Systems packaged and sold to homeowners for remote environmental and video monitoring pretty much uniformly suck -- expensive, proprietary and often Windows only. It turns out that hardware designed for use in monitoring datacenters and telco closets is much cheaper, more usable and far more extensible and scalable. This setup shows an APC Netbotz purchased via Ebay. The system monitors a huge range of environmental values and has a massive array of add-on sensors, detectors and cameras. It works quite nicely and can be controlled/monitored 100% via a secure internet connection.

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O beija-flor é uma ave da família Trochilidae, composta por 108 gêneros e 322 espécies conhecidas. Entre as características distintivas do grupo contam-se o bico alongado, a alimentação à base de néctar, oito pares de costelas, catorze a quinze vértebras cervicais, plumagem iridescente e uma língua extensível e bifurcada. O grupo é originário das Américas e ocorre desde o Alasca à Terra do Fogo. A maioria das espécies é tropical e subtropical, vivendo entre as latitudes 10ºN e 25ºS. A maior biodiversidade do grupo encontra-se no Brasil e no Equador, que contam com cerca de metade das espécies conhecidas de beija-flor. Os beija-flores são aves de pequeno porte, que medem em média de seis a doze centímetros de comprimento e pesam de dois a seis gramas. O bico é normalmente longo, mas o formato preciso varia bastante com a espécie e está adaptado ao formato da flor que constitui a base da alimentação de cada tipo de beija-flor. Uma característica comum é a língua bifurcada e extensível, usada para extrair o néctar das flores.

 

The hummingbird is a bird of the family Trochilidae, composed of 108 genera and 322 known species. Among the distinguishing characteristics of the group are elongated beak, nectar-based feeding, eight pairs of ribs, fourteen to fifteen cervical vertebrae, iridescent plumage and an extensible and forked tongue. The group originates in the Americas and occurs from Alaska to Tierra del Fuego. Most species are tropical and subtropical, living between latitudes 10ºN and 25ºS. The group's greatest biodiversity is in Brazil and Ecuador, which account for about half of the known species of hummingbird. Hummingbirds are small birds, measuring an average of six to twelve centimeters in length and weighing two to six grams. The beak is usually long, but the precise shape varies greatly with the species and is adapted to the shape of the flower that forms the basis of the feeding of each type of hummingbird. A common feature is the forked and extensible tongue used to extract nectar from flowers.

 

Adaptado de @Wikipedia pt.wikipedia.org/wiki/Beija-flor

 

Adapted from @Wikipedia

This dragonfly is carrying its eggs

 

A dragonfly is an insect belonging to the order Odonata, infraorder Anisoptera (from Greek ἄνισος anisos, "unequal" and πτερόν pteron, "wing", because the hindwing is broader than the forewing). Adult dragonflies are characterized by large, multifaceted eyes, two pairs of strong, transparent wings, sometimes with coloured patches, and an elongated body. Dragonflies can be mistaken for the related group, damselflies (Zygoptera), which are similar in structure, though usually lighter in build; however, the wings of most dragonflies are held flat and away from the body, while damselflies hold their wings folded at rest, along or above the abdomen. Dragonflies are agile fliers, while damselflies have a weaker, fluttery flight. Many dragonflies have brilliant iridescent or metallic colours produced by structural colouration, making them conspicuous in flight. An adult dragonfly's compound eyes have nearly 24,000 ommatidia each.

 

Fossils of very large dragonfly-like insects, sometimes called griffinflies, are found from 325 million years ago (Mya) in Upper Carboniferous rocks; these had wingspans up to about 750 mm (30 in), but were only distant ancestors, not true dragonflies. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens dragonfly populations around the world.

 

Dragonflies are predators, both in their aquatic nymphs stage (also known as naiads) and as adults. In some species, the nymphal stage lasts for up to five years, and the adult stage may be as long as ten weeks, but most species have an adult lifespan in the order of five weeks or less, and some survive for only a few days. They are fast, agile fliers, sometimes migrating across oceans, and often live near water. They have a uniquely complex mode of reproduction involving indirect insemination, delayed fertilization, and sperm competition. During mating, the male grasps the female at the back of the head, and the female curls her abdomen under her body to pick up sperm from the male's secondary genitalia at the front of his abdomen, forming the "heart" or "wheel" posture.

 

Dragonflies are represented in human culture on artefacts such as pottery, rock paintings, statues and Art Nouveau jewellery. They are used in traditional medicine in Japan and China, and caught for food in Indonesia. They are symbols of courage, strength, and happiness in Japan, but seen as sinister in European folklore. Their bright colours and agile flight are admired in the poetry of Lord Tennyson and the prose of H. E. Bates.

   

Evolution

 

Dragonflies and their relatives are similar in structure to an ancient group, meganisoptera, from the 325 Mya Upper Carboniferous of Europe, a group that included the largest insect that ever lived, Meganeuropsis permiana from the Early Permian, with a wingspan around 750 mm (30 in);. Known informally as "griffinflies", their fossil record ends with the Permian–Triassic extinction event (about 247 Mya). The Protanisoptera, another ancestral group that lacks certain wing vein characters found in modern Odonata, lived from the Early to Late Permian age until the end Permian event, and are known from fossil wings from current-day United States, Russia, and Australia, suggesting they might have been cosmopolitan in distribution. While both of those groups are sometimes referred to as "giant dragonflies", in fact true dragonflies/odonata are more modern insects that had not evolved yet.

 

Modern dragonflies do retain some traits of their distant predecessors, and are in a group known as palaeoptera, ancient-winged. They, like the gigantic pre-dinosaur griffinflies, lack the ability to fold their wings up against their bodies in the way modern insects do, although some evolved their own different way to do so. The forerunners of modern Odonata are included in a clade called the Panodonata, which include the basal Zygoptera (damselflies) and the Anisoptera (true dragonflies). Today, some 3,000 species are extant around the world.

 

The relationships of anisopteran families are not fully resolved as of 2013, but all the families are monophyletic except the Corduliidae; the Gomphidae are a sister taxon to all other Anisoptera, the Austropetaliidae are sister to the Aeshnoidea, and the Chlorogomphidae are sister to a clade that includes the Synthemistidae and Libellulidae. On the cladogram, dashed lines indicate unresolved relationships; English names are given (in parentheses)

   

Distribution and diversity

 

About 3,012 species of dragonflies were known in 2010; these are classified into 348 genera in 11 families. The distribution of diversity within the biogeographical regions are summarized below (the world numbers are not ordinary totals, as overlaps in species occur).

 

Dragonflies live on every continent except Antarctica. In contrast to the damselflies (Zygoptera), which tend to have restricted distributions, some genera and species are spread across continents. For example, the blue-eyed darner Rhionaeschna multicolor lives all across North America, and in Central America; emperors Anax live throughout the Americas from as far north as Newfoundland to as far south as Bahia Blanca in Argentina, across Europe to central Asia, North Africa, and the Middle East. The globe skimmer Pantala flavescens is probably the most widespread dragonfly species in the world; it is cosmopolitan, occurring on all continents in the warmer regions. Most Anisoptera species are tropical, with far fewer species in temperate regions.

 

Some dragonflies, including libellulids and aeshnids, live in desert pools, for example in the Mojave Desert, where they are active in shade temperatures between 18 and 45 °C (64.4 to 113 °F); these insects were able to survive body temperatures above the thermal death point of insects of the same species in cooler places.

 

Dragonflies live from sea level up to the mountains, decreasing in species diversity with altitude. Their altitudinal limit is about 3700 m, represented by a species of Aeshna in the Pamirs.

 

Dragonflies become scarce at higher latitudes. They are not native to Iceland, but individuals are occasionally swept in by strong winds, including a Hemianax ephippiger native to North Africa, and an unidentified darter species. In Kamchatka, only a few species of dragonfly including the treeline emerald Somatochlora arctica and some aeshnids such as Aeshna subarctica are found, possibly because of the low temperature of the lakes there. The treeline emerald also lives in northern Alaska, within the Arctic Circle, making it the most northerly of all dragonflies.

   

General description

 

Dragonflies (suborder Anisoptera) are heavy-bodied, strong-flying insects that hold their wings horizontally both in flight and at rest. By contrast, damselflies (suborder Zygoptera) have slender bodies and fly more weakly; most species fold their wings over the abdomen when stationary, and the eyes are well separated on the sides of the head.

 

An adult dragonfly has three distinct segments, the head, thorax, and abdomen, as in all insects. It has a chitinous exoskeleton of hard plates held together with flexible membranes. The head is large with very short antennae. It is dominated by the two compound eyes, which cover most of its surface. The compound eyes are made up of ommatidia, the numbers being greater in the larger species. Aeshna interrupta has 22650 ommatidia of two varying sizes, 4500 being large. The facets facing downward tend to be smaller. Petalura gigantea has 23890 ommatidia of just one size. These facets provide complete vision in the frontal hemisphere of the dragonfly. The compound eyes meet at the top of the head (except in the Petaluridae and Gomphidae, as also in the genus Epiophlebia). Also, they have three simple eyes or ocelli. The mouthparts are adapted for biting with a toothed jaw; the flap-like labrum, at the front of the mouth, can be shot rapidly forward to catch prey. The head has a system for locking it in place that consists of muscles and small hairs on the back of the head that grip structures on the front of the first thoracic segment. This arrester system is unique to the Odonata, and is activated when feeding and during tandem flight.

 

The thorax consists of three segments as in all insects. The prothorax is small and is flattened dorsally into a shield-like disc, which has two transverse ridges. The mesothorax and metathorax are fused into a rigid, box-like structure with internal bracing, and provide a robust attachment for the powerful wing muscles inside. The thorax bears two pairs of wings and three pairs of legs. The wings are long, veined, and membranous, narrower at the tip and wider at the base. The hindwings are broader than the forewings and the venation is different at the base. The veins carry haemolymph, which is analogous to blood in vertebrates, and carries out many similar functions, but which also serves a hydraulic function to expand the body between nymphal stages (instars) and to expand and stiffen the wings after the adult emerges from the final nymphal stage. The leading edge of each wing has a node where other veins join the marginal vein, and the wing is able to flex at this point. In most large species of dragonflies, the wings of females are shorter and broader than those of males. The legs are rarely used for walking, but are used to catch and hold prey, for perching, and for climbing on plants. Each has two short basal joints, two long joints, and a three-jointed foot, armed with a pair of claws. The long leg joints bear rows of spines, and in males, one row of spines on each front leg is modified to form an "eyebrush", for cleaning the surface of the compound eye.

 

The abdomen is long and slender and consists of 10 segments. Three terminal appendages are on segment 10; a pair of superiors (claspers) and an inferior. The second and third segments are enlarged, and in males, on the underside of the second segment has a cleft, forming the secondary genitalia consisting of the lamina, hamule, genital lobe, and penis. There are remarkable variations in the presence and the form of the penis and the related structures, the flagellum, cornua, and genital lobes. Sperm is produced at the 9th segment, and is transferred to the secondary genitalia prior to mating. The male holds the female behind the head using a pair of claspers on the terminal segment. In females, the genital opening is on the underside of the eighth segment, and is covered by a simple flap (vulvar lamina) or an ovipositor, depending on species and the method of egg-laying. Dragonflies having simple flaps shed the eggs in water, mostly in flight. Dragonflies having ovipositors use them to puncture soft tissues of plants and place the eggs singly in each puncture they make.

 

Dragonfly nymphs vary in form with species, and are loosely classed into claspers, sprawlers, hiders, and burrowers. The first instar is known as a prolarva, a relatively inactive stage from which it quickly moults into the more active nymphal form. The general body plan is similar to that of an adult, but the nymph lacks wings and reproductive organs. The lower jaw has a huge, extensible labium, armed with hooks and spines, which is used for catching prey. This labium is folded under the body at rest and struck out at great speed by hydraulic pressure created by the abdominal muscles. Whereas damselfly nymphs have three feathery external gills, dragonfly nymphs have internal gills, located around the fourth and fifth abdominal segments. Water is pumped in and out of the abdomen through an opening at the tip. The naiads of some clubtails (Gomphidae) that burrow into the sediment, have a snorkel-like tube at the end of the abdomen enabling them to draw in clean water while they are buried in mud. Naiads can forcefully expel a jet of water to propel themselves with great rapidity.

   

Colouration

 

Many adult dragonflies have brilliant iridescent or metallic colours produced by structural colouration, making them conspicuous in flight. Their overall colouration is often a combination of yellow, red, brown, and black pigments, with structural colours. Blues are typically created by microstructures in the cuticle that reflect blue light. Greens often combine a structural blue with a yellow pigment. Freshly emerged adults, known as tenerals, are often pale-coloured and obtain their typical colours after a few days, some have their bodies covered with a pale blue, waxy powderiness called pruinosity; it wears off when scraped during mating, leaving darker areas.

 

Some dragonflies, such as the green darner, Anax junius, have a noniridescent blue that is produced structurally by scatter from arrays of tiny spheres in the endoplasmic reticulum of epidermal cells underneath the cuticle.

 

The wings of dragonflies are generally clear, apart from the dark veins and pterostigmata. In the chasers (Libellulidae), however, many genera have areas of colour on the wings: for example, groundlings (Brachythemis) have brown bands on all four wings, while some scarlets (Crocothemis) and dropwings (Trithemis) have bright orange patches at the wing bases. Some aeshnids such as the brown hawker (Aeshna grandis) have translucent, pale yellow wings.

 

Dragonfly nymphs are usually a well-camouflaged blend of dull brown, green, and grey.

   

Biology

 

Ecology

 

Dragonflies and damselflies are predatory both in the aquatic nymphal and adult stages. Nymphs feed on a range of freshwater invertebrates and larger ones can prey on tadpoles and small fish. Adults capture insect prey in the air, making use of their acute vision and highly controlled flight. The mating system of dragonflies is complex, and they are among the few insect groups that have a system of indirect sperm transfer along with sperm storage, delayed fertilization, and sperm competition.

 

Adult males vigorously defend territories near water; these areas provide suitable habitat for the nymphs to develop, and for females to lay their eggs. Swarms of feeding adults aggregate to prey on swarming prey such as emerging flying ants or termites.

 

Dragonflies as a group occupy a considerable variety of habitats, but many species, and some families, have their own specific environmental requirements. Some species prefer flowing waters, while others prefer standing water. For example, the Gomphidae (clubtails) live in running water, and the Libellulidae (skimmers) live in still water. Some species live in temporary water pools and are capable of tolerating changes in water level, desiccation, and the resulting variations in temperature, but some genera such as Sympetrum (darters) have eggs and nymphs that can resist drought and are stimulated to grow rapidly in warm, shallow pools, also often benefiting from the absence of predators there. Vegetation and its characteristics including submerged, floating, emergent, or waterside are also important. Adults may require emergent or waterside plants to use as perches; others may need specific submerged or floating plants on which to lay eggs. Requirements may be highly specific, as in Aeshna viridis (green hawker), which lives in swamps with the water-soldier, Stratiotes aloides. The chemistry of the water, including its trophic status (degree of enrichment with nutrients) and pH can also affect its use by dragonflies. Most species need moderate conditions, not too eutrophic, not too acidic; a few species such as Sympetrum danae (black darter) and Libellula quadrimaculata (four-spotted chaser) prefer acidic waters such as peat bogs, while others such as Libellula fulva (scarce chaser) need slow-moving, eutrophic waters with reeds or similar waterside plants.

   

Behaviour

 

Many dragonflies, particularly males, are territorial. Some defend a territory against others of their own species, some against other species of dragonfly and a few against insects in unrelated groups. A particular perch may give a dragonfly a good view over an insect-rich feeding ground; males of many species such as the Pachydiplax longipennis (blue dasher) jostle other dragonflies to maintain the right to alight there. Defending a breeding territory is common among male dragonflies, especially in species that congregate around ponds. The territory contains desirable features such as a sunlit stretch of shallow water, a special plant species, or the preferred substrate for egg-laying. The territory may be small or large, depending on its quality, the time of day, and the number of competitors, and may be held for a few minutes or several hours. Dragonflies including Tramea lacerata (black saddlebags) may notice landmarks that assist in defining the boundaries of the territory. Landmarks may reduce the costs of territory establishment, or might serve as a spatial reference. Some dragonflies signal ownership with striking colours on the face, abdomen, legs, or wings. The Plathemis lydia (common whitetail) dashes towards an intruder holding its white abdomen aloft like a flag. Other dragonflies engage in aerial dogfights or high-speed chases. A female must mate with the territory holder before laying her eggs. There is also conflict between the males and females. Females may sometimes be harassed by males to the extent that it affects their normal activities including foraging and in some dimorphic species females have evolved multiple forms with some forms appearing deceptively like males. In some species females have evolved behavioural responses such as feigning death to escape the attention of males. Similarly, selection of habitat by adult dragonflies is not random, and terrestrial habitat patches may be held for up to 3 months. A species tightly linked to its birth site utilises a foraging area that is several orders of magnitude larger than the birth site.

   

Reproduction

 

Mating in dragonflies is a complex, precisely choreographed process. First, the male has to attract a female to his territory, continually driving off rival males. When he is ready to mate, he transfers a packet of sperm from his primary genital opening on segment 9, near the end of his abdomen, to his secondary genitalia on segments 2–3, near the base of his abdomen. The male then grasps the female by the head with the claspers at the end of his abdomen; the structure of the claspers varies between species, and may help to prevent interspecific mating. The pair flies in tandem with the male in front, typically perching on a twig or plant stem. The female then curls her abdomen downwards and forwards under her body to pick up the sperm from the male's secondary genitalia, while the male uses his "tail" claspers to grip the female behind the head: this distinctive posture is called the "heart" or "wheel"; the pair may also be described as being "in cop".

 

Egg-laying (ovipositing) involves not only the female darting over floating or waterside vegetation to deposit eggs on a suitable substrate, but also the male hovering above her or continuing to clasp her and flying in tandem. The male attempts to prevent rivals from removing his sperm and inserting their own, something made possible by delayed fertilisation and driven by sexual selection. If successful, a rival male uses his penis to compress or scrape out the sperm inserted previously; this activity takes up much of the time that a copulating pair remains in the heart posture. Flying in tandem has the advantage that less effort is needed by the female for flight and more can be expended on egg-laying, and when the female submerges to deposit eggs, the male may help to pull her out of the water.

 

Egg-laying takes two different forms depending on the species. The female in some families has a sharp-edged ovipositor with which she slits open a stem or leaf of a plant on or near the water, so she can push her eggs inside. In other families such as clubtails (Gomphidae), cruisers (Macromiidae), emeralds (Corduliidae), and skimmers (Libellulidae), the female lays eggs by tapping the surface of the water repeatedly with her abdomen, by shaking the eggs out of her abdomen as she flies along, or by placing the eggs on vegetation. In a few species, the eggs are laid on emergent plants above the water, and development is delayed until these have withered and become immersed.

   

Life cycle

 

Dragonflies are hemimetabolous insects; they do not have a pupal stage and undergo an incomplete metamorphosis with a series of nymphal stages from which the adult emerges. Eggs laid inside plant tissues are usually shaped like grains of rice, while other eggs are the size of a pinhead, ellipsoidal, or nearly spherical. A clutch may have as many as 1500 eggs, and they take about a week to hatch into aquatic nymphs or naiads which moult between six and 15 times (depending on species) as they grow. Most of a dragonfly's life is spent as a nymph, beneath the water's surface. The nymph extends its hinged labium (a toothed mouthpart similar to a lower mandible, which is sometimes termed as a "mask" as it is normally folded and held before the face) that can extend forward and retract rapidly to capture prey such as mosquito larvae, tadpoles, and small fish. They breathe through gills in their rectum, and can rapidly propel themselves by suddenly expelling water through the anus. Some naiads, such as the later stages of Antipodophlebia asthenes, hunt on land.

 

The nymph stage of dragonflies lasts up to five years in large species, and between two months and three years in smaller species. When the naiad is ready to metamorphose into an adult, it stops feeding and makes its way to the surface, generally at night. It remains stationary with its head out of the water, while its respiration system adapts to breathing air, then climbs up a reed or other emergent plant, and moults (ecdysis). Anchoring itself firmly in a vertical position with its claws, its skin begins to split at a weak spot behind the head. The adult dragonfly crawls out of its nymph skin, the exuvia, arching backwards when all but the tip of its abdomen is free, to allow its exoskeleton to harden. Curling back upwards, it completes its emergence, swallowing air, which plumps out its body, and pumping haemolymph into its wings, which causes them to expand to their full extent.

