceylon) under the binomial Elephas maximus in 1758. In 1798, Georges Cuvier classified the Indian elephant under the binomial Elephas indicus. Dutch zoologist Coenraad Jacob Temminck described the Sumatran elephant in 1847 under the binomial Elephas sumatranus. English zoologist Frederick Nutter Chasen classified all three as subspecies of the Asian elephant in 1940. Asian elephants vary geographically in their colour and amount of depigmentation. The Sri Lankan elephant (Elephas maximus maximus) inhabits Sri Lanka, the Indian elephant (E. m. indicus) is native to mainland Asia (on the Indian subcontinent and Indochina), and the Sumatran elephant (E. m. sumatranus) is found in Sumatra. One disputed subspecies, the Borneo elephant, lives in northern Borneo and is smaller than all the other subspecies. It has larger ears, a longer tail, and straighter tusks than the typical elephant. Sri Lankan zoologist Paules Edward Pieris Deraniyagala described it in 1950 under the trinomial Elephas maximus borneensis, taking as his type an illustration in National Geographic. It was subsequently subsumed under either E. m. indicus or E. m. sumatranus. Results of a 2003 genetic analysis indicate its ancestors separated from the mainland population about 300,000 years ago. A 2008 study found that Borneo elephants are not indigenous to the island but were brought there before 1521 by the Sultan of Sulu from Java, where elephants are now extinct.

 

The African elephant was first named by German naturalist Johann Friedrich Blumenbach in 1797 as Elephas africanus. The genus Loxodonta was named by Frédéric Cuvier in 1825. Cuvier spelled it Loxodonte, but in 1827 an anonymous author romanised the spelling to Loxodonta; the International Code of Zoological Nomenclature recognises this as the proper authority. In 1942, 18 subspecies of African elephant were recognised by Henry Fairfield Osborn, but further morphological data has reduced the number of classified subspecies, and by the 1990s, only two were recognised, the savannah or bush elephant (L. a. africana) and the forest elephant (L. a. cyclotis), the latter having been named in 1900 by German zoologist Paul Matschie. Forest elephants have smaller and more rounded ears and thinner and straighter tusks than bush elephants, and are limited in range to the forested areas of western and Central Africa. A 2000 study argued for the elevation of the two forms into separate species (L. africana and L. cyclotis respectively) based on differences in skull morphology. DNA studies published in 2001 and 2007 also suggested they were distinct species while studies in 2002 and 2005 concluded that they were the same species. Further studies (2010, 2011, 2015) have supported African savannah and forest elephants' status as separate species. The two species are believed to have diverged 6 million years ago. and have been completely genetically isolated for the past 500,000 years. In 2017, DNA sequence analysis showed that L. cyclotis is more closely related to the extinct Palaeoloxodon antiquus, than it is to L. africana, possibly undermining the genus Loxodonta as a whole. Some evidence suggests that elephants of western Africa are a separate species, although this is disputed. The pygmy elephants of the Congo Basin, which have been suggested to be a separate species (Loxodonta pumilio) are probably forest elephants whose small size and/or early maturity are due to environmental conditions.

 

EVOLUTION AND EXTINCT RELATIVES

Over 185 extinct members and three major evolutionary radiations of the order Proboscidea have been recorded. The earliest proboscids, the African Eritherium and Phosphatherium of the late Paleocene, heralded the first radiation. The Eocene included Numidotherium, Moeritherium, and Barytherium from Africa. These animals were relatively small and aquatic. Later on, genera such as Phiomia and Palaeomastodon arose; the latter likely inhabited forests and open woodlands. Proboscidean diversity declined during the Oligocene. One notable species of this epoch was Eritreum melakeghebrekristosi of the Horn of Africa, which may have been an ancestor to several later species. The beginning of the Miocene saw the second diversification, with the appearance of the deinotheres and the mammutids. The former were related to Barytherium and lived in Africa and Eurasia, while the latter may have descended from Eritreum and spread to North America.

 

At the beginning of the Pleistocene, elephantids experienced a high rate of speciation. The Pleistocene also saw the arrival of Palaeoloxodon namadicus, the largest terrestrial mammal of all time. Loxodonta atlantica became the most common species in northern and southern Africa but was replaced by Elephas iolensis later in the Pleistocene. Only when Elephas disappeared from Africa did Loxodonta become dominant once again, this time in the form of the modern species. Elephas diversified into new species in Asia, such as E. hysudricus and E. platycephus; the latter the likely ancestor of the modern Asian elephant. Mammuthus evolved into several species, including the well-known woolly mammoth. Interbreeding appears to have been common among elephantid species, with some hybridisation which in some cases led to species with three ancestral genetic components, such as the straight-tusked elephants. In the Late Pleistocene, most proboscidean species vanished during the Quaternary glaciation which killed off 50% of genera weighing over 5 kg worldwide.

 

Proboscideans experienced several evolutionary trends, such as an increase in size, which led to many giant species that stood up to 5 m tall. As with other megaherbivores, including the extinct sauropod dinosaurs, the large size of elephants likely developed to allow them to survive on vegetation with low nutritional value. Their limbs grew longer and the feet shorter and broader. The feet were originally plantigrade and developed into a digitigrade stance with cushion pads and the sesamoid bone providing support. Early proboscideans developed longer mandibles and smaller craniums while more derived ones developed shorter mandibles, which shifted the head's centre of gravity. The skull grew larger, especially the cranium, while the neck shortened to provide better support for the skull. The increase in size led to the development and elongation of the mobile trunk to provide reach. The number of premolars, incisors and canines decreased. The cheek teeth (molars and premolars) became larger and more specialized, especially after elephants started to switch from C3-plants to C4-grasses, which caused their teeth to undergo a three-fold increase in teeth height as well as substantial multiplication of lamellae after about five million years ago. Only in the last million years or so did they return to a diet mainly consisting of C3 trees and shrubs. The upper second incisors grew into tusks, which varied in shape from straight, to curved (either upward or downward), to spiralled, depending on the species. Some proboscideans developed tusks from their lower incisors. Elephants retain certain features from their aquatic ancestry, such as their middle ear anatomy and the internal testes of the males.

 

There has been some debate over the relationship of Mammuthus to Loxodonta or Elephas. Some DNA studies suggest Mammuthus is more closely related to the former while others point to the latter. However, analysis of the complete mitochondrial genome profile of the woolly mammoth (sequenced in 2005) supports Mammuthus being more closely related to Elephas.Morphological evidence supports Mammuthus and Elephas as sister taxa while comparisons of protein albumin and collagen have concluded that all three genera are equally related to each other. Some scientists believe a cloned mammoth embryo could one day be implanted in an Asian elephant's womb.

 

DWARF SPECIES

Several species of proboscideans lived on islands and experienced insular dwarfism. This occurred primarily during the Pleistocene when some elephant populations became isolated by fluctuating sea levels, although dwarf elephants did exist earlier in the Pliocene. These elephants likely grew smaller on islands due to a lack of large or viable predator populations and limited resources. By contrast, small mammals such as rodents develop gigantism in these conditions. Dwarf proboscideans are known to have lived in Indonesia, the Channel Islands of California, and several islands of the Mediterranean.

 

Elephas celebensis of Sulawesi is believed to have descended from Elephas planifrons. Elephas falconeri of Malta and Sicily was only 1 m and had probably evolved from the straight-tusked elephant. Other descendants of the straight-tusked elephant existed in Cyprus. Dwarf elephants of uncertain descent lived in Crete, Cyclades, and Dodecanese while dwarf mammoths are known to have lived in Sardinia. The Columbian mammoth colonised the Channel Islands and evolved into the pygmy mammoth. This species reached a height of 1.2–1.8 m and weighed 200–2,000 kg. A population of small woolly mammoths survived on Wrangel Island, now 140 km north of the Siberian coast, as recently as 4,000 years ago. After their discovery in 1993, they were considered dwarf mammoths. This classification has been re-evaluated and since the Second International Mammoth Conference in 1999, these animals are no longer considered to be true "dwarf mammoths".

 

ANATOMY AND MORPHOLOGY

Elephants are the largest living terrestrial animals. On average, male African bush elephants are 3.20 m tall at the shoulder and mass/weigh 6,000 kg, whereas females are 2.60 m tall at the shoulder and mass/weigh 3,000 kg. Asian elephants are smaller, with males 2.75 m tall at the shoulder and 4,000 kg on average, and females 2.40 m tall at the shoulder and 2,700 kg on average. African forest elephants are the smallest extant species, with the average height for the species 2.00 m at the shoulder and average mass/weight 2,000 kg. Male African elephants are typically 23% taller than females, whereas male Asian elephants are only around 15% taller than females. The skeleton of the elephant is made up of 326–351 bones. The vertebrae are connected by tight joints, which limit the backbone's flexibility. African elephants have 21 pairs of ribs, while Asian elephants have 19 or 20 pairs.

 

An elephant's skull is resilient enough to withstand the forces generated by the leverage of the tusks and head-to-head collisions. The back of the skull is flattened and spread out, creating arches that protect the brain in every direction. The skull contains air cavities (sinuses) that reduce the weight of the skull while maintaining overall strength. These cavities give the inside of the skull a honeycomb-like appearance. The cranium is particularly large and provides enough room for the attachment of muscles to support the entire head. The lower jaw is solid and heavy. Because of the size of the head, the neck is relatively short to provide better support. Lacking a lacrimal apparatus, the eye relies on the harderian gland to keep it moist. A durable nictitating membrane protects the eye globe. The animal's field of vision is compromised by the location and limited mobility of the eyes. Elephants are considered dichromats and they can see well in dim light but not in bright light. The core body temperature averages 35.9 °C, similar to that of a human. Like all mammals, an elephant can raise or lower its temperature a few degrees from the average in response to extreme environmental conditions

 

EARS

Elephant ears have thick bases with thin tips. The ear flaps, or pinnae, contain numerous blood vessels called capillaries. Warm blood flows into the capillaries, helping to release excess body heat into the environment. This occurs when the pinnae are still, and the animal can enhance the effect by flapping them. Larger ear surfaces contain more capillaries, and more heat can be released. Of all the elephants, African bush elephants live in the hottest climates, and have the largest ear flaps. Elephants are capable of hearing at low frequencies and are most sensitive at 1 kHz.

 

TRUNK

The trunk, or proboscis, is a fusion of the nose and upper lip, although in early fetal life, the upper lip and trunk are separated. The trunk is elongated and specialised to become the elephant's most important and versatile appendage. It contains up to 150,000 separate muscle fascicles, with no bone and little fat. These paired muscles consist of two major types: superficial (surface) and internal. The former are divided into dorsals, ventrals, and laterals while the latter are divided into transverse and radiating muscles. The muscles of the trunk connect to a bony opening in the skull. The nasal septum is composed of tiny muscle units that stretch horizontally between the nostrils. Cartilage divides the nostrils at the base. As a muscular hydrostat, the trunk moves by precisely coordinated muscle contractions. The muscles work both with and against each other. A unique proboscis nerve – formed by the maxillary and facial nerves – runs along both sides of the trunk.

 

Elephant trunks have multiple functions, including breathing, olfaction, touching, grasping, and sound production. The animal's sense of smell may be four times as sensitive as that of a bloodhound. The trunk's ability to make powerful twisting and coiling movements allows it to collect food, wrestle with other elephants, and lift up to 350 kg). It can be used for delicate tasks, such as wiping an eye and checking an orifice, and is capable of cracking a peanut shell without breaking the seed. With its trunk, an elephant can reach items at heights of up to 7 m and dig for water under mud or sand. Individuals may show lateral preference when grasping with their trunks: some prefer to twist them to the left, others to the right. Elephants can suck up water both to drink and to spray on their bodies. An adult Asian elephant is capable of holding 8.5 L of water in its trunk. They will also spray dust or grass on themselves. When underwater, the elephant uses its trunk as a snorkel.

 

The African elephant has two finger-like extensions at the tip of the trunk that allow it to grasp and bring food to its mouth. The Asian elephant has only one, and relies more on wrapping around a food item and squeezing it into its mouth. Asian elephants have more muscle coordination and can perform more complex tasks. Losing the trunk would be detrimental to an elephant's survival, although in rare cases, individuals have survived with shortened ones. One elephant has been observed to graze by kneeling on its front legs, raising on its hind legs and taking in grass with its lips. Floppy trunk syndrome is a condition of trunk paralysis in African bush elephants caused by the degradation of the peripheral nerves and muscles beginning at the tip.

 

TEETH

Elephants usually have 26 teeth: the incisors, known as the tusks, 12 deciduous premolars, and 12 molars. Unlike most mammals, which grow baby teeth and then replace them with a single permanent set of adult teeth, elephants are polyphyodonts that have cycles of tooth rotation throughout their lives. The chewing teeth are replaced six times in a typical elephant's lifetime. Teeth are not replaced by new ones emerging from the jaws vertically as in most mammals. Instead, new teeth grow in at the back of the mouth and move forward to push out the old ones. The first chewing tooth on each side of the jaw falls out when the elephant is two to three years old. The second set of chewing teeth falls out at four to six years old. The third set falls out at 9–15 years of age, and set four lasts until 18–28 years of age. The fifth set of teeth falls out at the early 40s. The sixth (and usually final) set must last the elephant the rest of its life. Elephant teeth have loop-shaped dental ridges, which are thicker and more diamond-shaped in African elephants.

 

TUSKS

The tusks of an elephant are modified second incisors in the upper jaw. They replace deciduous milk teeth at 6–12 months of age and grow continuously at about 17 cm a year. A newly developed tusk has a smooth enamel cap that eventually wears off. The dentine is known as ivory and its cross-section consists of crisscrossing line patterns, known as "engine turning", which create diamond-shaped areas. As a piece of living tissue, a tusk is relatively soft; it is as hard as the mineral calcite. Much of the tusk can be seen outside; the rest is in a socket in the skull. At least one-third of the tusk contains the pulp and some have nerves stretching to the tip. Thus it would be difficult to remove it without harming the animal. When removed, ivory begins to dry up and crack if not kept cool and moist. Tusks serve multiple purposes. They are used for digging for water, salt, and roots; debarking or marking trees; and for moving trees and branches when clearing a path. When fighting, they are used to attack and defend, and to protect the trunk.

 

Like humans, who are typically right- or left-handed, elephants are usually right- or left-tusked. The dominant tusk, called the master tusk, is generally more worn down, as it is shorter with a rounder tip. For the African elephants, tusks are present in both males and females, and are around the same length in both sexes, reaching up to 3 m, but those of males tend to be thicker. In earlier times, elephant tusks weighing more than 90 kg were not uncommon, though it is rare today to see any over 45 kg.

 

In the Asian species, only the males have large tusks. Female Asians have very small tusks, or none at all. Tuskless males exist and are particularly common among Sri Lankan elephants. Asian males can have tusks as long as Africans', but they are usually slimmer and lighter; the largest recorded was 3.02 m long and weighed 39 kg. Hunting for elephant ivory in Africa and Asia has led to natural selection for shorter tusks and tusklessness.

 

SKIN

An elephant's skin is generally very tough, at 2.5 cm thick on the back and parts of the head. The skin around the mouth, anus, and inside of the ear is considerably thinner. Elephants typically have grey skin, but African elephants look brown or reddish after wallowing in coloured mud. Asian elephants have some patches of depigmentation, particularly on the forehead and ears and the areas around them. Calves have brownish or reddish hair, especially on the head and back. As elephants mature, their hair darkens and becomes sparser, but dense concentrations of hair and bristles remain on the end of the tail as well as the chin, genitals and the areas around the eyes and ear openings. Normally the skin of an Asian elephant is covered with more hair than its African counterpart.An elephant uses mud as a sunscreen, protecting its skin from ultraviolet light. Although tough, an elephant's skin is very sensitive. Without regular mud baths to protect it from burning, insect bites and moisture loss, an elephant's skin suffers serious damage. After bathing, the elephant will usually use its trunk to blow dust onto its body and this dries into a protective crust. Elephants have difficulty releasing heat through the skin because of their low surface-area-to-volume ratio, which is many times smaller than that of a human. They have even been observed lifting up their legs, presumably in an effort to expose their soles to the air.

 

LEGS, LOCOMOTION AND POSTURE

To support the animal's weight, an elephant's limbs are positioned more vertically under the body than in most other mammals. The long bones of the limbs have cancellous bone in place of medullary cavities. This strengthens the bones while still allowing haematopoiesis. Both the front and hind limbs can support an elephant's weight, although 60% is borne by the front. Since the limb bones are placed on top of each other and under the body, an elephant can stand still for long periods of time without using much energy. Elephants are incapable of rotating their front legs, as the ulna and radius are fixed in pronation; the "palm" of the manus faces backward. The pronator quadratus and the pronator teres are either reduced or absent. The circular feet of an elephant have soft tissues or "cushion pads" beneath the manus or pes, which distribute the weight of the animal. They appear to have a sesamoid, an extra "toe" similar in placement to a giant panda's extra "thumb", that also helps in weight distribution. As many as five toenails can be found on both the front and hind feet.

 

Elephants can move both forwards and backwards, but cannot trot, jump, or gallop. They use only two gaits when moving on land: the walk and a faster gait similar to running. In walking, the legs act as pendulums, with the hips and shoulders rising and falling while the foot is planted on the ground. With no "aerial phase", the fast gait does not meet all the criteria of running, although the elephant uses its legs much like other running animals, with the hips and shoulders falling and then rising while the feet are on the ground. Fast-moving elephants appear to 'run' with their front legs, but 'walk' with their hind legs and can reach a top speed of 25 km/h. At this speed, most other quadrupeds are well into a gallop, even accounting for leg length. Spring-like kinetics could explain the difference between the motion of elephants and other animals. During locomotion, the cushion pads expand and contract, and reduce both the pain and noise that would come from a very heavy animal moving. Elephants are capable swimmers. They have been recorded swimming for up to six hours without touching the bottom, and have travelled as far as 48 km at a stretch and at speeds of up to 2.1 km/h.

 

INTERNAL AND SEXUAL ORGANS

The brain of an elephant weighs 4.5–5.5 kg compared to 1.6 kg for a human brain. While the elephant brain is larger overall, it is proportionally smaller. At birth, an elephant's brain already weighs 30–40% of its adult weight. The cerebrum and cerebellum are well developed, and the temporal lobes are so large that they bulge out laterally. The throat of an elephant appears to contain a pouch where it can store water for later use.

 

The heart of an elephant weighs 12–21 kg. It has a double-pointed apex, an unusual trait among mammals. In addition, the ventricles separate near the top of the heart, a trait they share with sirenians. When standing, the elephant's heart beats approximately 30 times per minute. Unlike many other animals, the heart rate speeds up by 8 to 10 beats per minute when the elephant is lying down. The blood vessels in most of the body are wide and thick and can withstand high blood pressures. The lungs are attached to the diaphragm, and breathing relies mainly on the diaphragm rather than the expansion of the ribcage. Connective tissue exists in place of the pleural cavity. This may allow the animal to deal with the pressure differences when its body is underwater and its trunk is breaking the surface for air, although this explanation has been questioned. Another possible function for this adaptation is that it helps the animal suck up water through the trunk. Elephants inhale mostly through the trunk, although some air goes through the mouth. They have a hindgut fermentation system, and their large and small intestines together reach 35 m in length. The majority of an elephant's food intake goes undigested despite the process lasting up to a day.

 

A male elephant's testes are located internally near the kidneys. The elephant's penis can reach a length of 100 cm and a diameter of 16 cm at the base. It is S-shaped when fully erect and has a Y-shaped orifice. The female has a well-developed clitoris at up to 40 cm. The vulva is located between the hind legs instead of near the tail as in most mammals. Determining pregnancy status can be difficult due to the animal's large abdominal cavity. The female's mammary glands occupy the space between the front legs, which puts the suckling calf within reach of the female's trunk. Elephants have a unique organ, the temporal gland, located in both sides of the head. This organ is associated with sexual behaviour, and males secrete a fluid from it when in musth. Females have also been observed with secretions from the temporal glands.

 

BEHAVIOUR AND LIFE HISTORY

ECOLOGY AND ACTIVITIES

The African bush elephant can be found in habitats as diverse as dry savannahs, deserts, marshes, and lake shores, and in elevations from sea level to mountain areas above the snow line. Forest elephants mainly live in equatorial forests but will enter gallery forests and ecotones between forests and savannahs. Asian elephants prefer areas with a mix of grasses, low woody plants, and trees, primarily inhabiting dry thorn-scrub forests in southern India and Sri Lanka and evergreen forests in Malaya. Elephants are herbivorous and will eat leaves, twigs, fruit, bark, grass and roots. They are born with sterile intestines and require bacteria obtained from their mother's feces to digest vegetation. African elephants are mostly browsers while Asian elephants are mainly grazers. They can consume as much as 150 kg of food and 40 L (11 US gal) of water in a day. Elephants tend to stay near water sources. Major feeding bouts take place in the morning, afternoon and night. At midday, elephants rest under trees and may doze off while standing. Sleeping occurs at night while the animal is lying down. Elephants average 3–4 hours of sleep per day. Both males and family groups typically move 10–20 km a day, but distances as far as 90–180 km have been recorded in the Etosha region of Namibia. Elephants go on seasonal migrations in search of food, water, minerals, and mates. At Chobe National Park, Botswana, herds travel 325 km to visit the river when the local waterholes dry up.

 

Because of their large size, elephants have a huge impact on their environments and are considered keystone species. Their habit of uprooting trees and undergrowth can transform savannah into grasslands; when they dig for water during drought, they create waterholes that can be used by other animals. They can enlarge waterholes when they bathe and wallow in them. At Mount Elgon, elephants excavate caves that are used by ungulates, hyraxes, bats, birds and insects. Elephants are important seed dispersers; African forest elephants ingest and defecate seeds, with either no effect or a positive effect on germination. The seeds are typically dispersed in large amounts over great distances. In Asian forests, large seeds require giant herbivores like elephants and rhinoceros for transport and dispersal. This ecological niche cannot be filled by the next largest herbivore, the tapir. Because most of the food elephants eat goes undigested, their dung can provide food for other animals, such as dung beetles and monkeys. Elephants can have a negative impact on ecosystems. At Murchison Falls National Park in Uganda, the overabundance of elephants has threatened several species of small birds that depend on woodlands. Their weight can compact the soil, which causes the rain to run off, leading to erosion.

 

Elephants typically coexist peacefully with other herbivores, which will usually stay out of their way. Some aggressive interactions between elephants and rhinoceros have been recorded. At Aberdare National Park, Kenya, a rhino attacked an elephant calf and was killed by the other elephants in the group. At Hluhluwe-Umfolozi Game Reserve, South Africa, introduced young orphan elephants went on a killing spree that claimed the lives of 36 rhinos during the 1990s, but ended with the introduction of older males. The size of adult elephants makes them nearly invulnerable to predators, though there are rare reports of adult elephants falling prey to tigers. Calves may be preyed on by lions, spotted hyenas, and wild dogs in Africa and tigers in Asia. The lions of Savuti, Botswana, have adapted to hunting juvenile elephants during the dry season, and a pride of 30 lions has been recorded killing juvenile individuals between the ages of four and eleven years. Elephants appear to distinguish between the growls of larger predators like tigers and smaller predators like leopards (which have not been recorded killing calves); they react to leopards less fearfully and more aggressively. Elephants tend to have high numbers of parasites, particularly nematodes, compared to other herbivores. This is due to lower predation pressures that would otherwise kill off many of the individuals with significant parasite loads.

 

SOCIAL ORGANISATION

Female elephants spend their entire lives in tight-knit matrilineal family groups, some of which are made up of more than ten members, including three pairs of mothers with offspring, and are led by the matriarch which is often the eldest female. She remains leader of the group until death or if she no longer has the energy for the role; a study on zoo elephants showed that when the matriarch died, the levels of faecal corticosterone ('stress hormone') dramatically increased in the surviving elephants. When her tenure is over, the matriarch's eldest daughter takes her place; this occurs even if her sister is present. The older matriarchs tend to be more effective decision-makers.

 

The social circle of the female elephant does not necessarily end with the small family unit. In the case of elephants in Amboseli National Park, Kenya, a female's life involves interaction with other families, clans, and subpopulations. Families may associate and bond with each other, forming what are known as bond groups. These are typically made of two family groups, which may be closely related due to previously being part of the same family group which split after becoming too large for the available resources. During the dry season, elephant families may cluster together and form another level of social organisation known as the clan. Groups within these clans do not form strong bonds, but they defend their dry-season ranges against other clans. There are typically nine groups in a clan. The Amboseli elephant population is further divided into the "central" and "peripheral" subpopulations.

 

Some elephant populations in India and Sri Lanka have similar basic social organisations. There appear to be cohesive family units and loose aggregations. They have been observed to have "nursing units" and "juvenile-care units". In southern India, elephant populations may contain family groups, bond groups and possibly clans. Family groups tend to be small, consisting of one or two adult females and their offspring. A group containing more than two adult females plus offspring is known as a "joint family". Malay elephant populations have even smaller family units, and do not have any social organisation higher than a family or bond group. Groups of African forest elephants typically consist of one adult female with one to three offspring. These groups appear to interact with each other, especially at forest clearings.

The social life of the adult male is very different. As he matures, a male spends more time at the edge of his group and associates with outside males or even other families. At Amboseli, young males spend over 80% of their time away from their families when they are 14–15. When males permanently leave, they either live alone or with other males. The former is typical of bulls in dense forests. Asian males are usually solitary, but occasionally form groups of two or more individuals; the largest consisted of seven bulls. Larger bull groups consisting of over 10 members occur only among African bush elephants, the largest of which numbered up to 144 individuals. These elephants can be quite sociable when not competing for dominance or mates, and will form long-term relationships. A dominance hierarchy exists among males, whether they range socially or solitarily. Dominance depends on the age, size and sexual condition, and when in groups, males follow the lead of the dominant bull. Young bulls may seek out the company and leadership of older, more experienced males, whose presence appears to control their aggression and prevent them from exhibiting "deviant" behaviour. Adult males and females come together for reproduction. Bulls associate with family groups if an oestrous cow is present.

 

SEXUAL BEHAVIOUR

MUSTH

Adult males enter a state of increased testosterone known as musth. In a population in southern India, males first enter musth at the age of 15, but it is not very intense until they are older than 25. At Amboseli, bulls under 24 do not go into musth, while half of those aged 25–35 and all those over 35 do. Young bulls appear to enter musth during the dry season (January–May), while older bulls go through it during the wet season (June–December). The main characteristic of a bull's musth is a fluid secreted from the temporal gland that runs down the side of his face. He may urinate with his penis still in his sheath, which causes the urine to spray on his hind legs. Behaviours associated with musth include walking with the head held high and swinging, picking at the ground with the tusks, marking, rumbling and waving only one ear at a time. This can last from a day to four months.

 

Males become extremely aggressive during musth. Size is the determining factor in agonistic encounters when the individuals have the same condition. In contests between musth and non-musth individuals, musth bulls win the majority of the time, even when the non-musth bull is larger. A male may stop showing signs of musth when he encounters a musth male of higher rank. Those of equal rank tend to avoid each other. Agonistic encounters typically consist of threat displays, chases, and minor sparring with the tusks. Serious fights are rare.

 

MATING

Elephants are polygynous breeders, and copulations are most frequent during the peak of the wet season. A cow in oestrus releases chemical signals (pheromones) in her urine and vaginal secretions to signal her readiness to mate. A bull will follow a potential mate and assess her condition with the flehmen response, which requires the male to collect a chemical sample with his trunk and bring it to the vomeronasal organ. The oestrous cycle of a cow lasts 14–16 weeks with a 4–6-week follicular phase and an 8- to 10-week luteal phase. While most mammals have one surge of luteinizing hormone during the follicular phase, elephants have two. The first (or anovulatory) surge, could signal to males that the female is in oestrus by changing her scent, but ovulation does not occur until the second (or ovulatory) surge. Fertility rates in cows decline around 45–50 years of age.

_____________________________

. . . for Part 2 go to: Elephants - 2

 

WIKIPEDIA

Those two lower incisors were pulled back in 2014 because they couldn't be saved:(

Now we just have to say that he is definitely MR. PERSONALITY!

Phnom Penh

Cambodia

21 Oct 2013

From Wikipedia, the free encyclopedia

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This article is about a paraphyletic group. For close extinct relatives, see Elephantidae. For other uses, see Elephant (disambiguation).

Elephants

Temporal range: Pliocene–Present

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From top left to right: the African bush elephant, the Asian elephant and African forest elephant.

From top left to right: the African bush elephant, the Asian elephant and African forest elephant.

Scientific classificationEdit this classification

Kingdom:Animalia

Phylum:Chordata

Class:Mammalia

Order:Proboscidea

Family:Elephantidae

Subfamily:Elephantinae

Groups included

Loxodonta Anonymous, 1827

Elephas Linnaeus, 1758

†Palaeoloxodon Matsumoto, 1925

Cladistically included but traditionally excluded taxa

†Mammuthus Brookes, 1828

†Primelephas Maglio, 1970

Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are an informal grouping within the proboscidean family Elephantidae. Elephantidae is the only surviving family of proboscideans; extinct members include the mastodons. Elephantidae also contains several extinct groups, including the mammoths and straight-tusked elephants. African elephants have larger ears and concave backs, whereas Asian elephants have smaller ears, and convex or level backs. Distinctive features of all elephants include a long proboscis called a trunk, tusks, large ear flaps, massive legs, and tough but sensitive skin. The trunk is used for breathing, bringing food and water to the mouth, and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. The pillar-like legs carry their great weight.

 

Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia and are found in different habitats, including savannahs, forests, deserts, and marshes. They are herbivorous, and they stay near water when it is accessible. They are considered to be keystone species, due to their impact on their environments. Elephants have a fission–fusion society, in which multiple family groups come together to socialise. Females (cows) tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups, which do not include bulls, are usually led by the oldest cow, known as the matriarch.

 

Males (bulls) leave their family groups when they reach puberty and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate. They enter a state of increased testosterone and aggression known as musth, which helps them gain dominance over other males as well as reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell, and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness, and appear to show empathy for dying and dead family members.

 

African bush elephants and Asian elephants are listed as endangered and African forest elephants as critically endangered by the International Union for Conservation of Nature (IUCN). One of the biggest threats to elephant populations is the ivory trade, as the animals are poached for their ivory tusks. Other threats to wild elephants include habitat destruction and conflicts with local people. Elephants are used as working animals in Asia. In the past, they were used in war; today, they are often controversially put on display in zoos, or exploited for entertainment in circuses. Elephants are highly recognisable and have been featured in art, folklore, religion, literature, and popular culture.

Etymology

The word "elephant" is based on the Latin elephas (genitive elephantis) ("elephant"), which is the Latinised form of the Greek ἐλέφας (elephas) (genitive ἐλέφαντος (elephantos[1]), probably from a non-Indo-European language, likely Phoenician.[2] It is attested in Mycenaean Greek as e-re-pa (genitive e-re-pa-to) in Linear B syllabic script.[3][4] As in Mycenaean Greek, Homer used the Greek word to mean ivory, but after the time of Herodotus, it also referred to the animal.[1] The word "elephant" appears in Middle English as olyfaunt (c.1300) and was borrowed from Old French oliphant (12th century).[2]

 

Taxonomy and phylogeny

Afrotheria

Afroinsectiphilia

Tubulidentata

Orycteropodidae Aardvark2 (PSF) colourised.png

  

Afroinsectivora

Macroscelidea

Macroscelididae Rhynchocyon chrysopygus-J Smit white background.jpg

  

Afrosoricida

 

Chrysochloridae The animal kingdom, arranged according to its organization, serving as a foundation for the natural history of animals (Pl. 18) (Chrysochloris asiatica).jpg

   

Tenrecidae Brehms Thierleben - Allgemeine Kunde des Thierreichs (1876) (Tenrec ecaudatus).jpg

     

Paenungulata

Hyracoidea

Procaviidae DendrohyraxEminiSmit white background.jpg

  

Tethytheria

Proboscidea

Elephantidae Elephas africanus - 1700-1880 - Print - Iconographia Zoologica - (white background).jpg

  

Sirenia

 

Dugongidae Dugong dugon Hardwicke white background.jpg

   

Trichechidae Manatee white background.jpg

      

A cladogram of the elephants within Afrotheria based on molecular evidence[5]

Proboscidea

 

early proboscideans, e.g. Moeritherium Moeritherium NT small.jpg

    

Deinotheriidae Deinotherium12.jpg

  

Elephantiformes

 

Mammutidae BlankMastodon.jpg

    

Gomphotheriidae Gomphotherium NT small.jpg

    

Stegodontidae Stegodon Siwalik Hills.jpg

  

Elephantidae

 

Loxodonta African Bush Elephant.jpg

    

Mammuthus Mammuthus trogontherii122DB.jpg

   

Elephas Elephas maximus (Bandipur).jpg

         

Proboscidea phylogeny based on upper molars.[6]

Elephantimorpha

Elephantidae

   

Mammuthus primigenius Woolly mammoth model Royal BC Museum in Victoria.jpg

   

Mammuthus columbi Archidiskodon imperator121.jpg

    

Elephas maximus Elephas maximus (Bandipur).jpg

      

Loxodonta cyclotis African Forest Elephant.jpg

   

Palaeoloxodon antiquus Elephas-antiquus.jpg

    

Loxodonta africana African Bush Elephant.jpg

     

Mammut americanum BlankMastodon.jpg

   

Phylogeny of modern elephants and close extinct relatives based on molecular evidence[7]

See also: List of elephant species

Elephants belong to the family Elephantidae, the sole remaining family within the order Proboscidea which belongs to the superorder Afrotheria. Their closest extant relatives are the sirenians (dugongs and manatees) and the hyraxes, with which they share the clade Paenungulata within the superorder Afrotheria.[8] Elephants and sirenians are further grouped in the clade Tethytheria.[9]

 

Three species of elephants are recognised; the African bush elephant (Loxodonta africana) and forest elephant (Loxodonta cyclotis) of sub-Saharan Africa, and the Asian elephant (Elephas maximus) of South and Southeast Asia.[10] African elephants have larger ears, a concave back, more wrinkled skin, a sloping abdomen, and two finger-like extensions at the tip of the trunk. Asian elephants have smaller ears, a convex or level back, smoother skin, a horizontal abdomen that occasionally sags in the middle and one extension at the tip of the trunk. The looped ridges on the molars are narrower in the Asian elephant while those of the African are more diamond-shaped. The Asian elephant also has dorsal bumps on its head and some patches of depigmentation on its skin.[11]

 

Among African elephants, forest elephants have smaller and more rounded ears and thinner and straighter tusks than bush elephants and are limited in range to the forested areas of western and Central Africa.[12] Both were traditionally considered a single species, Loxodonta africana, but molecular studies have affirmed their status as separate species.[13][14][15] In 2017, DNA sequence analysis showed that L. cyclotis is more closely related to the extinct Palaeoloxodon antiquus, than it is to L. africana, possibly undermining the genus Loxodonta as a whole.[16]

 

Evolution and extinct relatives

Over 180 extinct members and three major evolutionary radiations of the order Proboscidea have been recorded.[17] The earliest proboscids, the African Eritherium and Phosphatherium of the late Paleocene, heralded the first radiation.[18] The Eocene included Numidotherium, Moeritherium, and Barytherium from Africa. These animals were relatively small and aquatic. Later on, genera such as Phiomia and Palaeomastodon arose; the latter likely inhabited forests and open woodlands. Proboscidean diversity declined during the Oligocene.[19] One notable species of this epoch was Eritreum melakeghebrekristosi of the Horn of Africa, which may have been an ancestor to several later species.[20] The beginning of the Miocene saw the second diversification, with the appearance of the deinotheres and the mammutids. The former were related to Barytherium and lived in Africa and Eurasia,[21] while the latter may have descended from Eritreum[20] and spread to North America.[21]

 

The second radiation was represented by the emergence of the gomphotheres in the Miocene,[21] which likely evolved from Eritreum[20] and originated in Africa, spreading to every continent except Australia and Antarctica. Members of this group included Gomphotherium and Platybelodon.[21] The third radiation started in the late Miocene and led to the arrival of the elephantids, which descended from, and slowly replaced, the gomphotheres.[22] The African Primelephas gomphotheroides gave rise to Loxodonta, Mammuthus, and Elephas. Loxodonta branched off earliest around the Miocene and Pliocene boundary while Mammuthus and Elephas diverged later during the early Pliocene. Loxodonta remained in Africa while Mammuthus and Elephas spread to Eurasia, and the former reached North America. At the same time, the stegodontids, another proboscidean group descended from gomphotheres, spread throughout Asia, including the Indian subcontinent, China, southeast Asia, and Japan. Mammutids continued to evolve into new species, such as the American mastodon.[23]