 

Dragonflies in temperate areas can be categorized into two groups, an early group and a later one. In any one area, individuals of a particular "spring species" emerge within a few days of each other. The springtime darner (Basiaeschna janata), for example, is suddenly very common in the spring, but disappears a few weeks later and is not seen again until the following year. By contrast, a "summer species" emerges over a period of weeks or months, later in the year. They may be seen on the wing for several months, but this may represent a whole series of individuals, with new adults hatching out as earlier ones complete their lifespans.

   

Sex ratios

 

The sex ratio of male to female dragonflies varies both temporally and spatially. Adult dragonflies have a high male-biased ratio at breeding habitats. The male-bias ratio has contributed partially to the females using different habitats to avoid male harassment. As seen in Hine's emerald dragonfly (Somatochlora hineana), male populations use wetland habitats, while females use dry meadows and marginal breeding habitats, only migrating to the wetlands to lay their eggs or to find mating partners. Unwanted mating is energetically costly for females because it affects the amount of time that they are able to spend foraging.

   

Flight

 

Dragonflies are powerful and agile fliers, capable of migrating across the sea, moving in any direction, and changing direction suddenly. In flight, the adult dragonfly can propel itself in six directions: upward, downward, forward, backward, to left and to right. They have four different styles of flight: A number of flying modes are used that include counter-stroking, with forewings beating 180° out of phase with the hindwings, is used for hovering and slow flight. This style is efficient and generates a large amount of lift; phased-stroking, with the hindwings beating 90° ahead of the forewings, is used for fast flight. This style creates more thrust, but less lift than counter-stroking; synchronised-stroking, with forewings and hindwings beating together, is used when changing direction rapidly, as it maximises thrust; and gliding, with the wings held out, is used in three situations: free gliding, for a few seconds in between bursts of powered flight; gliding in the updraft at the crest of a hill, effectively hovering by falling at the same speed as the updraft; and in certain dragonflies such as darters, when "in cop" with a male, the female sometimes simply glides while the male pulls the pair along by beating his wings.

 

The wings are powered directly, unlike most families of insects, with the flight muscles attached to the wing bases. Dragonflies have a high power/weight ratio, and have been documented accelerating at 4 G linearly and 9 G in sharp turns while pursuing prey.

 

Dragonflies generate lift in at least four ways at different times, including classical lift like an aircraft wing; supercritical lift with the wing above the critical angle, generating high lift and using very short strokes to avoid stalling; and creating and shedding vortices. Some families appear to use special mechanisms, as for example the Libellulidae which take off rapidly, their wings beginning pointed far forward and twisted almost vertically. Dragonfly wings behave highly dynamically during flight, flexing and twisting during each beat. Among the variables are wing curvature, length and speed of stroke, angle of attack, forward/back position of wing, and phase relative to the other wings.

   

Flight speed

 

Old and unreliable claims are made that dragonflies such as the southern giant darner can fly up to 97 km/h (60 mph). However, the greatest reliable flight speed records are for other types of insects. In general, large dragonflies like the hawkers have a maximum speed of 36–54 km/h (22–34 mph) with average cruising speed of about 16 km/h (9.9 mph). Dragonflies can travel at 100 body-lengths per second in forward flight, and three lengths per second backwards.

   

Motion camouflage

 

n high-speed territorial battles between male Australian emperors (Hemianax papuensis), the fighting dragonflies adjust their flight paths to appear stationary to their rivals, minimizing the chance of being detected as they approach.[a] To achieve the effect, the attacking dragonfly flies towards his rival, choosing his path to remain on a line between the rival and the start of his attack path. The attacker thus looms larger as he closes on the rival, but does not otherwise appear to move. Researchers found that six of 15 encounters involved motion camouflage.

   

Temperature control

 

The flight muscles need to be kept at a suitable temperature for the dragonfly to be able to fly. Being cold-blooded, they can raise their temperature by basking in the sun. Early in the morning, they may choose to perch in a vertical position with the wings outstretched, while in the middle of the day, a horizontal stance may be chosen. Another method of warming up used by some larger dragonflies is wing-whirring, a rapid vibration of the wings that causes heat to be generated in the flight muscles. The green darner (Anax junius) is known for its long-distance migrations, and often resorts to wing-whirring before dawn to enable it to make an early start.

 

Becoming too hot is another hazard, and a sunny or shady position for perching can be selected according to the ambient temperature. Some species have dark patches on the wings which can provide shade for the body, and a few use the obelisk posture to avoid overheating. This behaviour involves doing a "handstand", perching with the body raised and the abdomen pointing towards the sun, thus minimising the amount of solar radiation received. On a hot day, dragonflies sometimes adjust their body temperature by skimming over a water surface and briefly touching it, often three times in quick succession. This may also help to avoid desiccation.

   

Feeding

 

Adult dragonflies hunt on the wing using their exceptionally acute eyesight and strong, agile flight. They are almost exclusively carnivorous, eating a wide variety of insects ranging from small midges and mosquitoes to butterflies, moths, damselflies, and smaller dragonflies. A large prey item is subdued by being bitten on the head and is carried by the legs to a perch. Here, the wings are discarded and the prey usually ingested head first. A dragonfly may consume as much as a fifth of its body weight in prey per day. Dragonflies are also some of the insect world's most efficient hunters, catching up to 95% of the prey they pursue.

 

The nymphs are voracious predators, eating most living things that are smaller than they are. Their staple diet is mostly bloodworms and other insect larvae, but they also feed on tadpoles and small fish. A few species, especially those that live in temporary waters, are likely to leave the water to feed. Nymphs of Cordulegaster bidentata sometimes hunt small arthropods on the ground at night, while some species in the Anax genus have even been observed leaping out of the water to attack and kill full-grown tree frogs.

   

Eyesight

 

Dragonfly vision is thought to be like slow motion for humans. Dragonflies see faster than we do; they see around 200 images per second. A dragonfly can see in 360 degrees, and nearly 80 percent of the insect's brain is dedicated to its sight.

   

Predators

 

Although dragonflies are swift and agile fliers, some predators are fast enough to catch them. These include falcons such as the American kestrel, the merlin, and the hobby; nighthawks, swifts, flycatchers and swallows also take some adults; some species of wasps, too, prey on dragonflies, using them to provision their nests, laying an egg on each captured insect. In the water, various species of ducks and herons eat dragonfly nymphs and they are also preyed on by newts, frogs, fish, and water spiders. Amur falcons, which migrate over the Indian Ocean at a period that coincides with the migration of the globe skimmer dragonfly, Pantala flavescens, may actually be feeding on them while on the wing.

   

Parasites

 

Dragonflies are affected by three major groups of parasites: water mites, gregarine protozoa, and trematode flatworms (flukes). Water mites, Hydracarina, can kill smaller dragonfly nymphs, and may also be seen on adults. Gregarines infect the gut and may cause blockage and secondary infection. Trematodes are parasites of vertebrates such as frogs, with complex life cycles often involving a period as a stage called a cercaria in a secondary host, a snail. Dragonfly nymphs may swallow cercariae, or these may tunnel through a nymph's body wall; they then enter the gut and form a cyst or metacercaria, which remains in the nymph for the whole of its development. If the nymph is eaten by a frog, the amphibian becomes infected by the adult or fluke stage of the trematode.

   

Dragonflies and humans

 

Conservation

 

Most odonatologists live in temperate areas and the dragonflies of North America and Europe have been the subject of much research. However, the majority of species live in tropical areas and have been little studied. With the destruction of rainforest habitats, many of these species are in danger of becoming extinct before they have even been named. The greatest cause of decline is forest clearance with the consequent drying up of streams and pools which become clogged with silt. The damming of rivers for hydroelectric schemes and the drainage of low-lying land has reduced suitable habitat, as has pollution and the introduction of alien species.

 

In 1997, the International Union for Conservation of Nature set up a status survey and conservation action plan for dragonflies. This proposes the establishment of protected areas around the world and the management of these areas to provide suitable habitat for dragonflies. Outside these areas, encouragement should be given to modify forestry, agricultural, and industrial practices to enhance conservation. At the same time, more research into dragonflies needs to be done, consideration should be given to pollution control and the public should be educated about the importance of biodiversity.

 

Habitat degradation has reduced dragonfly populations across the world, for example in Japan. Over 60% of Japan's wetlands were lost in the 20th century, so its dragonflies now depend largely on rice fields, ponds, and creeks. Dragonflies feed on pest insects in rice, acting as a natural pest control. Dragonflies are steadily declining in Africa, and represent a conservation priority.

 

The dragonfly's long lifespan and low population density makes it vulnerable to disturbance, such as from collisions with vehicles on roads built near wetlands. Species that fly low and slow may be most at risk.

 

Dragonflies are attracted to shiny surfaces that produce polarization which they can mistake for water, and they have been known to aggregate close to polished gravestones, solar panels, automobiles, and other such structures on which they attempt to lay eggs. These can have a local impact on dragonfly populations; methods of reducing the attractiveness of structures such as solar panels are under experimentation.

   

In culture

 

A blue-glazed faience dragonfly amulet was found by Flinders Petrie at Lahun, from the Late Middle Kingdom of ancient Egypt.

 

Many Native American tribes consider dragonflies to be medicine animals that had special powers. For example, the southwestern tribes, including the Pueblo, Hopi, and Zuni, associated dragonflies with transformation. They referred to dragonflies as "snake doctors" because they believed dragonflies followed snakes into the ground and healed them if they were injured. For the Navajo, dragonflies symbolize pure water. Often stylized in a double-barred cross design, dragonflies are a common motif in Zuni pottery, as well as Hopi rock art and Pueblo necklaces.: 20–26 

 

As a seasonal symbol in Japan, the dragonflies are associated with season of autumn. In Japan, they are symbols of rebirth, courage, strength, and happiness. They are also depicted frequently in Japanese art and literature, especially haiku poetry. Japanese children catch large dragonflies as a game, using a hair with a small pebble tied to each end, which they throw into the air. The dragonfly mistakes the pebbles for prey, gets tangled in the hair, and is dragged to the ground by the weight.: 38 

 

In Chinese culture, dragonflies symbolize both change and instability. They are also symbols in the Chinese practices of Feng Shui, where placements of dragonfly statues and artwork in parts of a home or office are believed to bring new insights and positive changes.

 

In both China and Japan, dragonflies have been used in traditional medicine. In Indonesia, adult dragonflies are caught on poles made sticky with birdlime, then fried in oil as a delicacy.

 

Images of dragonflies are common in Art Nouveau, especially in jewellery designs. They have also been used as a decorative motif on fabrics and home furnishings. Douglas, a British motorcycle manufacturer based in Bristol, named its innovatively designed postwar 350-cc flat-twin model the Dragonfly.

 

Among the classical names of Japan are Akitsukuni (秋津国), Akitsushima (秋津島), Toyo-akitsushima (豊秋津島). Akitsu is an old word for dragonfly, so one interpretation of Akitsushima is "Dragonfly Island". This is attributed to a legend in which Japan's mythical founder, Emperor Jimmu, was bitten by a mosquito, which was then eaten by a dragonfly.

 

In Europe, dragonflies have often been seen as sinister. Some English vernacular names, such as "horse-stinger", "devil's darning needle", and "ear cutter", link them with evil or injury. Swedish folklore holds that the devil uses dragonflies to weigh people's souls.: 25–27  The Norwegian name for dragonflies is Øyenstikker ("eye-poker"), and in Portugal, they are sometimes called tira-olhos ("eyes-snatcher"). They are often associated with snakes, as in the Welsh name gwas-y-neidr, "adder's servant". The Southern United States terms "snake doctor" and "snake feeder" refer to a folk belief that dragonflies catch insects for snakes or follow snakes around and stitch them back together if they are injured. Interestingly, the Hungarian name for dragonfly is szitakötő ("sieve-knitter").

 

The watercolourist Moses Harris (1731–1785), known for his The Aurelian or natural history of English insects (1766), published in 1780, the first scientific descriptions of several Odonata including the banded demoiselle, Calopteryx splendens. He was the first English artist to make illustrations of dragonflies accurate enough to be identified to species (Aeshna grandis at top left of plate illustrated), though his rough drawing of a nymph (at lower left) with the mask extended appears to be plagiarised.[b]

 

More recently, dragonfly watching has become popular in America as some birdwatchers seek new groups to observe.

 

In heraldry, like other winged insects, the dragonfly is typically depicted tergiant (with its back facing the viewer), with its head to chief.

   

In poetry and literature

 

Lafcadio Hearn wrote in his 1901 book A Japanese Miscellany that Japanese poets had created dragonfly haiku "almost as numerous as are the dragonflies themselves in the early autumn." The poet Matsuo Bashō (1644–1694) wrote haiku such as "Crimson pepper pod / add two pairs of wings, and look / darting dragonfly", relating the autumn season to the dragonfly. Hori Bakusui (1718–1783) similarly wrote "Dyed he is with the / Colour of autumnal days, / O red dragonfly."

 

The poet Lord Tennyson, described a dragonfly splitting its old skin and emerging shining metallic blue like "sapphire mail" in his 1842 poem "The Two Voices", with the lines "An inner impulse rent the veil / Of his old husk: from head to tail / Came out clear plates of sapphire mail."

 

The novelist H. E. Bates described the rapid, agile flight of dragonflies in his 1937 nonfiction book Down the River:

 

I saw, once, an endless procession, just over an area of water-lilies, of small sapphire dragonflies, a continuous play of blue gauze over the snowy flowers above the sun-glassy water. It was all confined, in true dragonfly fashion, to one small space. It was a continuous turning and returning, an endless darting, poising, striking and hovering, so swift that it was often lost in sunlight.

 

In technology

 

A dragonfly has been genetically modified with light-sensitive "steering neurons" in its nerve cord to create a cyborg-like "DragonflEye". The neurons contain genes like those in the eye to make them sensitive to light. Miniature sensors, a computer chip and a solar panel were fitted in a "backpack" over the insect's thorax in front of its wings. Light is sent down flexible light-pipes named optrodes[c] from the backpack into the nerve cord to give steering commands to the insect. The result is a "micro-aerial vehicle that's smaller, lighter and stealthier than anything else that's manmade".

 

[Credit: en.wikipedia.org/]

DROMEDARY ...........................................................................

Arabian camel

DROMEDARIO ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

camello arábigo , camello árabe , camello de una joroba,

DROMEDÁRIO - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

camelo árabe

 

Camelus dromedarius Linnaeus, 1758

Orden: Artiodactyla Owen, 1848 (= Cetartiodactyla) (Artiodáctilos)

Suborden: Tylopoda Illiger, 1811 (= tilópodos = tylópodos)

Familia: Camelidae Gray, 1821 (Camélidos)

Tribu: Camelini ( = Camelinos = Camelínidos)

 

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Localidad tipo (Type Locality): Habitat in Africae desertis arenosis siticulosis", identificado como "desiertos de Libia y Arabia" por Thomas (1911); basado en materiales de animales domésticos.

 

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El dromedario es un artiodáctilo asiático, hoy extinto como animal silvestre, pero mantenido desde hace milenios como especie doméstica, aunque se encuentra asilvestrado en Australia.

Es el símbolo icónico de los desiertos del mundo.

 

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ORIGEN de su DOMESTICACIÓN:

Los dromedarios fueron domesticados por primera vez en el centro o el sur de la Península Arábiga hace algunos miles de años.

Los expertos están divididos acerca de la fecha: algunos creen que fue alrededor de 6000 años atrás, para otros fue hace 3400 años.

En todo el segundo milenio antes de Cristo, el dromedario fue introducido en Egipto, y el desierto del Sahara en el Norte de África.

Logró establecerse en la región por un tiempo, pero desaparecieron alrededor de 900 aC.

La invasión persa a Egipto de Cambises trajo camellos bactrianos a la zona para ser utilizados en gran parte del norte de África.

Los romanos mantuvieron un cuerpo de guerreros sobre estos camellos para patrullar las fronteras en el desierto.

Pero los camellos persas, sin embargo, no eran especialmente adecuados para el comercio o los viajes sobre el Sahara; los viajes a través del desierto se hicieron en carros tirados por caballos.

Los dromedarios, por ser más fuertes y durables, primero comenzaron a llegar a África en el siglo IV.

No fue hasta la conquista islámica del norte de África, sin embargo, que su estampa se convirtió en una imagen común.

Mientras que la invasión se llevó a cabo en gran medida a caballo, los nuevos enlaces a Oriente Medio permitieron que se importen dromedarios en masa.

Los dromedarios estaban bien adaptados a largos viajes por el desierto, y podían transportar una gran cantidad de carga.

Esto permitió el comercio sobre el Sahara por primera vez.

 

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CARACTERÍSTICAS:

Es similar al camello bactriano (conocido simplemente como camello) con el cual produce híbridos fértiles, al igual que con el guanaco.

Se diferencia del camello por su pelaje más corto, con el cuerpo proporcionalmente menos largo y robusto, pero más alto, y la presencia de una joroba en lugar de dos.

El dromedario es más rápido: puede mantener de 13 a 14,5 km por hora (de 8 a 9 millas / h) con un jinete sobre su lomo durante varias horas.

En comparación, un camello bactriano se mueve a alrededor de 4 km por hora (2,5 millas / h).

Posee pezuñas, el abdomen elevado y patas largas y delgadas.

Como en su primo, los orificios nasales forman aberturas oblicuas, y el labio superior es dividido, movible por separado, y extensible.

Su anatomía muestra todo tipo de adaptaciones a la vida en los desiertos cálidos y arenosos donde vive: Las rodillas y tobillos tienen callosidades que las hacen más resistentes al ardor de la arena cuando se sientan, sus pestañas largas y finas mantienen los ojos a salvo de que les entre arena, igual objetivo complen los abundantes pelos en sus pequeñas orejas.

En la joroba mantiene un depósito de grasa con la cual puede nutrirse e incluso extraerle el agua si es necesario.

Su capacidad de resistencia ante la deshidratación los ha hecho muy valiosos e indispensables en el desierto.

En los momentos en que dispone de agua, el dromedario puede llegar a beber hasta 150 litros en muy poco tiempo.

Para conservar el agua, demuestra una notable adaptación: la capacidad para adaptar su temperatura corporal, desde los 34 ° C a 41,7 ° C.

El dromedario macho tiene un paladar blando, que se infla para producir un saco de color rosa intenso, que se confunde a menudo con la lengua, llamado "doula" en árabe, colgando de los lados de su boca para atraer a las hembras durante la temporada de apareamiento.

 

Su peso varía entre los 350 kg (en las hembras más pequeñas), y como máximo los 1.000 kg (2200 lb), en los machos más grandes.

Los machos adultos crecen hasta una altura de 180 a 210 centímetros (6 a 7 ft), y las hembras de 170 a 190 centímetros.

El largo desde el hocico a la base de la cola es de unos 300 centímetros (10 ft.).

La cola es de 50 cm de largo (20 in).

Gesta una sola cría durante 12 ó 13 meses.

El destete se produce entre 1 a 2 años.

La madurez sexual en las hembras es a los 3 a 4 años, y en los machos es a los 5 a 6 años

 

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COMPORTAMIENTO:

Los dromedarios son animales sociales que viven formando rebaños que generalmente están compuestos por un macho dominante y unas hembras acompañadas de sus crías; el resto de los machos forman un rebaño aparte.

Los machos disputan por determinar su posición en la jerarquía social, mediante amenazas y ataques agresivos.

Los dromedarios son animales herbívoros, es decir, se alimentan exclusivamente de vegetales.

Es pasteador y ramoneador.

El dromedario es un animal resistente que puede pastar en cualquier tipo de ambiente, pudiendo estar varios días seguidos sin comer.

Normalmente viven de 40 a 50 años.

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DISTRIBUCIÓN:

Los dromedarios son originarios de la Península Arábiga en el sudoeste de Asia, aunque han sido introducidos por el hombre en multitud de lugares, y no son raros los casos en que estos animales han escapado y formado poblaciones semisalvajes, la más importante de ellas se encuentra en el interior de Australia.

En la actualidad abunda, sobre todo, en el área que abarca desde el noroeste de la India a través de Pakistán e Irán hasta el norte de África, Senegal, Mauritania, Somalia, y Kenia.

 

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RAZAS:

Esta especie se subdivide en 50 razas, o variedades, adaptadas a distintos ambientes, climas, y usos.

En líneas generales se las divide en dos grandes grupos, las de montar, caracterizadas por su cuerpo más estilizado; y las de carga, las que son típicamente más fornidas, lentas, de patas más fuertes, adaptadas para llevar carga pesada por largos trayectos en las clásicas "caravanas de camellos".

Algunas razas son:

AIT KHEBBACH ~ AJJER ~ ANAFI ~ ARAB CAMEL ~ ARABI ~ AZAOUAK NIGÉRIEN ~ BANAT HUMRA ~ BANAT KHABAR ~ BANAT USAYFIR ~ BÉRABICHE DU MALI ~ BIKANERI ~ BOTSWANA CAMEL ~ CHAMEAU DE L'AFTOUT ~ CHAMEAU DE LA STEPPE ~ CHAMI ~ EGGUIBI ~ ETHIOPIAN DROMEDARY ~ FELLAHI ~ IRAQI ~ JAISALMERI ~ JEBLI ~ KUTCHI ~ LE CHAMEAU DU KANEM ~ LE CHAMEAU GORANE ~ MAHAMID ~ MAGHRABI ~ MAGHREBI ~ MALVI ~ MARMOURI ~ MARWARI ~ MEWARI ~ MEWATI ~ MOWALLED ~ OULED SID CHEIKH ~ RED SEA HILLS ~ REGIBI ~ REGUIBI DE MAURITANIA ~ RENDILLE ~ SAHARAN CAMEL ~ SHAMELIA ~ SINDHI ~ SOMALI ~ SUDANI ~ TARGUI ~ TURKANA ~ YAHAOURI

 

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DROMEDARIO AUSTRALIANO SALVAJE (Australian feral camels):

En 1840 los primeros seis dromedarios fueron transportados a Adelaida Australia, desde Tenerife, en las Islas Canarias.

Sólo uno sobrevivió al viaje, llegando el 12 de octubre 1840.

Muchas diferentes razas de dromedarios fueron llevadas a Australia, pero la mayoría eran de la India.

Además del camello bactriano de dos jorobas de China y Mongolia, se importaron el gran dromedario lanero, el Bishari de montar, del norte de África y Arabia, el camello Bikaneri de guerra, de Rajastán en la India, y el poderoso dromedario indio de tierras bajas, capaz de desplazar grandes cargas de hasta 800 kg (1.764 libras).

Los dromedarios salvajes australianos son una mezcla de todas estas razas, pero se pueden dividir en dos grandes tipos: un tipo es de forma esbelta apta para montar, y el otro es un tipo de animal apto para carga pesada.

El explorador John Horrocks fue una de las primeras personas en utilizar dromedarios para explorar el árido interior de Australia entre 1840 a 1850.

Miles de dromedarios fueron importados entre 1840 y 1907, logrando la apertura de las zonas áridas del centro y el oeste de Australia.

Eran utilizados para montar, y como animales de carga para la exploración y la construcción de ferrocarriles y líneas telegráficas; también se utilizaron para el suministro de bienes a las minas y a los asentamientos remotos.

El Cuerpo australiano de dromedarios incluso sirvió en Egipto y Palestina en la Primera Guerra Mundial, como parte del Cuerpo Imperial de la Gran Bretaña de dromedarios.

Pero a mediados de la década de 1920, una nueva ola de importaciones de autos y camiones llegó al interior australiano. Pero mientras que desde la década de 1930 en adelante, el dromedario doméstico pasó a ser una pieza de museo, el dromedario salvaje prosperó en el monte.

El creciente número de dromedarios, y su impacto sobre la vegetación nativa, son motivo de preocupación, y los dromedarios salvajes en Australia se han convertido en plagas agrícolas de importancia, con una población estimada en 1 millón de ejemplares, creciendo un 10% por año, ante la ausencia de depredadores, lo que terminará por agotar las pasturas de las ovejas y vacunos...

Gracias a esta población cimarrona podemos saber un poco más sobre como habrían sido los hábitos de la especie salvaje original.

Otras poblaciones de dromedarios salvajes existieron en el siglo XX en Parque Nacional de Doñana en España, y en el suroeste de los Estados Unidos, hoy ambas están extintas.

Dromedarios vivos hoy son exportados a Arabia Saudita, el Reino Unido, Países Árabes, Brunei, y hasta a Malasia, donde los dromedarios libres de enfermedades son muy apreciados como un manjar.

Los dromedarios de Australia también se exportan como reproductores para las carreras de Dromedarios en Arabia; y para su empleo en localidades turísticas de los Estados Unidos, Argentina, Uruguay, etc.

 

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CONSERVACIÓN:

Ninguno logró sobrevivir en estado salvaje en su área de distribución original.

En la actualidad hay 15 millones de dromedarios domésticos, y 1 millón de ejemplares salvajes en Australia.

 

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APROVECHAMIENTO PRODUCTIVO:

Aunque los dromedarios tienen la reputación de ser criaturas malhumoradas y obstinadas, que escupen y patean, son utilizados como una bestia de carga en la mayoría de su geonemia como animal doméstico.

A diferencia de los caballos, se arrodillan para la monta de pasajeros y carga.

El uso de este animal como motor de trabajo en las tareas agrícolas ha sido común en el archipiélago de las Canarias hasta la reciente industrialización, generándose términos propios como "guelfo", para definir a la cría del dromedario.

En muchas localidades remotas en el desierto de Egipto los guardias fronterizos emplean dromedarios para realizar las patrullas.

 

La carne de dromedario se consume en gran escala en la Península Arábiga, Somalia, Sudán, y en menor medida, Egipto, entre otros países.

 

Son muy utilizados como animal lechero, en especial en la región de Somalia, en donde viven el 25 % del total de dromedarios del mundo.

 

Su pelo se utiliza como materia básica para productos tejidos, que van desde tiendas de campaña beduinas, a valiosas prendas.

 

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SINONIMIA:

Camelus aegyptiacus Kolenati, 1847

Camelus africanus (Gloger, 1841)

Camelus arabicus Desmoulins, 1823

Camelus dromas Pallas, 1811

Camelus dromos Kerr, 1792

Camelus ferus Falk, 1786

Camelus lukius Kolenati, 1847

Camelus polytrichus Kolenati, 1847

Camelus turcomanicus J. Fischer, 1829

Camelus vulgaris Kolenati, 1847

 

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Suborden TYLOPODA:

Los tilópodos (Tylopoda, gr. "pies con almohadillas") son un suborden de mamíferos artiodáctilos.

En el pasado fue mucho más diverso, y fueron descriptas varias familias, hoy todas extintas, solamente pudiendo llegar hasta el presente una única familia: los camélidos.

Lasotras familias, ya extintas son:

Xiphodontidae, Oromerycidae, Protoceratidae, y Merycoidodontidae.

El grupo tiene una larga historia fósil en América del Norte y Europa.

Aparecieron durante el Eoceno, hace alrededor de 46,2 millones de años.

 

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La familia CAMELIDAE:

Los camélidos representan la única familia viviente de mamíferos artiodáctilos del suborden Tylopoda, que en griego significa: "pies con almohadillas".

Ellos sobrevivieron solo en América del Sur y en Asia.

La familia está formada por 15 géneros, de los cuales 12 están extintos, y solo 3 aún viven.

Los géneros de camélidos extinguidos son:

Aepycamelus, Camelops, Floridatragulus, Eulamaops, Hemiauchenia, Oxydactylus , Palaeolama, Poebrotherium, Procamelus, Protylopus, Stenomylus, y Titanotylopus.

 

Los camélidos son inusuales pues su distribución moderna es muy lejana a su patria de origen.

Los camélidos aparecieron por primera vez muy temprano en la evolución de los ungulados artiodáctilos, hace unos 45 millones de años, durante el Eoceno medio de América del Norte.

Entre los primeros camélidos fue el Protylopus, del tamaño de un conejo, y que aún tenía cuatro dedos en cada pie.

En el Eoceno tardío, alrededor de 35 millones de años atrás, camélidos como Poebrotherium ya habían perdido los dos dedos laterales, y eran aproximadamente del tamaño de una cabra moderna.

La familia prosperó y se diversificó, pero se mantuvo confinada en América del Norte hasta hace sólo unos 2 ó 3 millones de años, cuando llegaron algunos representantes a Asia, y (como parte del Gran Intercambio Americano que siguió a la formación del Istmo de Panamá), a Sudamérica.

Igualmente, los camélidos siguieron siendo muy comunes en América del Norte hasta un pasado geológico muy reciente, pero luego desaparecieron, posiblemente como resultado de la caza directa o de las intervenciones realizadas en su hábitat por los primeros pobladores humanos.

Los camélidos del Viejo y Nuevo Mundo presentan un cariotipo muy conservado, 2n = 74, con patrones de bandas G y C aparentemente muy similares, siendo capaces de cruzarse y producir descendencia fértil bajo influencia humana.

 

Esta familia se subdivide en dos tribus vivientes, separadas entre sí por más de 8 millones de años:

LAMINI

Para algunos autores Lamini Webb, 1965 (Laminae) no tiene prioridad sobre Aucheniini Bonaparte, 1845 (Aucheniinae).

Esta tribu es hoy solamente endémica del oeste de la América del sur, compuesta por cuatro especies en dos géneros, separados entre sí por 1,4 millones de años: Lama, y Vicugna.

 

CAMELINI

Esta tribu es hoy solamente endémica del centro y sudoeste de Asia, con dos especies en un solo género: Camelus, con dos especies vivientes: Camelus bactrianus y Camelus dromedarius, y tres extintas:

†Camelus gigas

†Camelus hesternus

†Camelus sivalensis

 

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fotografía fotografías foto fotos photo photos imaje imajes imágenes imagen imajenes imajen picture pictures , Mamíferos , Mammalia , mammifère , mamífer , mammiferos , Artiodactyla , artiodattilos , sudokopytníci , 牛亚科 , 牛科 , Atrajotojai , 反芻亜目 , Porakanopiai , Partåiga hovdjur , Parrettåede hovdyr , Чифтокопитни , Paarhufer , Klaufdýr , Evenhoevigen , artiodactyles , מכפילי פרסה , Парнокопытные , Déieren , déi net idderzen , Klovdyr , klauvdyr , partåede hovdyr , Parzystokopytne , Sorkkaeläimet , 偶蹄目 , Mammiferi dell'ordine Artiodattili , artiodàctils , camelide , Kameelachtigen , Kamele , Kamelit , Kamelieläimet , Dəvəkimilər , Schwielensohler , Камили , velbloudovití , Kamelido , Kupranugariniai , Tevefélék , gamelidoa , Kaméiler ,낙타과 , شترسانان , גמליים , ラクダ亜科 ,ラクダ科 , აქლემისებრნი , 駱駝科 , devegiller , Wielbłądowate , Верблюдові , Iskay ruk'anayuq , Kameldjur , Верблюдовые , Kameldyr , camélidés , Animal hair products , animais domésticos , Domesticated animals , domestizierte Kamelform , camelidi, addomesticato , ganadería auquénida , pack animals , meat animals , Mammals of Africa , Mammals of Asia , Mammals of Pakistan , Fauna of Iran , Fauna of the Sahara , Megafauna of Africa , Megafauna of Eurasia , Livestock , Faune en Australie , Fauna naturalised in Australia , Feral animals , Invasive animal species in Australia , dromadaire australien , Dromadaire landais , Camel farming , Camel racing , Kamele in Australien , Dromedare , Einhöckriges , Arabisches Kamel , Dromedarioa , Dromedaren , Dromedar , dromedaris , Dromedari , Dremedal , Velbloud jednohrbý , Dromedár , Dromedář , Dromedaari , Dromadair , arapske deve , Jednogrbe deve , Dromedaro , Drómedari , Arabiese kameel , dromadaire , chameau d'Arabie , egypúpú teve , Unta Arab , Vienkupris kupranugaris , dromedaras , éénbultige kameel , dromader , Wielbłąd jednogarbny , Dromaderul , Одногорбый верблюд , Drumidariu , Dromedarska deva , Tek hörgüçlü deve , Enogrba kamela , Едногърба камила , Једногрба камила , جمل عربي , شتر یک‌کوهانه , ऊँट , Lạc đà một bướu , lạc đà Ả Rập , גמל חד-דבשתי , ヒトコブラクダ , 단봉낙타 , 單峰駱駝 , 阿拉伯駱駝 , 澳洲野生駱駝 ,

DROMEDARY ...........................................................................

Arabian camel

DROMEDARIO ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

camello arábigo , camello árabe , camello de una joroba,

DROMEDÁRIO - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

camelo árabe

 

Camelus dromedarius Linnaeus, 1758

Orden: Artiodactyla Owen, 1848 (= Cetartiodactyla) (Artiodáctilos)

Suborden: Tylopoda Illiger, 1811 (= tilópodos = tylópodos)

Familia: Camelidae Gray, 1821 (Camélidos)

Tribu: Camelini ( = Camelinos = Camelínidos)

 

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Localidad tipo (Type Locality): Habitat in Africae desertis arenosis siticulosis", identificado como "desiertos de Libia y Arabia" por Thomas (1911); basado en materiales de animales domésticos.

 

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El dromedario es un artiodáctilo asiático, hoy extinto como animal silvestre, pero mantenido desde hace milenios como especie doméstica, aunque se encuentra asilvestrado en Australia.

Es el símbolo icónico de los desiertos del mundo.

 

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ORIGEN de su DOMESTICACIÓN:

Los dromedarios fueron domesticados por primera vez en el centro o el sur de la Península Arábiga hace algunos miles de años.

Los expertos están divididos acerca de la fecha: algunos creen que fue alrededor de 6000 años atrás, para otros fue hace 3400 años.

En todo el segundo milenio antes de Cristo, el dromedario fue introducido en Egipto, y el desierto del Sahara en el Norte de África.

Logró establecerse en la región por un tiempo, pero desaparecieron alrededor de 900 aC.

La invasión persa a Egipto de Cambises trajo camellos bactrianos a la zona para ser utilizados en gran parte del norte de África.

Los romanos mantuvieron un cuerpo de guerreros sobre estos camellos para patrullar las fronteras en el desierto.

Pero los camellos persas, sin embargo, no eran especialmente adecuados para el comercio o los viajes sobre el Sahara; los viajes a través del desierto se hicieron en carros tirados por caballos.

Los dromedarios, por ser más fuertes y durables, primero comenzaron a llegar a África en el siglo IV.

No fue hasta la conquista islámica del norte de África, sin embargo, que su estampa se convirtió en una imagen común.

Mientras que la invasión se llevó a cabo en gran medida a caballo, los nuevos enlaces a Oriente Medio permitieron que se importen dromedarios en masa.

Los dromedarios estaban bien adaptados a largos viajes por el desierto, y podían transportar una gran cantidad de carga.

Esto permitió el comercio sobre el Sahara por primera vez.

 

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CARACTERÍSTICAS:

Es similar al camello bactriano (conocido simplemente como camello) con el cual produce híbridos fértiles, al igual que con el guanaco.

Se diferencia del camello por su pelaje más corto, con el cuerpo proporcionalmente menos largo y robusto, pero más alto, y la presencia de una joroba en lugar de dos.

El dromedario es más rápido: puede mantener de 13 a 14,5 km por hora (de 8 a 9 millas / h) con un jinete sobre su lomo durante varias horas.

En comparación, un camello bactriano se mueve a alrededor de 4 km por hora (2,5 millas / h).

Posee pezuñas, el abdomen elevado y patas largas y delgadas.

Como en su primo, los orificios nasales forman aberturas oblicuas, y el labio superior es dividido, movible por separado, y extensible.

Su anatomía muestra todo tipo de adaptaciones a la vida en los desiertos cálidos y arenosos donde vive: Las rodillas y tobillos tienen callosidades que las hacen más resistentes al ardor de la arena cuando se sientan, sus pestañas largas y finas mantienen los ojos a salvo de que les entre arena, igual objetivo complen los abundantes pelos en sus pequeñas orejas.

En la joroba mantiene un depósito de grasa con la cual puede nutrirse e incluso extraerle el agua si es necesario.

Su capacidad de resistencia ante la deshidratación los ha hecho muy valiosos e indispensables en el desierto.

En los momentos en que dispone de agua, el dromedario puede llegar a beber hasta 150 litros en muy poco tiempo.

Para conservar el agua, demuestra una notable adaptación: la capacidad para adaptar su temperatura corporal, desde los 34 ° C a 41,7 ° C.

El dromedario macho tienen un paladar blando, que se infla para producir un saco de color rosa intenso, que se confunde a menudo con la lengua, llamado "doula" en árabe, colgando de los lados de su boca para atraer a las hembras durante la temporada de apareamiento.

 

Su peso varía entre los 350 kg (en las hembras más pequeñas), y como máximo los 1.000 kg (2200 lb), en los machos más grandes.

Los machos adultos crecen hasta una altura de 180 a 210 centímetros (6 a 7 ft), y las hembras de 170 a 190 centímetros.

El largo desde el hocico a la base de la cola es de unos 300 centímetros (10 ft.).

La cola es de 50 cm de largo (20 in).

Gesta una sola cría durante 12 ó 13 meses.

El destete se produce entre 1 a 2 años.

La madurez sexual en las hembras es a los 3 a 4 años, y en los machos es a los 5 a 6 años

 

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COMPORTAMIENTO:

Las dromedarios son animales sociales que viven formando rebaños que generalmente están compuestos por un macho dominante y unas hembras acompañadas de sus crías; el resto de los machos forman un rebaño aparte.

Los machos disputan por determinar su posición en la jerarquía social, mediante amenazas y ataques agresivos.

Los dromedarios son animales herbívoros, es decir, se alimentan exclusivamente de vegetales.

Es pasteador y ramoneador.

El dromedario es un animal resistente que puede pastar en cualquier tipo de ambiente, pudiendo estar varios días seguidos sin comer.

Normalmente viven de 40 a 50 años.

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DISTRIBUCIÓN:

Los dromedarios son originarios de la Península Arábiga en el sudoeste de Asia, aunque han sido introducidos por el hombre en multitud de lugares, y no son raros los casos en que estos animales han escapado y formado poblaciones semisalvajes, la más importante de ellas se encuentra en el interior de Australia.

En la actualidad abunda, sobre todo, en el área que abarca desde el noroeste de la India a través de Pakistán e Irán hasta el norte de África, Senegal, Mauritania, Somalia, y Kenia.

 

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RAZAS:

Esta especie se subdivide en 50 razas, o variedades, adaptadas a distintos ambientes, climas, y usos.

En líneas generales se las divide en dos grandes grupos, las de montar, caracterizadas por su cuerpo más estilizado; y las de carga, las que son típicamente más fornidas, lentas, de patas más fuertes, adaptadas para llevar carga pesada por largos trayectos en las clásicas "caravanas de camellos".

Algunas razas son:

AIT KHEBBACH ~ AJJER ~ ANAFI ~ ARAB CAMEL ~ ARABI ~ AZAOUAK NIGÉRIEN ~ BANAT HUMRA ~ BANAT KHABAR ~ BANAT USAYFIR ~ BÉRABICHE DU MALI ~ BIKANERI ~ BOTSWANA CAMEL ~ CHAMEAU DE L'AFTOUT ~ CHAMEAU DE LA STEPPE ~ CHAMI ~ EGGUIBI ~ ETHIOPIAN DROMEDARY ~ FELLAHI ~ IRAQI ~ JAISALMERI ~ JEBLI ~ KUTCHI ~ LE CHAMEAU DU KANEM ~ LE CHAMEAU GORANE ~ MAHAMID ~ MAGHRABI ~ MAGHREBI ~ MALVI ~ MARMOURI ~ MARWARI ~ MEWARI ~ MEWATI ~ MOWALLED ~ OULED SID CHEIKH ~ RED SEA HILLS ~ REGIBI ~ REGUIBI DE MAURITANIA ~ RENDILLE ~ SAHARAN CAMEL ~ SHAMELIA ~ SINDHI ~ SOMALI ~ SUDANI ~ TARGUI ~ TURKANA ~ YAHAOURI

 

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DROMEDARIO AUSTRALIANO SALVAJE (Australian feral camels):

En 1840 los primeros seis dromedarios fueron transportados a Adelaida Australia, desde Tenerife, en las Islas Canarias.