 

At the beginning of the Pleistocene, elephantids experienced a high rate of speciation.[24] The Pleistocene also saw the arrival of Palaeoloxodon namadicus, the largest terrestrial mammal of all time.[25] Loxodonta atlantica became the most common species in northern and southern Africa but was replaced by Elephas iolensis later in the Pleistocene. Only when Elephas disappeared from Africa did Loxodonta become dominant once again, this time in the form of the modern species. Elephas diversified into new species in Asia, such as E. hysudricus and E. platycephus;[26] the latter the likely ancestor of the modern Asian elephant.[24] Mammuthus evolved into several species, including the well-known woolly mammoth.[26] Interbreeding appears to have been common among elephantid species, which in some cases led to species with three ancestral genetic components, such as the Palaeoloxodon antiquus.[7] In the Late Pleistocene, most proboscidean species vanished during the Quaternary glaciation which killed off 50% of genera weighing over 5 kg (11 lb) worldwide.[27]

 

Proboscideans experienced several evolutionary trends, such as an increase in size, which led to many giant species that stood up to 500 cm (16 ft 5 in) tall.[25] As with other megaherbivores, including the extinct sauropod dinosaurs, the large size of elephants likely developed to allow them to survive on vegetation with low nutritional value.[28] Their limbs grew longer and the feet shorter and broader.[6] The feet were originally plantigrade and developed into a digitigrade stance with cushion pads and the sesamoid bone providing support.[29] Early proboscideans developed longer mandibles and smaller craniums while more derived ones developed shorter mandibles, which shifted the head's centre of gravity. The skull grew larger, especially the cranium, while the neck shortened to provide better support for the skull. The increase in size led to the development and elongation of the mobile trunk to provide reach. The number of premolars, incisors and canines decreased.[6]

 

The cheek teeth (molars and premolars) of proboscideans became larger and more specialized, especially after elephants started to switch from C3-plants to C4-grasses, which caused their teeth to undergo a three-fold increase in teeth height as well as substantial multiplication of lamellae after about five million years ago. Only in the last million years or so did they return to a diet mainly consisting of C3 trees and shrubs.[30][31] The upper second incisors grew into tusks, which varied in shape from straight, to curved (either upward or downward), to spiralled, depending on the species. Some proboscideans developed tusks from their lower incisors.[6] Elephants retain certain features from their aquatic ancestry, such as their middle ear anatomy.[32]

 

Several species of proboscideans lived on islands and experienced insular dwarfism. This occurred primarily during the Pleistocene when some elephant populations became isolated by fluctuating sea levels, although dwarf elephants did exist earlier in the Pliocene. These elephants likely grew smaller on islands due to a lack of large or viable predator populations and limited resources. By contrast, small mammals such as rodents develop gigantism in these conditions. Dwarf elephants are known to have lived in Indonesia, the Channel Islands of California, and several islands of the Mediterranean.[33]

Anatomy and morphology

Size

 

African bush elephant skeleton

Elephants are the largest living terrestrial animals. African bush elephants are the largest species, with males being 304–336 cm (10 ft 0 in–11 ft 0 in) tall at the shoulder with a body mass of 5.2–6.9 t (5.7–7.6 short tons) and females standing 247–273 cm (8 ft 1 in–8 ft 11 in) tall at the shoulder with a body mass of 2.6–3.5 t (2.9–3.9 short tons). Male Asian elephants are usually about 261–289 cm (8 ft 7 in–9 ft 6 in) tall at the shoulder and 3.5–4.6 t (3.9–5.1 short tons) whereas females are 228–252 cm (7 ft 6 in–8 ft 3 in) tall at the shoulder and 2.3–3.1 t (2.5–3.4 short tons). African forest elephants are the smallest species, with males usually being around 209–231 cm (6 ft 10 in–7 ft 7 in) tall at the shoulder and 1.7–2.3 t (1.9–2.5 short tons). Male African bush elephants are typically 23% taller than females, whereas male Asian elephants are only around 15% taller than females.[25]

 

Bones

The skeleton of the elephant is made up of 326–351 bones.[34] The vertebrae are connected by tight joints, which limit the backbone's flexibility. African elephants have 21 pairs of ribs, while Asian elephants have 19 or 20 pairs.[35]

 

Head

An elephant's skull is resilient enough to withstand the forces generated by the leverage of the tusks and head-to-head collisions. The back of the skull is flattened and spread out, creating arches that protect the brain in every direction.[36] The skull contains air cavities (sinuses) that reduce the weight of the skull while maintaining overall strength. These cavities give the inside of the skull a honeycomb-like appearance. The cranium is particularly large and provides enough room for the attachment of muscles to support the entire head. The lower jaw is solid and heavy.[34] Because of the size of the head, the neck is relatively short to provide better support.[6] Lacking a lacrimal apparatus, the eye relies on the harderian gland to keep it moist. A durable nictitating membrane protects the eye globe. The animal's field of vision is compromised by the location and limited mobility of the eyes.[37] Elephants are considered dichromats[38] and they can see well in dim light but not in bright light.[39]

  

African bush elephant with ears spread in a threat or attentive position; note the visible blood vessels

Ears

Elephant ears have thick bases with thin tips. The ear flaps, or pinnae, contain numerous blood vessels called capillaries. Warm blood flows into the capillaries, helping to release excess body heat into the environment. This occurs when the pinnae are still, and the animal can enhance the effect by flapping them. Larger ear surfaces contain more capillaries, and more heat can be released. Of all the elephants, African bush elephants live in the hottest climates, and have the largest ear flaps.[40] Elephants are capable of hearing at low frequencies and are most sensitive at 1 kHz (in close proximity to the Soprano C).[41]

 

Trunk

 

African bush elephant with its trunk raised, a behaviour often adopted when trumpeting

 

Asian elephant drinking water with trunk

The trunk, or proboscis, is a fusion of the nose and upper lip, although in early fetal life, the upper lip and trunk are separated.[6] The trunk is elongated and specialised to become the elephant's most important and versatile appendage. It contains up to 150,000 separate muscle fascicles,[42] with no bone and little fat. These paired muscles consist of two major types: superficial (surface) and internal. The former are divided into dorsals, ventrals, and laterals while the latter are divided into transverse and radiating muscles. The muscles of the trunk connect to a bony opening in the skull. The nasal septum is composed of tiny muscle units that stretch horizontally between the nostrils. Cartilage divides the nostrils at the base.[43] As a muscular hydrostat, the trunk moves by precisely coordinated muscle contractions. The muscles work both with and against each other. A unique proboscis nerve – formed by the maxillary and facial nerves – runs along both sides of the trunk.[44]

 

Elephant trunks have multiple functions, including breathing, olfaction, touching, grasping, and sound production.[6] The animal's sense of smell may be four times as sensitive as that of a bloodhound.[45] The trunk's ability to make powerful twisting and coiling movements allows it to collect food, wrestle with other elephants,[46] and lift up to 350 kg (770 lb).[6] It can be used for delicate tasks, such as wiping an eye and checking an orifice,[46] and is capable of cracking a peanut shell without breaking the seed.[6] With its trunk, an elephant can reach items at heights of up to 7 m (23 ft) and dig for water under mud or sand.[46] Individuals may show lateral preference when grasping with their trunks: some prefer to twist them to the left, others to the right.[44] Elephants are capable of dilating their nostrils at a radius of nearly 30%, increasing the nasal volume by 64%, and can inhale at over 150 m/s (490 ft/s) which is around 30 times the speed of a human sneeze.[47] Elephants can suck up food and water both to spray in the mouth and, in the case of the later, to sprinkle on their bodies.[6][47] An adult Asian elephant is capable of holding 8.5 L (2.2 US gal) of water in its trunk.[43] They will also spray dust or grass on themselves.[6] When underwater, the elephant uses its trunk as a snorkel.[32]

 

The African elephant has two finger-like extensions at the tip of the trunk that allow it to grasp and bring food to its mouth. The Asian elephant has only one and relies more on wrapping around a food item and squeezing it into its mouth.[11] Asian elephants have more muscle coordination and can perform more complex tasks.[43] Losing the trunk would be detrimental to an elephant's survival,[6] although in rare cases, individuals have survived with shortened ones. One elephant has been observed to graze by kneeling on its front legs, raising on its hind legs and taking in grass with its lips.[43] Floppy trunk syndrome is a condition of trunk paralysis in African bush elephants caused by the degradation of the peripheral nerves and muscles beginning at the tip.[48]

 

Teeth

 

Closeup of the cheek teeth of a dead juvenile bush elephant

 

Asian elephant eating tree bark, using its tusks to peel it off.

Elephants usually have 26 teeth: the incisors, known as the tusks, 12 deciduous premolars, and 12 molars. Unlike most mammals, which grow baby teeth and then replace them with a single permanent set of adult teeth, elephants are polyphyodonts that have cycles of tooth rotation throughout their lives. The chewing teeth are replaced six times in a typical elephant's lifetime. Teeth are not replaced by new ones emerging from the jaws vertically as in most mammals. Instead, new teeth grow in at the back of the mouth and move forward to push out the old ones. The first chewing tooth on each side of the jaw falls out when the elephant is two to three years old. The second set of chewing teeth falls out at four to six years old. The third set falls out at 9–15 years of age and set four lasts until 18–28 years of age. The fifth set of teeth falls out at the early 40s. The sixth (and usually final) set must last the elephant the rest of its life. Elephant teeth have loop-shaped dental ridges, which are thicker and more diamond-shaped in African elephants.[49]

 

Tusks

The tusks of an elephant are modified second incisors in the upper jaw. They replace deciduous milk teeth at 6–12 months of age and grow continuously at about 17 cm (7 in) a year. A newly developed tusk has a smooth enamel cap that eventually wears off. The dentine is known as ivory and its cross-section consists of crisscrossing line patterns, known as "engine turning", which create diamond-shaped areas. As a piece of living tissue, a tusk is relatively soft; it is as hard as the mineral calcite. Much of the tusk can be seen outside; the rest is in a socket in the skull. At least one-third of the tusk contains the pulp and some have nerves stretching to the tip. Thus it would be difficult to remove it without harming the animal. When removed, ivory begins to dry up and crack if not kept cool and moist. Tusks serve multiple purposes. They are used for digging for water, salt, and roots; debarking or marking trees; and for moving trees and branches when clearing a path. When fighting, they are used to attack and defend, and to protect the trunk.[50]

 

Like humans, who are typically right- or left-handed, elephants are usually right- or left-tusked. The dominant tusk, called the master tusk, is generally more worn down, as it is shorter with a rounder tip. For the African elephants, tusks are present in both males and females, and are around the same length in both sexes, reaching up to 300 cm (9 ft 10 in),[50] but those of males tend to be thicker.[51] In earlier times, elephant tusks weighing over 200 pounds (more than 90 kg) were not uncommon, though it is rare today to see any over 100 pounds (45 kg).[52]

 

In the Asian species, only the males have large tusks. Female Asians have very small tusks, or none at all.[50] Tuskless males exist and are particularly common among Sri Lankan elephants.[53] Asian males can have tusks as long as Africans', but they are usually slimmer and lighter; the largest recorded was 302 cm (9 ft 11 in) long and weighed 39 kg (86 lb). Hunting for elephant ivory in Africa[54] and Asia[55] has led to natural selection for shorter tusks[56][57] and tusklessness.[58][59]

 

Skin

 

An African forest elephant covering its skin with mud

An elephant's skin is generally very tough, at 2.5 cm (1 in) thick on the back and parts of the head. The skin around the mouth, anus, and inside of the ear is considerably thinner. Elephants typically have grey skin, but African elephants look brown or reddish after wallowing in coloured mud. Asian elephants have some patches of depigmentation, particularly on the forehead and ears and the areas around them. Calves have brownish or reddish hair, especially on the head and back. As elephants mature, their hair darkens and becomes sparser, but dense concentrations of hair and bristles remain on the end of the tail as well as the chin, genitals and the areas around the eyes and ear openings. Normally the skin of an Asian elephant is covered with more hair than its African counterpart.[60] Their hair is thought to be for thermoregulation, helping them lose heat in their hot environments.[61]

 

An elephant uses mud as a sunscreen, protecting its skin from ultraviolet light. Although tough, an elephant's skin is very sensitive. Without regular mud baths to protect it from burning, insect bites and moisture loss, an elephant's skin suffers serious damage. After bathing, the elephant will usually use its trunk to blow dust onto its body and this dries into a protective crust. Elephants have difficulty releasing heat through the skin because of their low surface-area-to-volume ratio, which is many times smaller than that of a human. They have even been observed lifting up their legs, presumably in an effort to expose their soles to the air.[60]

 

Legs, locomotion, and posture

 

An Asian elephant walking

To support the animal's weight, an elephant's limbs are positioned more vertically under the body than in most other mammals. The long bones of the limbs have cancellous bone in place of medullary cavities. This strengthens the bones while still allowing haematopoiesis.[62] Both the front and hind limbs can support an elephant's weight, although 60% is borne by the front.[63] Since the limb bones are placed on top of each other and under the body, an elephant can stand still for long periods of time without using much energy. Elephants are incapable of rotating their front legs, as the ulna and radius are fixed in pronation; the "palm" of the manus faces backward.[62] The pronator quadratus and the pronator teres are either reduced or absent.[64] The circular feet of an elephant have soft tissues or "cushion pads" beneath the manus or pes, which distribute the weight of the animal.[63] They appear to have a sesamoid, an extra "toe" similar in placement to a giant panda's extra "thumb", that also helps in weight distribution.[65] As many as five toenails can be found on both the front and hind feet.[11]

 

Elephants can move both forwards and backwards, but cannot trot, jump, or gallop. They use only two gaits when moving on land: the walk and a faster gait similar to running.[62] In walking, the legs act as pendulums, with the hips and shoulders rising and falling while the foot is planted on the ground. With no "aerial phase", the fast gait does not meet all the criteria of running, although the elephant uses its legs much like other running animals, with the hips and shoulders falling and then rising while the feet are on the ground.[66] Fast-moving elephants appear to 'run' with their front legs, but 'walk' with their hind legs and can reach a top speed of 25 km/h (16 mph).[67] At this speed, most other quadrupeds are well into a gallop, even accounting for leg length. Spring-like kinetics could explain the difference between the motion of elephants and other animals.[67] During locomotion, the cushion pads expand and contract, and reduce both the pain and noise that would come from a very heavy animal moving.[63] Elephants are capable swimmers. They have been recorded swimming for up to six hours without touching the bottom, and have travelled as far as 48 km (30 mi) at a stretch and at speeds of up to 2.1 km/h (1 mph).[68]

 

Organs

 

African elephant heart in a jar

The brain of an elephant weighs 4.5–5.5 kg (10–12 lb) compared to 1.6 kg (4 lb) for a human brain. While the elephant brain is larger overall, it is proportionally smaller. At birth, an elephant's brain already weighs 30–40% of its adult weight. The cerebrum and cerebellum are well developed, and the temporal lobes are so large that they bulge out laterally.[69] The throat of an elephant appears to contain a pouch where it can store water for later use.[6] The larynx of the elephant is the largest known among mammals. The vocal folds are long and are attached close to the epiglottis base. When comparing an elephant's vocal folds to those of a human, an elephant's are longer, thicker, and have a larger cross-sectional area. In addition, they are tilted at 45 degrees and positioned more anteriorly than a human's vocal folds.[70]

 

The heart of an elephant weighs 12–21 kg (26–46 lb). It has a double-pointed apex, an unusual trait among mammals.[69] In addition, the ventricles separate near the top of the heart, a trait they share with sirenians.[71] When standing, the elephant's heart beats approximately 30 times per minute. Unlike many other animals, the heart rate speeds up by 8 to 10 beats per minute when the elephant is lying down.[72] The blood vessels in most of the body are wide and thick and can withstand high blood pressures.[71] The lungs are attached to the diaphragm, and breathing relies mainly on the diaphragm rather than the expansion of the ribcage.[69] Connective tissue exists in place of the pleural cavity. This may allow the animal to deal with the pressure differences when its body is underwater and its trunk is breaking the surface for air,[32] although this explanation has been questioned.[73] Another possible function for this adaptation is that it helps the animal suck up water through the trunk.[32] Elephants inhale mostly through the trunk, although some air goes through the mouth. They have a hindgut fermentation system, and their large and small intestines together reach 35 m (115 ft) in length. The majority of an elephant's food intake goes undigested despite the process lasting up to a day.[69]

 

A male elephant's testes are located internally near the kidneys.[74] The elephant's penis can reach a length of 100 cm (39 in) and a diameter of 16 cm (6 in) at the base. It is S-shaped when fully erect and has a Y-shaped orifice. The female has a well-developed clitoris at up to 40 cm (16 in). The vulva is located between the hind legs instead of near the tail as in most mammals. Determining pregnancy status can be difficult due to the animal's large abdominal cavity. The female's mammary glands occupy the space between the front legs, which puts the suckling calf within reach of the female's trunk.[69] Elephants have a unique organ, the temporal gland, located in both sides of the head. This organ is associated with sexual behaviour, and males secrete a fluid from it when in musth.[75] Females have also been observed with secretions from the temporal glands.[45]

 

Body temperature

Elephants are homeotherms, and maintain their average body temperature at ~ 36 °C, with minimum 35.2 °C during cool season, and maximum 38.0 °C during hot dry season.[76] Sweat glands are absent in the elephant's skin, but water diffuses through the skin, allowing cooling by evaporative loss.[77][78][79] Other physiological or behavioral features may assist with thermoregulation such as flapping ears,[80] mud bathing, spraying water on the skin, seeking shade,[76][81] and adopting different walking patterns.[82] In addition, the interconnected crevices in the elephant's skin is thought to impede dehydration and improve thermal regulation over a long period of time.[83]

  

BIG5 Elephant. Jock Safari Lodge. Kruger National Park. South Africa. Dec/2020

 

Elephant

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are currently recognised: the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.

All elephants have several distinctive features, the most notable of which is a long trunk (also called a proboscis), used for many purposes, particularly breathing, lifting water, and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts, and marshes. They prefer to stay near water. They are considered to be a keystone species due to their impact on their environments. Other animals tend to keep their distance from elephants while predators, such as lions, tigers, hyenas, and any wild dogs, usually target only young elephants (or "calves"). Elephants have a fission–fusion society in which multiple family groups come together to socialise. Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow.

Males ("bulls") leave their family groups when they reach puberty and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell, and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathyfor dying or dead individuals of their kind.

Source: Wikipedia

Elefante

Os elefantes são animais herbívoros, alimentando-se de ervas, gramíneas, frutas e folhas de árvores. Dado o seu tamanho, um elefante adulto pode ingerir entre 70 a 150 kg de alimentos por dia. As fêmeas vivem em manadas de 10 a 15 animais, lideradas por uma matriarca, compostas por várias reprodutoras e crias de variadas idades. O período de gestação das fêmeas é longo (20 a 22 meses), assim como o desenvolvimento do animal que leva anos a atingir a idade adulta. Os filhotes podem nascer com 90 kg. Os machos adolescentes tendem a viver em pequenos bandos e os machos adultos isolados, encontrando-se com as fêmeas apenas no período reprodutivo.

Devido ao seu porte, os elefantes têm poucos predadores. Exercem uma forte influência sobre as savanas, pois mantêm árvores e arbustos sob controle, permitindo que pastagens dominem o ambiente. Eles vivem cerca de 60 anos e morrem quando seus molares caem, impedindo que se alimentem de plantas.

Os elefantes-africanos são maiores que as variedades asiáticas e têm orelhas mais desenvolvidas, uma adaptação que permite libertar calor em condições de altas temperaturas. Outra diferença importante é a ausência de presas de marfim nas fêmeas dos elefantes asiáticos.

Durante a época de acasalamento, o aumento da produção de testosterona deixa os elefantes extremamente agressivos, fazendo-os atacar até humanos. Acidentes com elefantes utilizados em rituais geralmente são causados por esse motivo. Cerca de 400 humanos são mortos por elefantes a cada ano.

Elefante é o termo genérico e popular pelo qual são denominados os membros da família Elephantidae, um grupo de mamíferos proboscídeoselefantídeos, de grande porte, do qual há três espécies no mundo atual, duas africanas (Loxodonta sp.) e uma asiática (Elephas sp.). Há ainda os mamutes (Mammuthus sp.), hoje extintos. Até recentemente, acreditava-se que havia apenas duas espécies vivas de elefantes, o elefante-africano e o elefante-asiático, uma espécie menor. Entretanto, estudos recentes de DNA sugerem que havia, na verdade, duas espécies de elefante-africano: Loxodonta africana, da savana, e Loxodonta cyclotis, que vive nas florestas. Os elefantes são os maiores animais terrestres da actualidade, com a massa entre 4 a 6 toneladas e medindo em média quatro metros de altura, podem levantar até 10.000 kg. As suas características mais distintivas são as presas de marfim

Fonte: Wikipedia

  

Jock Safari Lodge

Located within 6, 000 ha of pristine bushveld, Jock Safari Lodge is an exclusive private concession, perfectly positioned in the southern part of the Kruger National Park, South Africa’s largest national park. The wildlife within this region have survived undisturbed without negative impact from mankind, encouraged to thrive. Jock Safari Lodge emerges where the Mitomeni and Biyamiti rivers flow as one – this natural unbroken landscape offers guests one of the best Big Five game viewing experiences in South Africa with its exclusive riverbed traversing rights. Steeped in history, Jock Safari Lodge was the first private concession granted within the Kruger National Park and is named after local legend, Jock of the Bushveld, the canine hero of Sir Percy FitzPatrick’s famous story of courage and loyalty that is set during South Africa’s first gold rush era. Relive one of South Africa’s cultural heritages through this wonderful story and view the original mementoes on display at the Main Lodge.

Source: jocksafarilodge.com/

Jock Safari Lodge

Localizado em 6.000 ha de savana intocada, o Jock Safari Lodge é uma concessão privada exclusiva, perfeitamente posicionada ao sul do Parque Nacional Kruger, o maior parque nacional da África do Sul. A vida selvagem nesta região sobreviveu sem ser perturbada, sem impacto negativo da humanidade, encorajada a prosperar. O Jock Safari Lodge surge onde os rios Mitomeni e Biyamiti fluem como um só - esta paisagem natural contínua oferece aos hóspedes uma das melhores experiências de observação do Big Five na África do Sul com seus direitos exclusivos de travessia do leito do rio. Repleto de história, Jock Safari Lodge foi a primeira concessão privada concedida dentro do Parque Nacional Kruger e leva o nome de uma lenda local, Jock of the Bushveld, o herói canino da famosa história de coragem e lealdade de Sir Percy FitzPatrick que se passa durante o primeiro era da corrida do ouro. Reviva uma das heranças culturais da África do Sul por meio desta história maravilhosa e veja as lembranças originais em exibição no Main Lodge.

Fonte: jocksafarilodge.com/ (tradução livre)

 

Custom color blends that are somehow striking and yet subtle. Reminds me of a lovely sunset. The red asymmetric circle is an uneven blend of dark red and gold clay. Note - the esthetic appeal to this shape is very similar to the central incisor tooth...yes, teeth are beautiful

I may be uploading this image on April 1st, but it is a genuine image of a real specimen held in Ludlow Museum, Shropshire, UK. It shows the skull of a rabbit (Oryctolagus cuniculus) with overgrown incisor teeth. I have always known that rodent and lagomorph teeth can grow in this way unless they are able to wear down by gnawing, but I have never seen a real specimen until this one. I don't actually know why this particular specimen's teeth have overgrown like this, since all six incisors seem to be undamaged, just overgrown. I can only imagine there was some problem with the animal not having enough hard food, something else to gnaw on, or possibly some sort of mis-articulation of the jaw had occurred to prevent the incisors working against each other. If you view the images full size you can see some limited overgrowth of the tiny second incisors behind the first uppers; and also note that the biting tips of each incisor seem very blunted as it is normal occlusal contact which keeps them sharp.

My twin sons even loose their incisors simultaneously...

 

Olympus PEN E-PL3 & m.Zuiko 45/1.8: ISO 200, f/3.2, 1/160s

 

Strobist info: Metz 48 AF-1 with a shoot-through umbrella on camera right, window on camera left, white wall as background. Triggered with Yongnuo RF-602

Fish, any of approximately 34,000 species of vertebrate animals (phylum Chordata) found in the fresh and salt waters of the world. Living species range from the primitive jawless lampreys and hagfishes through the cartilaginous sharks, skates, and rays to the abundant and diverse bony fishes. Most fish species are cold-blooded; however, one species, the opah (Lampris guttatus), is warm-blooded.

 

The term fish is applied to a variety of vertebrates of several evolutionary lines. It describes a life-form rather than a taxonomic group. As members of the phylum Chordata, fish share certain features with other vertebrates. These features are gill slits at some point in the life cycle, a notochord, or skeletal supporting rod, a dorsal hollow nerve cord, and a tail. Living fishes represent some five classes, which are as distinct from one another as are the four classes of familiar air-breathing animals—amphibians, reptiles, birds, and mammals. For example, the jawless fishes (Agnatha) have gills in pouches and lack limb girdles. Extant agnathans are the lampreys and the hagfishes. As the name implies, the skeletons of fishes of the class Chondrichthyes (from chondr, “cartilage,” and ichthyes, “fish”) are made entirely of cartilage. Modern fish of this class lack a swim bladder, and their scales and teeth are made up of the same placoid material. Sharks, skates, and rays are examples of cartilaginous fishes. The bony fishes are by far the largest class. Examples range from the tiny seahorse to the 450-kg (1,000-pound) blue marlin, from the flattened soles and flounders to the boxy puffers and ocean sunfishes. Unlike the scales of the cartilaginous fishes, those of bony fishes, when present, grow throughout life and are made up of thin overlapping plates of bone. Bony fishes also have an operculum that covers the gill slits.

 

The study of fishes, the science of ichthyology, is of broad importance. Fishes are of interest to humans for many reasons, the most important being their relationship with and dependence on the environment. A more obvious reason for interest in fishes is their role as a moderate but important part of the world’s food supply. This resource, once thought unlimited, is now realized to be finite and in delicate balance with the biological, chemical, and physical factors of the aquatic environment. Overfishing, pollution, and alteration of the environment are the chief enemies of proper fisheries management, both in fresh waters and in the ocean. (For a detailed discussion of the technology and economics of fisheries, see commercial fishing.) Another practical reason for studying fishes is their use in disease control. As predators on mosquito larvae, they help curb malaria and other mosquito-borne diseases.

 

Fishes are valuable laboratory animals in many aspects of medical and biological research. For example, the readiness of many fishes to acclimate to captivity has allowed biologists to study behaviour, physiology, and even ecology under relatively natural conditions. Fishes have been especially important in the study of animal behaviour, where research on fishes has provided a broad base for the understanding of the more flexible behaviour of the higher vertebrates. The zebra fish is used as a model in studies of gene expression.

 

There are aesthetic and recreational reasons for an interest in fishes. Millions of people keep live fishes in home aquariums for the simple pleasure of observing the beauty and behaviour of animals otherwise unfamiliar to them. Aquarium fishes provide a personal challenge to many aquarists, allowing them to test their ability to keep a small section of the natural environment in their homes. Sportfishing is another way of enjoying the natural environment, also indulged in by millions of people every year. Interest in aquarium fishes and sportfishing supports multimillion-dollar industries throughout the world.

 

Fishes have been in existence for more than 450 million years, during which time they have evolved repeatedly to fit into almost every conceivable type of aquatic habitat. In a sense, land vertebrates are simply highly modified fishes: when fishes colonized the land habitat, they became tetrapod (four-legged) land vertebrates. The popular conception of a fish as a slippery, streamlined aquatic animal that possesses fins and breathes by gills applies to many fishes, but far more fishes deviate from that conception than conform to it. For example, the body is elongate in many forms and greatly shortened in others; the body is flattened in some (principally in bottom-dwelling fishes) and laterally compressed in many others; the fins may be elaborately extended, forming intricate shapes, or they may be reduced or even lost; and the positions of the mouth, eyes, nostrils, and gill openings vary widely. Air breathers have appeared in several evolutionary lines.

 

Many fishes are cryptically coloured and shaped, closely matching their respective environments; others are among the most brilliantly coloured of all organisms, with a wide range of hues, often of striking intensity, on a single individual. The brilliance of pigments may be enhanced by the surface structure of the fish, so that it almost seems to glow. A number of unrelated fishes have actual light-producing organs. Many fishes are able to alter their coloration—some for the purpose of camouflage, others for the enhancement of behavioral signals.

 

Fishes range in adult length from less than 10 mm (0.4 inch) to more than 20 metres (60 feet) and in weight from about 1.5 grams (less than 0.06 ounce) to many thousands of kilograms. Some live in shallow thermal springs at temperatures slightly above 42 °C (100 °F), others in cold Arctic seas a few degrees below 0 °C (32 °F) or in cold deep waters more than 4,000 metres (13,100 feet) beneath the ocean surface. The structural and, especially, the physiological adaptations for life at such extremes are relatively poorly known and provide the scientifically curious with great incentive for study.

 

Almost all natural bodies of water bear fish life, the exceptions being very hot thermal ponds and extremely salt-alkaline lakes, such as the Dead Sea in Asia and the Great Salt Lake in North America. The present distribution of fishes is a result of the geological history and development of Earth as well as the ability of fishes to undergo evolutionary change and to adapt to the available habitats. Fishes may be seen to be distributed according to habitat and according to geographical area. Major habitat differences are marine and freshwater. For the most part, the fishes in a marine habitat differ from those in a freshwater habitat, even in adjacent areas, but some, such as the salmon, migrate from one to the other. The freshwater habitats may be seen to be of many kinds. Fishes found in mountain torrents, Arctic lakes, tropical lakes, temperate streams, and tropical rivers will all differ from each other, both in obvious gross structure and in physiological attributes. Even in closely adjacent habitats where, for example, a tropical mountain torrent enters a lowland stream, the fish fauna will differ. The marine habitats can be divided into deep ocean floors (benthic), mid-water oceanic (bathypelagic), surface oceanic (pelagic), rocky coast, sandy coast, muddy shores, bays, estuaries, and others. Also, for example, rocky coastal shores in tropical and temperate regions will have different fish faunas, even when such habitats occur along the same coastline.

 

Although much is known about the present geographical distribution of fishes, far less is known about how that distribution came about. Many parts of the fish fauna of the fresh waters of North America and Eurasia are related and undoubtedly have a common origin. The faunas of Africa and South America are related, extremely old, and probably an expression of the drifting apart of the two continents. The fauna of southern Asia is related to that of Central Asia, and some of it appears to have entered Africa. The extremely large shore-fish faunas of the Indian and tropical Pacific oceans comprise a related complex, but the tropical shore fauna of the Atlantic, although containing Indo-Pacific components, is relatively limited and probably younger. The Arctic and Antarctic marine faunas are quite different from each other. The shore fauna of the North Pacific is quite distinct, and that of the North Atlantic more limited and probably younger. Pelagic oceanic fishes, especially those in deep waters, are similar the world over, showing little geographical isolation in terms of family groups. The deep oceanic habitat is very much the same throughout the world, but species differences do exist, showing geographical areas determined by oceanic currents and water masses.

 

All aspects of the life of a fish are closely correlated with adaptation to the total environment, physical, chemical, and biological. In studies, all the interdependent aspects of fish, such as behaviour, locomotion, reproduction, and physical and physiological characteristics, must be taken into account.

 

Correlated with their adaptation to an extremely wide variety of habitats is the extremely wide variety of life cycles that fishes display. The great majority hatch from relatively small eggs a few days to several weeks or more after the eggs are scattered in the water. Newly hatched young are still partially undeveloped and are called larvae until body structures such as fins, skeleton, and some organs are fully formed. Larval life is often very short, usually less than a few weeks, but it can be very long, some lampreys continuing as larvae for at least five years. Young and larval fishes, before reaching sexual maturity, must grow considerably, and their small size and other factors often dictate that they live in a habitat different than that of the adults. For example, most tropical marine shore fishes have pelagic larvae. Larval food also is different, and larval fishes often live in shallow waters, where they may be less exposed to predators.

 

After a fish reaches adult size, the length of its life is subject to many factors, such as innate rates of aging, predation pressure, and the nature of the local climate. The longevity of a species in the protected environment of an aquarium may have nothing to do with how long members of that species live in the wild. Many small fishes live only one to three years at the most. In some species, however, individuals may live as long as 10 or 20 or even 100 years.

 

Fish behaviour is a complicated and varied subject. As in almost all animals with a central nervous system, the nature of a response of an individual fish to stimuli from its environment depends upon the inherited characteristics of its nervous system, on what it has learned from past experience, and on the nature of the stimuli. Compared with the variety of human responses, however, that of a fish is stereotyped, not subject to much modification by “thought” or learning, and investigators must guard against anthropomorphic interpretations of fish behaviour.

 

Fishes perceive the world around them by the usual senses of sight, smell, hearing, touch, and taste and by special lateral line water-current detectors. In the few fishes that generate electric fields, a process that might best be called electrolocation aids in perception. One or another of these senses often is emphasized at the expense of others, depending upon the fish’s other adaptations. In fishes with large eyes, the sense of smell may be reduced; others, with small eyes, hunt and feed primarily by smell (such as some eels).

 

Specialized behaviour is primarily concerned with the three most important activities in the fish’s life: feeding, reproduction, and escape from enemies. Schooling behaviour of sardines on the high seas, for instance, is largely a protective device to avoid enemies, but it is also associated with and modified by their breeding and feeding requirements. Predatory fishes are often solitary, lying in wait to dart suddenly after their prey, a kind of locomotion impossible for beaked parrot fishes, which feed on coral, swimming in small groups from one coral head to the next. In addition, some predatory fishes that inhabit pelagic environments, such as tunas, often school.

 

Sleep in fishes, all of which lack true eyelids, consists of a seemingly listless state in which the fish maintains its balance but moves slowly. If attacked or disturbed, most can dart away. A few kinds of fishes lie on the bottom to sleep. Most catfishes, some loaches, and some eels and electric fishes are strictly nocturnal, being active and hunting for food during the night and retiring during the day to holes, thick vegetation, or other protective parts of the environment.

 

Communication between members of a species or between members of two or more species often is extremely important, especially in breeding behaviour (see below Reproduction). The mode of communication may be visual, as between the small so-called cleaner fish and a large fish of a very different species. The larger fish often allows the cleaner to enter its mouth to remove gill parasites. The cleaner is recognized by its distinctive colour and actions and therefore is not eaten, even if the larger fish is normally a predator. Communication is often chemical, signals being sent by specific chemicals called pheromones.

 

Many fishes have a streamlined body and swim freely in open water. Fish locomotion is closely correlated with habitat and ecological niche (the general position of the animal to its environment).

 

Many fishes in both marine and fresh waters swim at the surface and have mouths adapted to feed best (and sometimes only) at the surface. Often such fishes are long and slender, able to dart at surface insects or at other surface fishes and in turn to dart away from predators; needlefishes, halfbeaks, and topminnows (such as killifish and mosquito fish) are good examples. Oceanic flying fishes escape their predators by gathering speed above the water surface, with the lower lobe of the tail providing thrust in the water. They then glide hundreds of yards on enlarged, winglike pectoral and pelvic fins. South American freshwater flying fishes escape their enemies by jumping and propelling their strongly keeled bodies out of the water.

 

So-called mid-water swimmers, the most common type of fish, are of many kinds and live in many habitats. The powerful fusiform tunas and the trouts, for example, are adapted for strong, fast swimming, the tunas to capture prey speedily in the open ocean and the trouts to cope with the swift currents of streams and rivers. The trout body form is well adapted to many habitats. Fishes that live in relatively quiet waters such as bays or lake shores or slow rivers usually are not strong, fast swimmers but are capable of short, quick bursts of speed to escape a predator. Many of these fishes have their sides flattened, examples being the sunfish and the freshwater angelfish of aquarists. Fish associated with the bottom or substrate usually are slow swimmers. Open-water plankton-feeding fishes almost always remain fusiform and are capable of rapid, strong movement (for example, sardines and herrings of the open ocean and also many small minnows of streams and lakes).