Sólo uno sobrevivió al viaje, llegando el 12 de octubre 1840.

Muchas diferentes razas de dromedarios fueron llevadas a Australia, pero la mayoría eran de la India.

Además del camello bactriano de dos jorobas de China y Mongolia, se importaron el gran dromedario lanero, el Bishari de montar, del norte de África y Arabia, el camello Bikaneri de guerra, de Rajastán en la India, y el poderoso dromedario indio de tierras bajas, capaz de desplazar grandes cargas de hasta 800 kg (1.764 libras).

Los dromedarios salvajes australianos son una mezcla de todas estas razas, pero se pueden dividir en dos grandes tipos: un tipo es de forma esbelta apta para montar, y el otro es un tipo de animal apto para carga pesada.

El explorador John Horrocks fue una de las primeras personas en utilizar dromedarios para explorar el árido interior de Australia entre 1840 a 1850.

Miles de dromedarios fueron importados entre 1840 y 1907, logrando la apertura de las zonas áridas del centro y el oeste de Australia.

Eran utilizados para montar, y como animales de carga para la exploración y la construcción de ferrocarriles y líneas telegráficas; también se utilizaron para el suministro de bienes a las minas y a los asentamientos remotos.

El Cuerpo australiano de dromedarios incluso sirvió en Egipto y Palestina en la Primera Guerra Mundial, como parte del Cuerpo Imperial de la Gran Bretaña de dromedarios.

Pero a mediados de la década de 1920, una nueva ola de importaciones de autos y camiones llegó al interior australiano. Pero mientras que desde la década de 1930 en adelante, el dromedario doméstico pasó a ser una pieza de museo, el dromedario salvaje prosperó en el monte.

El creciente número de dromedarios, y su impacto sobre la vegetación nativa, son motivo de preocupación, y los dromedarios salvajes en Australia se han convertido en plagas agrícolas de importancia, con una población estimada en 1 millón de ejemplares, creciendo un 10% por año, ante la ausencia de depredadores, lo que terminará por agotar las pasturas de las ovejas y vacunos...

Gracias a esta población cimarrona podemos saber un poco más sobre como habrían sido los hábitos de la especie salvaje original.

Otras poblaciones de dromedarios salvajes existieron en el siglo XX en Parque Nacional de Doñana en España, y en el suroeste de los Estados Unidos, hoy ambas están extintas.

Dromedarios vivos hoy son exportados a Arabia Saudita, el Reino Unido, Países Árabes, Brunei, y hasta a Malasia, donde los dromedarios libres de enfermedades son muy apreciados como un manjar.

Los dromedarios de Australia también se exportan como reproductores para las carreras de Dromedarios en Arabia; y para su empleo en localidades turísticas de los Estados Unidos, Argentina, Uruguay, etc.

 

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CONSERVACIÓN:

Ninguno logró sobrevivir en estado salvaje en su área de distribución original.

En la actualidad hay 15 millones de dromedarios domésticos, y 1 millón de ejemplares salvajes en Australia.

 

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APROVECHAMIENTO PRODUCTIVO:

Aunque los dromedarios tienen la reputación de ser criaturas malhumoradas y obstinadas, que escupen y patean, son utilizados como una bestia de carga en la mayoría de su geonemia como animal doméstico.

A diferencia de los caballos, se arrodillan para la monta de pasajeros y carga.

El uso de este animal como motor de trabajo en las tareas agrícolas ha sido común en el archipiélago de las Canarias hasta la reciente industrialización, generándose términos propios como "guelfo", para definir a la cría del dromedario.

En muchas localidades remotas en el desierto de Egipto los guardias fronterizos emplean dromedarios para realizar las patrullas.

 

La carne de dromedario se consume en gran escala en la Península Arábiga, Somalia, Sudán, y en menor medida, Egipto, entre otros países.

 

Son muy utilizados como animal lechero, en especial en la región de Somalia, en donde viven el 25 % del total de dromedarios del mundo.

 

Su pelo se utiliza como materia básica para productos tejidos, que van desde tiendas de campaña beduinas, a valiosas prendas.

 

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SINONIMIA:

Camelus aegyptiacus Kolenati, 1847

Camelus africanus (Gloger, 1841)

Camelus arabicus Desmoulins, 1823

Camelus dromas Pallas, 1811

Camelus dromos Kerr, 1792

Camelus ferus Falk, 1786

Camelus lukius Kolenati, 1847

Camelus polytrichus Kolenati, 1847

Camelus turcomanicus J. Fischer, 1829

Camelus vulgaris Kolenati, 1847

 

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Suborden TYLOPODA:

Los tilópodos (Tylopoda, gr. "pies con almohadillas") son un suborden de mamíferos artiodáctilos.

En el pasado fue mucho más diverso, y fueron descriptas varias familias, hoy todas extintas, solamente pudiendo llegar hasta el presente una única familia: los camélidos.

Lasotras familias, ya extintas son:

Xiphodontidae, Oromerycidae, Protoceratidae, y Merycoidodontidae.

El grupo tiene una larga historia fósil en América del Norte y Europa.

Aparecieron durante el Eoceno, hace alrededor de 46,2 millones de años.

 

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La familia CAMELIDAE:

Los camélidos representan la única familia viviente de mamíferos artiodáctilos del suborden Tylopoda, que en griego significa: "pies con almohadillas".

Ellos sobrevivieron solo en América del Sur y en Asia.

La familia está formada por 15 géneros, de los cuales 12 están extintos, y solo 3 aún viven.

Los géneros de camélidos extinguidos son:

Aepycamelus, Camelops, Floridatragulus, Eulamaops, Hemiauchenia, Oxydactylus , Palaeolama, Poebrotherium, Procamelus, Protylopus, Stenomylus, y Titanotylopus.

 

Los camélidos son inusuales pues su distribución moderna es muy lejana a su patria de origen.

Los camélidos aparecieron por primera vez muy temprano en la evolución de los ungulados artiodáctilos, hace unos 45 millones de años, durante el Eoceno medio de América del Norte.

Entre los primeros camélidos fue el Protylopus, del tamaño de un conejo, y que aún tenía cuatro dedos en cada pie.

En el Eoceno tardío, alrededor de 35 millones de años atrás, camélidos como Poebrotherium ya habían perdido los dos dedos laterales, y eran aproximadamente del tamaño de una cabra moderna.

La familia prosperó y se diversificó, pero se mantuvo confinada en América del Norte hasta hace sólo unos 2 ó 3 millones de años, cuando llegaron algunos representantes a Asia, y (como parte del Gran Intercambio Americano que siguió a la formación del Istmo de Panamá), a Sudamérica.

Igualmente, los camélidos siguieron siendo muy comunes en América del Norte hasta un pasado geológico muy reciente, pero luego desaparecieron, posiblemente como resultado de la caza directa o de las intervenciones realizadas en su hábitat por los primeros pobladores humanos.

Los camélidos del Viejo y Nuevo Mundo presentan un cariotipo muy conservado, 2n = 74, con patrones de bandas G y C aparentemente muy similares, siendo capaces de cruzarse y producir descendencia fértil bajo influencia humana.

 

Esta familia se subdivide en dos tribus vivientes, separadas entre sí por más de 8 millones de años:

LAMINI

Para algunos autores Lamini Webb, 1965 (Laminae) no tiene prioridad sobre Aucheniini Bonaparte, 1845 (Aucheniinae).

Esta tribu es hoy solamente endémica del oeste de la América del sur, compuesta por cuatro especies en dos géneros, separados entre sí por 1,4 millones de años: Lama, y Vicugna.

 

CAMELINI

Esta tribu es hoy solamente endémica del centro y sudoeste de Asia, con dos especies en un solo género: Camelus, con dos especies vivientes: Camelus bactrianus y Camelus dromedarius, y tres extintas:

†Camelus gigas

†Camelus hesternus

†Camelus sivalensis

 

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(10 de febrero del 2010)

Parque Nacional arqueológico de Petra, JORDANIA

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2022 FAI F1ABP Junior World Championships for Free Flight Model Aircraft

25 Jul - 30 Jul 2022

Pordim, BUL

 

www.mueblesartesanos.es

Universal bâton filaire pour IPhone5s 6 Appareil photo SAMSUNG Manfrotto extensible bâton à Auto pau de palo ordinateur de poche

Caractéristiques:

1. Filaire manfrotto, pas besoin...

 

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Vente! Manfrotto audio câble filaire bâton extensible Manfrotto pour l’iPhone IOS Samsung Android téléphones intelligents

Prêter attention à faits saillants

1. Pas besoin pour relier le bluetooth,...

 

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ANDAMAN SEA (Dec. 13, 2021) A twin boom extensible crane (TBEC) traverses an 11-meter rigid-hull inflatable boat (RHIB) in the mission bay during boat operations aboard Independence-variant littoral combat ship USS Tulsa (LCS 16). Tulsa, part of Destroyer Squadron (DESRON) 7, is on a rotational deployment, operating in U.S. 7th Fleet to enhance interoperability with partners and serve as a ready-response force in support of a free and open Indo-Pacific region. (U.S. Navy photo by Mass Communication Specialist 1st Class Devin M. Langer)

This is the Cave Shredder, a powerfull shredding machine used by the Power Miners.

 

Features:

 

- The torso can spin in 360 degrees through a gears system.

- The claw open and closes.

- 1-stud (:P) extensible chopper blades, which can spin through a system made using a rubber elastic piece.

 

Youtube Video

 

I didn't post in Flickr because of the length... =(

Crested Seriema (Cariama cristata)

Male and female Seriema look alike although the male is slightly larger than the female.

Their most striking feature is the crest , comprised of permanently raised slightly stiff feather at the base of the bill which can reach 10cm in height

Although omniverous, they have a highly carnivorous diet. in the wild the diet includes small rodents, lizards and birds.

They are thought to be the closest living relatives of a group of gigantic carnivorous “terrors birds”, the phorusrhacids.

They have an extensible second claw that is raised from the ground. This resembles the “sickle claw” of Velociraptor and its relatives.

SULU SEA (June 27, 2017) Sailors operate a twin-boom extensible crane during boat operations aboard littoral combat ship USS Coronado (LCS 4) during boat operations while the Philippine Navy ship Ramon Alcaraz steams astern. The U.S. and Philippine navies are conducting a coordinated counter-piracy patrol to protect maritime commerce and enhance maritime security in the region by enhancing both navies' ability to respond to transnational criminal and terror activity. (U.S. Navy photo by Mass Communication Specialist 3rd Class Deven Leigh Ellis/Released)

2014 Nouvelle Arrivée en acier inoxydable extensible poche Bluetooth Soutien IOS Monopied Et Android OS

caractéristiques:

1.momopd pour voyager pour les photos

2.fit pour toutes sortes téléphone intelligent

3.we ont différentes couleurs...

 

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KOM Flash Report

For week of

January 15, 2017

 

www.flickr.com/photos/60428361@N07/32105835606/

 

On January 20 the KOM league writing project will have outlived the presidential terms of; Bill Clinton, George Bush and Barack Obama. If I outlive the term(s) of Donald Trump I’ll be an old guy and probably won’t recall what the acronym, KOM, stood for. But, it gave a million fans seven years of high level Class D baseball and has given me 24 years to relive that era with a bunch of people and to introduce it to many others. Thanks for hanging in there for all these years and often burdensome reports.

__________________________________________________________________

Leftover from last week:

 

Not many people pulled up the Independence Yankee photo from last week. Therefore, I’m expanding on it for this week.

 

Back Row: Tom Gott, Paul Slaughter, Al Pilarcik, Charlie Joe Fontana, Malone Battle "Bones" Sanders, Bob Hamric, Jim Finigan, Jim Davis and Nick Ananias.

 

Front Row: Paul Nichols, Harland Coffman, Dennis Jent, Bill Bagwell, Al Thune, Gabe Padilla, Lou Michels and Art Quigley. Seated: Ray Haley, Doreece Abbott and Dick Duda.

 

Those in the photo still living on January 1, 2017 are: Gott, Fontana, Hamric, Nichols, Bagwell, Haley and possibly, Gabe Padilla. His fate or whereabouts has never been determined.

 

In 2007 another team photo of this same team was shared in this forum. In fact, there were three team photos taken that year with about the same cast of characters. Each was taken of the team after Bones Sanders replaced Goldie Howard as manager. I have made mention of the fact, numerous times, that the old spit ball pitcher, Burleigh Grimes, was behind the managerial change and even served as interim manager of this team between the time of Howard's departure and Sanders' arrival.

 

Two members of this team eventually played major league baseball, namely, Al Pilarcik and Jim Finigan. These two fellows made frequent trips back to Independence, over the years to visit the Don Day family who operated the Hilltop Motel where many of the players resided. When I first spoke with Pilarcik he said that when arriving in Independence he fell in love with the people. Eight years last he fell in love with a young lady and returned there, in February of 1957, with the former Theresa Grish, to spend their honeymoon. Think of it—a honeymoon in Independence, Kansas in the middle of winter.

 

Ballplayers, especially the single ones, formed long and lasting friendships with townsfolk who looked after them and followed their careers long after they had departed Class D baseball for higher classifications, even the major leagues.

 

At the close of the 1948 season Bill Bagwell, Jim Finigan, Ray Haley, Nick Ananias, Al Pilarcik, Jim Davis and Charlie Joe Fontana pooled their meager finances and purchased a gift for the Day family. It was a beautiful horse which the Day family cared for and loved for 48 years. At the time of Mrs. Day’s passing her daughter, Rosie, made the trip from Sparks, Nevada to attend the funeral and to settle the estate. Upon her trip back to Sparks she made sure the horse was well cared for and she took it home with her.

 

After a short time the newest owners of the horse, Rosie and husband Lee Baldrick, felt as though Nevada wasn’t the best place for it. In numerous e-mails and letters that horse was mentioned. I was never asked if I could care for it or even if I wanted it in the first place. One summer morning I was mowing my yard when a truck pulled up and the driver advised that he had a heavy object for me. I asked from whence it came and when he said “Nevada,” I was aware that I was about to be the guardian of a nearly 50-year old horse.

 

When I looked at the crate the first thing I saw was a black leg and shiny hoof. My first thought was “What is my wife going to say?” Over the years of writing about the KOM league I had received many pieces of memorabilia but nothing like a magnificent horse. When other things like KOM league uniforms, ball gloves, baseball bats, scrapbooks, photo albums, baseball card sets, baseball registers and guides, et. al. showed up my wife would exclaim “What are you going to do with that stuff?” But, being an animal lover the gift that the 1948 Independence Yankees presented to the Day family was “a horse of a different color.”

 

Coming as a complete surprise, my wife admonished me to bring it into the house and give it a prominent place. And, I believe this is the 21st year it has set on a shelf just behind the desk where I’m seated. This steed has a rich dark color with a golden mane and a golden removable saddle that is as in as good condition today as it was 49 years ago. All parts of it are made of solid brass. I believe I have shared photos of it in different forums over the years I would place it as an attachment to this report but I know that it would receive little to no attention. Billy Bagwell, when visiting my home a few years ago saw the horse and remembered it. He told me the money he and six of his other teammates raised to purchase it was $110. I wonder what the price on such an item would be today? For my way of thinking it is now priceless. Sometimes I ponder what will become of the relics of the past that I have accumulated with regard to the KOM league. I’m sure they will never mean to another person what they mean to me but I’m sure that I have had enough traffic from my grandsons, past that horse, that it will have a “Home on the Range” after I become fertilizer for the grass that grows to feed future generations of horses.

 

Let’s all hum “Home on the Range” as I ponder what to include to close out this report. www.youtube.com/watch?v=0KlZuk5N2co You might wish to leave your player going after hearing that song. There is good stuff to follow, most likely better than anything I’ll be able to pen to close out this second report for 2017.

 

One photo URL reference, mentioned in any Flash Report, might get a “look see” but if I place two references, the second is ignored. In fact, the photo for this report was shared last week and it didn’t even register on the Richter scale. Forty times as many people viewed the photos of the Iola Indian pitchers sitting in the grandstand, being very casual, than they did the 1948 Independence Yankees posing for a team photo and exhibiting their best behavior.

_______________________________________________________________________

The rest of the 1948 Independence Yankee story.

 

Like most minor league teams the Independence Yankees had a large number of players. In 1948 Independence had 35 different players appear in one or more games and had three managers. Goldie Howard served the first 10 days of the season until being replaced by Bones Sanders but due to Sanders distance from Independence, Burleigh Grimes filled in for a few games.

 

Take a look at the photo and there are 18 players, one manager and one batboy shown. A brief synopsis shows the young man was a bright person. Here is a brief tribute to him. Doreece Dixon Abbott was born in Pawhuska, OK in 1937 and was thus 11 years old in this photo. At that time he had 28 years of life remaining. He married in 1957 and after college he was an engineer for Boeing Aircraft in Wichita, Kansas before being transferred by that company to Seattle, Washington, around 1962. This following item, taken from a chemical engineers publication, shows that the former batboy was a "high flyer."

 

Patented May 29, 1973

SPACE STATION WITH SOLAR GENERATORS-- It has already been proposed to equip artificial satellites with solar generators of high power (of the order of 1 kilowatt or more), made up in large panels for extending outside the satellite, but stored at the start in the fuse cap so that their deployment takes place only in space. Some of these solar panels are flexible, and are folded or rolled up for storing; they are then deployed by means of extensible fittings so that their active surface is spread out. Such systems of flexible, deployable solar panels are well known in aero-space engineering and reference may be made in this respect to various projects mentioned by Doreece D. Abbott in an article entitled Lightweight large area solar arrays pages 772 to 777 in the publication 4th Intersociety Energy Conversion Engineering Conference Washington D.C., September 22-26, 1969 of the American Institute of Chemical Engineers.

 

He passed away 1976 in Seattle. The last reference I ever found on the former batboy was that he was baptized into the Latter Day Saints faith some 22 years after his death.

 

The rest of the team

 

Roster members of the 1948 Independence Yankees not appearing in any team photo were: Max Buzzard, Robert Childs, John M. Cochrane, Richard “Stokes” Dodson, Robert Mack Ehrlich, Paul J. Flores, Robert Joseph Hasten, James Talmadge Hudson, John C. “Beanstalk” Hurley, Robert Leroy Loddeke, James E. Petitt Jr., John Reynolds, Bruce Otto Schroeder, Lilburn Smith, Ermon Barrett Sparks (became a Dr.), Robert Paul Swiderski and Clarence Wheeler.

 

Of all the aforementioned names the only three for whom I can’t account are John Reynolds, Bruce Otto Schroeder and Gabriel Padilla. But, I’m pretty sure I know where both Schroeder and Padilla are residing.

 

The missing man

 

Whenever I have spoken with a former member of the Independence Yankees, from that season, they always inquired about one player. Each remarked they had lost contact with him over the years and never knew why. Since I was interested in locating every former KOM leaguer I too was struck by the “lost trail” on that member of the team.

 

When you know a person’s age, place of birth and all that type of information you are sure that you can find them. Over the first couple of years of writing about the KOM league I found nothing on this former member of the 1948 Independence club. Then, it happened. And, when I found out what became of the guy I wish I hadn’t. In short, when the fellow was old enough to know better he made a fatal decision. At the age of two-score ten and one he had a girlfriend. One morning, in a fit of rage, he went after her with a pistol. She ran from the house with the former ballplayer in hot pursuit. An off-duty fireman, in a Midwest town of 17,000 people, saw what was unfolding and interceded on behalf of the damsel in distress. According to the newspaper accounts the former ballplayer turned on the Good Samaritan and killed him on the spot. After shooting the fireman, and not being able to keep up with his girlfriend, the former ballplayer entered his garage and put a bullet into his head and ended his life on April 4, 1978.

 

So, now you know that not all KOM baseball stories wind up with everyone living happily ever after.

 

That concludes another report unless someone cares to know more about any member of the 1948 Independence Yankees that I haven’t addressed to their satisfaction.

 

Jellyfish, also known sea jellies, are the medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria.

 

Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles, although a few are anchored to the seabed by stalks rather than being mobile. The bell can pulsate to provide propulsion for highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle. The medusa is normally the sexual phase, which produces planula larvae; these then disperse widely and enter a sedentary polyp phase, before reaching sexual maturity.

 

Jellyfish are found all over the world, from surface waters to the deep sea. Scyphozoans (the "true jellyfish") are exclusively marine, but some hydrozoans with a similar appearance live in freshwater. Large, often colorful, jellyfish are common in coastal zones worldwide. The medusae of most species are fast-growing, and mature within a few months then die soon after breeding, but the polyp stage, attached to the seabed, may be much more long-lived. Jellyfish have been in existence for at least 500 million years, and possibly 700 million years or more, making them the oldest multi-organ animal group.

 

Jellyfish are eaten by humans in certain cultures. They are considered a delicacy in some Asian countries, where species in the Rhizostomeae order are pressed and salted to remove excess water. Australian researchers have described them as a "perfect food": sustainable and protein-rich but relatively low in food energy.

 

They are also used in research, where the green fluorescent protein used by some species to cause bioluminescence has been adapted as a fluorescent marker for genes inserted into other cells or organisms.

 

The stinging cells used by jellyfish to subdue their prey can injure humans. Thousands of swimmers worldwide are stung every year, with effects ranging from mild discomfort to serious injury or even death. When conditions are favourable, jellyfish can form vast swarms, which can be responsible for damage to fishing gear by filling fishing nets, and sometimes clog the cooling systems of power and desalination plants which draw their water from the sea.

  

Names

The name jellyfish, in use since 1796, has traditionally been applied to medusae and all similar animals including the comb jellies (ctenophores, another phylum). The term jellies or sea jellies is more recent, having been introduced by public aquaria in an effort to avoid use of the word "fish" with its modern connotation of an animal with a backbone, though shellfish, cuttlefish and starfish are not vertebrates either. In scientific literature, "jelly" and "jellyfish" have been used interchangeably. Many sources refer to only scyphozoans as "true jellyfish".

 

A group of jellyfish is called a "smack" or a "smuck".

 

Definition

The term jellyfish broadly corresponds to medusae, that is, a life-cycle stage in the Medusozoa. The American evolutionary biologist Paulyn Cartwright gives the following general definition:

 

Typically, medusozoan cnidarians have a pelagic, predatory jellyfish stage in their life cycle; staurozoans are the exceptions [as they are stalked].

 

The Merriam-Webster dictionary defines jellyfish as follows:

 

A free-swimming marine coelenterate that is the sexually reproducing form of a hydrozoan or scyphozoan and has a nearly transparent saucer-shaped body and extensible marginal tentacles studded with stinging cells.

 

Given that jellyfish is a common name, its mapping to biological groups is inexact. Some authorities have called the comb jellies and certain salps jellyfish, though other authorities state that neither of these are jellyfish, which they consider should be limited to certain groups within the medusozoa.

 

The non-medusozoan clades called jellyfish by some but not all authorities (both agreeing and disagreeing citations are given in each case) are indicated with on the following cladogram of the animal kingdom:

 

Jellyfish are not a clade, as they include most of the Medusozoa, barring some of the Hydrozoa. The medusozoan groups included by authorities are indicated on the following phylogenetic tree by the presence of citations. Names of included jellyfish, in English where possible, are shown in boldface; the presence of a named and cited example indicates that at least that species within its group has been called a jellyfish.

 

Taxonomy

The subphylum Medusozoa includes all cnidarians with a medusa stage in their life cycle. The basic cycle is egg, planula larva, polyp, medusa, with the medusa being the sexual stage. The polyp stage is sometimes secondarily lost. The subphylum include the major taxa, Scyphozoa (large jellyfish), Cubozoa (box jellyfish) and Hydrozoa (small jellyfish), and excludes Anthozoa (corals and sea anemones). This suggests that the medusa form evolved after the polyps. Medusozoans have tetramerous symmetry, with parts in fours or multiples of four.

 

The four major classes of medusozoan Cnidaria are:

Scyphozoa are sometimes called true jellyfish, though they are no more truly jellyfish than the others listed here. They have tetra-radial symmetry. Most have tentacles around the outer margin of the bowl-shaped bell, and long, oral arms around the mouth in the center of the subumbrella.

Cubozoa (box jellyfish) have a (rounded) box-shaped bell, and their velarium assists them to swim more quickly. Box jellyfish may be related more closely to scyphozoan jellyfish than either are to the Hydrozoa.

Hydrozoa medusae also have tetra-radial symmetry, nearly always have a velum (diaphragm used in swimming) attached just inside the bell margin, do not have oral arms, but a much smaller central stalk-like structure, the manubrium, with terminal mouth opening, and are distinguished by the absence of cells in the mesoglea. Hydrozoa show great diversity of lifestyle; some species maintain the polyp form for their entire life and do not form medusae at all (such as Hydra, which is hence not considered a jellyfish), and a few are entirely medusal and have no polyp form.

Staurozoa (stalked jellyfish) are characterized by a medusa form that is generally sessile, oriented upside down and with a stalk emerging from the apex of the "calyx" (bell), which attaches to the substrate. At least some Staurozoa also have a polyp form that alternates with the medusoid portion of the life cycle. Until recently, Staurozoa were classified within the Scyphozoa.

There are over 200 species of Scyphozoa, about 50 species of Staurozoa, about 50 species of Cubozoa, and the Hydrozoa includes about 1000–1500 species that produce medusae, but many more species that do not.

 

Fossil history

Since jellyfish have no hard parts, fossils are rare. The oldest unambiguous fossil of a free-swimming medusa is Burgessomedusa from the mid Cambrian Burgess Shale of Canada, which is likely either a stem group of box jellyfish (Cubozoa) or Acraspeda (the clade including Staurozoa, Cubozoa, and Scyphozoa). Other claimed records from the Cambrian of China and Utah in the United States are uncertain, and possibly represent ctenophores instead.

 

Anatomy

The main feature of a true jellyfish is the umbrella-shaped bell. This is a hollow structure consisting of a mass of transparent jelly-like matter known as mesoglea, which forms the hydrostatic skeleton of the animal. 95% or more of the mesogloea consists of water, but it also contains collagen and other fibrous proteins, as well as wandering amoebocytes which can engulf debris and bacteria. The mesogloea is bordered by the epidermis on the outside and the gastrodermis on the inside. The edge of the bell is often divided into rounded lobes known as lappets, which allow the bell to flex. In the gaps or niches between the lappets are dangling rudimentary sense organs known as rhopalia, and the margin of the bell often bears tentacles.

  

Anatomy of a scyphozoan jellyfish

On the underside of the bell is the manubrium, a stalk-like structure hanging down from the centre, with the mouth, which also functions as the anus, at its tip. There are often four oral arms connected to the manubrium, streaming away into the water below. The mouth opens into the gastrovascular cavity, where digestion takes place and nutrients are absorbed. This is subdivided by four thick septa into a central stomach and four gastric pockets. The four pairs of gonads are attached to the septa, and close to them four septal funnels open to the exterior, perhaps supplying good oxygenation to the gonads. Near the free edges of the septa, gastric filaments extend into the gastric cavity; these are armed with nematocysts and enzyme-producing cells and play a role in subduing and digesting the prey. In some scyphozoans, the gastric cavity is joined to radial canals which branch extensively and may join a marginal ring canal. Cilia in these canals circulate the fluid in a regular direction.

  

Discharge mechanism of a nematocyst

The box jellyfish is largely similar in structure. It has a squarish, box-like bell. A short pedalium or stalk hangs from each of the four lower corners. One or more long, slender tentacles are attached to each pedalium. The rim of the bell is folded inwards to form a shelf known as a velarium which restricts the bell's aperture and creates a powerful jet when the bell pulsates, allowing box jellyfish to swim faster than true jellyfish. Hydrozoans are also similar, usually with just four tentacles at the edge of the bell, although many hydrozoans are colonial and may not have a free-living medusal stage. In some species, a non-detachable bud known as a gonophore is formed that contains a gonad but is missing many other medusal features such as tentacles and rhopalia. Stalked jellyfish are attached to a solid surface by a basal disk, and resemble a polyp, the oral end of which has partially developed into a medusa with tentacle-bearing lobes and a central manubrium with four-sided mouth.

 

Most jellyfish do not have specialized systems for osmoregulation, respiration and circulation, and do not have a central nervous system. Nematocysts, which deliver the sting, are located mostly on the tentacles; true jellyfish also have them around the mouth and stomach. Jellyfish do not need a respiratory system because sufficient oxygen diffuses through the epidermis. They have limited control over their movement, but can navigate with the pulsations of the bell-like body; some species are active swimmers most of the time, while others largely drift. The rhopalia contain rudimentary sense organs which are able to detect light, water-borne vibrations, odour and orientation. A loose network of nerves called a "nerve net" is located in the epidermis. Although traditionally thought not to have a central nervous system, nerve net concentration and ganglion-like structures could be considered to constitute one in most species. A jellyfish detects stimuli, and transmits impulses both throughout the nerve net and around a circular nerve ring, to other nerve cells. The rhopalial ganglia contain pacemaker neurones which control swimming rate and direction.

 

In many species of jellyfish, the rhopalia include ocelli, light-sensitive organs able to tell light from dark. These are generally pigment spot ocelli, which have some of their cells pigmented. The rhopalia are suspended on stalks with heavy crystals at one end, acting like gyroscopes to orient the eyes skyward. Certain jellyfish look upward at the mangrove canopy while making a daily migration from mangrove swamps into the open lagoon, where they feed, and back again.

 

Box jellyfish have more advanced vision than the other groups. Each individual has 24 eyes, two of which are capable of seeing colour, and four parallel information processing areas that act in competition, supposedly making them one of the few kinds of animal to have a 360-degree view of its environment.

 

Box jellyfish eye

The study of jellyfish eye evolution is an intermediary to a better understanding of how visual systems evolved on Earth. Jellyfish exhibit immense variation in visual systems ranging from photoreceptive cell patches seen in simple photoreceptive systems to more derived complex eyes seen in box jellyfish. Major topics of jellyfish visual system research (with an emphasis on box jellyfish) include: the evolution of jellyfish vision from simple to complex visual systems), the eye morphology and molecular structures of box jellyfish (including comparisons to vertebrate eyes), and various uses of vision including task-guided behaviors and niche specialization.

 

Evolution

Experimental evidence for photosensitivity and photoreception in cnidarians antecedes the mid 1900s, and a rich body of research has since covered evolution of visual systems in jellyfish. Jellyfish visual systems range from simple photoreceptive cells to complex image-forming eyes. More ancestral visual systems incorporate extraocular vision (vision without eyes) that encompass numerous receptors dedicated to single-function behaviors. More derived visual systems comprise perception that is capable of multiple task-guided behaviors.

 

Although they lack a true brain, cnidarian jellyfish have a "ring" nervous system that plays a significant role in motor and sensory activity. This net of nerves is responsible for muscle contraction and movement and culminates the emergence of photosensitive structures. Across Cnidaria, there is large variation in the systems that underlie photosensitivity. Photosensitive structures range from non-specialized groups of cells, to more "conventional" eyes similar to those of vertebrates. The general evolutionary steps to develop complex vision include (from more ancestral to more derived states): non-directional photoreception, directional photoreception, low-resolution vision, and high-resolution vision. Increased habitat and task complexity has favored the high-resolution visual systems common in derived cnidarians such as box jellyfish.

 

Basal visual systems observed in various cnidarians exhibit photosensitivity representative of a single task or behavior. Extraocular photoreception (a form of non-directional photoreception), is the most basic form of light sensitivity and guides a variety of behaviors among cnidarians. It can function to regulate circadian rhythm (as seen in eyeless hydrozoans) and other light-guided behaviors responsive to the intensity and spectrum of light. Extraocular photoreception can function additionally in positive phototaxis (in planula larvae of hydrozoans), as well as in avoiding harmful amounts of UV radiation via negative phototaxis. Directional photoreception (the ability to perceive direction of incoming light) allows for more complex phototactic responses to light, and likely evolved by means of membrane stacking. The resulting behavioral responses can range from guided spawning events timed by moonlight to shadow responses for potential predator avoidance. Light-guided behaviors are observed in numerous scyphozoans including the common moon jelly, Aurelia aurita, which migrates in response to changes in ambient light and solar position even though they lack proper eyes.

 

The low-resolution visual system of box jellyfish is more derived than directional photoreception, and thus box jellyfish vision represents the most basic form of true vision in which multiple directional photoreceptors combine to create the first imaging and spatial resolution. This is different from the high-resolution vision that is observed in camera or compound eyes of vertebrates and cephalopods that rely on focusing optics. Critically, the visual systems of box jellyfish are responsible for guiding multiple tasks or behaviors in contrast to less derived visual systems in other jellyfish that guide single behavioral functions. These behaviors include phototaxis based on sunlight (positive) or shadows (negative), obstacle avoidance, and control of swim-pulse rate.

 

Box jellyfish possess "proper eyes" (similar to vertebrates) that allow them to inhabit environments that lesser derived medusae cannot. In fact, they are considered the only class in the clade Medusozoa that have behaviors necessitating spatial resolution and genuine vision. However, the lens in their eyes are more functionally similar to cup-eyes exhibited in low-resolution organisms, and have very little to no focusing capability. The lack of the ability to focus is due to the focal length exceeding the distance to the retina, thus generating unfocused images and limiting spatial resolution. The visual system is still sufficient for box jellyfish to produce an image to help with tasks such as object avoidance.

 

Utility as a model organism

Box jellyfish eyes are a visual system that is sophisticated in numerous ways. These intricacies include the considerable variation within the morphology of box jellyfishes' eyes (including their task/behavior specification), and the molecular makeup of their eyes including: photoreceptors, opsins, lenses, and synapses. The comparison of these attributes to more derived visual systems can allow for a further understanding of how the evolution of more derived visual systems may have occurred, and puts into perspective how box jellyfish can play the role as an evolutionary/developmental model for all visual systems.

 

Characteristics

Box jellyfish visual systems are both diverse and complex, comprising multiple photosystems. There is likely considerable variation in visual properties between species of box jellyfish given the significant inter-species morphological and physiological variation. Eyes tend to differ in size and shape, along with number of receptors (including opsins), and physiology across species of box jellyfish.

 

Box jellyfish have a series of intricate lensed eyes that are similar to those of more derived multicellular organisms such as vertebrates. Their 24 eyes fit into four different morphological categories. These categories consist of two large, morphologically different medial eyes (a lower and upper lensed eye) containing spherical lenses, a lateral pair of pigment slit eyes, and a lateral pair of pigment pit eyes. The eyes are situated on rhopalia (small sensory structures) which serve sensory functions of the box jellyfish and arise from the cavities of the exumbrella (the surface of the body) on the side of the bells of the jellyfish. The two large eyes are located on the mid-line of the club and are considered complex because they contain lenses. The four remaining eyes lie laterally on either side of each rhopalia and are considered simple. The simple eyes are observed as small invaginated cups of epithelium that have developed pigmentation. The larger of the complex eyes contains a cellular cornea created by a mono ciliated epithelium, cellular lens, homogenous capsule to the lens, vitreous body with prismatic elements, and a retina of pigmented cells. The smaller of the complex eyes is said to be slightly less complex given that it lacks a capsule but otherwise contains the same structure as the larger eye.

 

Box jellyfish have multiple photosystems that comprise different sets of eyes. Evidence includes immunocytochemical and molecular data that show photopigment differences among the different morphological eye types, and physiological experiments done on box jellyfish to suggest behavioral differences among photosystems. Each individual eye type constitutes photosystems that work collectively to control visually guided behaviors.

 

Box jellyfish eyes primarily use c-PRCs (ciliary photoreceptor cells) similar to that of vertebrate eyes. These cells undergo phototransduction cascades (process of light absorption by photoreceptors) that are triggered by c-opsins. Available opsin sequences suggest that there are two types of opsins possessed by all cnidarians including an ancient phylogenetic opsin, and a sister ciliary opsin to the c-opsins group. Box jellyfish could have both ciliary and cnidops (cnidarian opsins), which is something not previously believed to appear in the same retina. Nevertheless, it is not entirely evident whether cnidarians possess multiple opsins that are capable of having distinctive spectral sensitivities.

 

Comparison with other organisms

Comparative research on genetic and molecular makeup of box jellyfishes' eyes versus more derived eyes seen in vertebrates and cephalopods focuses on: lenses and crystallin composition, synapses, and Pax genes and their implied evidence for shared primordial (ancestral) genes in eye evolution.

 

Box jellyfish eyes are said to be an evolutionary/developmental model of all eyes based on their evolutionary recruitment of crystallins and Pax genes. Research done on box jellyfish including Tripedalia cystophora has suggested that they possess a single Pax gene, PaxB. PaxB functions by binding to crystallin promoters and activating them. PaxB in situ hybridization resulted in PaxB expression in the lens, retina, and statocysts. These results and the rejection of the prior hypothesis that Pax6 was an ancestral Pax gene in eyes has led to the conclusion that PaxB was a primordial gene in eye evolution, and that the eyes of all organisms likely share a common ancestor.

 

The lens structure of box jellyfish appears very similar to those of other organisms, but the crystallins are distinct in both function and appearance. Weak reactions were seen within the sera and there were very weak sequence similarities within the crystallins among vertebrate and invertebrate lenses. This is likely due to differences in lower molecular weight proteins and the subsequent lack of immunological reactions with antisera that other organisms' lenses exhibit.

 

All four of the visual systems of box jellyfish species investigated with detail (Carybdea marsupialis, Chiropsalmus quadrumanus, Tamoya haplonema and Tripedalia cystophora) have invaginated synapses, but only in the upper and lower lensed eyes. Different densities were found between the upper and lower lenses, and between species. Four types of chemical synapses have been discovered within the rhopalia which could help in understanding neural organization including: clear unidirectional, dense-core unidirectional, clear bidirectional, and clear and dense-core bidirectional. The synapses of the lensed eyes could be useful as markers to learn more about the neural circuit in box jellyfish retinal areas.

 

Evolution as a response to natural stimuli

The primary adaptive responses to environmental variation observed in box jellyfish eyes include pupillary constriction speeds in response to light environments, as well as photoreceptor tuning and lens adaptations to better respond to shifts between light environments and darkness. Interestingly, some box jellyfish species' eyes appear to have evolved more focused vision in response to their habitat.

 

Pupillary contraction appears to have evolved in response to variation in the light environment across ecological niches across three species of box jellyfish (Chironex fleckeri, Chiropsella bronzie, and Carukia barnesi). Behavioral studies suggest that faster pupil contraction rates allow for greater object avoidance, and in fact, species with more complex habitats exhibit faster rates. Ch. bronzie inhabit shallow beach fronts that have low visibility and very few obstacles, thus, faster pupil contraction in response to objects in their environment is not important. Ca. barnesi and Ch. fleckeri are found in more three-dimensionally complex environments like mangroves with an abundance of natural obstacles, where faster pupil contraction is more adaptive. Behavioral studies support the idea that faster pupillary contraction rates assist with obstacle avoidance as well as depth adjustments in response to differing light intensities.

 

Light/dark adaptation via pupillary light reflexes is an additional form of an evolutionary response to the light environment. This relates to the pupil's response to shifts between light intensity (generally from sunlight to darkness). In the process of light/dark adaptation, the upper and lower lens eyes of different box jellyfish species vary in specific function. The lower lens-eyes contain pigmented photoreceptors and long pigment cells with dark pigments that migrate on light/dark adaptation, while the upper-lens eyes play a concentrated role in light direction and phototaxis given that they face upward towards the water surface (towards the sun or moon). The upper lens of Ch. bronzie does not exhibit any considerable optical power while Tr. cystophora (a box jellyfish species that tends to live in mangroves) does. The ability to use light to visually guide behavior is not of as much importance to Ch. bronzie as it is to species in more obstacle-filled environments. Differences in visually guided behavior serve as evidence that species that share the same number and structure of eyes can exhibit differences in how they control behavior.