 

Bottom-living fishes are of many kinds and have undergone many types of modification of their body shape and swimming habits. Rays, which evolved from strong-swimming mid-water sharks, usually stay close to the bottom and move by undulating their large pectoral fins. Flounders live in a similar habitat and move over the bottom by undulating the entire body. Many bottom fishes dart from place to place, resting on the bottom between movements, a motion common in gobies. One goby relative, the mudskipper, has taken to living at the edge of pools along the shore of muddy mangrove swamps. It escapes its enemies by flipping rapidly over the mud, out of the water. Some catfishes, synbranchid eels, the so-called climbing perch, and a few other fishes venture out over damp ground to find more promising waters than those that they left. They move by wriggling their bodies, sometimes using strong pectoral fins; most have accessory air-breathing organs. Many bottom-dwelling fishes live in mud holes or rocky crevices. Marine eels and gobies commonly are found in such habitats and for the most part venture far beyond their cavelike homes. Some bottom dwellers, such as the clingfishes (Gobiesocidae), have developed powerful adhesive disks that enable them to remain in place on the substrate in areas such as rocky coasts, where the action of the waves is great.

 

The methods of reproduction in fishes are varied, but most fishes lay a large number of small eggs, fertilized and scattered outside of the body. The eggs of pelagic fishes usually remain suspended in the open water. Many shore and freshwater fishes lay eggs on the bottom or among plants. Some have adhesive eggs. The mortality of the young and especially of the eggs is very high, and often only a few individuals grow to maturity out of hundreds, thousands, and in some cases millions of eggs laid.

 

Males produce sperm, usually as a milky white substance called milt, in two (sometimes one) testes within the body cavity. In bony fishes a sperm duct leads from each testis to a urogenital opening behind the vent or anus. In sharks and rays and in cyclostomes the duct leads to a cloaca. Sometimes the pelvic fins are modified to help transmit the milt to the eggs at the female’s vent or on the substrate where the female has placed them. Sometimes accessory organs are used to fertilize females internally—for example, the claspers of many sharks and rays.

 

In the females the eggs are formed in two ovaries (sometimes only one) and pass through the ovaries to the urogenital opening and to the outside. In some fishes the eggs are fertilized internally but are shed before development takes place. Members of about a dozen families each of bony fishes (teleosts) and sharks bear live young. Many skates and rays also bear live young. In some bony fishes the eggs simply develop within the female, the young emerging when the eggs hatch (ovoviviparous). Others develop within the ovary and are nourished by ovarian tissues after hatching (viviparous). There are also other methods utilized by fishes to nourish young within the female. In all live-bearers the young are born at a relatively large size and are few in number. In one family of primarily marine fishes, the surfperches from the Pacific coast of North America, Japan, and Korea, the males of at least one species are born sexually mature, although they are not fully grown.

 

Some fishes are hermaphroditic—an individual producing both sperm and eggs, usually at different stages of its life. Self-fertilization, however, is probably rare.

 

Successful reproduction and, in many cases, defense of the eggs and the young are assured by rather stereotypical but often elaborate courtship and parental behaviour, either by the male or the female or both. Some fishes prepare nests by hollowing out depressions in the sand bottom (cichlids, for example), build nests with plant materials and sticky threads excreted by the kidneys (sticklebacks), or blow a cluster of mucus-covered bubbles at the water surface (gouramis). The eggs are laid in these structures. Some varieties of cichlids and catfishes incubate eggs in their mouths.

 

Some fishes, such as salmon, undergo long migrations from the ocean and up large rivers to spawn in the gravel beds where they themselves hatched (anadromous fishes). Some, such as the freshwater eels (family Anguillidae), live and grow to maturity in fresh water and migrate to the sea to spawn (catadromous fishes). Other fishes undertake shorter migrations from lakes into streams, within the ocean, or enter spawning habitats that they do not ordinarily occupy in other ways.

 

The basic structure and function of the fish body are similar to those of all other vertebrates. The usual four types of tissues are present: surface or epithelial, connective (bone, cartilage, and fibrous tissues, as well as their derivative, blood), nerve, and muscle tissues. In addition, the fish’s organs and organ systems parallel those of other vertebrates.

 

The typical fish body is streamlined and spindle-shaped, with an anterior head, a gill apparatus, and a heart, the latter lying in the midline just below the gill chamber. The body cavity, containing the vital organs, is situated behind the head in the lower anterior part of the body. The anus usually marks the posterior termination of the body cavity and most often occurs just in front of the base of the anal fin. The spinal cord and vertebral column continue from the posterior part of the head to the base of the tail fin, passing dorsal to the body cavity and through the caudal (tail) region behind the body cavity. Most of the body is of muscular tissue, a high proportion of which is necessitated by swimming. In the course of evolution this basic body plan has been modified repeatedly into the many varieties of fish shapes that exist today.

 

The skeleton forms an integral part of the fish’s locomotion system, as well as serving to protect vital parts. The internal skeleton consists of the skull bones (except for the roofing bones of the head, which are really part of the external skeleton), the vertebral column, and the fin supports (fin rays). The fin supports are derived from the external skeleton but will be treated here because of their close functional relationship to the internal skeleton. The internal skeleton of cyclostomes, sharks, and rays is of cartilage; that of many fossil groups and some primitive living fishes is mostly of cartilage but may include some bone. In place of the vertebral column, the earliest vertebrates had a fully developed notochord, a flexible stiff rod of viscous cells surrounded by a strong fibrous sheath. During the evolution of modern fishes the rod was replaced in part by cartilage and then by ossified cartilage. Sharks and rays retain a cartilaginous vertebral column; bony fishes have spool-shaped vertebrae that in the more primitive living forms only partially replace the notochord. The skull, including the gill arches and jaws of bony fishes, is fully, or at least partially, ossified. That of sharks and rays remains cartilaginous, at times partially replaced by calcium deposits but never by true bone.

 

The supportive elements of the fins (basal or radial bones or both) have changed greatly during fish evolution. Some of these changes are described in the section below (Evolution and paleontology). Most fishes possess a single dorsal fin on the midline of the back. Many have two and a few have three dorsal fins. The other fins are the single tail and anal fins and paired pelvic and pectoral fins. A small fin, the adipose fin, with hairlike fin rays, occurs in many of the relatively primitive teleosts (such as trout) on the back near the base of the caudal fin.

 

The skin of a fish must serve many functions. It aids in maintaining the osmotic balance, provides physical protection for the body, is the site of coloration, contains sensory receptors, and, in some fishes, functions in respiration. Mucous glands, which aid in maintaining the water balance and offer protection from bacteria, are extremely numerous in fish skin, especially in cyclostomes and teleosts. Since mucous glands are present in the modern lampreys, it is reasonable to assume that they were present in primitive fishes, such as the ancient Silurian and Devonian agnathans. Protection from abrasion and predation is another function of the fish skin, and dermal (skin) bone arose early in fish evolution in response to this need. It is thought that bone first evolved in skin and only later invaded the cartilaginous areas of the fish’s body, to provide additional support and protection. There is some argument as to which came first, cartilage or bone, and fossil evidence does not settle the question. In any event, dermal bone has played an important part in fish evolution and has different characteristics in different groups of fishes. Several groups are characterized at least in part by the kind of bony scales they possess.

 

Scales have played an important part in the evolution of fishes. Primitive fishes usually had thick bony plates or thick scales in several layers of bone, enamel, and related substances. Modern teleost fishes have scales of bone, which, while still protective, allow much more freedom of motion in the body. A few modern teleosts (some catfishes, sticklebacks, and others) have secondarily acquired bony plates in the skin. Modern and early sharks possessed placoid scales, a relatively primitive type of scale with a toothlike structure, consisting of an outside layer of enamel-like substance (vitrodentine), an inner layer of dentine, and a pulp cavity containing nerves and blood vessels. Primitive bony fishes had thick scales of either the ganoid or the cosmoid type. Cosmoid scales have a hard, enamel-like outer layer, an inner layer of cosmine (a form of dentine), and then a layer of vascular bone (isopedine). In ganoid scales the hard outer layer is different chemically and is called ganoin. Under this is a cosminelike layer and then a vascular bony layer. The thin, translucent bony scales of modern fishes, called cycloid and ctenoid (the latter distinguished by serrations at the edges), lack enameloid and dentine layers.

 

Skin has several other functions in fishes. It is well supplied with nerve endings and presumably receives tactile, thermal, and pain stimuli. Skin is also well supplied with blood vessels. Some fishes breathe in part through the skin, by the exchange of oxygen and carbon dioxide between the surrounding water and numerous small blood vessels near the skin surface.

 

Skin serves as protection through the control of coloration. Fishes exhibit an almost limitless range of colours. The colours often blend closely with the surroundings, effectively hiding the animal. Many fishes use bright colours for territorial advertisement or as recognition marks for other members of their own species, or sometimes for members of other species. Many fishes can change their colour to a greater or lesser degree, by movement of pigment within the pigment cells (chromatophores). Black pigment cells (melanophores), of almost universal occurrence in fishes, are often juxtaposed with other pigment cells. When placed beneath iridocytes or leucophores (bearing the silvery or white pigment guanine), melanophores produce structural colours of blue and green. These colours are often extremely intense, because they are formed by refraction of light through the needlelike crystals of guanine. The blue and green refracted colours are often relatively pure, lacking the red and yellow rays, which have been absorbed by the black pigment (melanin) of the melanophores. Yellow, orange, and red colours are produced by erythrophores, cells containing the appropriate carotenoid pigments. Other colours are produced by combinations of melanophores, erythrophores, and iridocytes.

 

The major portion of the body of most fishes consists of muscles. Most of the mass is trunk musculature, the fin muscles usually being relatively small. The caudal fin is usually the most powerful fin, being moved by the trunk musculature. The body musculature is usually arranged in rows of chevron-shaped segments on each side. Contractions of these segments, each attached to adjacent vertebrae and vertebral processes, bends the body on the vertebral joint, producing successive undulations of the body, passing from the head to the tail, and producing driving strokes of the tail. It is the latter that provides the strong forward movement for most fishes.

 

The digestive system, in a functional sense, starts at the mouth, with the teeth used to capture prey or collect plant foods. Mouth shape and tooth structure vary greatly in fishes, depending on the kind of food normally eaten. Most fishes are predacious, feeding on small invertebrates or other fishes and have simple conical teeth on the jaws, on at least some of the bones of the roof of the mouth, and on special gill arch structures just in front of the esophagus. The latter are throat teeth. Most predacious fishes swallow their prey whole, and the teeth are used for grasping and holding prey, for orienting prey to be swallowed (head first) and for working the prey toward the esophagus. There are a variety of tooth types in fishes. Some fishes, such as sharks and piranhas, have cutting teeth for biting chunks out of their victims. A shark’s tooth, although superficially like that of a piranha, appears in many respects to be a modified scale, while that of the piranha is like that of other bony fishes, consisting of dentine and enamel. Parrot fishes have beaklike mouths with short incisor-like teeth for breaking off coral and have heavy pavementlike throat teeth for crushing the coral. Some catfishes have small brushlike teeth, arranged in rows on the jaws, for scraping plant and animal growth from rocks. Many fishes (such as the Cyprinidae or minnows) have no jaw teeth at all but have very strong throat teeth.

 

Some fishes gather planktonic food by straining it from their gill cavities with numerous elongate stiff rods (gill rakers) anchored by one end to the gill bars. The food collected on these rods is passed to the throat, where it is swallowed. Most fishes have only short gill rakers that help keep food particles from escaping out the mouth cavity into the gill chamber.

 

Once reaching the throat, food enters a short, often greatly distensible esophagus, a simple tube with a muscular wall leading into a stomach. The stomach varies greatly in fishes, depending upon the diet. In most predacious fishes it is a simple straight or curved tube or pouch with a muscular wall and a glandular lining. Food is largely digested there and leaves the stomach in liquid form.

 

Between the stomach and the intestine, ducts enter the digestive tube from the liver and pancreas. The liver is a large, clearly defined organ. The pancreas may be embedded in it, diffused through it, or broken into small parts spread along some of the intestine. The junction between the stomach and the intestine is marked by a muscular valve. Pyloric ceca (blind sacs) occur in some fishes at this junction and have a digestive or absorptive function or both.

 

The intestine itself is quite variable in length, depending upon the fish’s diet. It is short in predacious forms, sometimes no longer than the body cavity, but long in herbivorous forms, being coiled and several times longer than the entire length of the fish in some species of South American catfishes. The intestine is primarily an organ for absorbing nutrients into the bloodstream. The larger its internal surface, the greater its absorptive efficiency, and a spiral valve is one method of increasing its absorption surface.

 

Sharks, rays, chimaeras, lungfishes, surviving chondrosteans, holosteans, and even a few of the more primitive teleosts have a spiral valve or at least traces of it in the intestine. Most modern teleosts have increased the area of the intestinal walls by having numerous folds and villi (fingerlike projections) somewhat like those in humans. Undigested substances are passed to the exterior through the anus in most teleost fishes. In lungfishes, sharks, and rays, it is first passed through the cloaca, a common cavity receiving the intestinal opening and the ducts from the urogenital system.

 

Oxygen and carbon dioxide dissolve in water, and most fishes exchange dissolved oxygen and carbon dioxide in water by means of the gills. The gills lie behind and to the side of the mouth cavity and consist of fleshy filaments supported by the gill arches and filled with blood vessels, which give gills a bright red colour. Water taken in continuously through the mouth passes backward between the gill bars and over the gill filaments, where the exchange of gases takes place. The gills are protected by a gill cover in teleosts and many other fishes but by flaps of skin in sharks, rays, and some of the older fossil fish groups. The blood capillaries in the gill filaments are close to the gill surface to take up oxygen from the water and to give up excess carbon dioxide to the water.

 

Most modern fishes have a hydrostatic (ballast) organ, called the swim bladder, that lies in the body cavity just below the kidney and above the stomach and intestine. It originated as a diverticulum of the digestive canal. In advanced teleosts, especially the acanthopterygians, the bladder has lost its connection with the digestive tract, a condition called physoclistic. The connection has been retained (physostomous) by many relatively primitive teleosts. In several unrelated lines of fishes, the bladder has become specialized as a lung or, at least, as a highly vascularized accessory breathing organ. Some fishes with such accessory organs are obligate air breathers and will drown if denied access to the surface, even in well-oxygenated water. Fishes with a hydrostatic form of swim bladder can control their depth by regulating the amount of gas in the bladder. The gas, mostly oxygen, is secreted into the bladder by special glands, rendering the fish more buoyant; the gas is absorbed into the bloodstream by another special organ, reducing the overall buoyancy and allowing the fish to sink. Some deep-sea fishes may have oils, rather than gas, in the bladder. Other deep-sea and some bottom-living forms have much-reduced swim bladders or have lost the organ entirely.

 

The swim bladder of fishes follows the same developmental pattern as the lungs of land vertebrates. There is no doubt that the two structures have the same historical origin in primitive fishes. More or less intermediate forms still survive among the more primitive types of fishes, such as the lungfishes Lepidosiren and Protopterus.

 

The circulatory, or blood vascular, system consists of the heart, the arteries, the capillaries, and the veins. It is in the capillaries that the interchange of oxygen, carbon dioxide, nutrients, and other substances such as hormones and waste products takes place. The capillaries lead to the veins, which return the venous blood with its waste products to the heart, kidneys, and gills. There are two kinds of capillary beds: those in the gills and those in the rest of the body. The heart, a folded continuous muscular tube with three or four saclike enlargements, undergoes rhythmic contractions and receives venous blood in a sinus venosus. It passes the blood to an auricle and then into a thick muscular pump, the ventricle. From the ventricle the blood goes to a bulbous structure at the base of a ventral aorta just below the gills. The blood passes to the afferent (receiving) arteries of the gill arches and then to the gill capillaries. There waste gases are given off to the environment, and oxygen is absorbed. The oxygenated blood enters efferent (exuant) arteries of the gill arches and then flows into the dorsal aorta. From there blood is distributed to the tissues and organs of the body. One-way valves prevent backflow. The circulation of fishes thus differs from that of the reptiles, birds, and mammals in that oxygenated blood is not returned to the heart prior to distribution to the other parts of the body.

 

The primary excretory organ in fishes, as in other vertebrates, is the kidney. In fishes some excretion also takes place in the digestive tract, skin, and especially the gills (where ammonia is given off). Compared with land vertebrates, fishes have a special problem in maintaining their internal environment at a constant concentration of water and dissolved substances, such as salts. Proper balance of the internal environment (homeostasis) of a fish is in a great part maintained by the excretory system, especially the kidney.

 

The kidney, gills, and skin play an important role in maintaining a fish’s internal environment and checking the effects of osmosis. Marine fishes live in an environment in which the water around them has a greater concentration of salts than they can have inside their body and still maintain life. Freshwater fishes, on the other hand, live in water with a much lower concentration of salts than they require inside their bodies. Osmosis tends to promote the loss of water from the body of a marine fish and absorption of water by that of a freshwater fish. Mucus in the skin tends to slow the process but is not a sufficient barrier to prevent the movement of fluids through the permeable skin. When solutions on two sides of a permeable membrane have different concentrations of dissolved substances, water will pass through the membrane into the more concentrated solution, while the dissolved chemicals move into the area of lower concentration (diffusion).

 

The kidney of freshwater fishes is often larger in relation to body weight than that of marine fishes. In both groups the kidney excretes wastes from the body, but the kidney of freshwater fishes also excretes large amounts of water, counteracting the water absorbed through the skin. Freshwater fishes tend to lose salt to the environment and must replace it. They get some salt from their food, but the gills and skin inside the mouth actively absorb salt from water passed through the mouth. This absorption is performed by special cells capable of moving salts against the diffusion gradient. Freshwater fishes drink very little water and take in little water with their food.

 

Marine fishes must conserve water, and therefore their kidneys excrete little water. To maintain their water balance, marine fishes drink large quantities of seawater, retaining most of the water and excreting the salt. Most nitrogenous waste in marine fishes appears to be secreted by the gills as ammonia. Marine fishes can excrete salt by clusters of special cells (chloride cells) in the gills.

 

There are several teleosts—for example, the salmon—that travel between fresh water and seawater and must adjust to the reversal of osmotic gradients. They adjust their physiological processes by spending time (often surprisingly little time) in the intermediate brackish environment.

 

Marine hagfishes, sharks, and rays have osmotic concentrations in their blood about equal to that of seawater and so do not have to drink water nor perform much physiological work to maintain their osmotic balance. In sharks and rays the osmotic concentration is kept high by retention of urea in the blood. Freshwater sharks have a lowered concentration of urea in the blood.

 

Endocrine glands secrete their products into the bloodstream and body tissues and, along with the central nervous system, control and regulate many kinds of body functions. Cyclostomes have a well-developed endocrine system, and presumably it was well developed in the early Agnatha, ancestral to modern fishes. Although the endocrine system in fishes is similar to that of higher vertebrates, there are numerous differences in detail. The pituitary, the thyroid, the suprarenals, the adrenals, the pancreatic islets, the sex glands (ovaries and testes), the inner wall of the intestine, and the bodies of the ultimobranchial gland make up the endocrine system in fishes. There are some others whose function is not well understood. These organs regulate sexual activity and reproduction, growth, osmotic pressure, general metabolic activities such as the storage of fat and the utilization of foodstuffs, blood pressure, and certain aspects of skin colour. Many of these activities are also controlled in part by the central nervous system, which works with the endocrine system in maintaining the life of a fish. Some parts of the endocrine system are developmentally, and undoubtedly evolutionarily, derived from the nervous system.

 

As in all vertebrates, the nervous system of fishes is the primary mechanism coordinating body activities, as well as integrating these activities in the appropriate manner with stimuli from the environment. The central nervous system, consisting of the brain and spinal cord, is the primary integrating mechanism. The peripheral nervous system, consisting of nerves that connect the brain and spinal cord to various body organs, carries sensory information from special receptor organs such as the eyes, internal ears, nares (sense of smell), taste glands, and others to the integrating centres of the brain and spinal cord. The peripheral nervous system also carries information via different nerve cells from the integrating centres of the brain and spinal cord. This coded information is carried to the various organs and body systems, such as the skeletal muscular system, for appropriate action in response to the original external or internal stimulus. Another branch of the nervous system, the autonomic nervous system, helps to coordinate the activities of many glands and organs and is itself closely connected to the integrating centres of the brain.

 

The brain of the fish is divided into several anatomical and functional parts, all closely interconnected but each serving as the primary centre of integrating particular kinds of responses and activities. Several of these centres or parts are primarily associated with one type of sensory perception, such as sight, hearing, or smell (olfaction).

 

The sense of smell is important in almost all fishes. Certain eels with tiny eyes depend mostly on smell for location of food. The olfactory, or nasal, organ of fishes is located on the dorsal surface of the snout. The lining of the nasal organ has special sensory cells that perceive chemicals dissolved in the water, such as substances from food material, and send sensory information to the brain by way of the first cranial nerve. Odour also serves as an alarm system. Many fishes, especially various species of freshwater minnows, react with alarm to a chemical released from the skin of an injured member of their own species.

 

Many fishes have a well-developed sense of taste, and tiny pitlike taste buds or organs are located not only within their mouth cavities but also over their heads and parts of their body. Catfishes, which often have poor vision, have barbels (“whiskers”) that serve as supplementary taste organs, those around the mouth being actively used to search out food on the bottom. Some species of naturally blind cave fishes are especially well supplied with taste buds, which often cover most of their body surface.

 

Sight is extremely important in most fishes. The eye of a fish is basically like that of all other vertebrates, but the eyes of fishes are extremely varied in structure and adaptation. In general, fishes living in dark and dim water habitats have large eyes, unless they have specialized in some compensatory way so that another sense (such as smell) is dominant, in which case the eyes will often be reduced. Fishes living in brightly lighted shallow waters often will have relatively small but efficient eyes. Cyclostomes have somewhat less elaborate eyes than other fishes, with skin stretched over the eyeball perhaps making their vision somewhat less effective. Most fishes have a spherical lens and accommodate their vision to far or near subjects by moving the lens within the eyeball. A few sharks accommodate by changing the shape of the lens, as in land vertebrates. Those fishes that are heavily dependent upon the eyes have especially strong muscles for accommodation. Most fishes see well, despite the restrictions imposed by frequent turbidity of the water and by light refraction.

 

Fossil evidence suggests that colour vision evolved in fishes more than 300 million years ago, but not all living fishes have retained this ability. Experimental evidence indicates that many shallow-water fishes, if not all, have colour vision and see some colours especially well, but some bottom-dwelling shore fishes live in areas where the water is sufficiently deep to filter out most if not all colours, and these fishes apparently never see colours. When tested in shallow water, they apparently are unable to respond to colour differences.

 

Sound perception and balance are intimately associated senses in a fish. The organs of hearing are entirely internal, located within the skull, on each side of the brain and somewhat behind the eyes. Sound waves, especially those of low frequencies, travel readily through water and impinge directly upon the bones and fluids of the head and body, to be transmitted to the hearing organs. Fishes readily respond to sound; for example, a trout conditioned to escape by the approach of fishermen will take flight upon perceiving footsteps on a stream bank even if it cannot see a fisherman. Compared with humans, however, the range of sound frequencies heard by fishes is greatly restricted. Many fishes communicate with each other by producing sounds in their swim bladders, in their throats by rasping their teeth, and in other ways.

 

A fish or other vertebrate seldom has to rely on a single type of sensory information to determine the nature of the environment around it. A catfish uses taste and touch when examining a food object with its oral barbels. Like most other animals, fishes have many touch receptors over their body surface. Pain and temperature receptors also are present in fishes and presumably produce the same kind of information to a fish as to humans. Fishes react in a negative fashion to stimuli that would be painful to human beings, suggesting that they feel a sensation of pain.

 

An important sensory system in fishes that is absent in other vertebrates (except some amphibians) is the lateral line system. This consists of a series of heavily innervated small canals located in the skin and bone around the eyes, along the lower jaw, over the head, and down the mid-side of the body, where it is associated with the scales. Intermittently along these canals are located tiny sensory organs (pit organs) that apparently detect changes in pressure. The system allows a fish to sense changes in water currents and pressure, thereby helping the fish to orient itself to the various changes that occur in the physical environment.

 

Although a great many fossil fishes have been found and described, they represent a tiny portion of the long and complex evolution of fishes, and knowledge of fish evolution remains relatively fragmentary. In the classification presented in this article, fishlike vertebrates are divided into seven categories, the members of each having a different basic structural organization and different physical and physiological adaptations for the problems presented by the environment. The broad basic pattern has been one of successive replacement of older groups by newer, better-adapted groups. One or a few members of a group evolved a basically more efficient means of feeding, breathing, or swimming or several better ways of living. These better-adapted groups then forced the extinction of members of the older group with which they competed for available food, breeding places, or other necessities of life. As the new fishes became well established, some of them evolved further and adapted to other habitats, where they continued to replace members of the old group already there. The process was repeated until all or almost all members of the old group in a variety of habitats had been replaced by members of the newer evolutionary line.

 

The earliest vertebrate fossils of certain relationships are fragments of dermal armour of jawless fishes (superclass Agnatha, order Heterostraci) from the Upper Ordovician Period in North America, about 450 million years in age. Early Ordovician toothlike fragments from the former Soviet Union are less certainly remains of agnathans. It is uncertain whether the North American jawless fishes inhabited shallow coastal marine waters, where their remains became fossilized, or were freshwater vertebrates washed into coastal deposits by stream action.

 

Jawless fishes probably arose from ancient, small, soft-bodied filter-feeding organisms much like and probably also ancestral to the modern sand-dwelling filter feeders, the Cephalochordata (Amphioxus and its relatives). The body in the ancestral animals was probably stiffened by a notochord. Although a vertebrate origin in fresh water is much debated by paleontologists, it is possible that mobility of the body and protection provided by dermal armour arose in response to streamflow in the freshwater environment and to the need to escape from and resist the clawed invertebrate eurypterids that lived in the same waters. Because of the marine distribution of the surviving primitive chordates, however, many paleontologists doubt that the vertebrates arose in fresh water.

 

Heterostracan remains are next found in what appear to be delta deposits in two North American localities of Silurian age. By the close of the Silurian, about 416 million years ago, European heterostracan remains are found in what appear to be delta or coastal deposits. In the Late Silurian of the Baltic area, lagoon or freshwater deposits yield jawless fishes of the order Osteostraci. Somewhat later in the Silurian from the same region, layers contain fragments of jawed acanthodians, the earliest group of jawed vertebrates, and of jawless fishes. These layers lie between marine beds but appear to be washed out from fresh waters of a coastal region.

 

It is evident, therefore, that by the end of the Silurian both jawed and jawless vertebrates were well established and already must have had a long history of development. Yet paleontologists have remains only of specialized forms that cannot have been the ancestors of the placoderms and bony fishes that appear in the next period, the Devonian. No fossils are known of the more primitive ancestors of the agnathans and acanthodians. The extensive marine beds of the Silurian and those of the Ordovician are essentially void of vertebrate history. It is believed that the ancestors of fishlike vertebrates evolved in upland fresh waters, where whatever few and relatively small fossil beds were made probably have been long since eroded away. Remains of the earliest vertebrates may never be found.

 

By the close of the Silurian, all known orders of jawless vertebrates had evolved, except perhaps the modern cyclostomes, which are without the hard parts that ordinarily are preserved as fossils. Cyclostomes were unknown as fossils until 1968, when a lamprey of modern body structure was reported from the Middle Pennsylvanian of Illinois, in deposits more than 300 million years old. Fossil evidence of the four orders of armoured jawless vertebrates is absent from deposits later than the Devonian. Presumably, these vertebrates became extinct at that time, being replaced by the more efficient and probably more aggressive placoderms, acanthodians, selachians (sharks and relatives), and by early bony fishes. Cyclostomes survived probably because early on they evolved from anaspid agnathans and developed a rasping tonguelike structure and a sucking mouth, enabling them to prey on other fishes. With this way of life they apparently had no competition from other fish groups. Cyclostomes, the hagfishes and lampreys, were once thought to be closely related because of the similarity in their suctorial mouths, but it is now understood that the hagfishes, order Myxiniformes, are the most primitive living chordates, and they are classified separately from the lampreys, order Petromyzontiformes.

 

Early jawless vertebrates probably fed on tiny organisms by filter feeding, as do the larvae of their descendants, the modern lampreys. The gill cavity of the early agnathans was large. It is thought that small organisms taken from the bottom by a nibbling action of the mouth, or more certainly by a sucking action through the mouth, were passed into the gill cavity along with water for breathing. Small organisms then were strained out by the gill apparatus and directed to the food canal. The gill apparatus thus evolved as a feeding, as well as a breathing, structure. The head and gills in the agnathans were protected by a heavy dermal armour; the tail region was free, allowing motion for swimming.

 

Most important for the evolution of fishes and vertebrates in general was the early appearance of bone, cartilage, and enamel-like substance. These materials became modified in later fishes, enabling them to adapt to many aquatic environments and finally even to land. Other basic organs and tissues of the vertebrates—such as the central nervous system, heart, liver, digestive tract, kidney, and circulatory system— undoubtedly were present in the ancestors of the agnathans. In many ways, bone, both external and internal, was the key to vertebrate evolution.

 

The next class of fishes to appear was the Acanthodii, containing the earliest known jawed vertebrates, which arose in the Late Silurian, more than 416 million years ago. The acanthodians declined after the Devonian but lasted into the Early Permian, a little less than 280 million years ago. The first complete specimens appear in Lower Devonian freshwater deposits, but later in the Devonian and Permian some members appear to have been marine. Most were small fishes, not more than 75 cm (approximately 30 inches) in length.

 

We know nothing of the ancestors of the acanthodians. They must have arisen from some jawless vertebrate, probably in fresh water. They appear to have been active swimmers with almost no head armour but with large eyes, indicating that they depended heavily on vision. Perhaps they preyed on invertebrates. The rows of spines and spinelike fins between the pectoral and pelvic fins give some credence to the idea that paired fins arose from “fin folds” along the body sides.

 

The relationships of the acanthodians to other jawed vertebrates are obscure. They possess features found in both sharks and bony fishes. They are like early bony fishes in possessing ganoidlike scales and a partially ossified internal skeleton. Certain aspects of the jaw appear to be more like those of bony fishes than sharks, but the bony fin spines and certain aspects of the gill apparatus would seem to favour relationships with early sharks. Acanthodians do not seem particularly close to the Placodermi, although, like the placoderms, they apparently possessed less efficient tooth replacement and tooth structure than the sharks and the bony fishes, possibly one reason for their subsequent extinction.

My website: www.Peregontsev.com

 

You can buy my pictures of hamster in good quality on photo stocks: on iStockphoto.

 

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Dwarf hamster

 

The dwarf hamsters represent a group of small hamsters in the genus Phodopus. Although they do not belong to this genus.

 

Campbell's Russian dwarf hamster (Phodopus campbelli) is a species of dwarf hamster. It was discovered by W.C. Campbell in 1902 in Tuva, an area that has historically been geographically linked with both China and Russia. The Campbell's dwarf is also native to the steppes and semi-arid areas of Central Asia, the Altay mountains, and the provinces of Heilungkiang and Hebei in Northeastern China.

 

This hamster is sometimes called Djungarian (or Dzungarian), or simply Russian, and often it is mistakenly labeled as a Siberian or Winter white Russian dwarf hamster, a closely related species of dwarf hamster. (See Winter White/Campbell's Dwarf Hybrids below.) In Tuva the species is called Pouched in the Tuvan language, referring to the well-known physical characteristic of most hamsters. There has been some debate over the classification of Campbell's dwarf and its closely related cousin, the Winter White, but now the two species are usually classified as Phodopus campbelli and P. sungorus, respectively. It has been claimed that the Campbell's hamster is less friendly in temperament (to humans) than the winter white and is consequently more likely to bite or nip, though of course temperament varies between different animals.

 

Habitat

In the steppes of eastern and central Asia, the Campbell's dwarf enjoys digging burrows which may extend up to three feet underground. These burrows are commonly lined with scavenged sheep's wool and dry grasses; the burrows maintain an average temperature of 62 degrees Fahrenheit(16°C). Natural predators include various owls, foxes, falcons, and weasels.

 

In captivity as pets, the smallness of this animal precludes the use of heavily-scented wood-based cage-litters such as pine or cedar, the former of which can lead to itching, sneezing and even severe allergic reaction and the later of which may lead to death. Catlitter makes a good alternative. Paper-based beddings are encouraged, with aspen shavings usually now being regarded as the only safe wood-based choice.

 

Commercial "fluffy" beddings, usually made of cotton or similar material, have come under some controversy as possibly being damaging to stomach or intestines if swallowed. While paper-based or aspen bedding is used to give the hamster burrowing opportunities while providing odor control, plain toilet tissue is frequently recommended as a nesting material to be used in addition to the "ground cover" of bedding.

 

Multiple owners find that the use of bathing sand is helpful. Chinchilla bathing sand can be found in most pet stores, although bathing dust is too fine and can thus cause resperitory problems. Bathing sand helps in improving coat and restoring oils in the fur. Bathing a hamster in water is not encouraged, as it is unhealthy for their skin and water removes needed oils. Without those oils any hamster could die easily from cold. Hamsters prefer dark places. Dwarf hamsters also can run extremely quickly. Hamsters cannot live in pine or cedar bedding, as it can kill the hamster.

 

Lifespan

Campbell's dwarf hamsters have an average lifespan in captivity of 18-36 months. Becoming sexually mature at only five weeks, their litters often consist of 4-6 pups, although up to 21 has been recorded in a single litter. The gestation period is 18-21 days, and Campbell's hamsters may mate again immediately after birth.

 

Breeding

Breeding Dwarf Russian Hamsters is much simpler than breeding Syrian Hamsters as they will live together in mixed sex pairs or groups and breed naturally. Pairs or groups are best established at a young age as introducing older hamsters can often result in fighting. Males will naturally mate with the females if kept together and when in season the female will mount the male to mount her. He will thrust a few times before dismounting and washing himself and then often will remount and mate again. The male will usually mate with the female several times. Not all unproven males will get a female pregnant after the first mating and some males may need to mate several times before a successful pregnancy occurs. The actual mating may not always be observed.The gestation period of Dwarf Russian Hamsters is 18-21 days and if mating was observed then the time of the expected arrival of the litter can be roughly calculated. If mating was not observed then it is often not possible to know tell when the litter is expected. Many females do not appear pregnant until a couple of days before the birth but an increased aggressiveness of the female towards her mate, colony hamsters or humans is often an indication of pregnancy. The female will often banish the male or other hamsters from the nest a couple of days before pregnancy and/or after the birth. Therefore as soon as it is noticed the female is pregnant it is best to clean the cage.Females usually give birth during the evening, night or early morning but sometimes give birth during the day. The female is active right up to the moment of birth. Before giving birth to each baby she tightens her abdominal muscles two or three times then sits up and crouches over as she gives birth to a single baby within a couple of minutes. A placenta, which looks like a small red blood sac, may be released after the birth of each baby and this is normally eaten by the mother as it is a good source of protein. Babies are born at approximately 10 minute intervals and the mother may be active between each birth. Therefore babies may be born around the cage but the mother will usually collect them all up and place them in the nest once birthing is complete. After the female has given birth there is often spots of blood on the bedding or around the cage. This is caused by the passing of the placentas and is normal and nothing to be alarmed about. Severe bleeding from the female though should be cause for alarm. The pups are born naked, blind and deaf, weighing only 3 grams. If the hamsters are to be dark eyed the eyes can be seen under the skin but if they are to be red eyed the eyes cannot be seen at birth. They are born with teeth which allow them to suckle and their skin is transparent and once fed the milk can be seen in the stomach.

 

Social Aspects

Unlike other hamster species, especially the Syrian hamsters, the male may play an active role in birth and rearing. He may assist the female in pulling pups from the birth canal, cleaning them, and ensuring the new mother has enough to eat. He may also guard them while the female is away from the nest. Since the pair is likely to mate again quickly, the male should be separated from the female before birth unless more pups are desired and the female is fit enough for a repeat pregnancy.

 

Like other hamsters, the Campbell's Russian dwarf will eat its young in certain emergency (or perceived emergency) situations, such as a protein deficiency in the mother or a threat toward the young. "Threat" may include anything from a predator (including a re-introduced father) to a habitat that the parent hamster does not believe will provide adequate size, covering, food, or water for its new inhabitants.

 

Unlike Syrian hamsters, Campbell's dwarfs are sociable and may be kept in colonies. If the hamsters are introduced at a young age, generally younger than eight weeks, they will often happily coexist in same- or mixed-sex groups. (Note that mixed-sex groups should be avoided as hamsters are lively breeders.) Contrary to some claims, the hamsters do not have to be related to live together peacefully. Some Campbell's dwarfs live together for long periods of time, such as over a year, only to eventually and unexpectedly end up fighting to the point of requiring separation. Pet owners should plan for the possibility of providing additional accommodations should this occur. Campbell's dwarfs are crepuscular, meaning that they are most active at dawn and at dusk.

 

Diet

Diabetes is becoming a common problem in Campbell's hamsters and is an inherited problem. Unless an individual hamster's ancestry is known to be free of the illness, a Campbell's dwarf should not be fed any sugary foods (including fruit, corn, peas, carrots, yogurt drops, and some mass-manufactured "treats"), nor should they be bred.It can make it bleed and make it die in 5 to 6 weeks.

 

Like all hamsters, Campbell's dwarfs are rodents and therefore must gnaw regularly to keep the incisors from growing into the skin of the mouth and causing health problems. Some pet owners provide dog biscuits to assist with this. Wooden chew toys should be used with care as splinters may injure the hamster. Teeth should be examined regularly to ensure they are not growing unchecked.

 

In the wild, Campbell's dwarfs consume a variety of grains, seeds, and vegetables. For the pet hamster, commercial seed mixes and food pellets are available and should be augmented with occasional fresh vegetables. Care should be taken in selecting a seed mix that does not include harmful foods, some of which are suitable for other rodents (including other types of hamsters).

 

The following items should be avoided:

almonds

garlic

potato tops

raw potatoes

rhubarb

rhubarb leaves

tomato leaves

raisins (can get lodged in cheek pouches)

anything sweet unless diabetes has been ruled out

 

Other Health Issues

Campbell's hamsters have extremely poor eyesight and even worse depth perception. Cataracts can be common in older hamsters. To compensate for this disability, the hamster has many scent glands, which are located on the face, behind the ears, on the cheek pouches, and on the belly near the rectum and genitals. Many pet owners observe that the hamster may groom itself when in an unfamiliar location. This is done to scent the feet, creating a trail which enables the hamster to find its way back to the burrow. This behavior may also be used to revisit a location with plentiful food. These scent trails may persist for up to eight days.

 

In addition to diabetes, hamsters can develop tumors (both benign and malignant), as well as glaucoma. It is possible to remove benign and malignant tumors with surgery. Unfortunately, there is not much that can be done about glaucoma, as the eye will eventually prolapse.

 

The "starter pet" reputation of hamsters may cause some to dismiss the idea of veterinary care. Although many pet hamsters live their entire lives without needing to visit a veterinarian, prospective hamster owners should remember this possible expense when considering the dwarf hamster for a pet.

 

Colors and Markings

Campbell's hamsters are born with one of four coat types: normal, satin, wavy and rex. The normal coat is short and flat. The satin coat is shiny and gives the appearance of being wet or greasy and the gene enhances the fur's color and gives it lift. The wavy coat is slightly long and wavy; the whiskers are curly when young and, although the coat moults out to a normal coat, the curly whiskers remain through adulthood. The rex coat is a soft, short coat which is curled so as to be "lifted" from the body and the whiskers are curly. The rex coat is often sparse and remains curled even in adult hamsters.

 

Campbell's dwarfs are available in six basic colors plus many variations thereof.

 

Basic colors include:

agouti (the normal grey brown wild color with white belly and black eyes)

argente (cinnamon or sandy with white belly and red eyes)

black eyed argente (dull brownish orange with white belly and black eyes)

albino (white with red eyes)

opal (blue grey with white belly and red eyes)

black (black all over with black eyes)

 

Marking types include:

mottled (irregular white patches or spots - also called banded, spotted, or collared, if the mottling is confined to the neck)

ruby-eyed mottled (mottled with ruby eyes which usually appear black)

platinum (white hairs mingled in the coat ranging from a few to almost total coverage - sometimes incorrectly called pearl)

Not all white hamsters with red/pink eyes are albino. Some are so heavily mottled or tinged with platinum that they will appear to be white. Hamsters carrying the black gene (almost half of all variations) are prone to "silvering"; in extreme cases the eventual result is an almost white hamster.

 

When two ruby-eyed mottled hamsters are bred, approximately 25% of the litter are born lacking teeth and eyes; these pups, called "eyeless toothless," generally do not live past weaning. Whether a mottled hamster has ruby eyes (which often appear black) can be difficult to determine; pointing a flashlight at the hamster in the dark may reveal the hint of ruby. Furthermore, some mottling may be too small to be noticed, or the mottling may be misidentified as platinum markings, and in these cases two ruby-eyed mottleds may accidentally be bred, resulting in the ill-fated pups.

 

Combining the different mutations has produced new colors, including blue, blue fawn, lilac fawn, beige, chocolate, champagne, dove, and others. Contrary to some claims, the different colors and markings of hamsters do not indicate personality differences. Most breeders attempt to predict personality by closely examining the bloodline and any neurological diseases the hamster's ancestors displayed.

 

Winter White/Campbell's Dwarf Hybrids

Of the five species of hamsters usually kept as pets, only the Winter White and Campbell's dwarfs are able to interbreed and produce live offspring (hybrids). Hybrids are most often unknowingly produced through incorrect identification of the two similar species of hamsters, such as mislabeling at a pet store.

 

Unfortunately, the number of hybrids is increasing, leading to a rise in health problems (such as the emergence of diabetes in the Winter White and glaucoma in the Campbell's Russian) and a decrease of pure species in captivity. Breeding of hybrids is discouraged, and the amount of accidental hybrid breeding and its repercussions underscores the cautions of casual breeding already expressed above.

_______________________________________________________________________

 

По-русски

 

Хомячок джунгарский (джунгарик, Phodopus sungorus) — разновидность хомяка рода мохноногих. Обычно по размеру уступают сирийскому хомяку в 2 раза (рост до 10 см, вес до 45 граммов), поэтому джунгарские хомячки считаются карликовыми, наряду с другими представителями рода мохноногих. Данный вид грызунов имеет специфические внешние особенности — пушистые ноги, тёмная толстая полоса на спине (обычно серая), очень короткий хвост (часто его практически не видно, когда зверёк сидит). Мех отличается значительными белыми вкраплениями. Подобная окраска объясняется тем, что хомячок джунгарийский — степное животное: он часто укрывается от хищников, зарываясь в снег. Живут, главным образом, в Сибири, однако встречаются в Казахстане, Монголии и Маньчжурии.

 

Вплоть до недавнего времени велись дискуссии, является ли джунгарский хомячок разновидностью хомячка Кэмпбелла (Phodopus campbelli) или нет. Однако, теперь известно, что джунгарики имеют собственные разновидности.

 

Одомашнивание джунгарского хомячка

Джунгарики в изобилии встречаются в зоомагазинах Европы и Азии, реже — в США. В Канаде распространены мало. Уход за джунгарийским хомячком заключается в следующем:

 

Полноценное питание (смеси, зерновые палочки, сушёные кукурузные початки, специальные фруктовые смеси);

Небольшой Запас питьевой воды (джунгарики редко пьют воду из-за особенностей их происхождения (в пустыне трудно достать воду), но миска с водой всегда должна быть);

Чистка клетки (в среднем раз в неделю, или чаще из-за характерного мышиного запаха);

Чистка шерсти песком (купание может повредить здоровью джунгарийского хомячка);

Поддержание физической формы хомячка (беговое колесо).

Джунгарики — отличные домашние животные, однако, требуют тщательного ухода. По сравнению с ними, сирийские хомячки более неприхотливы. Например, клетка для джунгарийского хомячка должна быть достаточно просторной, ибо зверьки очень подвижны. Также джунгарику необходим меловой камень для стачивания зубов. При кормлении джунгарика необходимо учитывать их предрасположенность к сахарному диабету, поэтому пищу, богатую моносахаридами, лучше исключить из рациона.

 

Домашний джунгарский хомячок по кличке "Кузя"Джунгарийские хомячки хорошо размножаются, их семейства больше, чем у сирийского хомяка, однако, обитать в домашних условиях зверькам лучше поодиночке, так как совместное проживание может вызвать у них замешательство и агрессию.

 

Одомашненные джунгарики часто отличаются от диких по окраске. Различают следующие виды окраски: нормальная домашняя (коричневато-серая с белыми вкраплениями), сапфир (серо-синеватая), жемчуг (матово-белая с серыми промежутками). Однако синеватых и белых хомячков найти трудно, поэтому большинство домашних хомячков коричневатые.

 

Многие белые хомячки (белые джунгарики и сибирские хомячки) обладают сезонной адаптацией: зимой они линяют, и их мех становится практически полностью белым (серые вкрапления исчезают, остаётся лишь полоса на спине). Линька во многом зависит от светового режима дня: при короткой продолжительности дня хомячок меняет окраску за 6 недель. Этот процесс обусловлен выработкой мелатонина (гормона шишковидной железы). Короткие длины дня также вызывают у хомячков регресс гонад, поэтому они становятся неплодовитыми.

 

Продолжительность жизни домашнего джунгарика — 1,5-2 года, хотя при правильном уходе могут жить дольше.

 

From Wikipedia

stencil: Laboratorio Okkupato SKA - Napoli - Centro Storico - Calata Trinità Maggiore

 

Questo stencil ricalca l'opera dell'incisore messicano José Guadalupe Posada. Sono diversi gli artisti che si sono ispirati alle sue incisioni, come Gorellaume (Francia) e 999 (Torino), ma questo stencil realizzato sulla facciata dello SKA non è di nessuno di loro.

 

it.wikipedia.org/wiki/Jos%c3%a9_Guadalupe_Posada

 

www.necessaryexperience.net/main.php

www.flickr.com/photos/neufneufneuf/

 

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Matschie's Tree-kangaroo

 

"With a body and head length of 20 to 32 inches, Matschie's Tree-kangaroo are much smaller than Australia's well-known red kangaroo. An adult male weighs between 20 and 25 lb (9–11 kg). An adult female weighs between 15 and 20 lb (7–9 kg).

There is no particular season in which they breed. Gestation lasts 32 days and joeys of captive bred individuals leave the pouch after 13 ½ months. The average life span of the Matschie's Tree-kangaroo in the wild is unknown, but is at least 14 years. The life span of the kangaroo in a zoo is about 20 years.

The most distinctive trait of all tree kangaroos is the hair whorl they possess. It is a patch of hair that goes out in many directions and its location ranges from up near the shoulders all the way down to the tail. The Matschie’s tree kangaroo is golden on its ventral side, lower parts of its limbs, ear edges, belly, and tail, and the rest of its body is a chestnut brown color, except for usually having a dark stripe down its back. Their faces are typically an array of yellow and white colors. The Matschies’ are similar in color and size to Dendrolagus dorianus, the Doria’s tree kangaroo. Matschies’ ears are small and bear-like looking and they do not have a good sense of hearing because of it. They have curved claws on their forelimbs and soft pads on their hind limbs that aid in their climbing ability, and they have some independent movement of their digits as well as good dexterity due to their forelimbs being able to bend a great deal. The 4th and 5th digit of their feet are enlarged, the 1st digit is absent, and the 2nd and 3rd digits are syndactylous (two digits that look like one fused together). Scientists have discovered that the Matschie’s are able to walk bipedally and there’s a lot of rotation in their limbs for climbing. Out of all of the Dendrolagus species, the Matschie’s tree kangaroo is the best vertical climber and has more strength in its muscles than any others. Their tails help to offset their balance while moving swiftly through the trees since their tails are about the same length as their head and body size. Sexual dimorphism is very low, with males and females being of about equal sizes. The upper and lower jaws of the Matschie’s tree kangaroos are different too in addition to them being different in body size. The upper jaw has three incisors, one canine, one premolar, and four molars, while the lower jaw has one very sharp incisor, no canines and low crowned molars.

 

Ecology and Behaviour:

Matschie's Tree-kangaroo lives in the mountainous rainforests at elevations of between 1000 and 3300m. The kangaroo tends to live either alone or with very small groups, usually comprising of just a mother, joey and a male. They spend most of their time in the trees and come down occasionally to feed. They are very adept at hopping and can leap up to 30 feet (9 m).

Instead of sweating, Matschie's Tree-kangaroo licks its forearms and allows the evaporation to help cool its body.

In the wild, it will usually feed on leaves, fruits and mosses. When kept in zoos, it feeds on apples, carrots, yams, corn on the cob, celery, kale/romaine, high fiber monkey biscuits, tofu, hard boiled eggs, and various types of tree boughs (elm, willow, etc.)

Matschies’ appear to be scared of humans because they scramble around when humans are nearby and they are very difficult to find in the forests. They spend about 14 to 15 hours of their days sleeping and resting. The Matschie’s tree kangaroos are known for defending their home territory and marking their boundaries.

Range:

Matschie’s tree kangaroos are restricted to the Huon peninsula of Papua New Guinea, a subdivision of Tumbanan faunal province, and are the only tree kangaroos found there. They are also residents on the island of Umboi which is just off the coast of Papua New Guinea.. The Matschies’ prefer to live in deciduous forests and tropical rainforests because they remain in trees for most of their days.

Diet:

Matschie’s tree kangaroos are mainly folivorous, eating anything from leaves, sap, insects, flowers, and nuts. It was also found that they have eaten chickens in captivity as well as feeding on a variety of plants, carrots, lettuce, bananas, potatoes, hard-boiled eggs, and yams. Since they eat high fiber foods, they only eat maybe about 1 to 2 hours throughout the day and the other time of the day they are resting and digesting their food. Their digestion is similar to that of the ruminants; they have a large, “tubiform forestomach”, where most of the fermentation and breakdown of tough material takes place at; in the hind stomach, there is a mucosa lining with many glands that help absorption begin here.

Reproduction:

Tim Flannery documents the mating techniques of the Matschies’ in his text Mammals of New Guinea by stating mating occurs when a female advances on a male while on the ground; they touch each other’s noses and click their tongues. Usually the female is aggressive and hits the male but permits him to climb on her within ten minutes, and copulation can last up to sixty minutes afterwards. The gestation period lasts approximately 44.2 days, which is known to be the longest for any of the marsupials. The Matschie’s tree kangaroos have no embryonic diapauses or delayed implantations and are able to get pregnant as soon as the joey leaves the pouch. The joey usually peeks out of the pouch around 22 weeks, will feed on its own about 27.5 weeks, will leave the pouch around 28 weeks, and permanently leave for good around 41 weeks. These tree kangaroos have been found to reach fourteen years in age. In captivity, the tree kangaroos can get pregnant at any time of the year and are known to breed well. The female oestrus cycle is between 54.2 and 56.8 days and is able to produce young between the ages of 2 and 2.5 years of age."

- Courtesy of Wikipedia

   

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BIG5. Elephant. Kruger National Park. South Africa. Mar/2021

 

Elephant

Elephants are large mammals of the family Elephantidae and the order Proboscidea. Three species are currently recognised: the African bush elephant (Loxodonta africana), the African forest elephant (L. cyclotis), and the Asian elephant (Elephas maximus). Elephants are scattered throughout sub-Saharan Africa, South Asia, and Southeast Asia. Elephantidae is the only surviving family of the order Proboscidea; other, now extinct, members of the order include deinotheres, gomphotheres, mammoths, and mastodons.

All elephants have several distinctive features, the most notable of which is a long trunk (also called a proboscis), used for many purposes, particularly breathing, lifting water, and grasping objects. Their incisors grow into tusks, which can serve as weapons and as tools for moving objects and digging. Elephants' large ear flaps help to control their body temperature. Their pillar-like legs can carry their great weight. African elephants have larger ears and concave backs while Asian elephants have smaller ears and convex or level backs.

Elephants are herbivorous and can be found in different habitats including savannahs, forests, deserts, and marshes. They prefer to stay near water. They are considered to be a keystone species due to their impact on their environments. Other animals tend to keep their distance from elephants while predators, such as lions, tigers, hyenas, and any wild dogs, usually target only young elephants (or "calves"). Elephants have a fission–fusion society in which multiple family groups come together to socialise. Females ("cows") tend to live in family groups, which can consist of one female with her calves or several related females with offspring. The groups are led by an individual known as the matriarch, often the oldest cow.

Males ("bulls") leave their family groups when they reach puberty and may live alone or with other males. Adult bulls mostly interact with family groups when looking for a mate and enter a state of increased testosterone and aggression known as musth, which helps them gain dominance and reproductive success. Calves are the centre of attention in their family groups and rely on their mothers for as long as three years. Elephants can live up to 70 years in the wild. They communicate by touch, sight, smell, and sound; elephants use infrasound, and seismic communication over long distances. Elephant intelligence has been compared with that of primates and cetaceans. They appear to have self-awareness and show empathyfor dying or dead individuals of their kind.

Source: Wikipedia

Elefante

Os elefantes são animais herbívoros, alimentando-se de ervas, gramíneas, frutas e folhas de árvores. Dado o seu tamanho, um elefante adulto pode ingerir entre 70 a 150 kg de alimentos por dia. As fêmeas vivem em manadas de 10 a 15 animais, lideradas por uma matriarca, compostas por várias reprodutoras e crias de variadas idades. O período de gestação das fêmeas é longo (20 a 22 meses), assim como o desenvolvimento do animal que leva anos a atingir a idade adulta. Os filhotes podem nascer com 90 kg. Os machos adolescentes tendem a viver em pequenos bandos e os machos adultos isolados, encontrando-se com as fêmeas apenas no período reprodutivo.

Devido ao seu porte, os elefantes têm poucos predadores. Exercem uma forte influência sobre as savanas, pois mantêm árvores e arbustos sob controle, permitindo que pastagens dominem o ambiente. Eles vivem cerca de 60 anos e morrem quando seus molares caem, impedindo que se alimentem de plantas.

Os elefantes-africanos são maiores que as variedades asiáticas e têm orelhas mais desenvolvidas, uma adaptação que permite libertar calor em condições de altas temperaturas. Outra diferença importante é a ausência de presas de marfim nas fêmeas dos elefantes asiáticos.

Durante a época de acasalamento, o aumento da produção de testosterona deixa os elefantes extremamente agressivos, fazendo-os atacar até humanos. Acidentes com elefantes utilizados em rituais geralmente são causados por esse motivo. Cerca de 400 humanos são mortos por elefantes a cada ano.

Elefante é o termo genérico e popular pelo qual são denominados os membros da família Elephantidae, um grupo de mamíferos proboscídeoselefantídeos, de grande porte, do qual há três espécies no mundo atual, duas africanas (Loxodonta sp.) e uma asiática (Elephas sp.). Há ainda os mamutes (Mammuthus sp.), hoje extintos. Até recentemente, acreditava-se que havia apenas duas espécies vivas de elefantes, o elefante-africano e o elefante-asiático, uma espécie menor. Entretanto, estudos recentes de DNA sugerem que havia, na verdade, duas espécies de elefante-africano: Loxodonta africana, da savana, e Loxodonta cyclotis, que vive nas florestas. Os elefantes são os maiores animais terrestres da actualidade, com a massa entre 4 a 6 toneladas e medindo em média quatro metros de altura, podem levantar até 10.000 kg. As suas características mais distintivas são as presas de marfim

Fonte: Wikipedia

 

Kruger National Park

Kruger National Park is one of the largest game reserves in Africa. It covers an area of around 20,000 square kilometres in the provinces of Limpopo and Mpumalanga in northeastern South Africa, and extends 360 kilometres (220 mi) from north to south and 65 kilometres (40 mi) from east to west.

Source: Wikipedia

Parque Nacional Kruger

O Parque Nacional Kruger é a maior área protegida de fauna bravia da África do Sul, cobrindo cerca de 20 000 km2. Está localizado no nordeste do país, nas províncias de Mpumalanga e Limpopo e tem uma extensão de cerca de 360 km de norte a sul e 65 km de leste a oeste.

Os parques nacionais africanos, nas regiões da savana africana são importantes pelo turismo com safári de observação e fotográfico.

O seu nome foi dado em homenagem a Stephanus Johannes Paul Kruger, último presidente da República Sul-Africana bôere. Foi criado em 31 de Maio de 1926

Fonte: Wikipedia

 

The eastern gray squirrel (Sciurus carolinensis), also known, particularly outside of North America, as simply the grey squirrel, is a tree squirrel in the genus Sciurus. It is native to eastern North America, where it is the most prodigious and ecologically essential natural forest regenerator. Widely introduced to certain places around the world, the eastern gray squirrel in Europe, in particular, is regarded as an invasive species.

 

In Europe, Sciurus carolinensis is included since 2016 in the list of Invasive Alien Species of Union concern (the Union list). This implies that this species cannot be imported, bred, transported, commercialized, or intentionally released into the environment in the whole of the European Union.

 

Distribution

Sciurus carolinensis is native to the eastern and midwestern United States, and to the southerly portions of the central provinces of Canada. In the mid-1800s the population in the midwestern United States was described as being "truly astonishing", but human predation and habitat destruction through deforestation resulted in drastic population reductions, to the point that the animal was almost absent from Illinois by 1900.

 

The native range of the eastern gray squirrel overlaps with that of the fox squirrel (Sciurus niger), with which it is sometimes confused, although the core of the fox squirrel's range is slightly more to the west. The eastern gray squirrel is found from New Brunswick, through southwestern Quebec and throughout southern Ontario plus in southern Manitoba, south to East Texas and Florida. Breeding eastern gray squirrels are found in Nova Scotia, but whether this population was introduced or came from natural range expansion is not known.

 

A prolific and adaptable species, the eastern gray squirrel has also been introduced to, and thrives in, several regions of the western United States and in 1966, this squirrel was introduced onto Vancouver Island in Western Canada in the area of Metchosin, and has spread widely from there. They are considered highly invasive and a threat to both the local ecosystem and the native squirrel, the American red squirrel.

 

Overseas, eastern gray squirrels in Europe are a concern because they have displaced some of the native squirrels there. They have been introduced into Ireland, Britain, Italy, South Africa, and Australia (where it was extirpated by 1973).

 

In Ireland, the native squirrel – also colored red – the Eurasian red squirrel S. vulgaris – has been displaced in several eastern counties, though it still remains common in the south and west of the country. The gray squirrel is also an invasive species in Britain; it has spread across the country and has largely displaced the red squirrel. That such a displacement might happen in Italy is of concern, as gray squirrels might spread to other parts of mainland Europe.

 

The generic name, Sciurus, is derived from two Greek words, skia 'shadow' and oura 'tail'. This name alludes to the squirrel sitting in the shadow of its tail. The specific epithet, carolinensis, refers to the Carolinas, where the species was first recorded and where the animal is still extremely common. In the United Kingdom and Canada, it is simply referred to as the "grey squirrel". In the US, "eastern" is used to differentiate the species from the western gray squirrel (Sciurus griseus).

 

Characteristics

The eastern gray squirrel has predominantly gray fur, but it can have a brownish color. It has a usual white underside as compared to the typical brownish-orange underside of the fox squirrel. It has a large bushy tail. Particularly in urban situations where the risk of predation is reduced, both white – and black-colored individuals are quite often found. The melanistic form, which is almost entirely black, is predominant in certain populations and in certain geographic areas, such as in large parts of southeastern Canada. Melanistic squirrels appear to exhibit a higher cold tolerance than the common gray morph; when exposed to −10 °C, black squirrels showed an 18% reduction in heat loss, a 20% reduction in basal metabolic rate, and an 11% increase to non-shivering thermogenesis capacity when compared to the common gray morph. The black coloration is caused by an incomplete dominant mutation of MC1R, where E+/E+ is a wild type squirrel, E+/EB is brown-black, and EB/EB is black.

 

The head and body length is from 23 to 30 cm (9.1 to 11.8 in), the tail from 19 to 25 cm (7.5 to 9.8 in), and the adult weight varies between 400 and 600 g (14 and 21 oz). They do not display sexual dimorphism, meaning there is no gender difference in size or coloration.

 

The tracks of an eastern gray squirrel are difficult to distinguish from the related fox squirrel and Abert's squirrel, though the latter's range is almost entirely different from the gray's. Like all squirrels, the eastern gray shows four toes on the front feet and five on the hind feet. The hind foot-pad is often not visible in the track. When bounding or moving at speed, the front foot tracks will be behind the hind foot tracks. The bounding stride can be two to three feet long.

 

The dental formula of the eastern gray squirrel is 1023/1013 (upper teeth/lower teeth).

 

1.0.2.3

1.0.1.3

× 2 = 22 total teeth.

 

Incisors exhibit indeterminate growth, meaning they grow consistently throughout life, and their cheek teeth exhibit brachydont (low-crowned teeth) and bunodont (having tubercles on crowns) structures.

 

Growth and ontogeny

Newborn gray squirrels weigh 13–18 grams and are entirely hairless and pink, although vibrissae are present at birth. 7–10 days postpartum, the skin begins to darken, just before the juvenile pelage grows in. Lower incisors erupt 19–21 days postpartum, while upper incisors erupt after 4 weeks. Cheek teeth erupt during week 6. Eyes open after 21–42 days, and ears open 3–4 weeks postpartum. Weaning is initiated around 7 weeks postpartum, and is usually finished by week 10, followed by the loss of the juvenile pelage. Full adult body mass is achieved by 8–9 months after birth.

 

Diseases

Diseases such as typhus, plague, and tularemia are spread by eastern gray squirrels. If not properly treated, these diseases have the potential to kill squirrels. When bitten or exposed to bodily fluids, humans can contract these diseases. Also carried by eastern gray squirrels are parasites such as ringworm, fleas, lice, mites, and ticks which can kill their squirrel host. Their skin may become rough, blotchy, and prone to hair loss due to the mite parasite during the chilly winter months. The parasites are not transferred to people when these squirrels reside in attics or homes. A frequent illness spread by ticks is Lyme disease. Ticks can also spread Rocky Mountain spotted fever. It can result in damage to internal organs including the heart and kidney if not properly treated. An eastern gray squirrel is susceptible to illness. They are susceptible to diseases including fibromatosis and squirrelpox. A squirrel with fibromatosis, a virus-induced illness, may grow massive skin tumors all over the body. Blindness could result from a tumor that is located close to a squirrel's eye.

 

Behavior and ecology

Like many members of the family Sciuridae, the eastern gray squirrel is a scatter-hoarder; it hoards food in numerous small caches for later recovery. Some caches are quite temporary, especially those made near the site of a sudden abundance of food which can be retrieved within hours or days for reburial in a more secure site. Others are more permanent and are not retrieved until months later. Each squirrel is estimated to make several thousand caches each season. The squirrels have very accurate spatial memory for the locations of these caches, using distant and nearby landmarks to retrieve them. Smell is used partly to uncover food caches, and also to find food in other squirrels' caches. Scent can be unreliable when the ground is too dry or covered in snow.

 

Squirrels sometimes use deceptive behavior to prevent other animals from retrieving cached food. For example, they will pretend to bury the object if they feel that they are being watched. They do this by preparing the spot as usual, for instance, digging a hole or widening a crack, miming the placement of the food, while actually concealing it in their mouths, and then covering up the "cache" as if they had deposited the object. They also hide behind vegetation while burying food or hide it high up in trees (if their rival is not arboreal). Such a complex repertoire suggests that the behaviours are not innate, and imply theory of mind thinking.

 

The eastern gray squirrel is one of very few mammalian species that can descend a tree head-first. It does this by turning its feet so the claws of its hind paws are backward-pointing and can grip the tree bark.

 

Eastern gray squirrels build a type of nest, known as a drey, in the forks of trees, consisting mainly of dry leaves and twigs. The dreys are roughly spherical, about 30 to 60 cm in diameter and are usually insulated with moss, thistledown, dried grass, and feathers to reduce heat loss. Males and females may share the same nest for short times during the breeding season, and during cold winter spells. Squirrels may share a drey to stay warm. They may also nest in the attic or exterior walls of a house, where they may be regarded as pests, as well as fire hazards due to their habit of gnawing on electrical cables. In addition, squirrels may inhabit a permanent tree den hollowed out in the trunk or a large branch of a tree.

 

Eastern gray squirrels are crepuscular, or more active during the early and late hours of the day, and tend to avoid the heat in the middle of a summer day. They do not hibernate.

 

Eastern gray squirrels can breed twice a year, but younger and less experienced mothers normally have a single litter per year in the spring. Depending on forage availability, older and more experienced females may breed again in summer. In a year of abundant food, 36% of females bear two litters, but none will do so in a year of poor food. Their breeding seasons are December to February and May to June, though this is slightly delayed in more northern latitudes. The first litter is born in February or March, the second in June or July, though, again, bearing may be advanced or delayed by a few weeks depending on climate, temperature, and forage availability. In any given breeding season, an average of 61 – 66% of females bear young. If a female fails to conceive or loses her young to unusually cold weather or predation, she re-enters estrus and has a later litter. Five days before a female enters estrus, she may attract up to 34 males from up to 500 meters away. Eastern gray squirrels exhibit a form of polyandry, in which the competing males will form a hierarchy of dominance, and the female will mate with multiple males depending on the hierarchy established.

 

Normally, one to four young are born in each litter, but the largest possible litter size is eight. The gestation period is about 44 days. The young are weaned around 10 weeks, though some may wean up to six weeks later in the wild. They begin to leave the nest after 12 weeks, with autumn born young often wintering with their mother. Only one in four squirrel kits survives to one year of age, with mortality around 55% for the following year. Mortality rates then decrease to around 30% for following years until they increase sharply at eight years of age.

 

Rarely, eastern gray females can enter estrus as early as five and a half months old, but females are not normally fertile until at least one year of age. Their mean age of first estrus is 1.25 years. The presence of a fertile male will induce ovulation in a female going through estrus. Male eastern grays are sexually mature between one and two years of age. Reproductive longevity for females appears to be over 8 years, with 12.5 years documented in North Carolina. These squirrels can live to be 20 years old in captivity, but in the wild live much shorter lives due to predation and the challenges of their habitat. At birth, their life expectancy is 1–2 years, an adult typically can live to be six, with exceptional individuals making it to 12 years.

 

Communication

As in most other mammals, communication among eastern gray squirrel individuals involves both vocalizations and posturing. The species has a quite varied repertoire of vocalizations, including a squeak similar to that of a mouse, a low-pitched noise, a chatter, and a raspy "mehr mehr mehr". Other methods of communication include tail-flicking and other gestures, including facial expressions. Tail flicking and the "kuk" or "quaa" call are used to ward off and warn other squirrels about predators, as well as to announce when a predator is leaving the area. Squirrels also make an affectionate coo-purring sound that biologists call the "muk-muk" sound. This is used as a contact sound between a mother and her kits and in adulthood, by the male when he courts the female during mating season. The use of vocal and visual communication has been shown to vary by location, based on elements such as noise pollution and the amount of open space. For instance, populations living in large cities generally rely more on the visual signals, due to the generally louder environment with more areas without much visual restriction. However, in heavily wooded areas, vocal signals are used more often due to the relatively lower noise levels and a dense canopy restricting visual range.

 

Habitat

In the wild, eastern gray squirrels can be found inhabiting large areas of mature, dense woodland ecosystems, generally covering 100 acres (40 hectares) of land. These forests usually contain large mast-producing trees such as oaks and hickories, providing ample food sources. Oak-hickory hardwood forests are generally preferred over coniferous forests due to the greater abundance of mast forage. This is why they are found only in parts of eastern Canada which do not contain boreal forest (i.e. they are found in some parts of New Brunswick, in southwestern Quebec, throughout southern Ontario and in southern Manitoba).

 

Eastern gray squirrels generally prefer constructing their dens upon large tree branches and within the hollow trunks of trees. They also have been known to take shelter within abandoned bird nests. The dens are usually lined with moss plants, thistledown, dried grass, and feathers. These perhaps provide and assist in the insulation of the den, used to reduce heat loss. A cover to the den is usually built afterwards. Eastern grays squirrels also use dens for protection from prey and helps them look after their young. Young survive 40 percent less if they lived in a leaf nest compared to a den. Squirrels tend to claim 2-3 dens at the same time. Canopy and midstory Trees are used by squirrels to hide from predators such as hawks and owls. The typical squirrel ranges over 1.5 to 8 acres (0.61 to 3.24 ha) and tend to be smaller where more of them are found.

 

Close to human settlements, eastern gray squirrels are found in parks and back yards of houses within urban environments and in the farmlands of rural environments.

 

Ecosystem

Eastern Grey Squirrels are important to the ecosystem by eating a lot of seeds. By caching seeds, they help in the spread of tree seeds. Also, by eating truffles, they contribute to the spread of fungal spores. In addition, they are essential to the environment because they transport parasites. The ecology is influenced by the contribution of squirrels to nature. They often collect seeds and bury them for later consumption, but they often forget where have left them, and they have effectively planted those seeds. These seeds increase the diversity of trees by bringing additional trees into the environment. They are an important key to the forest ecosystem that they belong to.

 

Predation

Eastern gray squirrels predators include hawks, weasels, raccoons, bobcats, foxes, domestic and feral cats, snakes, owls, and dogs. Their primary predators are hawks, owls, and snakes. Raccoons and weasels may consume a squirrel depending on where it lives in the United States. Rattlesnakes eat squirrels in California as they are searching for food in a heavy forest. The squirrel is susceptible to be eaten by a fox in the eastern region of the United States.

 

In its introduced range in South Africa, it has been preyed on by African harrier-hawks. When a predator is approaching the eastern gray squirrel, other squirrels will inform the squirrel of the predator by sending an acoustic signal to let the squirrel know. The speed of a squirrel makes it hard for it to be captured by the predators.

 

Fossil record of the eastern gray squirrel

Twenty different Pleistocene fauna specimens contain S. carolinensis, found in Florida and dated to be as early as the late Irvingtonian period. Body size seems to have increased during the early to middle Holocene and then decreased to the present size seen today.

 

Diet

Eastern gray squirrels eat a range of foods, such as tree bark, tree buds, flowers, berries, many types of seeds and acorns, walnuts, and other nuts, like hazelnuts (see picture) and some types of fungi found in the forests, including fly agaric mushrooms and truffles. They can cause damage to trees by tearing the bark and eating the soft cambial tissue underneath. In Europe, sycamore and beech suffer the greatest damage. Mast-bearing gymnosperms such as cedar, hemlock, pine, and spruce are another food source, as well as angiosperms such as hickory, oak, and walnut. These trees produce important foods for them during the spring and fall months. The squirrels will vary the species they forage from depending on the season. The squirrels also raid gardens for wheat, tomatoes, corn, strawberries, and other garden crops. Sometimes they eat the tomato seeds and discard the rest. On occasion, eastern gray squirrels also prey upon insects, frogs, small rodents including other squirrels, and small birds, their eggs, and young. They also gnaw on bones, antlers, and turtle shells – likely as a source of minerals scarce in their normal diet. In urban and suburban areas, these squirrels scavenge for food in trash bins. However, these foods are not safe for them to digest because they include sugar, fat, as well as additives that can make them sick. Eastern gray squirrels are sometimes mistakenly thought to be herbivores, but they are omnivores.

 

Eastern gray squirrels have a high enough tolerance for humans to inhabit residential neighborhoods and raid bird feeders for millet, corn, and sunflower seeds. Some people who feed and watch birds for entertainment also intentionally feed seeds and nuts to the squirrels for the same reason. However, in the UK eastern gray squirrels can take a significant proportion of supplementary food from feeders, preventing access and reducing use by wild birds. Attraction to supplementary feeders can increase local bird nest predation, as eastern gray squirrels are more likely to forage near feeders, resulting in increased likelihood of finding nests, eggs and nestlings of small passerines.

 

Introductions and impact

The eastern gray squirrel is an introduced species in a variety of locations in western North America: in western Canada, to the southwest corner of British Columbia and to the city of Calgary, Alberta; in the United States, to the states of Washington and Oregon and, in California, to the city of San Francisco and the San Francisco Peninsula area in San Mateo and Santa Clara Counties, south of the city. It has become the most common squirrel in many urban and suburban habitats in western North America, from north of central California to southwest British Columbia.

 

By the turn of the 20th century, breeding populations of the eastern gray squirrel had been introduced into South Africa, Ireland, Italy, Australia (extirpated by 1973), and the United Kingdom.

 

In South Africa, though exotic, it is not usually considered an invasive species owing to its small range (only found in the extreme southwestern part of the Western Cape, going north as far as the small farming town of Franschhoek), as well because it inhabits urban areas and places greatly affected by humans, such as agricultural areas and exotic pine plantations. Here, it mostly eats acorns and pine seeds, although it will take indigenous and commercial fruit, as well. Even so, it is unable to use the natural vegetation (fynbos) found in the area, a factor which has helped to limit its spread. It does not come into contact with native squirrels due to geographic isolation (a native tree squirrel, Paraxerus cepapi, is found only in the savanna regions in the northeast of the country) and different habitats.