 

Largest and smallest

Jellyfish range from about one millimeter in bell height and diameter, to nearly 2 metres (6+1⁄2 ft) in bell height and diameter; the tentacles and mouth parts usually extend beyond this bell dimension.

 

The smallest jellyfish are the peculiar creeping jellyfish in the genera Staurocladia and Eleutheria, which have bell disks from 0.5 millimetres (1⁄32 in) to a few millimeters in diameter, with short tentacles that extend out beyond this, which these jellyfish use to move across the surface of seaweed or the bottoms of rocky pools; many of these tiny creeping jellyfish cannot be seen in the field without a hand lens or microscope. They can reproduce asexually by fission (splitting in half). Other very small jellyfish, which have bells about one millimeter, are the hydromedusae of many species that have just been released from their parent polyps; some of these live only a few minutes before shedding their gametes in the plankton and then dying, while others will grow in the plankton for weeks or months. The hydromedusae Cladonema radiatum and Cladonema californicum are also very small, living for months, yet never growing beyond a few mm in bell height and diameter.

 

The lion's mane jellyfish, Cyanea capillata, was long-cited as the largest jellyfish, and arguably the longest animal in the world, with fine, thread-like tentacles that may extend up to 36.5 m (119 ft 9 in) long (though most are nowhere near that large). They have a moderately painful, but rarely fatal, sting. The increasingly common giant Nomura's jellyfish, Nemopilema nomurai, found in some, but not all years in the waters of Japan, Korea and China in summer and autumn is another candidate for "largest jellyfish", in terms of diameter and weight, since the largest Nomura's jellyfish in late autumn can reach 2 m (6 ft 7 in) in bell (body) diameter and about 200 kg (440 lb) in weight, with average specimens frequently reaching 0.9 m (2 ft 11 in) in bell diameter and about 150 kg (330 lb) in weight. The large bell mass of the giant Nomura's jellyfish can dwarf a diver and is nearly always much greater than the Lion's Mane, whose bell diameter can reach 1 m (3 ft 3 in).

 

The rarely encountered deep-sea jellyfish Stygiomedusa gigantea is another candidate for "largest jellyfish", with its thick, massive bell up to 100 cm (3 ft 3 in) wide, and four thick, "strap-like" oral arms extending up to 6 m (19+1⁄2 ft) in length, very different from the typical fine, threadlike tentacles that rim the umbrella of more-typical-looking jellyfish, including the Lion's Mane.

 

Desmonema glaciale, which lives in the Antarctic region, can reach a very large size (several meters). Purple-striped jelly (Chrysaora colorata) can also be extremely long (up to 15 feet).

 

Life history and behavior

Life cycle

Jellyfish have a complex life cycle which includes both sexual and asexual phases, with the medusa being the sexual stage in most instances. Sperm fertilize eggs, which develop into larval planulae, become polyps, bud into ephyrae and then transform into adult medusae. In some species certain stages may be skipped.

 

Upon reaching adult size, jellyfish spawn regularly if there is a sufficient supply of food. In most species, spawning is controlled by light, with all individuals spawning at about the same time of day; in many instances this is at dawn or dusk. Jellyfish are usually either male or female (with occasional hermaphrodites). In most cases, adults release sperm and eggs into the surrounding water, where the unprotected eggs are fertilized and develop into larvae. In a few species, the sperm swim into the female's mouth, fertilizing the eggs within her body, where they remain during early development stages. In moon jellies, the eggs lodge in pits on the oral arms, which form a temporary brood chamber for the developing planula larvae.

 

The planula is a small larva covered with cilia. When sufficiently developed, it settles onto a firm surface and develops into a polyp. The polyp generally consists of a small stalk topped by a mouth that is ringed by upward-facing tentacles. The polyps resemble those of closely related anthozoans, such as sea anemones and corals. The jellyfish polyp may be sessile, living on the bottom, boat hulls or other substrates, or it may be free-floating or attached to tiny bits of free-living plankton or rarely, fish or other invertebrates. Polyps may be solitary or colonial. Most polyps are only millimetres in diameter and feed continuously. The polyp stage may last for years.

 

After an interval and stimulated by seasonal or hormonal changes, the polyp may begin reproducing asexually by budding and, in the Scyphozoa, is called a segmenting polyp, or a scyphistoma. Budding produces more scyphistomae and also ephyrae. Budding sites vary by species; from the tentacle bulbs, the manubrium (above the mouth), or the gonads of hydromedusae. In a process known as strobilation, the polyp's tentacles are reabsorbed and the body starts to narrow, forming transverse constrictions, in several places near the upper extremity of the polyp. These deepen as the constriction sites migrate down the body, and separate segments known as ephyra detach. These are free-swimming precursors of the adult medusa stage, which is the life stage that is typically identified as a jellyfish. The ephyrae, usually only a millimeter or two across initially, swim away from the polyp and grow. Limnomedusae polyps can asexually produce a creeping frustule larval form, which crawls away before developing into another polyp. A few species can produce new medusae by budding directly from the medusan stage. Some hydromedusae reproduce by fission.

 

Lifespan

Little is known of the life histories of many jellyfish as the places on the seabed where the benthic forms of those species live have not been found. However, an asexually reproducing strobila form can sometimes live for several years, producing new medusae (ephyra larvae) each year.

 

An unusual species, Turritopsis dohrnii, formerly classified as Turritopsis nutricula, might be effectively immortal because of its ability under certain circumstances to transform from medusa back to the polyp stage, thereby escaping the death that typically awaits medusae post-reproduction if they have not otherwise been eaten by some other organism. So far this reversal has been observed only in the laboratory.

 

Locomotion

Jellyfish locomotion is highly efficient. Muscles in the jellylike bell contract, setting up a start vortex and propelling the animal. When the contraction ends, the bell recoils elastically, creating a stop vortex with no extra energy input.

Using the moon jelly Aurelia aurita as an example, jellyfish have been shown to be the most energy-efficient swimmers of all animals. They move through the water by radially expanding and contracting their bell-shaped bodies to push water behind them. They pause between the contraction and expansion phases to create two vortex rings. Muscles are used for the contraction of the body, which creates the first vortex and pushes the animal forward, but the mesoglea is so elastic that the expansion is powered exclusively by relaxing the bell, which releases the energy stored from the contraction. Meanwhile, the second vortex ring starts to spin faster, sucking water into the bell and pushing against the centre of the body, giving a secondary and "free" boost forward. The mechanism, called passive energy recapture, only works in relatively small jellyfish moving at low speeds, allowing the animal to travel 30 percent farther on each swimming cycle. Jellyfish achieved a 48 percent lower cost of transport (food and oxygen intake versus energy spent in movement) than other animals in similar studies. One reason for this is that most of the gelatinous tissue of the bell is inactive, using no energy during swimming.

 

Ecology

Diet

Jellyfish are, like other cnidarians, generally carnivorous (or parasitic), feeding on planktonic organisms, crustaceans, small fish, fish eggs and larvae, and other jellyfish, ingesting food and voiding undigested waste through the mouth. They hunt passively using their tentacles as drift lines, or sink through the water with their tentacles spread widely; the tentacles, which contain nematocysts to stun or kill the prey, may then flex to help bring it to the mouth. Their swimming technique also helps them to capture prey; when their bell expands it sucks in water which brings more potential prey within reach of the tentacles.

 

A few species such as Aglaura hemistoma are omnivorous, feeding on microplankton which is a mixture of zooplankton and phytoplankton (microscopic plants) such as dinoflagellates. Others harbour mutualistic algae (Zooxanthellae) in their tissues; the spotted jellyfish (Mastigias papua) is typical of these, deriving part of its nutrition from the products of photosynthesis, and part from captured zooplankton. The upside-down jellyfish (Cassiopea andromeda) also has a symbiotic relationship with microalgae, but captures tiny animals to supplement their diet. This is done by releasing tiny balls of living cells composed of mesoglea. These use cilia to drive them through water and stinging cells which stun the prey. The blobs also seems to have digestive capabilities.

 

Predation

Other species of jellyfish are among the most common and important jellyfish predators. Sea anemones may eat jellyfish that drift into their range. Other predators include tunas, sharks, swordfish, sea turtles and penguins. Jellyfish washed up on the beach are consumed by foxes, other terrestrial mammals and birds. In general however, few animals prey on jellyfish; they can broadly be considered to be top predators in the food chain. Once jellyfish have become dominant in an ecosystem, for example through overfishing which removes predators of jellyfish larvae, there may be no obvious way for the previous balance to be restored: they eat fish eggs and juvenile fish, and compete with fish for food, preventing fish stocks from recovering.

 

Symbiosis

Some small fish are immune to the stings of the jellyfish and live among the tentacles, serving as bait in a fish trap; they are safe from potential predators and are able to share the fish caught by the jellyfish. The cannonball jellyfish has a symbiotic relationship with ten different species of fish, and with the longnose spider crab, which lives inside the bell, sharing the jellyfish's food and nibbling its tissues.

 

Main article: Jellyfish bloom

Jellyfish form large masses or blooms in certain environmental conditions of ocean currents, nutrients, sunshine, temperature, season, prey availability, reduced predation and oxygen concentration. Currents collect jellyfish together, especially in years with unusually high populations. Jellyfish can detect marine currents and swim against the current to congregate in blooms. Jellyfish are better able to survive in nutrient-rich, oxygen-poor water than competitors, and thus can feast on plankton without competition. Jellyfish may also benefit from saltier waters, as saltier waters contain more iodine, which is necessary for polyps to turn into jellyfish. Rising sea temperatures caused by climate change may also contribute to jellyfish blooms, because many species of jellyfish are able to survive in warmer waters. Increased nutrients from agricultural or urban runoff with nutrients including nitrogen and phosphorus compounds increase the growth of phytoplankton, causing eutrophication and algal blooms. When the phytoplankton die, they may create dead zones, so-called because they are hypoxic (low in oxygen). This in turn kills fish and other animals, but not jellyfish, allowing them to bloom. Jellyfish populations may be expanding globally as a result of land runoff and overfishing of their natural predators. Jellyfish are well placed to benefit from disturbance of marine ecosystems. They reproduce rapidly; they prey upon many species, while few species prey on them; and they feed via touch rather than visually, so they can feed effectively at night and in turbid waters. It may be difficult for fish stocks to re-establish themselves in marine ecosystems once they have become dominated by jellyfish, because jellyfish feed on plankton, which includes fish eggs and larvae.

 

As suspected at the turn of this century, jellyfish blooms are increasing in frequency. Between 2013 and 2020 the Mediterranean Science Commission monitored on a weekly basis the frequency of such outbreaks in coastal waters from Morocco to the Black Sea, revealing a relatively high frequency of these blooms nearly all year round, with peaks observed from March to July and often again in the autumn. The blooms are caused by different jellyfish species, depending on their localisation within the Basin: one observes a clear dominance of Pelagia noctiluca and Velella velella outbreaks in the western Mediterranean, of Rhizostoma pulmo and Rhopilema nomadica outbreaks in the eastern Mediterranean, and of Aurelia aurita and Mnemiopsis leidyi outbreaks in the Black Sea.

 

Some jellyfish populations that have shown clear increases in the past few decades are invasive species, newly arrived from other habitats: examples include the Black Sea, Caspian Sea, Baltic Sea, central and eastern Mediterranean, Hawaii, and tropical and subtropical parts of the West Atlantic (including the Caribbean, Gulf of Mexico and Brazil).

 

Jellyfish blooms can have significant impact on community structure. Some carnivorous jellyfish species prey on zooplankton while others graze on primary producers. Reductions in zooplankton and ichthyoplankton due to a jellyfish bloom can ripple through the trophic levels. High-density jellyfish populations can outcompete other predators and reduce fish recruitment. Increased grazing on primary producers by jellyfish can also interrupt energy transfer to higher trophic levels.

 

During blooms, jellyfish significantly alter the nutrient availability in their environment. Blooms require large amounts of available organic nutrients in the water column to grow, limiting availability for other organisms. Some jellyfish have a symbiotic relationship with single-celled dinoflagellates, allowing them to assimilate inorganic carbon, phosphorus, and nitrogen creating competition for phytoplankton. Their large biomass makes them an important source of dissolved and particulate organic matter for microbial communities through excretion, mucus production, and decomposition. The microbes break down the organic matter into inorganic ammonium and phosphate. However, the low carbon availability shifts the process from production to respiration creating low oxygen areas making the dissolved inorganic nitrogen and phosphorus largely unavailable for primary production.

 

These blooms have very real impacts on industries. Jellyfish can outcompete fish by utilizing open niches in over-fished fisheries. Catch of jellyfish can strain fishing gear and lead to expenses relating to damaged gear. Power plants have been shut down due to jellyfish blocking the flow of cooling water. Blooms have also been harmful for tourism, causing a rise in stings and sometimes the closure of beaches.

 

Jellyfish form a component of jelly-falls, events where gelatinous zooplankton fall to the seafloor, providing food for the benthic organisms there. In temperate and subpolar regions, jelly-falls usually follow immediately after a bloom.

 

Habitats

Most jellyfish are marine animals, although a few hydromedusae inhabit freshwater. The best known freshwater example is the cosmopolitan hydrozoan jellyfish, Craspedacusta sowerbii. It is less than an inch (2.5 cm) in diameter, colorless and does not sting. Some jellyfish populations have become restricted to coastal saltwater lakes, such as Jellyfish Lake in Palau. Jellyfish Lake is a marine lake where millions of golden jellyfish (Mastigias spp.) migrate horizontally across the lake daily.

 

Although most jellyfish live well off the ocean floor and form part of the plankton, a few species are closely associated with the bottom for much of their lives and can be considered benthic. The upside-down jellyfish in the genus Cassiopea typically lie on the bottom of shallow lagoons where they sometimes pulsate gently with their umbrella top facing down. Even some deep-sea species of hydromedusae and scyphomedusae are usually collected on or near the bottom. All of the stauromedusae are found attached to either seaweed or rocky or other firm material on the bottom.

 

Some species explicitly adapt to tidal flux. In Roscoe Bay, jellyfish ride the current at ebb tide until they hit a gravel bar, and then descend below the current. They remain in still waters until the tide rises, ascending and allowing it to sweep them back into the bay. They also actively avoid fresh water from mountain snowmelt, diving until they find enough salt.

  

Parasites

Jellyfish are hosts to a wide variety of parasitic organisms. They act as intermediate hosts of endoparasitic helminths, with the infection being transferred to the definitive host fish after predation. Some digenean trematodes, especially species in the family Lepocreadiidae, use jellyfish as their second intermediate hosts. Fish become infected by the trematodes when they feed on infected jellyfish.

 

Relation to humans

Jellyfish have long been eaten in some parts of the world. Fisheries have begun harvesting the American cannonball jellyfish, Stomolophus meleagris, along the southern Atlantic coast of the United States and in the Gulf of Mexico for export to Asia.

 

Jellyfish are also harvested for their collagen, which is being investigated for use in a variety of applications including the treatment of rheumatoid arthritis.

 

Aquaculture and fisheries of other species often suffer severe losses – and so losses of productivity – due to jellyfish.

 

Products

Main article: Jellyfish as food

In some countries, including China, Japan, and Korea, jellyfish are a delicacy. The jellyfish is dried to prevent spoiling. Only some 12 species of scyphozoan jellyfish belonging to the order Rhizostomeae are harvested for food, mostly in southeast Asia. Rhizostomes, especially Rhopilema esculentum in China (海蜇 hǎizhé, 'sea stingers') and Stomolophus meleagris (cannonball jellyfish) in the United States, are favored because of their larger and more rigid bodies and because their toxins are harmless to humans.

 

Traditional processing methods, carried out by a jellyfish master, involve a 20- to 40-day multi-phase procedure in which, after removing the gonads and mucous membranes, the umbrella and oral arms are treated with a mixture of table salt and alum, and compressed. Processing makes the jellyfish drier and more acidic, producing a crisp texture. Jellyfish prepared this way retain 7–10% of their original weight, and the processed product consists of approximately 94% water and 6% protein. Freshly processed jellyfish has a white, creamy color and turns yellow or brown during prolonged storage.

 

In China, processed jellyfish are desalted by soaking in water overnight and eaten cooked or raw. The dish is often served shredded with a dressing of oil, soy sauce, vinegar and sugar, or as a salad with vegetables. In Japan, cured jellyfish are rinsed, cut into strips and served with vinegar as an appetizer. Desalted, ready-to-eat products are also available.

 

Biotechnology

The hydromedusa Aequorea victoria was the source of green fluorescent protein, studied for its role in bioluminescence and later for use as a marker in genetic engineering.

Pliny the Elder reported in his Natural History that the slime of the jellyfish "Pulmo marinus" produced light when rubbed on a walking stick.

 

In 1961, Osamu Shimomura extracted green fluorescent protein (GFP) and another bioluminescent protein, called aequorin, from the large and abundant hydromedusa Aequorea victoria, while studying photoproteins that cause bioluminescence in this species. Three decades later, Douglas Prasher sequenced and cloned the gene for GFP. Martin Chalfie figured out how to use GFP as a fluorescent marker of genes inserted into other cells or organisms. Roger Tsien later chemically manipulated GFP to produce other fluorescent colors to use as markers. In 2008, Shimomura, Chalfie and Tsien won the Nobel Prize in Chemistry for their work with GFP. Man-made GFP became widely used as a fluorescent tag to show which cells or tissues express specific genes. The genetic engineering technique fuses the gene of interest to the GFP gene. The fused DNA is then put into a cell, to generate either a cell line or (via IVF techniques) an entire animal bearing the gene. In the cell or animal, the artificial gene turns on in the same tissues and the same time as the normal gene, making a fusion of the normal protein with GFP attached to the end, illuminating the animal or cell reveals what tissues express that protein—or at what stage of development. The fluorescence shows where the gene is expressed.

 

Aquarium display

Jellyfish are displayed in many public aquariums. Often the tank's background is blue and the animals are illuminated by side light, increasing the contrast between the animal and the background. In natural conditions, many jellies are so transparent that they are nearly invisible. Jellyfish are not adapted to closed spaces. They depend on currents to transport them from place to place. Professional exhibits as in the Monterey Bay Aquarium feature precise water flows, typically in circular tanks to avoid trapping specimens in corners. The outflow is spread out over a large surface area and the inflow enters as a sheet of water in front of the outflow, so the jellyfish do not get sucked into it. As of 2009, jellyfish were becoming popular in home aquariums, where they require similar equipment.

 

Stings

Jellyfish are armed with nematocysts, a type of specialized stinging cell. Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom, but only some species' venom causes an adverse reaction in humans. In a study published in Communications Biology, researchers found a jellyfish species called Cassiopea xamachana which when triggered will release tiny balls of cells that swim around the jellyfish stinging everything in their path. Researchers described these as "self-propelling microscopic grenades" and named them cassiosomes.

 

The effects of stings range from mild discomfort to extreme pain and death. Most jellyfish stings are not deadly, but stings of some box jellyfish (Irukandji jellyfish), such as the sea wasp, can be deadly. Stings may cause anaphylaxis (a form of shock), which can be fatal. Jellyfish kill 20 to 40 people a year in the Philippines alone. In 2006 the Spanish Red Cross treated 19,000 stung swimmers along the Costa Brava.

 

Vinegar (3–10% aqueous acetic acid) may help with box jellyfish stings but not the stings of the Portuguese man o' war. Clearing the area of jelly and tentacles reduces nematocyst firing. Scraping the affected skin, such as with the edge of a credit card, may remove remaining nematocysts. Once the skin has been cleaned of nematocysts, hydrocortisone cream applied locally reduces pain and inflammation. Antihistamines may help to control itching. Immunobased antivenins are used for serious box jellyfish stings.

 

In Elba Island and Corsica dittrichia viscosa is now used by residents and tourists to heal stings from jellyfish, bees and wasps pressing fresh leaves on the skin with quick results.

 

Mechanical issues

Jellyfish in large quantities can fill and split fishing nets and crush captured fish. They can clog cooling equipment, having disabled power stations in several countries; jellyfish caused a cascading blackout in the Philippines in 1999, as well as damaging the Diablo Canyon Power Plant in California in 2008. They can also stop desalination plants and ships' engines.

A small slow-moving lizard with a long extensible tongue and tail.It has protruding eyes that rotate independently, and has the ability to change body colour hence the name 'Chameleon' I always thought a chameleon changed colour to hide but have just recently found out it's in fact the way that they communicate with each other.

East Jesus is an experimental, habitable, extensible artwork in progress since 2006 begun by the late Charles Stephen Russell in Slab City, California. The inhabitants of East Jesus and offsite members provide a refuge for artists, musicians, survivalists, writers, scientists, and laymen. They are dedicated to providing a working model of an improbable improvised community. Completely self-contained and run entirely on solar power, East Jesus attempts to use and recycle every bit of consumable trash. They are unique in the Slabs in that they have Human Manure composting to reduce and improve the impact on the local desert environment.

White Sands Missile Range Museum

 

The BGM-71 TOW ("Tube-launched, Optically tracked, Wire-guided or Wireless") is an anti-tank missile, much smaller than the SS.10 and ENTAC, offering roughly twice the effective range, a more powerful warhead, and a greatly improved semi-automatic guidance system that could also be equipped with infrared cameras for night time use. First produced in 1970, the TOW is one of the most widely used anti-tank guided missiles.

 

In its basic form, the system comprises a missile in a sealed tube which is clipped to a launch tube prior to use. When required, the missile tube is attached to the rear of the launch tube, the target sighted and the missile fired. The launch motor ejects the missile from the launch tube, at which point four wings indexed at 45 degrees just forward of the booster nozzles spring open forward, four tail control surfaces flip open rearward, and sustained propulsion is provided by the flight motor (sustainer) which fires through lateral nozzles and propels the missile to the target. An optical sensor on the sight continuously monitors the position of a light source on the missile relative to the line-of- sight, and then corrects the trajectory of the missile by generating electrical signals that are passed down two wires to command the control surface actuators. After launch, the operator simply has to keep the cross-hairs of his sight pointing at the target, and the guidance system will automatically transmit corrective commands to the missile through the wire.

 

The TOW missile has been continually upgraded for a wide variety of platforms and uses, with an improved TOW missile (ITOW) appearing in 1978 that had a new warhead triggered by a long probe, which was extended after launch, that gave a stand-off distance of 15 inches for improved armor penetration. The 1983 TOW 2 featured a larger 13 pound warhead with a 21.25 inch extensible probe, improved guidance and a motor that provided around 30% more thrust. This was followed by the TOW 2A/B which appeared in 1987. Hughes developed a TOW missile with a wireless data link in 1989, referred to as TOW-2N, but this weapon was not adopted for use by the. In 1999 TOW received the Improved Target Acquisition System (ITAS).

 

The TOW missile in its current variations is not a fire-and-forget weapon, and like most second generation wire-guided missiles has Semi-Automatic Command Line of Sight guidance. This means that the guidance system is directly linked to the platform, and requires that the target be kept in the shooter's line of sight until the missile impacts. This has been the major impetus to develop either a fire-and-forget version of the system or to develop a successor with this ability. The M41 TOW improved target acquisition system (ITAS) is a block upgrade to the M220 ground/high-mobility multi- purpose wheeled vehicle (HMMWV)-mounted TOW 2 missile system. The TOW ITAS is currently be- ing fielded to airborne, air assault, and light infantry forces throughout the active and reserve components of the U.S. Army and U.S. Marine Corps where it is called the SABER. The ITAS, in addition to providing better anti-armor capabilities to antitank units, also has capabilities that make it an integral part of the combined arms team. Even when organized in heavy-light task forces, where the preponderance of antiarmor capabilities traditionally has resided in the heavy elements, TOW ITAS- equipped antitank units can not only destroy threat targets but also provide superior reconnaissance, surveillance, and target acquisition (RSTA), rear area protection, and urban operations capabilities.

 

The TOW ITAS consists of three new line replaceable units: the target acquisition subsystem (TAS), the fire control subsystem (FCS), and the lithium battery box (LBB); a modified TOW 2 traversing unit; the existing TOW launch tube and tripod; and a TOW Humvee modification kit. The TAS integrates into a single housing the direct view optics, a second-generation forward looking infrared (FLIR) night vision sight (NVS), missile trackers, and a laser rangefinder. TAS electronics provide automatic boresighting for these components, eliminating both tactical collimation and 180-day verification requirements.

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This dragonfly is carrying its eggs

 

A dragonfly is an insect belonging to the order Odonata, infraorder Anisoptera (from Greek ἄνισος anisos, "unequal" and πτερόν pteron, "wing", because the hindwing is broader than the forewing). Adult dragonflies are characterized by large, multifaceted eyes, two pairs of strong, transparent wings, sometimes with coloured patches, and an elongated body. Dragonflies can be mistaken for the related group, damselflies (Zygoptera), which are similar in structure, though usually lighter in build; however, the wings of most dragonflies are held flat and away from the body, while damselflies hold their wings folded at rest, along or above the abdomen. Dragonflies are agile fliers, while damselflies have a weaker, fluttery flight. Many dragonflies have brilliant iridescent or metallic colours produced by structural colouration, making them conspicuous in flight. An adult dragonfly's compound eyes have nearly 24,000 ommatidia each.

 

Fossils of very large dragonfly-like insects, sometimes called griffinflies, are found from 325 million years ago (Mya) in Upper Carboniferous rocks; these had wingspans up to about 750 mm (30 in), but were only distant ancestors, not true dragonflies. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens dragonfly populations around the world.

 

Dragonflies are predators, both in their aquatic nymphs stage (also known as naiads) and as adults. In some species, the nymphal stage lasts for up to five years, and the adult stage may be as long as ten weeks, but most species have an adult lifespan in the order of five weeks or less, and some survive for only a few days. They are fast, agile fliers, sometimes migrating across oceans, and often live near water. They have a uniquely complex mode of reproduction involving indirect insemination, delayed fertilization, and sperm competition. During mating, the male grasps the female at the back of the head, and the female curls her abdomen under her body to pick up sperm from the male's secondary genitalia at the front of his abdomen, forming the "heart" or "wheel" posture.

 

Dragonflies are represented in human culture on artefacts such as pottery, rock paintings, statues and Art Nouveau jewellery. They are used in traditional medicine in Japan and China, and caught for food in Indonesia. They are symbols of courage, strength, and happiness in Japan, but seen as sinister in European folklore. Their bright colours and agile flight are admired in the poetry of Lord Tennyson and the prose of H. E. Bates.

   

Evolution

 

Dragonflies and their relatives are similar in structure to an ancient group, meganisoptera, from the 325 Mya Upper Carboniferous of Europe, a group that included the largest insect that ever lived, Meganeuropsis permiana from the Early Permian, with a wingspan around 750 mm (30 in);. Known informally as "griffinflies", their fossil record ends with the Permian–Triassic extinction event (about 247 Mya). The Protanisoptera, another ancestral group that lacks certain wing vein characters found in modern Odonata, lived from the Early to Late Permian age until the end Permian event, and are known from fossil wings from current-day United States, Russia, and Australia, suggesting they might have been cosmopolitan in distribution. While both of those groups are sometimes referred to as "giant dragonflies", in fact true dragonflies/odonata are more modern insects that had not evolved yet.

 

Modern dragonflies do retain some traits of their distant predecessors, and are in a group known as palaeoptera, ancient-winged. They, like the gigantic pre-dinosaur griffinflies, lack the ability to fold their wings up against their bodies in the way modern insects do, although some evolved their own different way to do so. The forerunners of modern Odonata are included in a clade called the Panodonata, which include the basal Zygoptera (damselflies) and the Anisoptera (true dragonflies). Today, some 3,000 species are extant around the world.

 

The relationships of anisopteran families are not fully resolved as of 2013, but all the families are monophyletic except the Corduliidae; the Gomphidae are a sister taxon to all other Anisoptera, the Austropetaliidae are sister to the Aeshnoidea, and the Chlorogomphidae are sister to a clade that includes the Synthemistidae and Libellulidae. On the cladogram, dashed lines indicate unresolved relationships; English names are given (in parentheses)

   

Distribution and diversity

 

About 3,012 species of dragonflies were known in 2010; these are classified into 348 genera in 11 families. The distribution of diversity within the biogeographical regions are summarized below (the world numbers are not ordinary totals, as overlaps in species occur).

 

Dragonflies live on every continent except Antarctica. In contrast to the damselflies (Zygoptera), which tend to have restricted distributions, some genera and species are spread across continents. For example, the blue-eyed darner Rhionaeschna multicolor lives all across North America, and in Central America; emperors Anax live throughout the Americas from as far north as Newfoundland to as far south as Bahia Blanca in Argentina, across Europe to central Asia, North Africa, and the Middle East. The globe skimmer Pantala flavescens is probably the most widespread dragonfly species in the world; it is cosmopolitan, occurring on all continents in the warmer regions. Most Anisoptera species are tropical, with far fewer species in temperate regions.

 

Some dragonflies, including libellulids and aeshnids, live in desert pools, for example in the Mojave Desert, where they are active in shade temperatures between 18 and 45 °C (64.4 to 113 °F); these insects were able to survive body temperatures above the thermal death point of insects of the same species in cooler places.

 

Dragonflies live from sea level up to the mountains, decreasing in species diversity with altitude. Their altitudinal limit is about 3700 m, represented by a species of Aeshna in the Pamirs.

 

Dragonflies become scarce at higher latitudes. They are not native to Iceland, but individuals are occasionally swept in by strong winds, including a Hemianax ephippiger native to North Africa, and an unidentified darter species. In Kamchatka, only a few species of dragonfly including the treeline emerald Somatochlora arctica and some aeshnids such as Aeshna subarctica are found, possibly because of the low temperature of the lakes there. The treeline emerald also lives in northern Alaska, within the Arctic Circle, making it the most northerly of all dragonflies.

   

General description

 

Dragonflies (suborder Anisoptera) are heavy-bodied, strong-flying insects that hold their wings horizontally both in flight and at rest. By contrast, damselflies (suborder Zygoptera) have slender bodies and fly more weakly; most species fold their wings over the abdomen when stationary, and the eyes are well separated on the sides of the head.

 

An adult dragonfly has three distinct segments, the head, thorax, and abdomen, as in all insects. It has a chitinous exoskeleton of hard plates held together with flexible membranes. The head is large with very short antennae. It is dominated by the two compound eyes, which cover most of its surface. The compound eyes are made up of ommatidia, the numbers being greater in the larger species. Aeshna interrupta has 22650 ommatidia of two varying sizes, 4500 being large. The facets facing downward tend to be smaller. Petalura gigantea has 23890 ommatidia of just one size. These facets provide complete vision in the frontal hemisphere of the dragonfly. The compound eyes meet at the top of the head (except in the Petaluridae and Gomphidae, as also in the genus Epiophlebia). Also, they have three simple eyes or ocelli. The mouthparts are adapted for biting with a toothed jaw; the flap-like labrum, at the front of the mouth, can be shot rapidly forward to catch prey. The head has a system for locking it in place that consists of muscles and small hairs on the back of the head that grip structures on the front of the first thoracic segment. This arrester system is unique to the Odonata, and is activated when feeding and during tandem flight.

 

The thorax consists of three segments as in all insects. The prothorax is small and is flattened dorsally into a shield-like disc, which has two transverse ridges. The mesothorax and metathorax are fused into a rigid, box-like structure with internal bracing, and provide a robust attachment for the powerful wing muscles inside. The thorax bears two pairs of wings and three pairs of legs. The wings are long, veined, and membranous, narrower at the tip and wider at the base. The hindwings are broader than the forewings and the venation is different at the base. The veins carry haemolymph, which is analogous to blood in vertebrates, and carries out many similar functions, but which also serves a hydraulic function to expand the body between nymphal stages (instars) and to expand and stiffen the wings after the adult emerges from the final nymphal stage. The leading edge of each wing has a node where other veins join the marginal vein, and the wing is able to flex at this point. In most large species of dragonflies, the wings of females are shorter and broader than those of males. The legs are rarely used for walking, but are used to catch and hold prey, for perching, and for climbing on plants. Each has two short basal joints, two long joints, and a three-jointed foot, armed with a pair of claws. The long leg joints bear rows of spines, and in males, one row of spines on each front leg is modified to form an "eyebrush", for cleaning the surface of the compound eye.

 

The abdomen is long and slender and consists of 10 segments. Three terminal appendages are on segment 10; a pair of superiors (claspers) and an inferior. The second and third segments are enlarged, and in males, on the underside of the second segment has a cleft, forming the secondary genitalia consisting of the lamina, hamule, genital lobe, and penis. There are remarkable variations in the presence and the form of the penis and the related structures, the flagellum, cornua, and genital lobes. Sperm is produced at the 9th segment, and is transferred to the secondary genitalia prior to mating. The male holds the female behind the head using a pair of claspers on the terminal segment. In females, the genital opening is on the underside of the eighth segment, and is covered by a simple flap (vulvar lamina) or an ovipositor, depending on species and the method of egg-laying. Dragonflies having simple flaps shed the eggs in water, mostly in flight. Dragonflies having ovipositors use them to puncture soft tissues of plants and place the eggs singly in each puncture they make.

 

Dragonfly nymphs vary in form with species, and are loosely classed into claspers, sprawlers, hiders, and burrowers. The first instar is known as a prolarva, a relatively inactive stage from which it quickly moults into the more active nymphal form. The general body plan is similar to that of an adult, but the nymph lacks wings and reproductive organs. The lower jaw has a huge, extensible labium, armed with hooks and spines, which is used for catching prey. This labium is folded under the body at rest and struck out at great speed by hydraulic pressure created by the abdominal muscles. Whereas damselfly nymphs have three feathery external gills, dragonfly nymphs have internal gills, located around the fourth and fifth abdominal segments. Water is pumped in and out of the abdomen through an opening at the tip. The naiads of some clubtails (Gomphidae) that burrow into the sediment, have a snorkel-like tube at the end of the abdomen enabling them to draw in clean water while they are buried in mud. Naiads can forcefully expel a jet of water to propel themselves with great rapidity.

   

Colouration

 

Many adult dragonflies have brilliant iridescent or metallic colours produced by structural colouration, making them conspicuous in flight. Their overall colouration is often a combination of yellow, red, brown, and black pigments, with structural colours. Blues are typically created by microstructures in the cuticle that reflect blue light. Greens often combine a structural blue with a yellow pigment. Freshly emerged adults, known as tenerals, are often pale-coloured and obtain their typical colours after a few days, some have their bodies covered with a pale blue, waxy powderiness called pruinosity; it wears off when scraped during mating, leaving darker areas.

 

Some dragonflies, such as the green darner, Anax junius, have a noniridescent blue that is produced structurally by scatter from arrays of tiny spheres in the endoplasmic reticulum of epidermal cells underneath the cuticle.

 

The wings of dragonflies are generally clear, apart from the dark veins and pterostigmata. In the chasers (Libellulidae), however, many genera have areas of colour on the wings: for example, groundlings (Brachythemis) have brown bands on all four wings, while some scarlets (Crocothemis) and dropwings (Trithemis) have bright orange patches at the wing bases. Some aeshnids such as the brown hawker (Aeshna grandis) have translucent, pale yellow wings.

 

Dragonfly nymphs are usually a well-camouflaged blend of dull brown, green, and grey.

   

Biology

 

Ecology

 

Dragonflies and damselflies are predatory both in the aquatic nymphal and adult stages. Nymphs feed on a range of freshwater invertebrates and larger ones can prey on tadpoles and small fish. Adults capture insect prey in the air, making use of their acute vision and highly controlled flight. The mating system of dragonflies is complex, and they are among the few insect groups that have a system of indirect sperm transfer along with sperm storage, delayed fertilization, and sperm competition.

 

Adult males vigorously defend territories near water; these areas provide suitable habitat for the nymphs to develop, and for females to lay their eggs. Swarms of feeding adults aggregate to prey on swarming prey such as emerging flying ants or termites.

 

Dragonflies as a group occupy a considerable variety of habitats, but many species, and some families, have their own specific environmental requirements. Some species prefer flowing waters, while others prefer standing water. For example, the Gomphidae (clubtails) live in running water, and the Libellulidae (skimmers) live in still water. Some species live in temporary water pools and are capable of tolerating changes in water level, desiccation, and the resulting variations in temperature, but some genera such as Sympetrum (darters) have eggs and nymphs that can resist drought and are stimulated to grow rapidly in warm, shallow pools, also often benefiting from the absence of predators there. Vegetation and its characteristics including submerged, floating, emergent, or waterside are also important. Adults may require emergent or waterside plants to use as perches; others may need specific submerged or floating plants on which to lay eggs. Requirements may be highly specific, as in Aeshna viridis (green hawker), which lives in swamps with the water-soldier, Stratiotes aloides. The chemistry of the water, including its trophic status (degree of enrichment with nutrients) and pH can also affect its use by dragonflies. Most species need moderate conditions, not too eutrophic, not too acidic; a few species such as Sympetrum danae (black darter) and Libellula quadrimaculata (four-spotted chaser) prefer acidic waters such as peat bogs, while others such as Libellula fulva (scarce chaser) need slow-moving, eutrophic waters with reeds or similar waterside plants.

   

Behaviour

 

Many dragonflies, particularly males, are territorial. Some defend a territory against others of their own species, some against other species of dragonfly and a few against insects in unrelated groups. A particular perch may give a dragonfly a good view over an insect-rich feeding ground; males of many species such as the Pachydiplax longipennis (blue dasher) jostle other dragonflies to maintain the right to alight there. Defending a breeding territory is common among male dragonflies, especially in species that congregate around ponds. The territory contains desirable features such as a sunlit stretch of shallow water, a special plant species, or the preferred substrate for egg-laying. The territory may be small or large, depending on its quality, the time of day, and the number of competitors, and may be held for a few minutes or several hours. Dragonflies including Tramea lacerata (black saddlebags) may notice landmarks that assist in defining the boundaries of the territory. Landmarks may reduce the costs of territory establishment, or might serve as a spatial reference. Some dragonflies signal ownership with striking colours on the face, abdomen, legs, or wings. The Plathemis lydia (common whitetail) dashes towards an intruder holding its white abdomen aloft like a flag. Other dragonflies engage in aerial dogfights or high-speed chases. A female must mate with the territory holder before laying her eggs. There is also conflict between the males and females. Females may sometimes be harassed by males to the extent that it affects their normal activities including foraging and in some dimorphic species females have evolved multiple forms with some forms appearing deceptively like males. In some species females have evolved behavioural responses such as feigning death to escape the attention of males. Similarly, selection of habitat by adult dragonflies is not random, and terrestrial habitat patches may be held for up to 3 months. A species tightly linked to its birth site utilises a foraging area that is several orders of magnitude larger than the birth site.

   

Reproduction

 

Mating in dragonflies is a complex, precisely choreographed process. First, the male has to attract a female to his territory, continually driving off rival males. When he is ready to mate, he transfers a packet of sperm from his primary genital opening on segment 9, near the end of his abdomen, to his secondary genitalia on segments 2–3, near the base of his abdomen. The male then grasps the female by the head with the claspers at the end of his abdomen; the structure of the claspers varies between species, and may help to prevent interspecific mating. The pair flies in tandem with the male in front, typically perching on a twig or plant stem. The female then curls her abdomen downwards and forwards under her body to pick up the sperm from the male's secondary genitalia, while the male uses his "tail" claspers to grip the female behind the head: this distinctive posture is called the "heart" or "wheel"; the pair may also be described as being "in cop".

 

Egg-laying (ovipositing) involves not only the female darting over floating or waterside vegetation to deposit eggs on a suitable substrate, but also the male hovering above her or continuing to clasp her and flying in tandem. The male attempts to prevent rivals from removing his sperm and inserting their own, something made possible by delayed fertilisation and driven by sexual selection. If successful, a rival male uses his penis to compress or scrape out the sperm inserted previously; this activity takes up much of the time that a copulating pair remains in the heart posture. Flying in tandem has the advantage that less effort is needed by the female for flight and more can be expended on egg-laying, and when the female submerges to deposit eggs, the male may help to pull her out of the water.