 

Gray squirrels were first introduced to Britain in the 1870s, as fashionable additions to estates. In 1921 it was reported in The Times that the Zoological Society of London had released eastern greys to breed at liberty in Regents Park:

 

A dozen years ago the Zoological Society of London obtained a number from a private collection in Bedfordshire for the purpose of inducing them to breed at liberty in the Gardens in Regent's Park. They were first kept in a large enclosure from which, when they had become used to visitors, they were allowed to pass in and out by a rope bridge to a tree. It was hoped that they would spread from the Gardens to the Park. After two or three years in which they seemed to be disappearing, they suddenly became ubiquitous...The grey squirrels are plainly happy and plainly give happiness to Londoners...On the other hand, grey squirrels, whether by taking advantage of tubes and buses, or by deliberate human connivance, have spread from London and are invading the country over very wide areas. They are said to drive out the red squirrel, to raid gardens, and to add to the anxieties of the pheasant breeder. We hope that fuller inquiry will not sustain these charges.

 

They spread rapidly across England, and then became established in both Wales and parts of southern Scotland. On mainland Britain, they have almost entirely displaced native red squirrels. Larger than red squirrels and capable of storing up to four times more fat, gray squirrels are better able to survive winter conditions. They produce more young and can live at higher densities. Gray squirrels also carry the squirrelpox virus, to which red squirrels have no immunity. When an infected gray squirrel introduces squirrelpox to a red squirrel population, its decline is 17–25 times greater than through competition alone.

 

In Ireland, the displacement of red squirrels has not been as rapid because only a single introduction occurred, in County Longford. Schemes have been introduced to control the population of gray squirrels in Ireland to encourage the native red squirrels. Eastern gray squirrels have also been introduced to Italy, and the European Union has expressed concern that they will similarly displace the red squirrel from parts of the European continent.

 

Main article: Tree squirrel § As food

Gray squirrels were eaten in earlier times by Native Americans and their meat is still popular with hunters across most of their range in North America. Today, it is still available for human consumption and is occasionally sold in the United Kingdom. However, physicians in the United States have warned that squirrel brains should not be eaten, because of the risk that they may carry Creutzfeldt–Jakob disease.

 

Displacement of red squirrels

Further information: Eastern gray squirrels in Europe

In Britain and Ireland, the eastern gray squirrel is not regulated by natural predators, other than the European pine marten, which is generally absent from England and Wales. This has aided its rapid population growth and has led to the species being classed as a pest. Measures are being devised to reduce its numbers, including a campaign starting in 2006 named "Save Our Squirrels" using the slogan "Save a red, eat a grey!" which attempted to re-introduce squirrel meat in to the local market, with celebrity chefs promoting the idea, cookbooks introducing recipes containing squirrel and the Forestry Commission providing a regular supply of squirrel meat to British restaurants, factories and butchers. In areas where relict populations of red squirrels survive, such as the islands of Anglesey, Brownsea and the Isle of Wight, programs exist to eradicate gray squirrels and prevent them from reaching these areas in order to allow red squirrel populations to recover and grow.

 

Although complex and controversial, the main factor in the eastern gray squirrel's displacement of the red squirrel is thought to be its greater fitness, hence a competitive advantage over the red squirrel on all measures. Within 15 years of the grey squirrel's introduction to a red squirrel habitat, red squirrel populations are extinct. The eastern gray squirrel tends to be larger and stronger than the red squirrel and has been shown to have a greater ability to store fat for winter. Due to the lack of trees in their native Ireland for them to reside in, red squirrels are the only species being harmed by the invasion of grey squirrels. The squirrel can, therefore, compete more effectively for a larger share of the available food, resulting in relatively lower survival and breeding rates among the red squirrel. Parapoxvirus may also be a strongly contributing factor; red squirrels have long been fatally affected by the disease, while the eastern gray squirrels are unaffected, but thought to be carriers – although how the virus is transmitted has yet to be determined. Red squirrel extinction rates can be 20–25 times greater in areas with confirmed cases of squirrel pox than they are in areas without the disease. This competitive action done between these two squirrels is reasoned to qualify the eastern gray squirrel as a keystone species because since the eastern gray squirrel is coming and wiping out the red squirrels, there would be a reduced chance of competition hence more eastern gray squirrels will come in to Ireland. However, several cases of red squirrels surviving have been reported, as they have developed an immunity – although their population is still being massively affected. The red squirrel is also less tolerant of habitat destruction and fragmentation, which has led to its population decline, while the more adaptable eastern gray squirrel has taken advantage and expanded. Methods done to control this competition between these squirrels are that red squirrels should remain in their original habitats, such as Ireland, while the grey squirrels should be kept out of these places entirely as a means of controlling this squirrel competition.

 

Similar factors appear to have been at play in the Pacific region of North America, where the native American red squirrel has been largely displaced by the eastern gray squirrel in parks and forests throughout much of the region.

 

Ironically, "fears" for the future of the eastern gray squirrel arose in 2008, as the melanistic form (black) began to spread through the southern British population. In the UK, if a "grey squirrel" (eastern gray squirrel) is trapped, under the Wildlife and Countryside Act 1981, it is illegal to release it or to allow it to escape into the wild; instead, it is legally required be "humanely dispatched".

 

In the late 1990s, Italy's National Wildlife Institute and University of Turin launched an eradication attempt to halt the spread of gray squirrels in northwest Italy, but court action by animal rights groups blocked this. Hence gray squirrels are expected to cross the Alps into France and Switzerland in the next few decades

Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes the pikas). Oryctolagus cuniculus is the European rabbit, including its descendants, the world's 305 breeds[1] of domestic rabbit. Sylvilagus includes 13 wild rabbit species, among them the seven types of cottontail. The European rabbit, which has been introduced on every continent except Antarctica, is familiar throughout the world as a wild prey animal, a domesticated form of livestock and a pet. With its widespread effect on ecologies and cultures, in many areas of the world, the rabbit is a part of daily life – as food, clothing, a companion, and a source of artistic inspiration.

 

Although once considered rodents, lagomorphs like rabbits have been discovered to have diverged separately and earlier than their rodent cousins and have a number of traits rodents lack, like two extra incisors.

 

Terminology and etymology

A male rabbit is called a buck; a female is called a doe. An older term for an adult rabbit used until the 18th century is coney (derived ultimately from the Latin cuniculus), while rabbit once referred only to the young animals.[2] Another term for a young rabbit is bunny, though this term is often applied informally (particularly by children) to rabbits generally, especially domestic ones. More recently, the term kit or kitten has been used to refer to a young rabbit.

 

A group of rabbits is known as a colony or nest (or, occasionally, a warren, though this more commonly refers to where the rabbits live).[3] A group of baby rabbits produced from a single mating is referred to as a litter[4] and a group of domestic rabbits living together is sometimes called a herd.[5]

 

The word rabbit itself derives from the Middle English rabet, a borrowing from the Walloon robète, which was a diminutive of the French or Middle Dutch robbe.[6]

  

Taxonomy

See also: List of leporids

Rabbits and hares were formerly classified in the order Rodentia (rodent) until 1912, when they were moved into a new order, Lagomorpha (which also includes pikas).

 

Order Lagomorpha

Family Leporidae (in part)

Genus Brachylagus

Pygmy rabbit, Brachylagus idahoensis

Genus Bunolagus

Bushman rabbit, Bunolagus monticularis

Genus Lepus[a]

Genus Nesolagus

Sumatran striped rabbit, Nesolagus netscheri

Annamite striped rabbit, Nesolagus timminsi

Genus Oryctolagus

European rabbit, Oryctolagus cuniculus

Genus Pentalagus

Amami rabbit/Ryūkyū rabbit, Pentalagus furnessi

Genus Poelagus

Central African Rabbit, Poelagus marjorita

Genus Romerolagus

Volcano rabbit, Romerolagus diazi

Genus Sylvilagus

Swamp rabbit, Sylvilagus aquaticus

Desert cottontail, Sylvilagus audubonii

Brush rabbit, Sylvilagus bachmani

Forest rabbit, Sylvilagus brasiliensis

Mexican cottontail, Sylvilagus cunicularis

Dice's cottontail, Sylvilagus dicei

Eastern cottontail, Sylvilagus floridanus

Tres Marias rabbit, Sylvilagus graysoni

Omilteme cottontail, Sylvilagus insonus

San Jose brush rabbit, Sylvilagus mansuetus

Mountain cottontail, Sylvilagus nuttallii

Marsh rabbit, Sylvilagus palustris

New England cottontail, Sylvilagus transitionalis

Differences from hares

Main article: Hare

 

Hare

Johann Daniel Meyer (1748)

 

Rabbit

Johann Daniel Meyer (1748)

The term rabbit is typically used for all Leporidae species excluding the genus Lepus. Members of that genus are instead known as hares or jackrabbits.

 

Lepus species are precocial, born relatively mature and mobile with hair and good vision, while rabbit species are altricial, born hairless and blind. Hares & some rabbits live a relatively solitary life in a simple nest above the ground, while other rabbits live in social groups in burrows, which are grouped together to form warrens. Hares are generally larger than rabbits, with ears that are more elongated, and with hind legs that are larger and longer. Descendants of the European rabbit are commonly bred as livestock and kept as pets, whereas no hares have been domesticated – the breed called the Belgian hare is actually a domestic rabbit which has been selectively bred to resemble a hare.

 

Domestication

Main article: Domestic rabbit

Rabbits have long been domesticated. The European rabbit has been widely kept as livestock, starting in ancient Rome. Selective breeding, which began in the Middle Ages, has generated a wide variety of rabbit breeds, of which many (since the early 19th century) are also kept as pets.[7] Some strains of rabbit have been bred specifically as research subjects.

 

As livestock, rabbits are bred for their meat and fur. The earliest breeds were important sources of meat, and so became larger than wild rabbits, but domestic rabbits in modern times range in size from dwarf to giant. Rabbit fur, prized for its softness, can be found in a broad range of coat colors and patterns, as well as lengths. The Angora rabbit breed, for example, was developed for its long, silky fur, which is often hand-spun into yarn. Other domestic rabbit breeds have been developed primarily for the commercial fur trade, including the Rex, which has a short plush coat.

 

Biology

 

Wax models showing the development of the rabbit heart

Evolution

Because the rabbit's epiglottis is engaged over the soft palate except when swallowing, the rabbit is an obligate nasal breather. Rabbits have two sets of incisor teeth, one behind the other. This way they can be distinguished from rodents, with which they are often confused.[8] Another difference is that for rabbits, all of their teeth continue to grow, where as for most rodents, only their incisors continue to grow. Carl Linnaeus originally grouped rabbits and rodents under the class Glires; later, they were separated as the scientific consensus is that many of their similarities were a result of convergent evolution. Recent DNA analysis and the discovery of a common ancestor has supported the view that they share a common lineage, so rabbits and rodents are now often grouped together in the superorder Glires.[9]

 

Morphology

 

Skeleton of the rabbit

Since speed and agility are a rabbit's main defenses against predators (including the swift fox), rabbits have large hind leg bones and well-developed musculature. Though plantigrade at rest, rabbits are on their toes while running, assuming a more digitigrade posture. Rabbits use their strong claws for digging and (along with their teeth) for defense.[10] Each front foot has four toes plus a dewclaw. Each hind foot has four toes (but no dewclaw).[11]

  

Melanistic coloring

Oryctologus cuniculus

European rabbit (wild)

Most wild rabbits (especially compared to hares) have relatively full, egg-shaped bodies. The soft coat of the wild rabbit is agouti in coloration (or, rarely, melanistic), which aids in camouflage. The tail of the rabbit (with the exception of the cottontail species) is dark on top and white below. Cottontails have white on the top of their tails.[12]

 

As a result of the position of the eyes in its skull, the rabbit has a field of vision that encompasses nearly 360 degrees, with just a small blind spot at the bridge of the nose.[13]

 

Hind limb elements

 

This image comes from a specimen in the Pacific Lutheran University natural history collection. It displays all of the skeletal articulations of rabbit's hind limbs.

The anatomy of rabbits' hind limbs is structurally similar to that of other land mammals and contributes to their specialized form of locomotion. The bones of the hind limbs consist of long bones (the femur, tibia, fibula, and phalanges) as well as short bones (the tarsals). These bones are created through endochondral ossification during development. Like most land mammals, the round head of the femur articulates with the acetabulum of the os coxae. The femur articulates with the tibia, but not the fibula, which is fused to the tibia. The tibia and fibula articulate with the tarsals of the pes, commonly called the foot. The hind limbs of the rabbit are longer than the front limbs. This allows them to produce their hopping form of locomotion. Longer hind limbs are more capable of producing faster speeds. Hares, which have longer legs than cottontail rabbits, are able to move considerably faster.[14] Rabbits stay just on their toes when moving; this is called digitigrade locomotion. The hind feet have four long toes that allow for this and are webbed to prevent them from spreading when hopping.[15] Rabbits do not have paw pads on their feet like most other animals that use digitigrade locomotion. Instead, they have coarse compressed hair that offers protection.[16]

 

Musculature

 

The rabbit's hind limb (lateral view) includes muscles involved in the quadriceps and hamstrings.

Rabbits have muscled hind legs that allow for maximum force, maneuverability, and acceleration that is divided into three main parts: foot, thigh, and leg. The hind limbs of a rabbit are an exaggerated feature. They are much longer than the forelimbs, providing more force. Rabbits run on their toes to gain the optimal stride during locomotion. The force put out by the hind limbs is contributed by both the structural anatomy of the fusion tibia and fibula, and muscular features.[17] Bone formation and removal, from a cellular standpoint, is directly correlated to hind limb muscles. Action pressure from muscles creates force that is then distributed through the skeletal structures. Rabbits that generate less force, putting less stress on bones are more prone to osteoporosis due to bone rarefaction.[18] In rabbits, the more fibers in a muscle, the more resistant to fatigue. For example, hares have a greater resistance to fatigue than cottontails. The muscles of rabbit's hind limbs can be classified into four main categories: hamstrings, quadriceps, dorsiflexors, or plantar flexors. The quadriceps muscles are in charge of force production when jumping. Complementing these muscles are the hamstrings, which aid in short bursts of action. These muscles play off of one another in the same way as the plantar flexors and dorsiflexors, contributing to the generation and actions associated with force.[19]

 

Ears

 

Anatomy of mammalian ear

 

A Holland Lop resting with one ear up and one ear down. Some rabbits can adjust their ears to hear distant sounds.

Within the order lagomorphs, the ears are used to detect and avoid predators. In the family Leporidae, the ears are typically longer than they are wide. For example, in black tailed jack rabbits, their long ears cover a greater surface area relative to their body size that allow them to detect predators from far away. In contrast with cottontail rabbits, their ears are smaller and shorter, requiring that predators be closer before they can detect them and flee. Evolution has favored rabbits having shorter ears, so the larger surface area does not cause them to lose heat in more temperate regions. The opposite can be seen in rabbits that live in hotter climates; possessing longer ears with a larger surface area helps with dispersion of heat. Since sound travels less well in arid as opposed to cooler air, longer ears may aid the organism in detecting predators sooner rather than later, in warmer temperatures.[20][page needed] Rabbits are characterized by shorter ears than hares.[21][page needed] Rabbits' ears are an important structure to aid thermoregulation as well as in detecting predators due to the way the outer, middle, and inner ear muscles coordinate with one another. The ear muscles also aid in maintaining balance and movement when fleeing predators.[22]

 

Outer ear

The auricle, also known as the pinna, is a rabbit's outer ear.[23] The rabbit's pinnae represent a fair part of the body surface area. It is theorized that the ears aid in dispersion of heat at temperatures above 30 °C (86 °F), with rabbits in warmer climates having longer pinnae due to this. Another theory is that the ears function as shock absorbers that could aid and stabilize rabbits' vision when fleeing predators, but this has typically only been seen in hares.[24][page needed] The rest of the outer ear has bent canals that lead to the eardrum or tympanic membrane.[25]

 

Middle ear

The middle ear, separated by the outer eardrum in the back of the rabbit's skull, contains three bones: the hammer, anvil, and stirrup, collectively called ossicles, which act to decrease sound before it hits the inner ear; in general, the ossicles act as a barrier to the inner ear for sound energy.[25]

 

Inner ear

Inner ear fluid, called endolymph, receives the sound energy. After receiving the energy. The inner ear comprises two parts: the cochlea that uses sound waves from the ossicles, and the vestibular apparatus that manages the rabbit's position in regard to movement. Within the cochlea a basilar membrane contains sensory hair structures that send nerve signals to the brain, allowing it to recognize different sound frequencies. Within the vestibular apparatus three semicircular canals help detect angular motion.[25]

 

Dewlaps

 

A palomino rabbit displaying her dewlap beside a month-old kit

A dewlap is a longitudinal flap of skin or similar flesh that hangs beneath the lower jaw or neck. It is a secondary sex characteristic in rabbits, caused by the presence of female sex hormones. They develop with puberty. A female rabbit who has been neutered before reaching sexual maturity will not develop a dewlap, and even if a doe is neutered after developing a dewlap, the dewlap will gradually disappear over several months. This also aligns with the results of injecting male rabbits with female sex hormones, specifically the ones from pregnant women's urine. The male rabbits developed dewlaps, which then gradually disappeared once administration had ceased.[26] (This is not the process of the rabbit test, a common way to test for human female pregnancy in the 20th century; the pregnancy test involved dissecting female rabbits after injection with urine to see if their ovaries had enlarged.)[27] While it is unclear exactly what function a dewlap performs, pregnant female rabbits will pluck fur from their dewlaps shortly before giving birth to line a nest for their young.[28]

 

Thermoregulation

 

The blood flow through the rabbit's large ears help with thermoregulation.

Thermoregulation is the process that an organism uses to maintain an optimal body temperature independent of external conditions.[29] This process is carried out by the pinnae, which takes up most of the rabbit's body surface and contain a vascular network and arteriovenous shunts.[30] In a rabbit, the optimal body temperature is around 38.5–40.0 °C (101.3–104.0 °F).[31] If their body temperature exceeds or does not meet this optimal temperature, the rabbit must return to homeostasis. Homeostasis of body temperature is maintained by the use of their large, highly vascularized ears that are able to change the amount of blood flow that passes through the ears.

 

Respiratory system

 

Ventral view of dissected rabbit lungs with key structures labeled.

The rabbit's nasal cavity lies dorsal to the oral cavity, and the two compartments are separated by the hard and soft palate.[32] The nasal cavity itself is separated into a left and right side by a cartilage barrier, and it is covered in fine hairs that trap dust before it can enter the respiratory tract.[32][33][page needed] As the rabbit breathes, air flows in through the nostrils along the alar folds. From there, the air moves into the nasal cavity, also known as the nasopharynx, down through the trachea, through the larynx, and into the lungs.[33][page needed][34] The larynx functions as the rabbit's voice box, which enables it to produce a wide variety of sounds.[33][page needed] The trachea is a long tube embedded with cartilaginous rings that prevent the tube from collapsing as air moves in and out of the lungs. The trachea then splits into a left and right bronchus, which meet the lungs at a structure called the hilum. From there, the bronchi split into progressively more narrow and numerous branches. The bronchi branch into bronchioles, into respiratory bronchioles, and ultimately terminate at the alveolar ducts. The branching that is typically found in rabbit lungs is a clear example of monopodial branching, in which smaller branches divide out laterally from a larger central branch.[35]

 

The structure of the rabbit's nasal and oral cavities necessitates breathing through the nose. This is due to the fact that the epiglottis is fixed to the backmost portion of the soft palate.[34] Within the oral cavity, a layer of tissue sits over the opening of the glottis, which blocks airflow from the oral cavity to the trachea.[32] The epiglottis functions to prevent the rabbit from aspirating on its food. Further, the presence of a soft and hard palate allow the rabbit to breathe through its nose while it feeds.[33][page needed]

  

Monopodial branching as seen in dissected rabbit lungs.

Rabbits' lungs are divided into four lobes: the cranial, middle, caudal, and accessory lobes. The right lung is made up of all four lobes, while the left lung only has two: the cranial and caudal lobes.[35] To provide space for the heart, the left cranial lobe of the lungs is significantly smaller than that of the right.[32] The diaphragm is a muscular structure that lies caudal to the lungs and contracts to facilitate respiration.[32][34]

  

Digestion

 

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Rabbits are herbivores that feed by grazing on grass and other leafy plants. Consequently, their diet contains large amounts of cellulose, which is hard to digest. Rabbits solve this problem via a form of hindgut fermentation. They pass two distinct types of feces: hard droppings and soft black viscous pellets, the latter of which are known as cecotropes or "night droppings"[36] and are immediately eaten (a behaviour known as cecotrophy ). Rabbits reingest their own droppings (rather than chewing the cud as do cows and numerous other herbivores) to digest their food further and extract sufficient nutrients.[37]

 

Rabbits graze heavily and rapidly for roughly the first half-hour of a grazing period (usually in the late afternoon), followed by about half an hour of more selective feeding.[38] In this time, the rabbit will also excrete many hard fecal pellets, being waste pellets that will not be reingested. If the environment is relatively non-threatening, the rabbit will remain outdoors for many hours, grazing at intervals. The rabbit will reingest its soft, partially digested pellets in a process known as cecotrophy; this is rarely observed, since the pellets are reingested as they are produced.[39]

 

Hard pellets are made up of hay-like fragments of plant cuticle and stalk, being the final waste product after redigestion of soft pellets. These are only released outside the burrow or form and are not reingested. Soft pellets are usually produced several hours after grazing, after the hard pellets have all been excreted. They are made up of micro-organisms and undigested plant cell walls, among other necessary nutrients.[39]

 

Rabbits are hindgut digesters. This means that most of their digestion takes place in their large intestine and cecum. In rabbits, the cecum is about 10 times bigger than the stomach and it along with the large intestine makes up roughly 40% of the rabbit's digestive tract.[40] The unique musculature of the cecum allows the intestinal tract of the rabbit to separate fibrous material from more digestible material; the fibrous material is passed as feces, while the more nutritious material is encased in a mucous lining as a cecotrope. Cecotropes, sometimes called "night feces", are high in minerals, vitamins and proteins that are necessary to the rabbit's health. Rabbits eat these to meet their nutritional requirements; the mucous coating allows the nutrients to pass through the acidic stomach for digestion in the intestines. This process allows rabbits to extract the necessary nutrients from their food.[41]

 

The chewed plant material collects in the large cecum, a secondary chamber between the large and small intestine containing large quantities of symbiotic bacteria that help with the digestion of cellulose and also produce certain B vitamins. The pellets are about 56% bacteria by dry weight, largely accounting for the pellets being 24.4% protein on average. The soft feces form here and contain up to five times the vitamins of hard feces. After being excreted, they are eaten whole by the rabbit and redigested in a special part of the stomach. The pellets remain intact for up to six hours in the stomach; the bacteria within continue to digest the plant carbohydrates. This double-digestion process enables rabbits to use nutrients that they may have missed during the first passage through the gut, as well as the nutrients formed by the microbial activity and thus ensures that maximum nutrition is derived from the food they eat.[12] This process serves the same purpose in the rabbit as rumination does in cattle and sheep.[42]

  

Dissected image of the male rabbit reproductive system with key structures labeled

Because rabbits cannot vomit,[43] if buildup occurs within the intestines (due often to a diet with insufficient fibre),[44] intestinal blockage can occur.[45]

 

Reproduction

 

Diagram of the male rabbit reproductive system with main components labeled

The adult male reproductive system forms the same as most mammals with the seminiferous tubular compartment containing the Sertoli cells and an adluminal compartment that contains the Leydig cells.[46] The Leydig cells produce testosterone, which maintains libido[46] and creates secondary sex characteristics such as the genital tubercle and penis. The Sertoli cells triggers the production of Anti-Müllerian duct hormone, which absorbs the Müllerian duct. In an adult male rabbit, the sheath of the penis is cylinder-like and can be extruded as early as two months of age.[47] The scrotal sacs lay lateral to the penis and contain epididymal fat pads which protect the testes. Between 10 and 14 weeks, the testes descend and are able to retract into the pelvic cavity to thermoregulate.[47] Furthermore, the secondary sex characteristics, such as the testes, are complex and secrete many compounds. These compounds include fructose, citric acid, minerals, and a uniquely high amount of catalase.[46]

  

Diagram of the female rabbit reproductive system with main components labeled.

The adult female reproductive tract is bipartite, which prevents an embryo from translocating between uteri.[48] The two uterine horns communicate to two cervixes and forms one vaginal canal. Along with being bipartite, the female rabbit does not go through an estrus cycle, which causes mating induced ovulation.[47]

 

The average female rabbit becomes sexually mature at three to eight months of age and can conceive at any time of the year for the duration of her life. Egg and sperm production can begin to decline after three years.[46] During mating, the male rabbit will mount the female rabbit from behind and insert his penis into the female and make rapid pelvic hip thrusts. The encounter lasts only 20–40 seconds and after, the male will throw himself backwards off the female.[49]

 

The rabbit gestation period is short and ranges from 28 to 36 days with an average period of 31 days. A longer gestation period will generally yield a smaller litter while shorter gestation periods will give birth to a larger litter. The size of a single litter can range from four to 12 kits allowing a female to deliver up to 60 new kits a year. After birth, the female can become pregnant again as early as the next day.[47]

 

After mating, in some species, hormonal changes will cause the doe to begin to dig a burrow for her nest about a week before giving birth. Between three days and a few hours before giving birth another series of hormonal changes will cause her to prepare the nest structure. The doe will first gather grass for a structure, and an elevation in prolactin shortly before birth will cause her fur to shed that the doe will then use to line the nest, providing insulation for the newborn kits.[50]

 

The mortality rates of embryos are high in rabbits and can be due to infection, trauma, poor nutrition and environmental stress so a high fertility rate is necessary to counter this.

 

Sleep

Further information: Sleep (non-human)

Rabbits may appear to be crepuscular, but their natural inclination is toward nocturnal activity. In 2011, the average sleep time of a rabbit in captivity was calculated at 8.4 hours per day. As with other prey animals, rabbits often sleep with their eyes open, so that sudden movements will awaken the rabbit to respond to potential danger.

  

Diseases and immunity

See also: Category:Rabbit diseases

In addition to being at risk of disease from common pathogens such as Bordetella bronchiseptica and Escherichia coli, rabbits can contract the virulent, species-specific viruses RHD ("rabbit hemorrhagic disease", a form of calicivirus) or myxomatosis. Among the parasites that infect rabbits are tapeworms (such as Taenia serialis), external parasites (including fleas and mites), coccidia species, and Toxoplasma gondii. Domesticated rabbits with a diet lacking in high fiber sources, such as hay and grass, are susceptible to potentially lethal gastrointestinal stasis. Rabbits and hares are almost never found to be infected with rabies and have not been known to transmit rabies to humans.

 

Encephalitozoon cuniculi, a microsporidial parasite, is capable of infecting many mammals, including rabbits.

 

Rabbit immunity has significantly diverged from other tetrapods in the manner it employs immunoglobulin light chains. In one case McCartney-Francis et al., 1984 discover a unique additional disulfide bond between Cys 80 in Vκ and Cys 171 in Cκ. They suggest that this may serve to stabilise rabbit antibodies. Meanwhile IGKC1 shows high amino acid divergence between domesticated types and ferals derived from them.[61] This can be as high as 40%.

 

Rabbit hemorrhagic disease (RHD) is caused by strains of rabbit hemorrhagic disease virus (RHDV) including type 2 (RHDV2). RHDV2 was detected for the first time in Washington state, US in May 2022 and then in August once in Washington and twice in Oregon. Since then, it has spread to many states in the US.

 

Ecology

Rabbits are prey animals and are therefore constantly aware of their surroundings. For instance, in Mediterranean Europe, rabbits are the main prey of red foxes, badgers, and Iberian lynxes. If confronted by a potential threat, a rabbit may freeze and observe then warn others in the warren with powerful thumps on the ground. Rabbits have a remarkably wide field of vision, and a good deal of it is devoted to overhead scanning. The doe (mother) is aware that she gives off scent which can attract predators, so she will stay away from the nest to avoid putting the kits (babies) in danger, returning the nest only a few times a day to feed the kits.

 

Rabbits survive predation by burrowing (some species), hopping away in a zig-zag motion, and, if captured, delivering powerful kicks with their hind legs. Their strong teeth allow them to bite to escape a struggle. The longest-lived rabbit on record, a domesticated European rabbit living in Tasmania, died at age 18. The lifespan of wild rabbits is much shorter; the average longevity of an eastern cottontail, for instance, is less than one year.

 

Habitat and range

Rabbit habitats include meadows, woods, forests, grasslands, deserts and wetlands. While some rabbits live solitary lives, others live in groups, and the best known species, the European rabbit, lives in burrows, or rabbit holes. A group of burrows is called a warren.

 

More than half the world's rabbit population resides in North America. They are also native to southwestern Europe, Southeast Asia, Sumatra, some islands of Japan, and in parts of Africa and South America. They are not naturally found in most of Eurasia, where a number of species of hares are present. Rabbits first entered South America relatively recently, as part of the Great American Interchange. Much of the continent has just one species of rabbit, the tapeti, while most of South America's Southern Cone is without rabbits.

 

The European rabbit has been introduced to many places around the world. A recent study found that "the (so-called) Chinese rabbits were introduced from Europe. Genetic diversity in Chinese rabbits was very low."

 

Rabbits have been launched into space orbit.

 

Environmental problems

Rabbits have been a source of environmental problems when introduced into the wild by humans. As a result of their appetites, and the rate at which they breed, feral rabbit depredation can be problematic for agriculture. Gassing (fumigation of warrens), barriers (fences), shooting, snaring, and ferreting have been used to control rabbit populations, but the most effective measures are diseases such as myxomatosis (myxo or mixi, colloquially) and calicivirus. In Europe, where rabbits are farmed on a large scale, they are protected against myxomatosis and calicivirus with a genetically modified virus. The virus was developed in Spain, and is beneficial to rabbit farmers. If it were to make its way into wild populations in areas such as Australia, it could create a population boom, as those diseases are the most serious threats to rabbit survival. Rabbits in Australia and New Zealand are considered to be such a pest that land owners are legally obliged to control them.

 

Rabbits are known to be able to catch fire and spread wildfires, but the efficiency and relevance of this method has been doubted by forest experts who contend that a rabbit on fire could move some meters. Knowledge on fire-spreading rabbits is based on anecdotes as there is no known scientific investigation on the subject.

 

As food and clothingIn some areas, wild rabbits and hares are hunted for their meat, a lean source of high quality protein. In the wild, such hunting is accomplished with the aid of trained falcons, ferrets, or dogs, as well as with snares or other traps, and rifles. A caught rabbit may be dispatched with a sharp blow to the back of its head, a practice from which the term rabbit punch is derived.

 

Wild leporids comprise a small portion of global rabbit-meat consumption. Domesticated descendants of the European rabbit (Oryctolagus cuniculus) that are bred and kept as livestock (a practice called cuniculture) account for the estimated 200 million tons of rabbit meat produced annually. Approximately 1.2 billion rabbits are slaughtered each year for meat worldwide. In 1994, the countries with the highest consumption per capita of rabbit meat were Malta with 8.89 kg (19.6 lb), Italy with 5.71 kg (12.6 lb), and Cyprus with 4.37 kg (9.6 lb), falling to 0.03 kg (0.07 lb) in Japan. The figure for the United States was 0.14 kg (0.31 lb) per capita. The largest producers of rabbit meat in 1994 were China, Russia, Italy, France, and Spain. Rabbit meat was once a common commodity in Sydney, but declined after the myxomatosis virus was intentionally introduced to control the exploding population of feral rabbits in the area.

 

In the United Kingdom, fresh rabbit is sold in butcher shops and markets, and some supermarkets sell frozen rabbit meat. At farmers markets there, including the famous Borough Market in London, rabbit carcasses are sometimes displayed hanging, unbutchered (in the traditional style), next to braces of pheasant or other small game. Rabbit meat is a feature of Moroccan cuisine, where it is cooked in a tajine with "raisins and grilled almonds added a few minutes before serving". In China, rabbit meat is particularly popular in Sichuan cuisine, with its stewed rabbit, spicy diced rabbit, BBQ-style rabbit, and even spicy rabbit heads, which have been compared to spicy duck neck. Rabbit meat is comparatively unpopular elsewhere in the Asia-Pacific.

 

An extremely rare infection associated with rabbits-as-food is tularemia (also known as rabbit fever), which may be contracted from an infected rabbit. Hunters are at higher risk for tularemia because of the potential for inhaling the bacteria during the skinning process.

 

In addition to their meat, rabbits are used for their wool, fur, and pelts, as well as their nitrogen-rich manure and their high-protein milk. Production industries have developed domesticated rabbit breeds (such as the well-known Angora rabbit) to efficiently fill these needs.

  

Behaviors

Binkies in rabbits are characterized by a sudden kick with their hind legs, shaking their head sideways (usually mid-air), and running around rapidly; usually called zooming. Another term is half binky, which is characterized by a shorter span sharp flick of its head, both types of binkies indicate happiness or excitement. All of which typically only last for around a second. A rabbit might do quick rapid multiple binkies in one session. It's thought to be a practice run in case they need to escape from danger Such behavior commonly occurs in domesticated rabbits living in a comfortable environment, e.g. in home.

 

Rabbits mostly use full-body actions, like flopping to communicate emotion to other rabbits and humans. Rabbit displaying flopping in front of other rabbits can be meant as a non-aggressive insult. Rabbits commonly smell the ground first, then tilt their head to the side with a subtle jerky movement in order to lie down to its side, which exposes their belly.

 

They may thump their hind feet on the ground to signal other rabbits that they're feeling threatened or that potential dangers are near their territory. Some domesticated rabbits might thump to get their owner's attention. Not all rabbits thump.

 

Both sexes of rabbits often rub their chin to objects or people with their scent gland located under the chin. This is the rabbit's way of marking their territory or possessions for other rabbits to recognize by depositing scent gland secretions, similar to what cats and dogs do. It might also serve as a reminder for the rabbit to return and investigate the object later, helping them navigate in the dark and to help them in their recollection of where they have been. Rabbits who have bonded will respect each other's smell that indicates territorial border.

 

In art, literature, and culture

Rabbits are often used as a symbol of fertility or rebirth, and have long been associated with spring and Easter as the Easter Bunny. The species' role as a prey animal with few defenses evokes vulnerability and innocence, and in folklore and modern children's stories, rabbits often appear as sympathetic characters, able to connect easily with youth of all kinds (for example, the Velveteen Rabbit, or Thumper in Bambi).

 

With its reputation as a prolific breeder, the rabbit juxtaposes sexuality with innocence, as in the Playboy Bunny. The rabbit (as a swift prey animal) is also known for its speed, agility, and endurance, symbolized (for example) by the marketing icons the Energizer Bunny and the Duracell Bunny.

 

Folklore

Main article: List of fictional hares and rabbits

The rabbit often appears in folklore as the trickster archetype, as he uses his cunning to outwit his enemies.

 

In Aztec mythology, a pantheon of four hundred rabbit gods known as Centzon Totochtin, led by Ometochtli or Two Rabbit, represented fertility, parties, and drunkenness.

In Central Africa, the common hare (Kalulu), is "inevitably described" as a trickster figure.

In Chinese folklore, rabbits accompany Chang'e on the Moon. In the Chinese New Year, the zodiacal rabbit is one of the twelve celestial animals in the Chinese zodiac. Note that the Vietnamese zodiac includes a zodiacal cat in place of the rabbit, possibly because rabbits did not inhabit Vietnam. The most common explanation is that the ancient Vietnamese word for "rabbit" (mao) sounds like the Chinese word for "cat" (卯, mao).

In Japanese tradition, rabbits live on the Moon where they make mochi, the popular snack of mashed sticky rice. This comes from interpreting the pattern of dark patches on the moon as a rabbit standing on tiptoes on the left pounding on an usu, a Japanese mortar.

In Jewish folklore, rabbits (shfanim שפנים) are associated with cowardice, a usage still current in contemporary Israeli spoken Hebrew (similar to the English colloquial use of "chicken" to denote cowardice).

In Korean mythology, as in Japanese, rabbits live on the moon making rice cakes ("Tteok" in Korean).

In Anishinaabe traditional beliefs, held by the Ojibwe and some other Native American peoples, Nanabozho, or Great Rabbit, is an important deity related to the creation of the world.

A Vietnamese mythological story portrays the rabbit of innocence and youthfulness. The gods of the myth are shown to be hunting and killing rabbits to show off their power.

Buddhism, Christianity, and Judaism have associations with an ancient circular motif called the three rabbits (or "three hares"). Its meaning ranges from "peace and tranquility", to purity or the Holy Trinity, to Kabbalistic levels of the soul or to the Jewish diaspora. The tripartite symbol also appears in heraldry and even tattoos.

The rabbit as trickster is a part of American popular culture, as Br'er Rabbit (from African-American folktales and, later, Disney animation) and Bugs Bunny (the cartoon character from Warner Bros.), for example.

 

Anthropomorphized rabbits have appeared in film and literature, in Alice's Adventures in Wonderland (the White Rabbit and the March Hare characters), in Watership Down (including the film and television adaptations), in Rabbit Hill (by Robert Lawson), and in the Peter Rabbit stories (by Beatrix Potter). In the 1920s Oswald the Lucky Rabbit was a popular cartoon character.

 

A rabbit's foot may be carried as an amulet, believed to bring protection and good luck. This belief is found in many parts of the world, with the earliest use being recorded in Europe c. 600 BC.

 

On the Isle of Portland in Dorset, UK, the rabbit is said to be unlucky and even speaking the creature's name can cause upset among older island residents. This is thought to date back to early times in the local quarrying industry where (to save space) extracted stones that were not fit for sale were set aside in what became tall, unstable walls. The local rabbits' tendency to burrow there would weaken the walls and their collapse resulted in injuries or even death. Thus, invoking the name of the culprit became an unlucky act to be avoided. In the local culture to this day, the rabbit (when he has to be referred to) may instead be called a "long ears" or "underground mutton", so as not to risk bringing a downfall upon oneself.

 

In other parts of Britain and in North America, invoking the rabbit's name may instead bring good luck. "Rabbit rabbit rabbit" is one variant of an apotropaic or talismanic superstition that involves saying or repeating the word "rabbit" (or "rabbits" or "white rabbits" or some combination thereof) out loud upon waking on the first day of each month, because doing so will ensure good fortune for the duration of that month.

 

The "rabbit test" is a term, first used in 1949, for the Friedman test, an early diagnostic tool for detecting a pregnancy in humans. It is a common misconception (or perhaps an urban legend) that the test-rabbit would die if the woman was pregnant. This led to the phrase "the rabbit died" becoming a euphemism for a positive pregnancy test.

  

Fish, any of approximately 34,000 species of vertebrate animals (phylum Chordata) found in the fresh and salt waters of the world. Living species range from the primitive jawless lampreys and hagfishes through the cartilaginous sharks, skates, and rays to the abundant and diverse bony fishes. Most fish species are cold-blooded; however, one species, the opah (Lampris guttatus), is warm-blooded.

 

The term fish is applied to a variety of vertebrates of several evolutionary lines. It describes a life-form rather than a taxonomic group. As members of the phylum Chordata, fish share certain features with other vertebrates. These features are gill slits at some point in the life cycle, a notochord, or skeletal supporting rod, a dorsal hollow nerve cord, and a tail. Living fishes represent some five classes, which are as distinct from one another as are the four classes of familiar air-breathing animals—amphibians, reptiles, birds, and mammals. For example, the jawless fishes (Agnatha) have gills in pouches and lack limb girdles. Extant agnathans are the lampreys and the hagfishes. As the name implies, the skeletons of fishes of the class Chondrichthyes (from chondr, “cartilage,” and ichthyes, “fish”) are made entirely of cartilage. Modern fish of this class lack a swim bladder, and their scales and teeth are made up of the same placoid material. Sharks, skates, and rays are examples of cartilaginous fishes. The bony fishes are by far the largest class. Examples range from the tiny seahorse to the 450-kg (1,000-pound) blue marlin, from the flattened soles and flounders to the boxy puffers and ocean sunfishes. Unlike the scales of the cartilaginous fishes, those of bony fishes, when present, grow throughout life and are made up of thin overlapping plates of bone. Bony fishes also have an operculum that covers the gill slits.

 

The study of fishes, the science of ichthyology, is of broad importance. Fishes are of interest to humans for many reasons, the most important being their relationship with and dependence on the environment. A more obvious reason for interest in fishes is their role as a moderate but important part of the world’s food supply. This resource, once thought unlimited, is now realized to be finite and in delicate balance with the biological, chemical, and physical factors of the aquatic environment. Overfishing, pollution, and alteration of the environment are the chief enemies of proper fisheries management, both in fresh waters and in the ocean. (For a detailed discussion of the technology and economics of fisheries, see commercial fishing.) Another practical reason for studying fishes is their use in disease control. As predators on mosquito larvae, they help curb malaria and other mosquito-borne diseases.

 

Fishes are valuable laboratory animals in many aspects of medical and biological research. For example, the readiness of many fishes to acclimate to captivity has allowed biologists to study behaviour, physiology, and even ecology under relatively natural conditions. Fishes have been especially important in the study of animal behaviour, where research on fishes has provided a broad base for the understanding of the more flexible behaviour of the higher vertebrates. The zebra fish is used as a model in studies of gene expression.

 

There are aesthetic and recreational reasons for an interest in fishes. Millions of people keep live fishes in home aquariums for the simple pleasure of observing the beauty and behaviour of animals otherwise unfamiliar to them. Aquarium fishes provide a personal challenge to many aquarists, allowing them to test their ability to keep a small section of the natural environment in their homes. Sportfishing is another way of enjoying the natural environment, also indulged in by millions of people every year. Interest in aquarium fishes and sportfishing supports multimillion-dollar industries throughout the world.

 

Fishes have been in existence for more than 450 million years, during which time they have evolved repeatedly to fit into almost every conceivable type of aquatic habitat. In a sense, land vertebrates are simply highly modified fishes: when fishes colonized the land habitat, they became tetrapod (four-legged) land vertebrates. The popular conception of a fish as a slippery, streamlined aquatic animal that possesses fins and breathes by gills applies to many fishes, but far more fishes deviate from that conception than conform to it. For example, the body is elongate in many forms and greatly shortened in others; the body is flattened in some (principally in bottom-dwelling fishes) and laterally compressed in many others; the fins may be elaborately extended, forming intricate shapes, or they may be reduced or even lost; and the positions of the mouth, eyes, nostrils, and gill openings vary widely. Air breathers have appeared in several evolutionary lines.

 

Many fishes are cryptically coloured and shaped, closely matching their respective environments; others are among the most brilliantly coloured of all organisms, with a wide range of hues, often of striking intensity, on a single individual. The brilliance of pigments may be enhanced by the surface structure of the fish, so that it almost seems to glow. A number of unrelated fishes have actual light-producing organs. Many fishes are able to alter their coloration—some for the purpose of camouflage, others for the enhancement of behavioral signals.

 

Fishes range in adult length from less than 10 mm (0.4 inch) to more than 20 metres (60 feet) and in weight from about 1.5 grams (less than 0.06 ounce) to many thousands of kilograms. Some live in shallow thermal springs at temperatures slightly above 42 °C (100 °F), others in cold Arctic seas a few degrees below 0 °C (32 °F) or in cold deep waters more than 4,000 metres (13,100 feet) beneath the ocean surface. The structural and, especially, the physiological adaptations for life at such extremes are relatively poorly known and provide the scientifically curious with great incentive for study.

 

Almost all natural bodies of water bear fish life, the exceptions being very hot thermal ponds and extremely salt-alkaline lakes, such as the Dead Sea in Asia and the Great Salt Lake in North America. The present distribution of fishes is a result of the geological history and development of Earth as well as the ability of fishes to undergo evolutionary change and to adapt to the available habitats. Fishes may be seen to be distributed according to habitat and according to geographical area. Major habitat differences are marine and freshwater. For the most part, the fishes in a marine habitat differ from those in a freshwater habitat, even in adjacent areas, but some, such as the salmon, migrate from one to the other. The freshwater habitats may be seen to be of many kinds. Fishes found in mountain torrents, Arctic lakes, tropical lakes, temperate streams, and tropical rivers will all differ from each other, both in obvious gross structure and in physiological attributes. Even in closely adjacent habitats where, for example, a tropical mountain torrent enters a lowland stream, the fish fauna will differ. The marine habitats can be divided into deep ocean floors (benthic), mid-water oceanic (bathypelagic), surface oceanic (pelagic), rocky coast, sandy coast, muddy shores, bays, estuaries, and others. Also, for example, rocky coastal shores in tropical and temperate regions will have different fish faunas, even when such habitats occur along the same coastline.

 

Although much is known about the present geographical distribution of fishes, far less is known about how that distribution came about. Many parts of the fish fauna of the fresh waters of North America and Eurasia are related and undoubtedly have a common origin. The faunas of Africa and South America are related, extremely old, and probably an expression of the drifting apart of the two continents. The fauna of southern Asia is related to that of Central Asia, and some of it appears to have entered Africa. The extremely large shore-fish faunas of the Indian and tropical Pacific oceans comprise a related complex, but the tropical shore fauna of the Atlantic, although containing Indo-Pacific components, is relatively limited and probably younger. The Arctic and Antarctic marine faunas are quite different from each other. The shore fauna of the North Pacific is quite distinct, and that of the North Atlantic more limited and probably younger. Pelagic oceanic fishes, especially those in deep waters, are similar the world over, showing little geographical isolation in terms of family groups. The deep oceanic habitat is very much the same throughout the world, but species differences do exist, showing geographical areas determined by oceanic currents and water masses.

 

All aspects of the life of a fish are closely correlated with adaptation to the total environment, physical, chemical, and biological. In studies, all the interdependent aspects of fish, such as behaviour, locomotion, reproduction, and physical and physiological characteristics, must be taken into account.

 

Correlated with their adaptation to an extremely wide variety of habitats is the extremely wide variety of life cycles that fishes display. The great majority hatch from relatively small eggs a few days to several weeks or more after the eggs are scattered in the water. Newly hatched young are still partially undeveloped and are called larvae until body structures such as fins, skeleton, and some organs are fully formed. Larval life is often very short, usually less than a few weeks, but it can be very long, some lampreys continuing as larvae for at least five years. Young and larval fishes, before reaching sexual maturity, must grow considerably, and their small size and other factors often dictate that they live in a habitat different than that of the adults. For example, most tropical marine shore fishes have pelagic larvae. Larval food also is different, and larval fishes often live in shallow waters, where they may be less exposed to predators.

 

After a fish reaches adult size, the length of its life is subject to many factors, such as innate rates of aging, predation pressure, and the nature of the local climate. The longevity of a species in the protected environment of an aquarium may have nothing to do with how long members of that species live in the wild. Many small fishes live only one to three years at the most. In some species, however, individuals may live as long as 10 or 20 or even 100 years.

 

Fish behaviour is a complicated and varied subject. As in almost all animals with a central nervous system, the nature of a response of an individual fish to stimuli from its environment depends upon the inherited characteristics of its nervous system, on what it has learned from past experience, and on the nature of the stimuli. Compared with the variety of human responses, however, that of a fish is stereotyped, not subject to much modification by “thought” or learning, and investigators must guard against anthropomorphic interpretations of fish behaviour.

 

Fishes perceive the world around them by the usual senses of sight, smell, hearing, touch, and taste and by special lateral line water-current detectors. In the few fishes that generate electric fields, a process that might best be called electrolocation aids in perception. One or another of these senses often is emphasized at the expense of others, depending upon the fish’s other adaptations. In fishes with large eyes, the sense of smell may be reduced; others, with small eyes, hunt and feed primarily by smell (such as some eels).

 

Specialized behaviour is primarily concerned with the three most important activities in the fish’s life: feeding, reproduction, and escape from enemies. Schooling behaviour of sardines on the high seas, for instance, is largely a protective device to avoid enemies, but it is also associated with and modified by their breeding and feeding requirements. Predatory fishes are often solitary, lying in wait to dart suddenly after their prey, a kind of locomotion impossible for beaked parrot fishes, which feed on coral, swimming in small groups from one coral head to the next. In addition, some predatory fishes that inhabit pelagic environments, such as tunas, often school.

 

Sleep in fishes, all of which lack true eyelids, consists of a seemingly listless state in which the fish maintains its balance but moves slowly. If attacked or disturbed, most can dart away. A few kinds of fishes lie on the bottom to sleep. Most catfishes, some loaches, and some eels and electric fishes are strictly nocturnal, being active and hunting for food during the night and retiring during the day to holes, thick vegetation, or other protective parts of the environment.

 

Communication between members of a species or between members of two or more species often is extremely important, especially in breeding behaviour (see below Reproduction). The mode of communication may be visual, as between the small so-called cleaner fish and a large fish of a very different species. The larger fish often allows the cleaner to enter its mouth to remove gill parasites. The cleaner is recognized by its distinctive colour and actions and therefore is not eaten, even if the larger fish is normally a predator. Communication is often chemical, signals being sent by specific chemicals called pheromones.

 

Many fishes have a streamlined body and swim freely in open water. Fish locomotion is closely correlated with habitat and ecological niche (the general position of the animal to its environment).

 

Many fishes in both marine and fresh waters swim at the surface and have mouths adapted to feed best (and sometimes only) at the surface. Often such fishes are long and slender, able to dart at surface insects or at other surface fishes and in turn to dart away from predators; needlefishes, halfbeaks, and topminnows (such as killifish and mosquito fish) are good examples. Oceanic flying fishes escape their predators by gathering speed above the water surface, with the lower lobe of the tail providing thrust in the water. They then glide hundreds of yards on enlarged, winglike pectoral and pelvic fins. South American freshwater flying fishes escape their enemies by jumping and propelling their strongly keeled bodies out of the water.

 

So-called mid-water swimmers, the most common type of fish, are of many kinds and live in many habitats. The powerful fusiform tunas and the trouts, for example, are adapted for strong, fast swimming, the tunas to capture prey speedily in the open ocean and the trouts to cope with the swift currents of streams and rivers. The trout body form is well adapted to many habitats. Fishes that live in relatively quiet waters such as bays or lake shores or slow rivers usually are not strong, fast swimmers but are capable of short, quick bursts of speed to escape a predator. Many of these fishes have their sides flattened, examples being the sunfish and the freshwater angelfish of aquarists. Fish associated with the bottom or substrate usually are slow swimmers. Open-water plankton-feeding fishes almost always remain fusiform and are capable of rapid, strong movement (for example, sardines and herrings of the open ocean and also many small minnows of streams and lakes).

 

Bottom-living fishes are of many kinds and have undergone many types of modification of their body shape and swimming habits. Rays, which evolved from strong-swimming mid-water sharks, usually stay close to the bottom and move by undulating their large pectoral fins. Flounders live in a similar habitat and move over the bottom by undulating the entire body. Many bottom fishes dart from place to place, resting on the bottom between movements, a motion common in gobies. One goby relative, the mudskipper, has taken to living at the edge of pools along the shore of muddy mangrove swamps. It escapes its enemies by flipping rapidly over the mud, out of the water. Some catfishes, synbranchid eels, the so-called climbing perch, and a few other fishes venture out over damp ground to find more promising waters than those that they left. They move by wriggling their bodies, sometimes using strong pectoral fins; most have accessory air-breathing organs. Many bottom-dwelling fishes live in mud holes or rocky crevices. Marine eels and gobies commonly are found in such habitats and for the most part venture far beyond their cavelike homes. Some bottom dwellers, such as the clingfishes (Gobiesocidae), have developed powerful adhesive disks that enable them to remain in place on the substrate in areas such as rocky coasts, where the action of the waves is great.

 

The methods of reproduction in fishes are varied, but most fishes lay a large number of small eggs, fertilized and scattered outside of the body. The eggs of pelagic fishes usually remain suspended in the open water. Many shore and freshwater fishes lay eggs on the bottom or among plants. Some have adhesive eggs. The mortality of the young and especially of the eggs is very high, and often only a few individuals grow to maturity out of hundreds, thousands, and in some cases millions of eggs laid.

 

Males produce sperm, usually as a milky white substance called milt, in two (sometimes one) testes within the body cavity. In bony fishes a sperm duct leads from each testis to a urogenital opening behind the vent or anus. In sharks and rays and in cyclostomes the duct leads to a cloaca. Sometimes the pelvic fins are modified to help transmit the milt to the eggs at the female’s vent or on the substrate where the female has placed them. Sometimes accessory organs are used to fertilize females internally—for example, the claspers of many sharks and rays.

 

In the females the eggs are formed in two ovaries (sometimes only one) and pass through the ovaries to the urogenital opening and to the outside. In some fishes the eggs are fertilized internally but are shed before development takes place. Members of about a dozen families each of bony fishes (teleosts) and sharks bear live young. Many skates and rays also bear live young. In some bony fishes the eggs simply develop within the female, the young emerging when the eggs hatch (ovoviviparous). Others develop within the ovary and are nourished by ovarian tissues after hatching (viviparous). There are also other methods utilized by fishes to nourish young within the female. In all live-bearers the young are born at a relatively large size and are few in number. In one family of primarily marine fishes, the surfperches from the Pacific coast of North America, Japan, and Korea, the males of at least one species are born sexually mature, although they are not fully grown.

 

Some fishes are hermaphroditic—an individual producing both sperm and eggs, usually at different stages of its life. Self-fertilization, however, is probably rare.

 

Successful reproduction and, in many cases, defense of the eggs and the young are assured by rather stereotypical but often elaborate courtship and parental behaviour, either by the male or the female or both. Some fishes prepare nests by hollowing out depressions in the sand bottom (cichlids, for example), build nests with plant materials and sticky threads excreted by the kidneys (sticklebacks), or blow a cluster of mucus-covered bubbles at the water surface (gouramis). The eggs are laid in these structures. Some varieties of cichlids and catfishes incubate eggs in their mouths.

 

Some fishes, such as salmon, undergo long migrations from the ocean and up large rivers to spawn in the gravel beds where they themselves hatched (anadromous fishes). Some, such as the freshwater eels (family Anguillidae), live and grow to maturity in fresh water and migrate to the sea to spawn (catadromous fishes). Other fishes undertake shorter migrations from lakes into streams, within the ocean, or enter spawning habitats that they do not ordinarily occupy in other ways.

 

The basic structure and function of the fish body are similar to those of all other vertebrates. The usual four types of tissues are present: surface or epithelial, connective (bone, cartilage, and fibrous tissues, as well as their derivative, blood), nerve, and muscle tissues. In addition, the fish’s organs and organ systems parallel those of other vertebrates.

 

The typical fish body is streamlined and spindle-shaped, with an anterior head, a gill apparatus, and a heart, the latter lying in the midline just below the gill chamber. The body cavity, containing the vital organs, is situated behind the head in the lower anterior part of the body. The anus usually marks the posterior termination of the body cavity and most often occurs just in front of the base of the anal fin. The spinal cord and vertebral column continue from the posterior part of the head to the base of the tail fin, passing dorsal to the body cavity and through the caudal (tail) region behind the body cavity. Most of the body is of muscular tissue, a high proportion of which is necessitated by swimming. In the course of evolution this basic body plan has been modified repeatedly into the many varieties of fish shapes that exist today.

 

The skeleton forms an integral part of the fish’s locomotion system, as well as serving to protect vital parts. The internal skeleton consists of the skull bones (except for the roofing bones of the head, which are really part of the external skeleton), the vertebral column, and the fin supports (fin rays). The fin supports are derived from the external skeleton but will be treated here because of their close functional relationship to the internal skeleton. The internal skeleton of cyclostomes, sharks, and rays is of cartilage; that of many fossil groups and some primitive living fishes is mostly of cartilage but may include some bone. In place of the vertebral column, the earliest vertebrates had a fully developed notochord, a flexible stiff rod of viscous cells surrounded by a strong fibrous sheath. During the evolution of modern fishes the rod was replaced in part by cartilage and then by ossified cartilage. Sharks and rays retain a cartilaginous vertebral column; bony fishes have spool-shaped vertebrae that in the more primitive living forms only partially replace the notochord. The skull, including the gill arches and jaws of bony fishes, is fully, or at least partially, ossified. That of sharks and rays remains cartilaginous, at times partially replaced by calcium deposits but never by true bone.

 

The supportive elements of the fins (basal or radial bones or both) have changed greatly during fish evolution. Some of these changes are described in the section below (Evolution and paleontology). Most fishes possess a single dorsal fin on the midline of the back. Many have two and a few have three dorsal fins. The other fins are the single tail and anal fins and paired pelvic and pectoral fins. A small fin, the adipose fin, with hairlike fin rays, occurs in many of the relatively primitive teleosts (such as trout) on the back near the base of the caudal fin.

 

The skin of a fish must serve many functions. It aids in maintaining the osmotic balance, provides physical protection for the body, is the site of coloration, contains sensory receptors, and, in some fishes, functions in respiration. Mucous glands, which aid in maintaining the water balance and offer protection from bacteria, are extremely numerous in fish skin, especially in cyclostomes and teleosts. Since mucous glands are present in the modern lampreys, it is reasonable to assume that they were present in primitive fishes, such as the ancient Silurian and Devonian agnathans. Protection from abrasion and predation is another function of the fish skin, and dermal (skin) bone arose early in fish evolution in response to this need. It is thought that bone first evolved in skin and only later invaded the cartilaginous areas of the fish’s body, to provide additional support and protection. There is some argument as to which came first, cartilage or bone, and fossil evidence does not settle the question. In any event, dermal bone has played an important part in fish evolution and has different characteristics in different groups of fishes. Several groups are characterized at least in part by the kind of bony scales they possess.

 

Scales have played an important part in the evolution of fishes. Primitive fishes usually had thick bony plates or thick scales in several layers of bone, enamel, and related substances. Modern teleost fishes have scales of bone, which, while still protective, allow much more freedom of motion in the body. A few modern teleosts (some catfishes, sticklebacks, and others) have secondarily acquired bony plates in the skin. Modern and early sharks possessed placoid scales, a relatively primitive type of scale with a toothlike structure, consisting of an outside layer of enamel-like substance (vitrodentine), an inner layer of dentine, and a pulp cavity containing nerves and blood vessels. Primitive bony fishes had thick scales of either the ganoid or the cosmoid type. Cosmoid scales have a hard, enamel-like outer layer, an inner layer of cosmine (a form of dentine), and then a layer of vascular bone (isopedine). In ganoid scales the hard outer layer is different chemically and is called ganoin. Under this is a cosminelike layer and then a vascular bony layer. The thin, translucent bony scales of modern fishes, called cycloid and ctenoid (the latter distinguished by serrations at the edges), lack enameloid and dentine layers.

 

Skin has several other functions in fishes. It is well supplied with nerve endings and presumably receives tactile, thermal, and pain stimuli. Skin is also well supplied with blood vessels. Some fishes breathe in part through the skin, by the exchange of oxygen and carbon dioxide between the surrounding water and numerous small blood vessels near the skin surface.

 

Skin serves as protection through the control of coloration. Fishes exhibit an almost limitless range of colours. The colours often blend closely with the surroundings, effectively hiding the animal. Many fishes use bright colours for territorial advertisement or as recognition marks for other members of their own species, or sometimes for members of other species. Many fishes can change their colour to a greater or lesser degree, by movement of pigment within the pigment cells (chromatophores). Black pigment cells (melanophores), of almost universal occurrence in fishes, are often juxtaposed with other pigment cells. When placed beneath iridocytes or leucophores (bearing the silvery or white pigment guanine), melanophores produce structural colours of blue and green. These colours are often extremely intense, because they are formed by refraction of light through the needlelike crystals of guanine. The blue and green refracted colours are often relatively pure, lacking the red and yellow rays, which have been absorbed by the black pigment (melanin) of the melanophores. Yellow, orange, and red colours are produced by erythrophores, cells containing the appropriate carotenoid pigments. Other colours are produced by combinations of melanophores, erythrophores, and iridocytes.

 

The major portion of the body of most fishes consists of muscles. Most of the mass is trunk musculature, the fin muscles usually being relatively small. The caudal fin is usually the most powerful fin, being moved by the trunk musculature. The body musculature is usually arranged in rows of chevron-shaped segments on each side. Contractions of these segments, each attached to adjacent vertebrae and vertebral processes, bends the body on the vertebral joint, producing successive undulations of the body, passing from the head to the tail, and producing driving strokes of the tail. It is the latter that provides the strong forward movement for most fishes.

 

The digestive system, in a functional sense, starts at the mouth, with the teeth used to capture prey or collect plant foods. Mouth shape and tooth structure vary greatly in fishes, depending on the kind of food normally eaten. Most fishes are predacious, feeding on small invertebrates or other fishes and have simple conical teeth on the jaws, on at least some of the bones of the roof of the mouth, and on special gill arch structures just in front of the esophagus. The latter are throat teeth. Most predacious fishes swallow their prey whole, and the teeth are used for grasping and holding prey, for orienting prey to be swallowed (head first) and for working the prey toward the esophagus. There are a variety of tooth types in fishes. Some fishes, such as sharks and piranhas, have cutting teeth for biting chunks out of their victims. A shark’s tooth, although superficially like that of a piranha, appears in many respects to be a modified scale, while that of the piranha is like that of other bony fishes, consisting of dentine and enamel. Parrot fishes have beaklike mouths with short incisor-like teeth for breaking off coral and have heavy pavementlike throat teeth for crushing the coral. Some catfishes have small brushlike teeth, arranged in rows on the jaws, for scraping plant and animal growth from rocks. Many fishes (such as the Cyprinidae or minnows) have no jaw teeth at all but have very strong throat teeth.

 

Some fishes gather planktonic food by straining it from their gill cavities with numerous elongate stiff rods (gill rakers) anchored by one end to the gill bars. The food collected on these rods is passed to the throat, where it is swallowed. Most fishes have only short gill rakers that help keep food particles from escaping out the mouth cavity into the gill chamber.

 

Once reaching the throat, food enters a short, often greatly distensible esophagus, a simple tube with a muscular wall leading into a stomach. The stomach varies greatly in fishes, depending upon the diet. In most predacious fishes it is a simple straight or curved tube or pouch with a muscular wall and a glandular lining. Food is largely digested there and leaves the stomach in liquid form.

 

Between the stomach and the intestine, ducts enter the digestive tube from the liver and pancreas. The liver is a large, clearly defined organ. The pancreas may be embedded in it, diffused through it, or broken into small parts spread along some of the intestine. The junction between the stomach and the intestine is marked by a muscular valve. Pyloric ceca (blind sacs) occur in some fishes at this junction and have a digestive or absorptive function or both.

 

The intestine itself is quite variable in length, depending upon the fish’s diet. It is short in predacious forms, sometimes no longer than the body cavity, but long in herbivorous forms, being coiled and several times longer than the entire length of the fish in some species of South American catfishes. The intestine is primarily an organ for absorbing nutrients into the bloodstream. The larger its internal surface, the greater its absorptive efficiency, and a spiral valve is one method of increasing its absorption surface.

 

Sharks, rays, chimaeras, lungfishes, surviving chondrosteans, holosteans, and even a few of the more primitive teleosts have a spiral valve or at least traces of it in the intestine. Most modern teleosts have increased the area of the intestinal walls by having numerous folds and villi (fingerlike projections) somewhat like those in humans. Undigested substances are passed to the exterior through the anus in most teleost fishes. In lungfishes, sharks, and rays, it is first passed through the cloaca, a common cavity receiving the intestinal opening and the ducts from the urogenital system.

 

Oxygen and carbon dioxide dissolve in water, and most fishes exchange dissolved oxygen and carbon dioxide in water by means of the gills. The gills lie behind and to the side of the mouth cavity and consist of fleshy filaments supported by the gill arches and filled with blood vessels, which give gills a bright red colour. Water taken in continuously through the mouth passes backward between the gill bars and over the gill filaments, where the exchange of gases takes place. The gills are protected by a gill cover in teleosts and many other fishes but by flaps of skin in sharks, rays, and some of the older fossil fish groups. The blood capillaries in the gill filaments are close to the gill surface to take up oxygen from the water and to give up excess carbon dioxide to the water.

 

Most modern fishes have a hydrostatic (ballast) organ, called the swim bladder, that lies in the body cavity just below the kidney and above the stomach and intestine. It originated as a diverticulum of the digestive canal. In advanced teleosts, especially the acanthopterygians, the bladder has lost its connection with the digestive tract, a condition called physoclistic. The connection has been retained (physostomous) by many relatively primitive teleosts. In several unrelated lines of fishes, the bladder has become specialized as a lung or, at least, as a highly vascularized accessory breathing organ. Some fishes with such accessory organs are obligate air breathers and will drown if denied access to the surface, even in well-oxygenated water. Fishes with a hydrostatic form of swim bladder can control their depth by regulating the amount of gas in the bladder. The gas, mostly oxygen, is secreted into the bladder by special glands, rendering the fish more buoyant; the gas is absorbed into the bloodstream by another special organ, reducing the overall buoyancy and allowing the fish to sink. Some deep-sea fishes may have oils, rather than gas, in the bladder. Other deep-sea and some bottom-living forms have much-reduced swim bladders or have lost the organ entirely.

 

The swim bladder of fishes follows the same developmental pattern as the lungs of land vertebrates. There is no doubt that the two structures have the same historical origin in primitive fishes. More or less intermediate forms still survive among the more primitive types of fishes, such as the lungfishes Lepidosiren and Protopterus.

 

The circulatory, or blood vascular, system consists of the heart, the arteries, the capillaries, and the veins. It is in the capillaries that the interchange of oxygen, carbon dioxide, nutrients, and other substances such as hormones and waste products takes place. The capillaries lead to the veins, which return the venous blood with its waste products to the heart, kidneys, and gills. There are two kinds of capillary beds: those in the gills and those in the rest of the body. The heart, a folded continuous muscular tube with three or four saclike enlargements, undergoes rhythmic contractions and receives venous blood in a sinus venosus. It passes the blood to an auricle and then into a thick muscular pump, the ventricle. From the ventricle the blood goes to a bulbous structure at the base of a ventral aorta just below the gills. The blood passes to the afferent (receiving) arteries of the gill arches and then to the gill capillaries. There waste gases are given off to the environment, and oxygen is absorbed. The oxygenated blood enters efferent (exuant) arteries of the gill arches and then flows into the dorsal aorta. From there blood is distributed to the tissues and organs of the body. One-way valves prevent backflow. The circulation of fishes thus differs from that of the reptiles, birds, and mammals in that oxygenated blood is not returned to the heart prior to distribution to the other parts of the body.

 

The primary excretory organ in fishes, as in other vertebrates, is the kidney. In fishes some excretion also takes place in the digestive tract, skin, and especially the gills (where ammonia is given off). Compared with land vertebrates, fishes have a special problem in maintaining their internal environment at a constant concentration of water and dissolved substances, such as salts. Proper balance of the internal environment (homeostasis) of a fish is in a great part maintained by the excretory system, especially the kidney.

 

The kidney, gills, and skin play an important role in maintaining a fish’s internal environment and checking the effects of osmosis. Marine fishes live in an environment in which the water around them has a greater concentration of salts than they can have inside their body and still maintain life. Freshwater fishes, on the other hand, live in water with a much lower concentration of salts than they require inside their bodies. Osmosis tends to promote the loss of water from the body of a marine fish and absorption of water by that of a freshwater fish. Mucus in the skin tends to slow the process but is not a sufficient barrier to prevent the movement of fluids through the permeable skin. When solutions on two sides of a permeable membrane have different concentrations of dissolved substances, water will pass through the membrane into the more concentrated solution, while the dissolved chemicals move into the area of lower concentration (diffusion).

 

The kidney of freshwater fishes is often larger in relation to body weight than that of marine fishes. In both groups the kidney excretes wastes from the body, but the kidney of freshwater fishes also excretes large amounts of water, counteracting the water absorbed through the skin. Freshwater fishes tend to lose salt to the environment and must replace it. They get some salt from their food, but the gills and skin inside the mouth actively absorb salt from water passed through the mouth. This absorption is performed by special cells capable of moving salts against the diffusion gradient. Freshwater fishes drink very little water and take in little water with their food.

 

Marine fishes must conserve water, and therefore their kidneys excrete little water. To maintain their water balance, marine fishes drink large quantities of seawater, retaining most of the water and excreting the salt. Most nitrogenous waste in marine fishes appears to be secreted by the gills as ammonia. Marine fishes can excrete salt by clusters of special cells (chloride cells) in the gills.

 

There are several teleosts—for example, the salmon—that travel between fresh water and seawater and must adjust to the reversal of osmotic gradients. They adjust their physiological processes by spending time (often surprisingly little time) in the intermediate brackish environment.

 

Marine hagfishes, sharks, and rays have osmotic concentrations in their blood about equal to that of seawater and so do not have to drink water nor perform much physiological work to maintain their osmotic balance. In sharks and rays the osmotic concentration is kept high by retention of urea in the blood. Freshwater sharks have a lowered concentration of urea in the blood.

 

Endocrine glands secrete their products into the bloodstream and body tissues and, along with the central nervous system, control and regulate many kinds of body functions. Cyclostomes have a well-developed endocrine system, and presumably it was well developed in the early Agnatha, ancestral to modern fishes. Although the endocrine system in fishes is similar to that of higher vertebrates, there are numerous differences in detail. The pituitary, the thyroid, the suprarenals, the adrenals, the pancreatic islets, the sex glands (ovaries and testes), the inner wall of the intestine, and the bodies of the ultimobranchial gland make up the endocrine system in fishes. There are some others whose function is not well understood. These organs regulate sexual activity and reproduction, growth, osmotic pressure, general metabolic activities such as the storage of fat and the utilization of foodstuffs, blood pressure, and certain aspects of skin colour. Many of these activities are also controlled in part by the central nervous system, which works with the endocrine system in maintaining the life of a fish. Some parts of the endocrine system are developmentally, and undoubtedly evolutionarily, derived from the nervous system.

 

As in all vertebrates, the nervous system of fishes is the primary mechanism coordinating body activities, as well as integrating these activities in the appropriate manner with stimuli from the environment. The central nervous system, consisting of the brain and spinal cord, is the primary integrating mechanism. The peripheral nervous system, consisting of nerves that connect the brain and spinal cord to various body organs, carries sensory information from special receptor organs such as the eyes, internal ears, nares (sense of smell), taste glands, and others to the integrating centres of the brain and spinal cord. The peripheral nervous system also carries information via different nerve cells from the integrating centres of the brain and spinal cord. This coded information is carried to the various organs and body systems, such as the skeletal muscular system, for appropriate action in response to the original external or internal stimulus. Another branch of the nervous system, the autonomic nervous system, helps to coordinate the activities of many glands and organs and is itself closely connected to the integrating centres of the brain.

 

The brain of the fish is divided into several anatomical and functional parts, all closely interconnected but each serving as the primary centre of integrating particular kinds of responses and activities. Several of these centres or parts are primarily associated with one type of sensory perception, such as sight, hearing, or smell (olfaction).

 

The sense of smell is important in almost all fishes. Certain eels with tiny eyes depend mostly on smell for location of food. The olfactory, or nasal, organ of fishes is located on the dorsal surface of the snout. The lining of the nasal organ has special sensory cells that perceive chemicals dissolved in the water, such as substances from food material, and send sensory information to the brain by way of the first cranial nerve. Odour also serves as an alarm system. Many fishes, especially various species of freshwater minnows, react with alarm to a chemical released from the skin of an injured member of their own species.

 

Many fishes have a well-developed sense of taste, and tiny pitlike taste buds or organs are located not only within their mouth cavities but also over their heads and parts of their body. Catfishes, which often have poor vision, have barbels (“whiskers”) that serve as supplementary taste organs, those around the mouth being actively used to search out food on the bottom. Some species of naturally blind cave fishes are especially well supplied with taste buds, which often cover most of their body surface.

 

Sight is extremely important in most fishes. The eye of a fish is basically like that of all other vertebrates, but the eyes of fishes are extremely varied in structure and adaptation. In general, fishes living in dark and dim water habitats have large eyes, unless they have specialized in some compensatory way so that another sense (such as smell) is dominant, in which case the eyes will often be reduced. Fishes living in brightly lighted shallow waters often will have relatively small but efficient eyes. Cyclostomes have somewhat less elaborate eyes than other fishes, with skin stretched over the eyeball perhaps making their vision somewhat less effective. Most fishes have a spherical lens and accommodate their vision to far or near subjects by moving the lens within the eyeball. A few sharks accommodate by changing the shape of the lens, as in land vertebrates. Those fishes that are heavily dependent upon the eyes have especially strong muscles for accommodation. Most fishes see well, despite the restrictions imposed by frequent turbidity of the water and by light refraction.

 

Fossil evidence suggests that colour vision evolved in fishes more than 300 million years ago, but not all living fishes have retained this ability. Experimental evidence indicates that many shallow-water fishes, if not all, have colour vision and see some colours especially well, but some bottom-dwelling shore fishes live in areas where the water is sufficiently deep to filter out most if not all colours, and these fishes apparently never see colours. When tested in shallow water, they apparently are unable to respond to colour differences.

 

Sound perception and balance are intimately associated senses in a fish. The organs of hearing are entirely internal, located within the skull, on each side of the brain and somewhat behind the eyes. Sound waves, especially those of low frequencies, travel readily through water and impinge directly upon the bones and fluids of the head and body, to be transmitted to the hearing organs. Fishes readily respond to sound; for example, a trout conditioned to escape by the approach of fishermen will take flight upon perceiving footsteps on a stream bank even if it cannot see a fisherman. Compared with humans, however, the range of sound frequencies heard by fishes is greatly restricted. Many fishes communicate with each other by producing sounds in their swim bladders, in their throats by rasping their teeth, and in other ways.

 

A fish or other vertebrate seldom has to rely on a single type of sensory information to determine the nature of the environment around it. A catfish uses taste and touch when examining a food object with its oral barbels. Like most other animals, fishes have many touch receptors over their body surface. Pain and temperature receptors also are present in fishes and presumably produce the same kind of information to a fish as to humans. Fishes react in a negative fashion to stimuli that would be painful to human beings, suggesting that they feel a sensation of pain.

 

An important sensory system in fishes that is absent in other vertebrates (except some amphibians) is the lateral line system. This consists of a series of heavily innervated small canals located in the skin and bone around the eyes, along the lower jaw, over the head, and down the mid-side of the body, where it is associated with the scales. Intermittently along these canals are located tiny sensory organs (pit organs) that apparently detect changes in pressure. The system allows a fish to sense changes in water currents and pressure, thereby helping the fish to orient itself to the various changes that occur in the physical environment.

  

 

 

 

 

 

 

 

Marino Marini,

Nudo,

terracotta, 1927-1930.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The Vatican Gardens (Italian: Giardini Vaticani) in Vatican City are urban gardens and parks which cover more than half of the Vatican territory in the South and Northeast. There are some buildings such as Radio Vatican within the gardens.

The gardens cover approximately 20 hectares (49 acres) which is most of the Vatican Hill. The highest point is 60 metres (200 ft) above mean sea level. Stone walls bound the area in the North, South and West.

The gardens and parks were established during the Renaissance and Baroque era and are decorated with fountains and sculptures. There are several springs under the earth which as of 2009 are not in use. There is a wide variety of flora, and the area is considered a biotope.

Tradition says that the site of the Vatican Gardens was spread with earth brought from Golgotha by Saint Helena to symbolically unite the blood of Christ with that shed by thousands of early Christians, who died in the persecutions of Nero.The gardens date back to medieval times when orchards and vineyards extended to the north of the Papal Apostolic Palace. In 1279 Pope Nicholas III (Giovanni Gaetano Orsini, 1277-1280) moved his residence back to the Vatican from the Lateran Palace and enclosed this area with walls.He planted an orchard (pomerium), a lawn (pratellum) and a garden (viridarium).The site received a major re-landscaping at the beginning of the 16th century,during the papacy of Julius II.[6] Donato Bramante's original design was then split into three new courtyards,[6] the Cortili del Belvedere, the “della Biblioteca” and the “della Pigna” (or Pine Cone) in the Renaissance landscape design style. Also in Renaissance style, a great rectangular Labyrinth, formal in design, set in boxwood and framed with Italian stone pines, (Pinus pinea) and cedars of Lebanon, (Cedrus libani).In place of Nicholas III's enclosure, Bramante built a great rectilinear defensive wall.

Today's Vatican Gardens are spread over nearly 23 hectares, they contain a variety of medieval fortifications, buildings and monuments from the ninth century to the present day, set amongst vibrant flower beds and topiary, green lawns and a 3 hectare patch of forest. A variety of fountains spread a veil of freshness over the gardens while sculpture and artificial grottoes proclaim devotion to the Madonna, and an olive tree donated by the government of Israel extends its three verdant branches.

 

I Giardini Vaticani occupano circa due terzi della superficie della Città del Vaticano e si estendono da sud a nord-ovest del piccolo Stato. I Musei Vaticani li separano dalla zona nord dove risiedono la banche, il giornale e i Palazzi Apostolici dove abita il Pontefice.

I giardini sono il luogo di riposo e di meditazione del Romano Pontefice sin dal 1279, quando papa Niccolò III (Giovanni Gaetano Orsini, 1277-1280) riportò la residenza papale dal Laterano al Vaticano. All'interno delle nuove mura, che fece erigere a difesa della sua residenza, il Papa fece impiantare un frutteto (pomerium), un prato (pratellum) e un vero e proprio giardino (viridarium); Questo primo nucleo sorse nei pressi del colle di Sant'Egidio, dove oggi si trova il Palazzetto del Belvedere ed i Cortili dei Musei Vaticani.

Il periodo di maggiore sviluppo architettonico dei Giardini è comunque tra il Cinquecento e il Seicento, quando vi lavorano artisti e architetti come Donato Bramante e Pirro Ligorio (sua è la Casina di Pio IV), oltre a pittori e incisori che ritraggono la bellezza del luogo, tra i quali Antonio Tempesta, Giovanni Magari e Giambattista Falda. La cultura, l’arte e la filosofia rinascimentale influenzano i giardini non solo attraverso l’architettura stessa, ma anche con la costruzione di bellissime fontane, statue e tempietti.

Grandi sono le testimonianze storico-artistiche rinvenibili nei giardini: dagli stessi giardini sono ancora visibili, ad esempio, le antiche Mura Leonine in due tratti: quello più antico vicino alla Palazzina della Zecca, in prossimità della Fontana del Sacramento (detta anche delle Torri) e l’altro tratto, restaurato da Niccolò V, visibile sul colle insieme alle due grandiose torri circolari, dette torre della Radio e Torre Gregoriana (la cui seconda è il luogo usato prima da Leone XIII per l'edificazione di una palazzina utilizzabile come residenza estiva e poi, trasformata, diventerà nel 1891, la sede della Specola Vaticana, grazie all'apposito motu proprio di Leone XIII Ut mysticam).

I Giardini visti dalla cupola di San PietroInnumerevoli sono anche le fontane, tutte di straordinaria bellezza, delle quali va ricordata in particolare quella della Galera. Essa è il risultato di tre secoli di elaborazioni e cambiamenti che l’hanno resa ancora più scenografica. Un magnifico galeone che spara getti d’acqua dai suoi cannoni, tanto che Papa Urbano VIII la celebrò con un distico latino: “Bellica Pontificem non fundit machina flammas/Sed dulcem belli qua perit ignis aquam” (La macchina da guerra dei papi non spara fiamme, bensì la dolce acqua che della guerra spegne il fuoco). Anche notevole è la fontana dell'Aquila, probabilmente la più cara ai romani: “vera e propria mostra dell' Acqua Paola a Roma, destinata a fare da pendant all'altra grande mostra, cioè al Fontanone del Gianicolo” (G. Morelli, Giardini Vaticani).

Nei Giardini si trovano, oltre alle Mura, alle Casine e ai giochi d’acqua, anche tempietti, santuari e grotte dedicate alla Madonna. È da segnalare quello dedicato alla Madonna della Guardia (1937) in ricordo della Grotta di Lourdes, dove si conclude il mese Mariano con la suggestiva processione “Aux Flambeaux”. A fare da sfondo a tutti questi importanti simboli della storia e della fede è la natura: piante, alberi, fiori, arbusti, rampicanti provenienti da ogni parte del mondo che rendono il giardino in qualunque stagione dell’anno un tripudio di colori, profumi.

I Giardini che sono composti di varie zone (Giardino all'italiana, Giardino all'inglese, Orto del Papa) sono anche sede di uffici statali, come il Palazzo del Governatorato e il Tribunale di Stato, della direzione della radio statale (Radio Vaticana), della Stazione ferroviaria Vaticana e dell'ex Specola Vaticana.

 

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The Pokot (or Pokhot) live in the Baringo district and in the Western Pokot district in Kenya. They are also inhabitants of Uganda.There are two main sub-groups depending of their location and way of life. The first group consist of the Hill Pokot who live in the rainy highlands in the west and in the central south, and are mainly farmers and pastoralists. The second group is made up of the Plains Pokot who live in dry and infertile plains, with their cattle. A homestead is composed of one or more buildings for a man, his wife and children; the prospective co-wives live in separate houses. Teaching children ethical rules is extremely important. Most of the Pokot are nomadic and thus have interacted with different peoples, incorporating their social customs.The Pokot are very proud of their culture. The songs, storytelling, and decorative arts, in particular body decoration, are very appreciated among the Pokot. They adorn the body with beads and hairstyling, and proceed to scarifications and the removal of the lower central incisors. Pokot girls wear a beaded necklace made of the stems of an asparagus tree. Most Pokot have some knowledge of herbal medicine, so they often use these treatments along with those of the hospitals. They belong to the Kenya's Nilotic-speaking peoples.For the Pokot, the universe has two realms: the above is the realm of the most powerful deities—Tororot, Asis (sun), and llat (rain); and the below is the one where live humans, animals, and plants. Humans are responsible for the realm that they inhabit, but they rely upon divinities to achieve and maintain peace and prosperity. They worship many deities like the sun, moon and believe in the spirit of death.The Pokot communicate with their deities through prayer and sacrifice. They perform it during ethnic festivals and dances. Oracles are responsible for maintaining the spiritual balance within the community. They are superstitious and believe in sorcery, so sometimes they call on shielding lucky sorcery. They have prophets, either male or female, who foresee and advise, usually by the means of animal sacrifices. Their abilities are considered as a divine gift. Clan histories recount the changes of location, through poetry and song, emphasizing the vulnerability of human beings and the importance of supernatural powers that help them overcome hunger, thirst, and even death. Ceremonies mark the transitions in the people's social lives. Among these are: the cleansing of a couple expecting their first child; the cleansing of newborn infants and their mothers; the cleansing of twins and other children who are born under unusual circumstances; male and female initiation; marriage; sapana, a coming-of-age ceremony for men; and summer-solstice, harvest, and healing ceremonies. The most important rite of passage for most Pokot is circumcision for boys and clitoridectomy for girls. These rites consist of a series of neighborhood-based ceremonies, emphasizing the importance of having a good behavior. When boys are circumcised, they acquire membership in one of eight age sets. Women do not belong to any age-set. After excision, for several months, girls have a white painting on their face and wear a hood made of blackened leather with charcoal and oil. This means they are untouchable until the lepan ceremony, that marks the passage to womanhood. Unlike other tribes, the Pokot keep the affiliation to their clan throughout their lives, there is no disruption with marriage. Surprisingly, the agreement before marriage is made by gift giving, from the groom and his family to the bride and her family (and not the contrary), often over a period of years. It often implies the gift of a combination of livestock, goods, and cash to the bride's family, and the allotment of milk cows and rights to land to the bride. The bond between a husband and wife lasts for 3 generations, after what marriages can take place again between the two groups. Polygamy exists but is not prevalent among men before 40. The spirits of the elder anticipate reincarnation in their living descendants: when a child is said to resemble the elder, the same name is given. Disputes are resolved in neighborhood councils and in government courts. Some of the sanctions include shaming, cursing, and bewitching.

   

Les Pokot vivent dans le district de Baringo et à l’ouest du district de Pokot au Kenya. Ce sont aussi des habitants de l’Ouganda.Il existe deux principaux sous-groupes selon leur localisation et mode de vie. Le premier groupe est constitué des Pokot des collines qui vivent dans les hautes terres humides dans l’ouest et dans le centre sud, et sont surtout des agriculteurs et pasteurs. Le second groupe est composé des Pokot des plaines qui vivent dans les plaines sèches et infertiles, avec leur bétail. Chaque propriété familiale est composée d’une ou plusieurs bâtiments pour un homme, sa femme et ses femmes, les éventuelles autres épouses vivent dans des maisons séparées. Enseigner aux enfants les règles éthiques est extrêmement important. La plupart des Pokot sont nomades et ont donc interagi avec différents peuples, incorporant leurs coutumes sociales. Les Pokot sont très fiers de leur culture. Les chants, contines, et arts décoratifs, en particulier la décoration du corps, sont particulièrement appréciés chez les Pokot. Ils parent leur corps de perles et coiffures originales, et procèdent à des scarifications et au retrait des incisives centrales inférieures. Les filles Pokot portent un collier de perles fait de tiges d’asparagus. La plupart des Pokot a des connaissances des médicaments à base de plantes, et ils utilisent donc souvent ces traitements avec ceux des hôpitaux. Ils appartiennent aux peuples parlant les langues nilotiques du Kenya.Pour les Pokot, l’univers a deux royaumes : celui d’en haut est le royaume des déités les plus puissantes –Torotot, Asis (soleil), et Ilat (pluie) ; celui d’en bas est celui où vivent les humains, animaux, et plantes. Les humains sont responsables du royaume qu’ils habitent, mais ils reposent sur les divinités pour atteindre et maintenir la paix et la prospérité. Ils vouent un culte à de nombreuses déités tels que le soleil et la lune et croient dans l’esprit de la mort. Les Pokot communiquent avec leurs déités par la prière et le sacrifice. Ils les accomplissent lors de festivals ethniques et de danses. Les oracles sont responsables du maintien de l’équilibre spirituel à l’intérieur de la communauté. Ils sont superstitieux et croient aux sortilèges, c’est pourquoi parfois ils invoquent des sortilèges de chance protecteurs. Ils ont des prophètes, hommes ou femmes, qui voient dans le futur et conseillent, habituellement au moyen de sacrifices d’animaux. Leurs capacités sont considérées comme un don divin. Les histoires claniques racontent les changements de leurs lieux de vie, à travers des poèmes et chansons, mettant en avant la vulnérabilité des êtres humains et l’importance de pouvoirs supernaturels qui les aident à surpasser la faim, la soif, et même la mort. Les cérémonies marquent les transitions dans la vie sociale des individus. Parmi celles-ci on compte : la purification d’un couple attendant leur premier enfant ; celle d’enfants nouveaux-nés et de leurs mères ; la purification de jumeaux et d’autres enfantgs qui sont nés dans des circonstances inhabituelles ; l’initiation pour hommes et femmes ; le mariage ; le sapana, une cérémonie pour la majorité chez les hommes ; le solstice d’été ; la moisson ; et les cérémonies de soins. Le rite de passage le plus important pour la plupart des Pokot est la circoncision pour les garçons et la clitorectomie pour les filles. Ces rites consistent en une série de cérémonies basées sur le voisinage, soulignant l’importance d’avoir une bonne conduite. Lorsque les garçons sont circoncis, ils deviennent membres de l’une des huit classes d’âge. Les femmes n’appartiennent à aucune classe d’âge. Après l’excision, pour plusieurs mois, les filles portent une painture blanche sur le visage et une capuche fait de cuir noirci au charbon de bois et à l’huile. Cela signifie qu’elle sont intouchables jusqu’à la cérémonie lepan, qui marque le passage à l’état de femme. Contrairement à d’autres tribus, les Pokot gardent l’affiliation à leur clan toute leur vie, il n’y a aucune rupture lors du mariage. De façon surprenante, l’accord avant le mariage est réalisé grâce à des cadeaux de la part du futur époux et de sa famille, à la fiancée et sa famille (et non le contraire), souvent pour une période donnée d’année. Cela implique souvent le don d’une association de bétail, biens, et argent à la famille de la mariée, et l’attribution de vaches à lait et des droits fonciers à la mariée. Le lien entre le mari et la femme dure pendant 3 générations, après quoi les mariages peuvent de nouveau avoir lieu entre les deux groupes. La polygamie existes mais ne prévaut pas chez les hommes de moins de 40 ans. Les esprits des plus vieux anticipent la réincarnation chez leurs descendants vivants : quand on dit d’un enfant qu’il ressemble à son aîné, le même nom lui est donné. Les disputes sont résolues dans des conseils de voisinage et dans les tribunaux du gouvernement. Certaines des sanctions incluent le déshonneur, la malédiction et l’ensorcellement.

  

© Eric Lafforgue

www.ericlafforgue.com

    

Saguis no terreno da Imprensa Nacional, em Brasília-DF, Brasil.

 

Um sagui[1][2] (do tupi sauín), soim ou mico são as designações comuns dadas a várias espécies de pequenos macacos pertencentes à família Callitrichidae. A palavra sagui tem origem no tupi e sua pronúncia é feita observando-se o som da vogal "u".

Estes primatas são representados por várias espécies em território brasileiro. Todos os quais possuem o dedo polegar da mão muito curto e não oponível, as unhas em forma de garras, e dentes molares de fórmula 2/2. São espécies de pequeno porte e de cauda longa.

São os menores símios do mundo, estão dispersos por toda a América do Sul e vivem geralmente em bandos que se hospedam em árvores, como os esquilos. Travessos e ágeis, movem-se em saltos bruscos, emitindo guinchos e assobios que são ouvidos de longe.

  

Sagui-de-tufos-brancos

Espécies

 

Família Callitrichidae

Callithrix jacchus - Sagui-de-tufos-brancos

Callithrix penicillata - Sagui-de-tufos-pretos

Callithrix kuhlii - Sagui-de-wied

Callithrix geoffroyi - Sagui-de-cara-branca

Callithrix flaviceps - Sagui-da-serra

Callithrix aurita - Sagui-da-serra-escuro

Callithrix argentata - Sagui-branco

Callithrix nigriceps - Sagui-de-cabeça-preta

Callithrix humeralifera - Sagui-de-santarém

Saguinus fuscicollis - Sagui-de-cara-suja

Saguinus imperator - Sagui-imperador

Saguinus labiatus - Sagui-de-bigode

Saguinus mystax - Sagui-de-boca-branca

Saguinus oedipus - Sagui-de-cabeça-branca

Saguinus bicolor - Sagui-de-coleira

Família Callimiconidae

Callimico goeldi - Sagui-goeldi

Referências

 

↑ michaelis.uol.com.br/moderno/portugues/index.php?lingua=p...

↑ Desde 1 de janeiro de 2009, em virtude da vigência do Acordo Ortográfico de 1990, a palavra não é mais grafada com trema (sagüi).

  

O sagüi (português brasileiro) ou sagui (português europeu) (AO 1990: sagui), soim, mico, marmoset (em inglês) ou tamarim (em inglês) são as designações comuns dadas a várias espécies de pequenos macacos pertencentes à família Callitrichidae.

Estes primatas são representados por várias espécies em território brasileiro. Todos os quais possuem o dedo polegar da mão muito curto e não oponível, as unhas em forma de garras, e dentes molares de fórmula 2/2. São espécies de pequeno porte e de cauda longa.

São os menores símios do mundo, estão dispersos por toda a América do Sul e vivem geralmente em bandos que se hospedam, como os esquilos em árvores. Travessos e ágeis, movem-se a saltos bruscos, emitindo guinchos e assobios que são ouvidos de longe.

 

Following, a text, in english, from Wikipedia the free encyclopédia:

 

Black-tufted marmoset at "Imprensa Nacional" (National Press)

The black-tufted marmoset (Callithrix penicillata), also known as Mico-estrela in Portuguese, is a species of New World monkey that lives primarily in the Neo-tropical gallery forests of the Brazilian Central Plateau. It ranges from Bahia to Paraná,[3] and as far inland as Goiás, between 14 and 25 degrees south of the equator. This marmoset typically resides in rainforests, living an arboreal life high in the trees, but below the canopy. They are only rarely spotted near the ground.

Physical description:

The black-tufted marmoset is characterized by black tufts of hair around their ears. It typically has some sparse white hairs on its face. It usually has a brown or black head and its limbs and upper body are gray, as well as its abdomen, while its rump and underside are usually black. Its tail is ringed with black and white and is not prehensile, but is used for balance. It does not have an opposable thumb and its nails tend to have a claw-like appearance. The black-tufted marmoset reaches a size of 19 to 22 cm and weighs up to 350 g.

Behavior:

Diurnal and arboreal, the black-tufted marmoset has a lifestyle very similar to other marmosets. It typically lives in family groups of 2 to 14. The groups usually consist of a reproductive couple and their offspring. Twins are very common among this species and the males, as well as juvenile offspring, often assist the female in the raising of the young.

Though the black-tufted marmoset lives in small family groups, it is believed that they share their food source, sap trees, with other marmoset groups. Scent marking does occur within these groups, but it is believed that the marking is to deter other species rather than other black-tufted marmoset groups, because other groups typically ignore these markings. They also appear to be migratory, often moving in relation to the wet or dry seasons, however, the extent of their migration is unknown.

Though communication between black-tufted marmosets has not been studied thoroughly, it is believed that it communicates through vocalizations. It has known predator-specific cries and appears to vocalize frequently outside of predator cries.

Food and predation:

The Black-tufted Marmoset diet consists primarily of tree sap which it gets by nibbling the bark with its long lower incisors. In periods of drought, it will also include fruit and insects in its diet. In periods of serious drought it has also been known to eat small arthropods, molluscs, bird eggs, baby birds and small vertebrates.

Large birds of prey are the greatest threat to the black-tufted marmoset, however, snakes and wild cats also pose a danger to them. Predator-specific vocalizations and visual scanning are its only anti-predation techniques.

Reproduction:

The black-tufted marmoset is monogamous and lives in family groups. It reproduces twice a year, producing 1 to 4 offspring, though most often just twins. Its gestation period is 150 days and offspring are weaned after 8 weeks. There is considerable parental investment by this species, with both parents, as well as older juveniles, helping to raise the young. The offspring are extremely dependent on their parents and though they are sexually mature at 18 months, they typically do not mate until much later, staying with their family group until they do.

Ecosystem roles and conservation status:

The black-tufted marmoset is a mutualist with many species of fruit trees because it distributes the seeds from the fruit it consumes throughout the forests. However, it is a parasite on other species of trees because it creates sores in trees in order to extract sap, while offering no apparent benefit to the trees. Though this marmoset is not a main food source to any specific species, it is a food source to a number of different species, specifically large birds of prey, wild cats, and snakes.

While there are no known negative effects of marmosets towards humans, it carries specific positive effects by being a highly valuable exotic pet. It is also used in zoo exhibits and scientific research.

The black-tufted marmoset is listed as having no special status on the IUCN Red List or the United States Endangered Species Act List. It is listed in Appendix II of CITES and is not currently considered an endangered or threatened species.

Just offshore from mainland Bahia Honda, (a short kayak hop) in the middle of the deep channel is a little scraggly hump of rock with three stunted trees. It doesn't look like much from above, but the rock ledges, tide pools, caves and little tunnels the fringe the island attract thousands of fish and creatures. I always leave here with a lot of great sights, some good shots, and usually a few bumps and bruises.

 

This swarm of Bermuda/Yellow Chubs made it's way back and forth along the rocks, in between the calmer lee shore and the crashing surf on the windward exposure.

 

Little Bahia Honda

Bahia Honda State Park

Monroe County, Florida, USA

SeaLife DC1400

Hippopotamuses love water, which is why the Greeks named them the "river horse." Hippos spend up to 16 hours a day submerged in rivers and lakes to keep their massive bodies cool under the hot African sun. Hippos are graceful in water, good swimmers, and can hold their breath underwater for up to five minutes. However, they are often large enough to simply walk or stand on the lake floor, or lie in the shallows. Their eyes and nostrils are located high on their heads, which allows them to see and breathe while mostly submerged. Hippos also bask on the shoreline and secrete an oily red substance, which gave rise to the myth that they sweat blood. The liquid is actually a skin moistener and sunblock that may also provide protection against germs. At sunset, hippopotamuses leave the water and travel overland to graze. They may travel 6 miles (10 kilometers) in a night, along single-file pathways, to consume some 80 pounds (35 kilograms) of grass. Considering their enormous size, a hippo's food intake is relatively low. If threatened on land hippos may run for the water—they can match a human's speed for short distances. Hippo calves weigh nearly 100 pounds (45 kilograms) at birth and can suckle on land or underwater by closing their ears and nostrils. Each female has only one calf every two years. Soon after birth, mother and young join schools that provide some protection against crocodiles, lions, and hyenas. Hippos once had a broader distribution but now live in eastern central and southern sub-Saharan Africa, where their populations are in decline. A partially submerged hippopotamus tries to keep cool in the hot African sun. The hippopotamus (Hippopotamus amphibius), or hippo, from the ancient Greek for "river horse" (ἱπποπόταμος), is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae (the other is the Pygmy Hippopotamus.) After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest extant artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, their closest living relatives are cetaceans (whales, porpoises, etc.) from which they diverged about 55 million years ago. The common ancestor of whales and hippos split from other even-toed ungulates around 60 million years ago. The earliest known hippopotamus fossils, belonging to the genus Kenyapotamus in Africa, date to around 16 million years ago.

The hippopotamus is semi-aquatic, inhabiting rivers, lakes and mangrove swamps, where territorial bulls preside over a stretch of river and groups of 5 to 30 females and young. During the day they remain cool by staying in the water or mud; reproduction and childbirth both occur in water. They emerge at dusk to graze on grass. While hippopotamuses rest near each other in the water, grazing is a solitary activity and hippos are not territorial on land. Hippos are recognizable by their barrel-shaped torso, enormous mouth and teeth, nearly hairless body, stubby legs and tremendous size. It is the third largest land mammal by weight (between 1½ and 3 tonnes), behind the white rhinoceros (1½ to 3½ tonnes) and the three species of elephant (3 to 9 tonnes). The hippopotamus is one of the largest quadrupeds and despite its stocky shape and short legs, it can easily outrun a human. Hippos have been clocked at 30 km/h (19 mph) over short distances. The hippopotamus is one of the most aggressive creatures in the world and is often regarded as one of the most dangerous animals in Africa. They are still threatened by habitat loss and poaching for their meat and ivory canine teeth. There is also a colony of non-zoo hippos in Colombia introduced by Pablo Escobar. The most recent theory of the origins of Hippopotamidae suggests that hippos and whales shared a common semi-aquatic ancestor that branched off from other artiodactyls around 60 million years ago.[13][15] This hypothesized ancestral group likely split into two branches around 54 million years ago.[12] One branch would evolve into cetaceans, possibly beginning about 52 million years ago with the proto-whale Pakicetus and other early whale ancestors collectively known as Archaeoceti, which eventually underwent aquatic adaptation into the completely aquatic cetaceans.[17] The other branch became the anthracotheres, a large family of four-legged beasts, the earliest of whom in the late Eocene would have resembled skinny hippopotamuses with comparatively small and narrow heads. All branches of the anthracotheres, except that which evolved into Hippopotamidae, became extinct during the Pliocene without leaving any descendants.[15]

A rough evolutionary lineage can be traced from Eocene and Oligocene species: Anthracotherium and Elomeryx to the Miocene Merycopotamus and Libycosaurus and the very latest anthracotheres in the Pliocene.[18] Merycopotamus, Libycosaurus and all hippopotamids can be considered to form a clade, with Libycosaurus being more closely related to hippos. Their common ancestor would have lived in the Miocene, about 20 million years ago. Hippopotamids are therefore deeply nested within the family Anthracotheriidae. The Hippopotamidae are believed to have evolved in Africa; the oldest known hippopotamid is the genus Kenyapotamus which lived in Africa from 16 to 8 million years ago. While hippopotamid species spread across Asia and Europe, no hippopotamuses have ever been discovered in the Americas, although various anthracothere genera emigrated into North America during the early Oligocene. From 7.5 to 1.8 million years ago an ancestor to the modern hippopotamus, Archaeopotamus, lived in Africa and the Middle East.[19]

While the fossil record of hippos is still poorly understood, the two modern genera, Hippopotamus and Choeropsis (sometimes Hexaprotodon), may have diverged as far back as 8 million years ago. Taxonomists disagree whether or not the modern Pygmy Hippopotamus is a member of Hexaprotodon —an apparently paraphyletic genus also embracing many extinct Asian hippopotamuses that is more closely related to Hippopotamus, or Choeropsis —an older and basal genus.[18][19]

[edit]Extinct species

Three species of Malagasy Hippopotamus became extinct during the Holocene on Madagascar, one of them within the past 1,000 years. The Malagasy Hippos were smaller than the modern hippopotamus, likely through the process of insular dwarfism.[20] There is fossil evidence that many Malagasy Hippos were hunted by humans, a likely factor in their eventual extinction.[20] Isolated members of Malagasy Hippopotamus may have survived in remote pockets; in 1976, villagers described a living animal called the Kilopilopitsofy, which may have been a Malagasy Hippopotamus.[21]

Two species of Hippopotamus, the European Hippopotamus (H. antiquus) and H. gorgops ranged throughout continental Europe and the British Isles. Both species became extinct before the last glaciation. Ancestors of European Hippos found their way to many islands of the Mediterranean during the Pleistocene.[22] Both species were larger than the modern hippopotamus, averaging about 1 meter (3.3 feet) longer. The Pleistocene also saw a number of dwarf species evolve on several Mediterranean islands including Crete (H. creutzburgi), Cyprus (H. minor), Malta (H. melitensis) and Sicily (H. pentlandi). Of these, the Cyprus Dwarf Hippopotamus, survived until the end of the Pleistocene or early Holocene. Evidence from an archaeological site Aetokremnos, continues to cause debate on whether or not the species was encountered, and was driven to extinction, by man. Hippopotamuses are among the largest living mammals; only elephants and some rhinoceroses and whales are heavier. They can live in the water or on land. Their specific gravity allows them to sink and walk or run along the bottom of a river. Hippos are considered megafauna, but unlike all other African megafauna, hippos have adapted for a semi-aquatic life in freshwater lakes and rivers.[9]:3 A hippo's lifespan is typically 40–50 years.[6]:277 Donna the Hippo, 60, was the oldest living hippo in captivity. She lived at the Mesker Park Zoo in Evansville, Indiana, USA[24][25] until her death on August 1, 2012. The oldest hippo ever recorded was called Tanga; she lived in Munich, Germany, and died in 1995 at the age of 61.[26]

Because of their enormous size, hippopotamuses are difficult to weigh in the wild. Most estimates of the weight come from culling operations that were carried out in the 1960s. The average weights for adult males ranged between 1,500–1,800 kg (3,300–4,000 lb). Females are smaller than their male counterparts, with average weights measuring between 1,300–1,500 kg (2,900–3,300 lb).[9]:12 Older males can get much larger, reaching at least 3,200 kg (7,100 lb) with a few exceptional specimens exceeding 3,600 kg (7,900 lb).[27][28] The heaviest known hippopotamus weighed approximately 4,500 kg (9,900 lb).[29] Male hippos appear to continue growing throughout their lives; females reach a maximum weight at around age 25.[30]

Hippos measure 3.3 to 5.2 meters (11 to 17 ft) long, including a tail of about 56 centimeters (22 in) in length and average about 1.5 meters (5 ft) tall at the shoulder.[31][32] The range of hippopotamus sizes overlaps with the range of the white rhinoceros; use of different metrics makes it unclear which is the largest land animal after elephants. Even though they are bulky animals, hippopotamuses can run faster than a human on land. Estimates of their running speed vary from 30 km/h (18 mph) to 40 km/h (25 mph), or even 50 km/h (30 mph). The hippo can maintain these higher speeds for only a few hundred meters. Despite being semi-aquatic and having webbed feet, an adult hippo is not a particularly good swimmer nor can it float. It is rarely found in deep water; when it is, the animal moves by porpoise-like leaps from the bottom. The eyes, ears, and nostrils of hippos are placed high on the roof of the skull. This allows them to be in the water with most of their body submerged in the waters and mud of tropical rivers to stay cool and prevent sunburn. Their skeletal structure is graviportal, adapted to carrying the animals' enormous weight. Hippopotamuses have small legs (relative to other megafauna) because the water in which they live reduces the weight burden. Unlike most other semi-aquatic animals, the hippopotamus has very little hair.[6]:260 The skin is 6 in (15 cm) thick,[33] providing it great protection against conspecifics and predators. The animals's upper parts are purplish-gray to blue-black while the under parts and areas around the eyes and ears can be brownish-pink.[6]:260 The testes of the males descend only partially and a scrotum is not present. In addition, the penis retracts into the body when not erect. The genitals of the female are unusual in that the vagina is ridged and two large diverticula protrude from the vulval vestibule. The function of these is unknown.[9]:28–29

The hippo's jaw is powered by a large masseter and a well developed digastric; the latter loops up behind the former to the hyoid.[6]:259 The jaw hinge is located far back enough to allow the animal to open its mouth at almost 180°.[9]:17 On the National Geographic Channel television program, "Dangerous Encounters with Brady Barr", Dr. Brady Barr measured the bite force of an adult female hippo at 8100 N (1821 lbf); Barr also attempted to measure the bite pressure of an adult male hippo, but had to abandon the attempt due to the male's aggressiveness.[34] Hippopotamus teeth sharpen themselves as they grind together. The lower canines and lower incisors are enlarged, especially in males, and grow continuously. The incisors can reach 40 cm (16 in) while the canines reach up to 50 cm (20 in).[33]

Their skin secretes a natural sunscreen substance which is red-colored. The secretion is sometimes referred to as "blood sweat," but is neither blood nor sweat. This secretion is initially colorless and turns red-orange within minutes, eventually becoming brown. Two distinct pigments have been identified in the secretions, one red (hipposudoric acid) and one orange (norhipposudoric acid). The two pigments are highly acidic compounds. Both pigments inhibit the growth of disease-causing bacteria; as well, the light absorption of both pigments peaks in the ultraviolet range, creating a sunscreen effect. All hippos, even those with different diets, secrete the pigments, so it does not appear that food is the source of the pigments. Instead, the animals may synthesize the pigments from precursors such as the amino acid tyrosine. Hippopotamus amphibius was widespread in North Africa and Europe during the Eemian[36] and late Pleistocene until about 30,000 years ago. The species was common in Egypt's Nile region during antiquity but has since been extirpated. Pliny the Elder writes that, in his time, the best location in Egypt for capturing this animal was in the Saite nome;[37] the animal could still be found along the Damietta branch after the Arab Conquest in 639. Hippos are still found in the rivers and lakes of the northern Democratic Republic of the Congo, Uganda, Tanzania and Kenya, north through to Ethiopia, Somalia and Sudan, west from Ghana to Gambia, and also in Southern Africa (Botswana, Republic of South Africa, Zimbabwe, Zambia, Mozambique). Genetic evidence suggests that common hippos in Africa experienced a marked population expansion during or after the Pleistocene Epoch, attributed to an increase in water bodies at the end of the era. These findings have important conservation implications as hippo populations across the continent are currently threatened by loss of access to fresh water.[10] Hippos are also subject to unregulated hunting and poaching. In May 2006 the hippopotamus was identified as a vulnerable species on the IUCN Red List drawn up by the World Conservation Union (IUCN), with an estimated population of between 125,000 and 150,000 hippos, a decline of between 7% and 20% since the IUCN's 1996 study. Zambia (40,000) and Tanzania (20,000–30,000) possess the largest populations.[1]

The hippo population declined most dramatically in the Democratic Republic of the Congo.[38] The population in Virunga National Park had dropped to 800 or 900 from around 29,000 in the mid 1970s.[39] The decline is attributed to the disruptions caused by the Second Congo War.[39] The poachers are believed to be former Hutu rebels, poorly paid Congolese soldiers, and local militia groups.[39] Reasons for poaching include the belief that hippos are harmful to society, and also for money.[40] The sale of hippo meat is illegal, but black-market sales are difficult for Virunga National Park officers to track. Invasive potential

In the late 1980s, Pablo Escobar kept four hippos in a private menagerie at his residence in Hacienda Napoles, 100 km east of Medellín, Colombia, after buying them in New Orleans. They were deemed too difficult to seize and move after Escobar's fall, and hence left on the untended estate. By 2007, the animals had multiplied to 16 and had taken to roaming the area for food in the nearby Magdalena River.[41] In 2009, two adults and one calf escaped the herd, and after attacking humans and killing cattle, one of the adults (called "Pepe") was killed by hunters under authorization of the local authorities.[42][43] It is unknown what kind of effects the presence of hippos might have on the ecosystem in Colombia. According to experts interviewed by W Radio Colombia, the animals could survive in the Colombian jungles. It is believed that the lack of control from the Colombian government, which is not used to dealing with this species, could result in human fatalities. Hippos spend most of their days wallowing in the water or the mud, with the other members of their pod. The water serves to keep their body temperature down, and to keep their skin from drying out. With the exception of eating, most of hippopotamuses' lives —from childbirth, fighting with other hippos, to reproduction— occur in the water. Hippos leave the water at dusk and travel inland, sometimes up to 8 kilometers (5 mi), to graze on short grass, their main source of food. They spend four to five hours grazing and can consume 68 kilograms (150 lb) of grass each night.[44] Like almost any herbivore, they will consume many other plants if presented with them, but their diet in nature consists almost entirely of grass, with only minimal consumption of aquatic plants.[45] Hippos have (rarely) been filmed eating carrion, usually close to the water. There are other reports of meat-eating, and even cannibalism and predation.[46] The stomach anatomy of a hippo is not suited to carnivory, and meat-eating is likely caused by aberrant behavior or nutritional stress.[9]:84

The diet of hippos consists mostly of terrestrial grasses, even though they spend most of their time in the water. Most of their defecation occurs in the water, creating allochthonous deposits of organic matter along the river beds. These deposits have an unclear ecological function.[45] Because of their size and their habit of taking the same paths to feed, hippos can have a significant impact on the land they walk across, both by keeping the land clear of vegetation and depressing the ground. Over prolonged periods hippos can divert the paths of swamps and channels.[47]

Adult hippos move at speeds up to 8 km/h (5 mph) in water. Adult hippos typically resurface to breathe every three to five minutes. The young have to breathe every two to three minutes.[9]:4 The process of surfacing and breathing is automatic, and even a hippo sleeping underwater will rise and breathe without waking. A hippo closes its nostrils when it submerges into the water. As with fish and turtles on a coral reef, hippo occasionally visit cleaning stations and signal by wide-open mouth their readiness for being cleaned of parasites by certain species of fish. This situation is an example of mutualism in which the hippo benefits from the cleansing while the fish receive food.[ Studying the interaction of male and female hippopotamuses has long been complicated by the fact that hippos are not sexually dimorphic and thus females and young males are almost indistinguishable in the field.[49] Although hippos like to lie close to each other, they do not seem to form social bonds except between mothers and daughters, and are not social animals. The reason they huddle close together is unknown.[9]:49

Hippopotamuses are territorial only in water, where a bull presides over a small stretch of river, on average 250 meters in length, and containing ten females. The largest pods can contain over 100 hippos.[9]:50 Other bachelors are allowed in a bull's stretch, as long as they behave submissively toward the bull. The territories of hippos exist to establish mating rights. Within the pods, the hippos tend to segregate by gender. Bachelors will lounge near other bachelors, females with other females, and the bull on his own. When hippos emerge from the water to graze, they do so individually.[9]:4

Hippopotamuses appear to communicate verbally, through grunts and bellows, and it is thought that they may practice echolocation, but the purpose of these vocalizations is currently unknown. Hippos have the unique ability to hold their head partially above the water and send out a cry that travels through both water and air; hippos above and under water will respond.[ Female hippos reach sexual maturity at five to six years of age and have a gestation period of 8 months. A study of endocrine systems revealed that female hippopotamuses may begin puberty as early as 3 or 4 years of age.[51] Males reach maturity at around 7.5 years. A study of hippopotamus reproductive behavior in Uganda showed that peak conceptions occurred during the end of the wet season in the summer, and peak births occurred toward the beginning of the wet season in late winter. This is because of the female's estrous cycle; as with most large mammals, male hippopotamus spermatozoa is active year round. Studies of hippos in Zambia and South Africa also showed evidence of births occurring at the start of the wet season.[9]:60–61 After becoming pregnant, a female hippopotamus will typically not begin ovulation again for 17 months.[51]

Mating occurs in the water with the female submerged for most of the encounter,[9]:63 her head emerging periodically to draw breath. Baby hippos are born underwater at a weight between 25 and 45 kg (60–110 lb) and an average length of around 127 cm (50 in) and must swim to the surface to take their first breath. A mother typically gives birth to only one hippo, although twins also occur. The young often rest on their mothers' backs when in water that is too deep for them, and they swim underwater to suckle. They also will suckle on land when the mother leaves the water. Weaning starts between six and eight months after birth and most calves are fully weaned after a year.[9]:64 Like many other large mammals, hippos are described as K-strategists, in this case typically producing just one large, well-developed infant every couple of years (rather than large numbers of small, poorly developed young several times per year as is common among small mammals such as rodents. Hippopotamuses are by nature very aggressive animals, especially when young calves are present. Frequent targets of their aggression include crocodiles, which often inhabit the same river habitat as hippos. Nile crocodiles, lions and spotted hyenas are known to prey on young hippos.[53] Hippos are very aggressive towards humans, whom they commonly attack whether in boats or on land with no apparent provocation.[54] They are widely considered to be one of the most dangerous large animals in Africa.[55][56]

To mark territory, hippos spin their tails while defecating to distribute their excrement over a greater area.[57] Likely for the same reason, hippos are retromingent – that is, they urinate backwards.[58] When in combat, male hippos use their incisors to block each others attacks, and their lower canines to inflict damage.[6]:260 Hippos rarely kill each other, even in territorial challenges. Usually a territorial bull and a challenging bachelor will stop fighting when it is clear that one hippo is stronger. When hippos become overpopulated, or when a habitat starts to shrink, bulls will sometimes attempt to kill infants, but this behavior is not common under normal conditions.[52] Some incidents of hippo cannibalism have been documented, but it is believed to be the behavior of distressed or sick hippos, and not healthy behavior. The earliest evidence of human interaction with hippos comes from butchery cut marks upon hippo bones at Bouri Formation dated around 160,000 years ago.[59] Later rock paintings and engravings showing hippos being hunted have been found in the mountains of the central Sahara dated 4,000–5,000 years ago near Djanet in the Tassili n'Ajjer Mountains.[9]:1 The ancient Egyptians recognized the hippo as a ferocious denizen of the Nile.

The hippopotamus was also known to the Greeks and Romans. The Greek historian Herodotus described the hippopotamus in The Histories (written circa 440 BC) and the Roman Historian Pliny the Elder wrote about the hippopotamus in his encyclopedia Naturalis Historia (written circa 77 AD).[37][60] Hippopotamus was one of the many exotic animals brought to fight gladiators in Rome by the emperor Philip I the Arab to commemorate Rome's 1000 years anniversary in 248 AD. Silver coins with hippo's image were minted that year.[citation needed]

Zulu warriors preferred to be as brave as a hippopotamus, since even lions were not considered as brave. "In 1888, Captain Baden-Powell was part of a column searching for the Zulu chief Dinizulu, who was leading the Usutu people in revolt against the British colonists. The column was joined by John Dunn, a white Zulu chief, who led an impi (army) of 2000 Zulu warriors to join the British." [61]

The words of the Zulu anthem sounded like this:

"Een-gonyama Gonyama! "Invooboo! Yah-bo! Yah-bo! Invooboo!"

"John Dunn was at the head of his impi. [Baden Powell] asked him to translate the Zulu anthem his men had been singing. Dunn laughed and replied: "He is a lion. Yes, he is better than a lion—he is a hippopotamus. Hippopotamuses have long been popular zoo animals. The first zoo hippo in modern history was Obaysch who arrived at the London Zoo on May 25, 1850, where he attracted up to 10,000 visitors a day and inspired a popular song, the Hippopotamus Polka.[63] Hippos have remained popular zoo animals since Obaysch, and generally breed well in captivity. Their birth rates are lower than in the wild, but this is attributed to zoos' not wanting to breed as many hippos as possible, since hippos are large and relatively expensive animals to maintain.[9]:129[63]

Like many zoo animals, hippos were traditionally displayed in concrete exhibits. In the case of hippos, they usually had a pool of water and patch of grass. In the 1980s, zoo designers increasingly designed exhibits that reflected the animals' native habitats. The best known of these, the Toledo Zoo Hippoquarium, features a 360,000 gallon pool for hippos.[64] In 1987, researchers were able to tape, for the first time, an underwater birth (as in the wild) at the Toledo Zoo. The exhibit was so popular that the hippos became the logo of the Toledo Zoo. A red hippo represented the Ancient Egyptian god Set; the thigh is the 'phallic leg of set' symbolic of virility. Set's consort Tawaret was also seen as part hippo.[66] The hippopotamus-headed Tawaret was a goddess of protection in pregnancy and childbirth, because ancient Egyptians recognized the protective nature of a female hippopotamus toward her young.[67] The Ijo people wore masks of aquatic animals like the hippo when practicing their water spirit cults.[68] The Behemoth from the Book of Job, 40:15–24 is also thought to be based on a hippo.[69]

Hippos have been the subjects of various African folktales. According to a Bushmen story; when the Creator assigned each animal their place in nature, the hippos wanted to live in the water, but were refused out of fear that they might eat all the fish. After begging and pleading, the hippos were finally allowed to live in the water on the conditions that they would eat grass instead of fish and would fling their dung so that it can be inspected for fish bones.[70] In a Ndebele tale, the hippo originally had long, beautiful hair but was set on fire by a jealous hare and had to jump into a nearby pool. The hippo lost most of his hair and was too embarrassed to leave the water.[70]

Ever since Obaysch inspired the Hippopotamus Polka, hippos have been popular animals in Western culture for their rotund appearance that many consider comical.[63] Stories of hippos like Huberta who became a celebrity in South Africa in the 1930s for trekking across the country;[71] or the tale of Owen and Mzee, a hippo and tortoise who developed an intimate bond; have amused people who have bought hippo books, merchandise, and many a stuffed hippo toy.[72][73] Hippos were mentioned in the novelty Christmas song "I Want a Hippopotamus for Christmas" that became a hit for child star Gayla Peevey in 1953.[74] They also feature in the songs "The Hippopotamus" and "Hippo Encore" by Flanders and Swann, with the famous refrain Mud, Mud, Glorious Mud. They even inspired a popular board game, Hungry Hungry Hippos. Hippos have also been popular cartoon characters, where their rotund frame is used for humorous effect. The Disney film Fantasia featured a ballerina hippopotamus dancing to the opera, La Gioconda.[38] Other cartoon hippos have included Hanna-Barbera's Peter Potamus, the book and TV series George and Martha, Flavio and Marita on the Animaniacs, Pat of the French duo Pat et Stanley, The Backyardigan's Tasha, and Gloria and Moto-Moto from the Madagascar franchise. A Sesame Street cartoon from the early 1970s features a hippo who lives in the country and likes it quiet, while being disturbed when the mouse who likes it loud moves in with her.[citation needed]

The hippopotamus characters "Happy Hippos" were created in 1988 by the French designer Andre Roche [77] based in Munich, to be hidden in the "Kinder Surprise egg" of the Italian chocolate company Ferrero SpA. These characters were not placid like real hippos[contradiction] but rather cute and lively, and had such a success that they reappeared several times in different products of this company in the following years, increasing their popularity worldwide each time.[citation needed] The Nintendo Company published in the years 2001 and 2007 Game Boy adventures of them. In the game of chess, the hippopotamus lends its name to the Hippopotamus Defense, an opening system, which is generally considered weak.The River Horse is a popular outdoor sculpture at George Washington University, Washington, D.C. Botswana, Moremi National Park, Moremi Game reserve, private Reserve, Farm, chobe National park, Chobe Game Reserve, Zambia, Zambezi River, Livingstone, Zimbabwe, Kenya, Tanzania, Wildlife Conservation Project, Maramba River Lodge, South Africa, Krugger National Park. art beach blue bw california canada canon china city concert de england europe family festival film flower flowers food france friends green instagramapp iphoneography italy japan live london music nature new newyork night nikon nyc paris park party people photography portrait red sky snow square squareformat street summer sunset travel trip uk usa vacation water wedding white winter

Hippopotamuses love water, which is why the Greeks named them the "river horse." Hippos spend up to 16 hours a day submerged in rivers and lakes to keep their massive bodies cool under the hot African sun. Hippos are graceful in water, good swimmers, and can hold their breath underwater for up to five minutes. However, they are often large enough to simply walk or stand on the lake floor, or lie in the shallows. Their eyes and nostrils are located high on their heads, which allows them to see and breathe while mostly submerged. Hippos also bask on the shoreline and secrete an oily red substance, which gave rise to the myth that they sweat blood. The liquid is actually a skin moistener and sunblock that may also provide protection against germs. At sunset, hippopotamuses leave the water and travel overland to graze. They may travel 6 miles (10 kilometers) in a night, along single-file pathways, to consume some 80 pounds (35 kilograms) of grass. Considering their enormous size, a hippo's food intake is relatively low. If threatened on land hippos may run for the water—they can match a human's speed for short distances. Hippo calves weigh nearly 100 pounds (45 kilograms) at birth and can suckle on land or underwater by closing their ears and nostrils. Each female has only one calf every two years. Soon after birth, mother and young join schools that provide some protection against crocodiles, lions, and hyenas. Hippos once had a broader distribution but now live in eastern central and southern sub-Saharan Africa, where their populations are in decline. A partially submerged hippopotamus tries to keep cool in the hot African sun. The hippopotamus (Hippopotamus amphibius), or hippo, from the ancient Greek for "river horse" (ἱπποπόταμος), is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae (the other is the Pygmy Hippopotamus.) After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest extant artiodactyl. Despite their physical resemblance to pigs and other terrestrial even-toed ungulates, their closest living relatives are cetaceans (whales, porpoises, etc.) from which they diverged about 55 million years ago. The common ancestor of whales and hippos split from other even-toed ungulates around 60 million years ago. The earliest known hippopotamus fossils, belonging to the genus Kenyapotamus in Africa, date to around 16 million years ago.

The hippopotamus is semi-aquatic, inhabiting rivers, lakes and mangrove swamps, where territorial bulls preside over a stretch of river and groups of 5 to 30 females and young. During the day they remain cool by staying in the water or mud; reproduction and childbirth both occur in water. They emerge at dusk to graze on grass. While hippopotamuses rest near each other in the water, grazing is a solitary activity and hippos are not territorial on land. Hippos are recognizable by their barrel-shaped torso, enormous mouth and teeth, nearly hairless body, stubby legs and tremendous size. It is the third largest land mammal by weight (between 1½ and 3 tonnes), behind the white rhinoceros (1½ to 3½ tonnes) and the three species of elephant (3 to 9 tonnes). The hippopotamus is one of the largest quadrupeds and despite its stocky shape and short legs, it can easily outrun a human. Hippos have been clocked at 30 km/h (19 mph) over short distances. The hippopotamus is one of the most aggressive creatures in the world and is often regarded as one of the most dangerous animals in Africa. They are still threatened by habitat loss and poaching for their meat and ivory canine teeth. There is also a colony of non-zoo hippos in Colombia introduced by Pablo Escobar. The most recent theory of the origins of Hippopotamidae suggests that hippos and whales shared a common semi-aquatic ancestor that branched off from other artiodactyls around 60 million years ago.[13][15] This hypothesized ancestral group likely split into two branches around 54 million years ago.[12] One branch would evolve into cetaceans, possibly beginning about 52 million years ago with the proto-whale Pakicetus and other early whale ancestors collectively known as Archaeoceti, which eventually underwent aquatic adaptation into the completely aquatic cetaceans.[17] The other branch became the anthracotheres, a large family of four-legged beasts, the earliest of whom in the late Eocene would have resembled skinny hippopotamuses with comparatively small and narrow heads. All branches of the anthracotheres, except that which evolved into Hippopotamidae, became extinct during the Pliocene without leaving any descendants.[15]

A rough evolutionary lineage can be traced from Eocene and Oligocene species: Anthracotherium and Elomeryx to the Miocene Merycopotamus and Libycosaurus and the very latest anthracotheres in the Pliocene.[18] Merycopotamus, Libycosaurus and all hippopotamids can be considered to form a clade, with Libycosaurus being more closely related to hippos. Their common ancestor would have lived in the Miocene, about 20 million years ago. Hippopotamids are therefore deeply nested within the family Anthracotheriidae. The Hippopotamidae are believed to have evolved in Africa; the oldest known hippopotamid is the genus Kenyapotamus which lived in Africa from 16 to 8 million years ago. While hippopotamid species spread across Asia and Europe, no hippopotamuses have ever been discovered in the Americas, although various anthracothere genera emigrated into North America during the early Oligocene. From 7.5 to 1.8 million years ago an ancestor to the modern hippopotamus, Archaeopotamus, lived in Africa and the Middle East.[19]

While the fossil record of hippos is still poorly understood, the two modern genera, Hippopotamus and Choeropsis (sometimes Hexaprotodon), may have diverged as far back as 8 million years ago. Taxonomists disagree whether or not the modern Pygmy Hippopotamus is a member of Hexaprotodon —an apparently paraphyletic genus also embracing many extinct Asian hippopotamuses that is more closely related to Hippopotamus, or Choeropsis —an older and basal genus.[18][19]

[edit]Extinct species

Three species of Malagasy Hippopotamus became extinct during the Holocene on Madagascar, one of them within the past 1,000 years. The Malagasy Hippos were smaller than the modern hippopotamus, likely through the process of insular dwarfism.[20] There is fossil evidence that many Malagasy Hippos were hunted by humans, a likely factor in their eventual extinction.[20] Isolated members of Malagasy Hippopotamus may have survived in remote pockets; in 1976, villagers described a living animal called the Kilopilopitsofy, which may have been a Malagasy Hippopotamus.[21]

Two species of Hippopotamus, the European Hippopotamus (H. antiquus) and H. gorgops ranged throughout continental Europe and the British Isles. Both species became extinct before the last glaciation. Ancestors of European Hippos found their way to many islands of the Mediterranean during the Pleistocene.[22] Both species were larger than the modern hippopotamus, averaging about 1 meter (3.3 feet) longer. The Pleistocene also saw a number of dwarf species evolve on several Mediterranean islands including Crete (H. creutzburgi), Cyprus (H. minor), Malta (H. melitensis) and Sicily (H. pentlandi). Of these, the Cyprus Dwarf Hippopotamus, survived until the end of the Pleistocene or early Holocene. Evidence from an archaeological site Aetokremnos, continues to cause debate on whether or not the species was encountered, and was driven to extinction, by man. Hippopotamuses are among the largest living mammals; only elephants and some rhinoceroses and whales are heavier. They can live in the water or on land. Their specific gravity allows them to sink and walk or run along the bottom of a river. Hippos are considered megafauna, but unlike all other African megafauna, hippos have adapted for a semi-aquatic life in freshwater lakes and rivers.[9]:3 A hippo's lifespan is typically 40–50 years.[6]:277 Donna the Hippo, 60, was the oldest living hippo in captivity. She lived at the Mesker Park Zoo in Evansville, Indiana, USA[24][25] until her death on August 1, 2012. The oldest hippo ever recorded was called Tanga; she lived in Munich, Germany, and died in 1995 at the age of 61.[26]

Because of their enormous size, hippopotamuses are difficult to weigh in the wild. Most estimates of the weight come from culling operations that were carried out in the 1960s. The average weights for adult males ranged between 1,500–1,800 kg (3,300–4,000 lb). Females are smaller than their male counterparts, with average weights measuring between 1,300–1,500 kg (2,900–3,300 lb).[9]:12 Older males can get much larger, reaching at least 3,200 kg (7,100 lb) with a few exceptional specimens exceeding 3,600 kg (7,900 lb).[27][28] The heaviest known hippopotamus weighed approximately 4,500 kg (9,900 lb).[29] Male hippos appear to continue growing throughout their lives; females reach a maximum weight at around age 25.[30]

Hippos measure 3.3 to 5.2 meters (11 to 17 ft) long, including a tail of about 56 centimeters (22 in) in length and average about 1.5 meters (5 ft) tall at the shoulder.[31][32] The range of hippopotamus sizes overlaps with the range of the white rhinoceros; use of different metrics makes it unclear which is the largest land animal after elephants. Even though they are bulky animals, hippopotamuses can run faster than a human on land. Estimates of their running speed vary from 30 km/h (18 mph) to 40 km/h (25 mph), or even 50 km/h (30 mph). The hippo can maintain these higher speeds for only a few hundred meters. Despite being semi-aquatic and having webbed feet, an adult hippo is not a particularly good swimmer nor can it float. It is rarely found in deep water; when it is, the animal moves by porpoise-like leaps from the bottom. The eyes, ears, and nostrils of hippos are placed high on the roof of the skull. This allows them to be in the water with most of their body submerged in the waters and mud of tropical rivers to stay cool and prevent sunburn. Their skeletal structure is graviportal, adapted to carrying the animals' enormous weight. Hippopotamuses have small legs (relative to other megafauna) because the water in which they live reduces the weight burden. Unlike most other semi-aquatic animals, the hippopotamus has very little hair.[6]:260 The skin is 6 in (15 cm) thick,[33] providing it great protection against conspecifics and predators. The animals's upper parts are purplish-gray to blue-black while the under parts and areas around the eyes and ears can be brownish-pink.[6]:260 The testes of the males descend only partially and a scrotum is not present. In addition, the penis retracts into the body when not erect. The genitals of the female are unusual in that the vagina is ridged and two large diverticula protrude from the vulval vestibule. The function of these is unknown.[9]:28–29

The hippo's jaw is powered by a large masseter and a well developed digastric; the latter loops up behind the former to the hyoid.[6]:259 The jaw hinge is located far back enough to allow the animal to open its mouth at almost 180°.[9]:17 On the National Geographic Channel television program, "Dangerous Encounters with Brady Barr", Dr. Brady Barr measured the bite force of an adult female hippo at 8100 N (1821 lbf); Barr also attempted to measure the bite pressure of an adult male hippo, but had to abandon the attempt due to the male's aggressiveness.[34] Hippopotamus teeth sharpen themselves as they grind together. The lower canines and lower incisors are enlarged, especially in males, and grow continuously. The incisors can reach 40 cm (16 in) while the canines reach up to 50 cm (20 in).[33]

Their skin secretes a natural sunscreen substance which is red-colored. The secretion is sometimes referred to as "blood sweat," but is neither blood nor sweat. This secretion is initially colorless and turns red-orange within minutes, eventually becoming brown. Two distinct pigments have been identified in the secretions, one red (hipposudoric acid) and one orange (norhipposudoric acid). The two pigments are highly acidic compounds. Both pigments inhibit the growth of disease-causing bacteria; as well, the light absorption of both pigments peaks in the ultraviolet range, creating a sunscreen effect. All hippos, even those with different diets, secrete the pigments, so it does not appear that food is the source of the pigments. Instead, the animals may synthesize the pigments from precursors such as the amino acid tyrosine. Hippopotamus amphibius was widespread in North Africa and Europe during the Eemian[36] and late Pleistocene until about 30,000 years ago. The species was common in Egypt's Nile region during antiquity but has since been extirpated. Pliny the Elder writes that, in his time, the best location in Egypt for capturing this animal was in the Saite nome;[37] the animal could still be found along the Damietta branch after the Arab Conquest in 639. Hippos are still found in the rivers and lakes of the northern Democratic Republic of the Congo, Uganda, Tanzania and Kenya, north through to Ethiopia, Somalia and Sudan, west from Ghana to Gambia, and also in Southern Africa (Botswana, Republic of South Africa, Zimbabwe, Zambia, Mozambique). Genetic evidence suggests that common hippos in Africa experienced a marked population expansion during or after the Pleistocene Epoch, attributed to an increase in water bodies at the end of the era. These findings have important conservation implications as hippo populations across the continent are currently threatened by loss of access to fresh water.[10] Hippos are also subject to unregulated hunting and poaching. In May 2006 the hippopotamus was identified as a vulnerable species on the IUCN Red List drawn up by the World Conservation Union (IUCN), with an estimated population of between 125,000 and 150,000 hippos, a decline of between 7% and 20% since the IUCN's 1996 study. Zambia (40,000) and Tanzania (20,000–30,000) possess the largest populations.[1]

The hippo population declined most dramatically in the Democratic Republic of the Congo.[38] The population in Virunga National Park had dropped to 800 or 900 from around 29,000 in the mid 1970s.[39] The decline is attributed to the disruptions caused by the Second Congo War.[39] The poachers are believed to be former Hutu rebels, poorly paid Congolese soldiers, and local militia groups.[39] Reasons for poaching include the belief that hippos are harmful to society, and also for money.[40] The sale of hippo meat is illegal, but black-market sales are difficult for Virunga National Park officers to track. Invasive potential

In the late 1980s, Pablo Escobar kept four hippos in a private menagerie at his residence in Hacienda Napoles, 100 km east of Medellín, Colombia, after buying them in New Orleans. They were deemed too difficult to seize and move after Escobar's fall, and hence left on the untended estate. By 2007, the animals had multiplied to 16 and had taken to roaming the area for food in the nearby Magdalena River.[41] In 2009, two adults and one calf escaped the herd, and after attacking humans and killing cattle, one of the adults (called "Pepe") was killed by hunters under authorization of the local authorities.[42][43] It is unknown what kind of effects the presence of hippos might have on the ecosystem in Colombia. According to experts interviewed by W Radio Colombia, the animals could survive in the Colombian jungles. It is believed that the lack of control from the Colombian government, which is not used to dealing with this species, could result in human fatalities. Hippos spend most of their days wallowing in the water or the mud, with the other members of their pod. The water serves to keep their body temperature down, and to keep their skin from drying out. With the exception of eating, most of hippopotamuses' lives —from childbirth, fighting with other hippos, to reproduction— occur in the water. Hippos leave the water at dusk and travel inland, sometimes up to 8 kilometers (5 mi), to graze on short grass, their main source of food. They spend four to five hours grazing and can consume 68 kilograms (150 lb) of grass each night.[44] Like almost any herbivore, they will consume many other plants if presented with them, but their diet in nature consists almost entirely of grass, with only minimal consumption of aquatic plants.[45] Hippos have (rarely) been filmed eating carrion, usually close to the water. There are other reports of meat-eating, and even cannibalism and predation.[46] The stomach anatomy of a hippo is not suited to carnivory, and meat-eating is likely caused by aberrant behavior or nutritional stress.[9]:84

The diet of hippos consists mostly of terrestrial grasses, even though they spend most of their time in the water. Most of their defecation occurs in the water, creating allochthonous deposits of organic matter along the river beds. These deposits have an unclear ecological function.[45] Because of their size and their habit of taking the same paths to feed, hippos can have a significant impact on the land they walk across, both by keeping the land clear of vegetation and depressing the ground. Over prolonged periods hippos can divert the paths of swamps and channels.[47]

Adult hippos move at speeds up to 8 km/h (5 mph) in water. Adult hippos typically resurface to breathe every three to five minutes. The young have to breathe every two to three minutes.[9]:4 The process of surfacing and breathing is automatic, and even a hippo sleeping underwater will rise and breathe without waking. A hippo closes its nostrils when it submerges into the water. As with fish and turtles on a coral reef, hippo occasionally visit cleaning stations and signal by wide-open mouth their readiness for being cleaned of parasites by certain species of fish. This situation is an example of mutualism in which the hippo benefits from the cleansing while the fish receive food.[ Studying the interaction of male and female hippopotamuses has long been complicated by the fact that hippos are not sexually dimorphic and thus females and young males are almost indistinguishable in the field.[49] Although hippos like to lie close to each other, they do not seem to form social bonds except between mothers and daughters, and are not social animals. The reason they huddle close together is unknown.[9]:49

Hippopotamuses are territorial only in water, where a bull presides over a small stretch of river, on average 250 meters in length, and containing ten females. The largest pods can contain over 100 hippos.[9]:50 Other bachelors are allowed in a bull's stretch, as long as they behave submissively toward the bull. The territories of hippos exist to establish mating rights. Within the pods, the hippos tend to segregate by gender. Bachelors will lounge near other bachelors, females with other females, and the bull on his own. When hippos emerge from the water to graze, they do so individually.[9]:4

Hippopotamuses appear to communicate verbally, through grunts and bellows, and it is thought that they may practice echolocation, but the purpose of these vocalizations is currently unknown. Hippos have the unique ability to hold their head partially above the water and send out a cry that travels through both water and air; hippos above and under water will respond.[ Female hippos reach sexual maturity at five to six years of age and have a gestation period of 8 months. A study of endocrine systems revealed that female hippopotamuses may begin puberty as early as 3 or 4 years of age.[51] Males reach maturity at around 7.5 years. A study of hippopotamus reproductive behavior in Uganda showed that peak conceptions occurred during the end of the wet season in the summer, and peak births occurred toward the beginning of the wet season in late winter. This is because of the female's estrous cycle; as with most large mammals, male hippopotamus spermatozoa is active year round. Studies of hippos in Zambia and South Africa also showed evidence of births occurring at the start of the wet season.[9]:60–61 After becoming pregnant, a female hippopotamus will typically not begin ovulation again for 17 months.[51]

Mating occurs in the water with the female submerged for most of the encounter,[9]:63 her head emerging periodically to draw breath. Baby hippos are born underwater at a weight between 25 and 45 kg (60–110 lb) and an average length of around 127 cm (50 in) and must swim to the surface to take their first breath. A mother typically gives birth to only one hippo, although twins also occur. The young often rest on their mothers' backs when in water that is too deep for them, and they swim underwater to suckle. They also will suckle on land when the mother leaves the water. Weaning starts between six and eight months after birth and most calves are fully weaned after a year.[9]:64 Like many other large mammals, hippos are described as K-strategists, in this case typically producing just one large, well-developed infant every couple of years (rather than large numbers of small, poorly developed young several times per year as is common among small mammals such as rodents. Hippopotamuses are by nature very aggressive animals, especially when young calves are present. Frequent targets of their aggression include crocodiles, which often inhabit the same river habitat as hippos. Nile crocodiles, lions and spotted hyenas are known to prey on young hippos.[53] Hippos are very aggressive towards humans, whom they commonly attack whether in boats or on land with no apparent provocation.[54] They are widely considered to be one of the most dangerous large animals in Africa.[55][56]

To mark territory, hippos spin their tails while defecating to distribute their excrement over a greater area.[57] Likely for the same reason, hippos are retromingent – that is, they urinate backwards.[58] When in combat, male hippos use their incisors to block each others attacks, and their lower canines to inflict damage.[6]:260 Hippos rarely kill each other, even in territorial challenges. Usually a territorial bull and a challenging bachelor will stop fighting when it is clear that one hippo is stronger. When hippos become overpopulated, or when a habitat starts to shrink, bulls will sometimes attempt to kill infants, but this behavior is not common under normal conditions.[52] Some incidents of hippo cannibalism have been documented, but it is believed to be the behavior of distressed or sick hippos, and not healthy behavior. The earliest evidence of human interaction with hippos comes from butchery cut marks upon hippo bones at Bouri Formation dated around 160,000 years ago.[59] Later rock paintings and engravings showing hippos being hunted have been found in the mountains of the central Sahara dated 4,000–5,000 years ago near Djanet in the Tassili n'Ajjer Mountains.[9]:1 The ancient Egyptians recognized the hippo as a ferocious denizen of the Nile.

The hippopotamus was also known to the Greeks and Romans. The Greek historian Herodotus described the hippopotamus in The Histories (written circa 440 BC) and the Roman Historian Pliny the Elder wrote about the hippopotamus in his encyclopedia Naturalis Historia (written circa 77 AD).[37][60] Hippopotamus was one of the many exotic animals brought to fight gladiators in Rome by the emperor Philip I the Arab to commemorate Rome's 1000 years anniversary in 248 AD. Silver coins with hippo's image were minted that year.[citation needed]

Zulu warriors preferred to be as brave as a hippopotamus, since even lions were not considered as brave. "In 1888, Captain Baden-Powell was part of a column searching for the Zulu chief Dinizulu, who was leading the Usutu people in revolt against the British colonists. The column was joined by John Dunn, a white Zulu chief, who led an impi (army) of 2000 Zulu warriors to join the British." [61]

The words of the Zulu anthem sounded like this:

"Een-gonyama Gonyama! "Invooboo! Yah-bo! Yah-bo! Invooboo!"

"John Dunn was at the head of his impi. [Baden Powell] asked him to translate the Zulu anthem his men had been singing. Dunn laughed and replied: "He is a lion. Yes, he is better than a lion—he is a hippopotamus. Hippopotamuses have long been popular zoo animals. The first zoo hippo in modern history was Obaysch who arrived at the London Zoo on May 25, 1850, where he attracted up to 10,000 visitors a day and inspired a popular song, the Hippopotamus Polka.[63] Hippos have remained popular zoo animals since Obaysch, and generally breed well in captivity. Their birth rates are lower than in the wild, but this is attributed to zoos' not wanting to breed as many hippos as possible, since hippos are large and relatively expensive animals to maintain.[9]:129[63]

Like many zoo animals, hippos were traditionally displayed in concrete exhibits. In the case of hippos, they usually had a pool of water and patch of grass. In the 1980s, zoo designers increasingly designed exhibits that reflected the animals' native habitats. The best known of these, the Toledo Zoo Hippoquarium, features a 360,000 gallon pool for hippos.[64] In 1987, researchers were able to tape, for the first time, an underwater birth (as in the wild) at the Toledo Zoo. The exhibit was so popular that the hippos became the logo of the Toledo Zoo. A red hippo represented the Ancient Egyptian god Set; the thigh is the 'phallic leg of set' symbolic of virility. Set's consort Tawaret was also seen as part hippo.[66] The hippopotamus-headed Tawaret was a goddess of protection in pregnancy and childbirth, because ancient Egyptians recognized the protective nature of a female hippopotamus toward her young.[67] The Ijo people wore masks of aquatic animals like the hippo when practicing their water spirit cults.[68] The Behemoth from the Book of Job, 40:15–24 is also thought to be based on a hippo.[69]

Hippos have been the subjects of various African folktales. According to a Bushmen story; when the Creator assigned each animal their place in nature, the hippos wanted to live in the water, but were refused out of fear that they might eat all the fish. After begging and pleading, the hippos were finally allowed to live in the water on the conditions that they would eat grass instead of fish and would fling their dung so that it can be inspected for fish bones.[70] In a Ndebele tale, the hippo originally had long, beautiful hair but was set on fire by a jealous hare and had to jump into a nearby pool. The hippo lost most of his hair and was too embarrassed to leave the water.[70]

Ever since Obaysch inspired the Hippopotamus Polka, hippos have been popular animals in Western culture for their rotund appearance that many consider comical.[63] Stories of hippos like Huberta who became a celebrity in South Africa in the 1930s for trekking across the country;[71] or the tale of Owen and Mzee, a hippo and tortoise who developed an intimate bond; have amused people who have bought hippo books, merchandise, and many a stuffed hippo toy.[72][73] Hippos were mentioned in the novelty Christmas song "I Want a Hippopotamus for Christmas" that became a hit for child star Gayla Peevey in 1953.[74] They also feature in the songs "The Hippopotamus" and "Hippo Encore" by Flanders and Swann, with the famous refrain Mud, Mud, Glorious Mud. They even inspired a popular board game, Hungry Hungry Hippos. Hippos have also been popular cartoon characters, where their rotund frame is used for humorous effect. The Disney film Fantasia featured a ballerina hippopotamus dancing to the opera, La Gioconda.[38] Other cartoon hippos have included Hanna-Barbera's Peter Potamus, the book and TV series George and Martha, Flavio and Marita on the Animaniacs, Pat of the French duo Pat et Stanley, The Backyardigan's Tasha, and Gloria and Moto-Moto from the Madagascar franchise. A Sesame Street cartoon from the early 1970s features a hippo who lives in the country and likes it quiet, while being disturbed when the mouse who likes it loud moves in with her.[citation needed]

The hippopotamus characters "Happy Hippos" were created in 1988 by the French designer Andre Roche [77] based in Munich, to be hidden in the "Kinder Surprise egg" of the Italian chocolate company Ferrero SpA. These characters were not placid like real hippos[contradiction] but rather cute and lively, and had such a success that they reappeared several times in different products of this company in the following years, increasing their popularity worldwide each time.[citation needed] The Nintendo Company published in the years 2001 and 2007 Game Boy adventures of them. In the game of chess, the hippopotamus lends its name to the Hippopotamus Defense, an opening system, which is generally considered weak.The River Horse is a popular outdoor sculpture at George Washington University, Washington, D.C. Botswana, Moremi National Park, Moremi Game reserve, private Reserve, Farm, chobe National park, Chobe Game Reserve, Zambia, Zambezi River, Livingstone, Zimbabwe, Kenya, Tanzania, Wildlife Conservation Project, Maramba River Lodge, South Africa, Krugger National Park. art beach blue bw california canada canon china city concert de england europe family festival film flower flowers food france friends green instagramapp iphoneography italy japan live london music nature new newyork night nikon nyc paris park party people photography portrait red sky snow square squareformat street summer sunset travel trip uk usa vacation water wedding white winter