 

Egg-laying takes two different forms depending on the species. The female in some families has a sharp-edged ovipositor with which she slits open a stem or leaf of a plant on or near the water, so she can push her eggs inside. In other families such as clubtails (Gomphidae), cruisers (Macromiidae), emeralds (Corduliidae), and skimmers (Libellulidae), the female lays eggs by tapping the surface of the water repeatedly with her abdomen, by shaking the eggs out of her abdomen as she flies along, or by placing the eggs on vegetation. In a few species, the eggs are laid on emergent plants above the water, and development is delayed until these have withered and become immersed.

   

Life cycle

 

Dragonflies are hemimetabolous insects; they do not have a pupal stage and undergo an incomplete metamorphosis with a series of nymphal stages from which the adult emerges. Eggs laid inside plant tissues are usually shaped like grains of rice, while other eggs are the size of a pinhead, ellipsoidal, or nearly spherical. A clutch may have as many as 1500 eggs, and they take about a week to hatch into aquatic nymphs or naiads which moult between six and 15 times (depending on species) as they grow. Most of a dragonfly's life is spent as a nymph, beneath the water's surface. The nymph extends its hinged labium (a toothed mouthpart similar to a lower mandible, which is sometimes termed as a "mask" as it is normally folded and held before the face) that can extend forward and retract rapidly to capture prey such as mosquito larvae, tadpoles, and small fish. They breathe through gills in their rectum, and can rapidly propel themselves by suddenly expelling water through the anus. Some naiads, such as the later stages of Antipodophlebia asthenes, hunt on land.

 

The nymph stage of dragonflies lasts up to five years in large species, and between two months and three years in smaller species. When the naiad is ready to metamorphose into an adult, it stops feeding and makes its way to the surface, generally at night. It remains stationary with its head out of the water, while its respiration system adapts to breathing air, then climbs up a reed or other emergent plant, and moults (ecdysis). Anchoring itself firmly in a vertical position with its claws, its skin begins to split at a weak spot behind the head. The adult dragonfly crawls out of its nymph skin, the exuvia, arching backwards when all but the tip of its abdomen is free, to allow its exoskeleton to harden. Curling back upwards, it completes its emergence, swallowing air, which plumps out its body, and pumping haemolymph into its wings, which causes them to expand to their full extent.

 

Dragonflies in temperate areas can be categorized into two groups, an early group and a later one. In any one area, individuals of a particular "spring species" emerge within a few days of each other. The springtime darner (Basiaeschna janata), for example, is suddenly very common in the spring, but disappears a few weeks later and is not seen again until the following year. By contrast, a "summer species" emerges over a period of weeks or months, later in the year. They may be seen on the wing for several months, but this may represent a whole series of individuals, with new adults hatching out as earlier ones complete their lifespans.

   

Sex ratios

 

The sex ratio of male to female dragonflies varies both temporally and spatially. Adult dragonflies have a high male-biased ratio at breeding habitats. The male-bias ratio has contributed partially to the females using different habitats to avoid male harassment. As seen in Hine's emerald dragonfly (Somatochlora hineana), male populations use wetland habitats, while females use dry meadows and marginal breeding habitats, only migrating to the wetlands to lay their eggs or to find mating partners. Unwanted mating is energetically costly for females because it affects the amount of time that they are able to spend foraging.

   

Flight

 

Dragonflies are powerful and agile fliers, capable of migrating across the sea, moving in any direction, and changing direction suddenly. In flight, the adult dragonfly can propel itself in six directions: upward, downward, forward, backward, to left and to right. They have four different styles of flight: A number of flying modes are used that include counter-stroking, with forewings beating 180° out of phase with the hindwings, is used for hovering and slow flight. This style is efficient and generates a large amount of lift; phased-stroking, with the hindwings beating 90° ahead of the forewings, is used for fast flight. This style creates more thrust, but less lift than counter-stroking; synchronised-stroking, with forewings and hindwings beating together, is used when changing direction rapidly, as it maximises thrust; and gliding, with the wings held out, is used in three situations: free gliding, for a few seconds in between bursts of powered flight; gliding in the updraft at the crest of a hill, effectively hovering by falling at the same speed as the updraft; and in certain dragonflies such as darters, when "in cop" with a male, the female sometimes simply glides while the male pulls the pair along by beating his wings.

 

The wings are powered directly, unlike most families of insects, with the flight muscles attached to the wing bases. Dragonflies have a high power/weight ratio, and have been documented accelerating at 4 G linearly and 9 G in sharp turns while pursuing prey.

 

Dragonflies generate lift in at least four ways at different times, including classical lift like an aircraft wing; supercritical lift with the wing above the critical angle, generating high lift and using very short strokes to avoid stalling; and creating and shedding vortices. Some families appear to use special mechanisms, as for example the Libellulidae which take off rapidly, their wings beginning pointed far forward and twisted almost vertically. Dragonfly wings behave highly dynamically during flight, flexing and twisting during each beat. Among the variables are wing curvature, length and speed of stroke, angle of attack, forward/back position of wing, and phase relative to the other wings.

   

Flight speed

 

Old and unreliable claims are made that dragonflies such as the southern giant darner can fly up to 97 km/h (60 mph). However, the greatest reliable flight speed records are for other types of insects. In general, large dragonflies like the hawkers have a maximum speed of 36–54 km/h (22–34 mph) with average cruising speed of about 16 km/h (9.9 mph). Dragonflies can travel at 100 body-lengths per second in forward flight, and three lengths per second backwards.

   

Motion camouflage

 

n high-speed territorial battles between male Australian emperors (Hemianax papuensis), the fighting dragonflies adjust their flight paths to appear stationary to their rivals, minimizing the chance of being detected as they approach.[a] To achieve the effect, the attacking dragonfly flies towards his rival, choosing his path to remain on a line between the rival and the start of his attack path. The attacker thus looms larger as he closes on the rival, but does not otherwise appear to move. Researchers found that six of 15 encounters involved motion camouflage.

   

Temperature control

 

The flight muscles need to be kept at a suitable temperature for the dragonfly to be able to fly. Being cold-blooded, they can raise their temperature by basking in the sun. Early in the morning, they may choose to perch in a vertical position with the wings outstretched, while in the middle of the day, a horizontal stance may be chosen. Another method of warming up used by some larger dragonflies is wing-whirring, a rapid vibration of the wings that causes heat to be generated in the flight muscles. The green darner (Anax junius) is known for its long-distance migrations, and often resorts to wing-whirring before dawn to enable it to make an early start.

 

Becoming too hot is another hazard, and a sunny or shady position for perching can be selected according to the ambient temperature. Some species have dark patches on the wings which can provide shade for the body, and a few use the obelisk posture to avoid overheating. This behaviour involves doing a "handstand", perching with the body raised and the abdomen pointing towards the sun, thus minimising the amount of solar radiation received. On a hot day, dragonflies sometimes adjust their body temperature by skimming over a water surface and briefly touching it, often three times in quick succession. This may also help to avoid desiccation.

   

Feeding

 

Adult dragonflies hunt on the wing using their exceptionally acute eyesight and strong, agile flight. They are almost exclusively carnivorous, eating a wide variety of insects ranging from small midges and mosquitoes to butterflies, moths, damselflies, and smaller dragonflies. A large prey item is subdued by being bitten on the head and is carried by the legs to a perch. Here, the wings are discarded and the prey usually ingested head first. A dragonfly may consume as much as a fifth of its body weight in prey per day. Dragonflies are also some of the insect world's most efficient hunters, catching up to 95% of the prey they pursue.

 

The nymphs are voracious predators, eating most living things that are smaller than they are. Their staple diet is mostly bloodworms and other insect larvae, but they also feed on tadpoles and small fish. A few species, especially those that live in temporary waters, are likely to leave the water to feed. Nymphs of Cordulegaster bidentata sometimes hunt small arthropods on the ground at night, while some species in the Anax genus have even been observed leaping out of the water to attack and kill full-grown tree frogs.

   

Eyesight

 

Dragonfly vision is thought to be like slow motion for humans. Dragonflies see faster than we do; they see around 200 images per second. A dragonfly can see in 360 degrees, and nearly 80 percent of the insect's brain is dedicated to its sight.

   

Predators

 

Although dragonflies are swift and agile fliers, some predators are fast enough to catch them. These include falcons such as the American kestrel, the merlin, and the hobby; nighthawks, swifts, flycatchers and swallows also take some adults; some species of wasps, too, prey on dragonflies, using them to provision their nests, laying an egg on each captured insect. In the water, various species of ducks and herons eat dragonfly nymphs and they are also preyed on by newts, frogs, fish, and water spiders. Amur falcons, which migrate over the Indian Ocean at a period that coincides with the migration of the globe skimmer dragonfly, Pantala flavescens, may actually be feeding on them while on the wing.

   

Parasites

 

Dragonflies are affected by three major groups of parasites: water mites, gregarine protozoa, and trematode flatworms (flukes). Water mites, Hydracarina, can kill smaller dragonfly nymphs, and may also be seen on adults. Gregarines infect the gut and may cause blockage and secondary infection. Trematodes are parasites of vertebrates such as frogs, with complex life cycles often involving a period as a stage called a cercaria in a secondary host, a snail. Dragonfly nymphs may swallow cercariae, or these may tunnel through a nymph's body wall; they then enter the gut and form a cyst or metacercaria, which remains in the nymph for the whole of its development. If the nymph is eaten by a frog, the amphibian becomes infected by the adult or fluke stage of the trematode.

   

Dragonflies and humans

 

Conservation

 

Most odonatologists live in temperate areas and the dragonflies of North America and Europe have been the subject of much research. However, the majority of species live in tropical areas and have been little studied. With the destruction of rainforest habitats, many of these species are in danger of becoming extinct before they have even been named. The greatest cause of decline is forest clearance with the consequent drying up of streams and pools which become clogged with silt. The damming of rivers for hydroelectric schemes and the drainage of low-lying land has reduced suitable habitat, as has pollution and the introduction of alien species.

 

In 1997, the International Union for Conservation of Nature set up a status survey and conservation action plan for dragonflies. This proposes the establishment of protected areas around the world and the management of these areas to provide suitable habitat for dragonflies. Outside these areas, encouragement should be given to modify forestry, agricultural, and industrial practices to enhance conservation. At the same time, more research into dragonflies needs to be done, consideration should be given to pollution control and the public should be educated about the importance of biodiversity.

 

Habitat degradation has reduced dragonfly populations across the world, for example in Japan. Over 60% of Japan's wetlands were lost in the 20th century, so its dragonflies now depend largely on rice fields, ponds, and creeks. Dragonflies feed on pest insects in rice, acting as a natural pest control. Dragonflies are steadily declining in Africa, and represent a conservation priority.

 

The dragonfly's long lifespan and low population density makes it vulnerable to disturbance, such as from collisions with vehicles on roads built near wetlands. Species that fly low and slow may be most at risk.

 

Dragonflies are attracted to shiny surfaces that produce polarization which they can mistake for water, and they have been known to aggregate close to polished gravestones, solar panels, automobiles, and other such structures on which they attempt to lay eggs. These can have a local impact on dragonfly populations; methods of reducing the attractiveness of structures such as solar panels are under experimentation.

   

In culture

 

A blue-glazed faience dragonfly amulet was found by Flinders Petrie at Lahun, from the Late Middle Kingdom of ancient Egypt.

 

Many Native American tribes consider dragonflies to be medicine animals that had special powers. For example, the southwestern tribes, including the Pueblo, Hopi, and Zuni, associated dragonflies with transformation. They referred to dragonflies as "snake doctors" because they believed dragonflies followed snakes into the ground and healed them if they were injured. For the Navajo, dragonflies symbolize pure water. Often stylized in a double-barred cross design, dragonflies are a common motif in Zuni pottery, as well as Hopi rock art and Pueblo necklaces.: 20–26 

 

As a seasonal symbol in Japan, the dragonflies are associated with season of autumn. In Japan, they are symbols of rebirth, courage, strength, and happiness. They are also depicted frequently in Japanese art and literature, especially haiku poetry. Japanese children catch large dragonflies as a game, using a hair with a small pebble tied to each end, which they throw into the air. The dragonfly mistakes the pebbles for prey, gets tangled in the hair, and is dragged to the ground by the weight.: 38 

 

In Chinese culture, dragonflies symbolize both change and instability. They are also symbols in the Chinese practices of Feng Shui, where placements of dragonfly statues and artwork in parts of a home or office are believed to bring new insights and positive changes.

 

In both China and Japan, dragonflies have been used in traditional medicine. In Indonesia, adult dragonflies are caught on poles made sticky with birdlime, then fried in oil as a delicacy.

 

Images of dragonflies are common in Art Nouveau, especially in jewellery designs. They have also been used as a decorative motif on fabrics and home furnishings. Douglas, a British motorcycle manufacturer based in Bristol, named its innovatively designed postwar 350-cc flat-twin model the Dragonfly.

 

Among the classical names of Japan are Akitsukuni (秋津国), Akitsushima (秋津島), Toyo-akitsushima (豊秋津島). Akitsu is an old word for dragonfly, so one interpretation of Akitsushima is "Dragonfly Island". This is attributed to a legend in which Japan's mythical founder, Emperor Jimmu, was bitten by a mosquito, which was then eaten by a dragonfly.

 

In Europe, dragonflies have often been seen as sinister. Some English vernacular names, such as "horse-stinger", "devil's darning needle", and "ear cutter", link them with evil or injury. Swedish folklore holds that the devil uses dragonflies to weigh people's souls.: 25–27  The Norwegian name for dragonflies is Øyenstikker ("eye-poker"), and in Portugal, they are sometimes called tira-olhos ("eyes-snatcher"). They are often associated with snakes, as in the Welsh name gwas-y-neidr, "adder's servant". The Southern United States terms "snake doctor" and "snake feeder" refer to a folk belief that dragonflies catch insects for snakes or follow snakes around and stitch them back together if they are injured. Interestingly, the Hungarian name for dragonfly is szitakötő ("sieve-knitter").

 

The watercolourist Moses Harris (1731–1785), known for his The Aurelian or natural history of English insects (1766), published in 1780, the first scientific descriptions of several Odonata including the banded demoiselle, Calopteryx splendens. He was the first English artist to make illustrations of dragonflies accurate enough to be identified to species (Aeshna grandis at top left of plate illustrated), though his rough drawing of a nymph (at lower left) with the mask extended appears to be plagiarised.[b]

 

More recently, dragonfly watching has become popular in America as some birdwatchers seek new groups to observe.

 

In heraldry, like other winged insects, the dragonfly is typically depicted tergiant (with its back facing the viewer), with its head to chief.

   

In poetry and literature

 

Lafcadio Hearn wrote in his 1901 book A Japanese Miscellany that Japanese poets had created dragonfly haiku "almost as numerous as are the dragonflies themselves in the early autumn." The poet Matsuo Bashō (1644–1694) wrote haiku such as "Crimson pepper pod / add two pairs of wings, and look / darting dragonfly", relating the autumn season to the dragonfly. Hori Bakusui (1718–1783) similarly wrote "Dyed he is with the / Colour of autumnal days, / O red dragonfly."

 

The poet Lord Tennyson, described a dragonfly splitting its old skin and emerging shining metallic blue like "sapphire mail" in his 1842 poem "The Two Voices", with the lines "An inner impulse rent the veil / Of his old husk: from head to tail / Came out clear plates of sapphire mail."

 

The novelist H. E. Bates described the rapid, agile flight of dragonflies in his 1937 nonfiction book Down the River:

 

I saw, once, an endless procession, just over an area of water-lilies, of small sapphire dragonflies, a continuous play of blue gauze over the snowy flowers above the sun-glassy water. It was all confined, in true dragonfly fashion, to one small space. It was a continuous turning and returning, an endless darting, poising, striking and hovering, so swift that it was often lost in sunlight.

 

In technology

 

A dragonfly has been genetically modified with light-sensitive "steering neurons" in its nerve cord to create a cyborg-like "DragonflEye". The neurons contain genes like those in the eye to make them sensitive to light. Miniature sensors, a computer chip and a solar panel were fitted in a "backpack" over the insect's thorax in front of its wings. Light is sent down flexible light-pipes named optrodes[c] from the backpack into the nerve cord to give steering commands to the insect. The result is a "micro-aerial vehicle that's smaller, lighter and stealthier than anything else that's manmade".

 

[Credit: en.wikipedia.org/]

Hola Bon dia!! Vull dir moltes cosses pero no se per on escomençar, aixi que dire lo que em ixca… Gràcies, gràcies i gràcies al "Fotoclub Fora Gata" per fer-nos disfrutar, per fer que esta pasió que sentim per la Fotografia, segueixca encesa (al meins a mi) i gràcies per tindre uns valors que molts politics deurien tindre molt en compte (pero que molt en compte) com son, el del treball la ilusió i per supost el de la onestitat, per el que es fa… Aixo ho faig extensible a totes les agrupacions, en primer lloc a la meua, Agrupació Fotogràfica Xàbia que des de que estic ahi, no han deixat de treballar per estos mateixos valors i als que vull dedicar-los un trocet de este Premi, per tot els bons moments i totes les llisons, tant fotogràficament parlant com les personals que m'han regalat. Donar la enhorabona a tots els premiats Jose Guillem Pérez a la Millor Colecció a Jaume Caselles (el rei dels bixos, jijij) a la Millor Foto del Ral.li i a Jaume Boronat Soler (10 anys participant que pessat, jajaja) a la Millor Foto del Tema Obligat, gran treball el que ho fet. Jo m'enportat el Premi a la Segon Millor Colecció de la que en senc molt orgullos…iujuuuuu!!!

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Les pélicans sont de grands oiseaux aquatiques piscivores dotés d'un grand bec avec une volumineuse poche extensible. Ils fréquentent les étendues d'eau libre.

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Pelicans are large water birds with a large beak with a large expandable pocket. They attend the open water.

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Photo C. Cavallera

Laced Woodpecker (Picus vittatus)

  

The laced woodpecker (Picus vittatus) is a species of bird in the Picidae family.

It is found in Cambodia, Indonesia, Laos, Malaysia, Myanmar, Singapore, Thailand, Vietnam and perhaps Bangladesh.

 

Its natural habitats are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, subtropical or tropical mangrove forests, and subtropical or tropical moist montane forests.

  

Species: Laced Woodpecker Picus vittatus *

* The generic name stems from a Latin word: picus = woodpecker. (In Roman mythology, Picus, a brave warrior, was turned into a woodpecker by Circe, whose love he rejected. Seen as the god of agriculture, with the power of prophecy, he was widely worshipped in ancient Italy and was represented as a woodpecker, an important bird in augury.) In Latin, the species name vittatus = striped or banded.

 

Other common names: Bamboo Green Woodpecker, Laced Green Woodpecker, Small Scaly-bellied Woodpecker, Small Scaly-bellied Green Woodpecker.

 

Taxonomy: Picus vittatus Vieillot 1818, Java.

 

Sub-species & Distribution: The species ranges from S China down to Myanmar, Thailand, Malaysia, Singapore, Sumatra, Java and Bali. It is not found in Borneo. It is sometimes seen as being conspecific with the Streak-breasted Woodpecker Picus viridanus. Some authors consider it to be monotypic, while others recognise three sub-forms. The nominate form is found in Singapore and peninsular Malaysia, while another race, connectens, usually considered invalid, is found on Langkawi Island only.

 

Size: 10 to 11" (25.5 to 28.0 cm). Sexes slightly differ.

 

Description: Forehead and crown red, often finely streaked with black, extending onto the nape. Lores pale buffy-brown. A black patch above the lores, extending as a thin superciliary stripe along the sides of crown, with a fine white line below it starting just above the eye. Broad black moustachial streak from the base of lower mandible to the sides of the neck. Above it, a fine white streak starting from the base of upper mandible. Lower face grey, ear coverts darker, sides of nape and upper back bright greenish-brown. Mantle bright olive, the feathers edged yellowish-green, brighter on rump and uppertail coverts. Primaries brownish-black, with regular white bands on outer webs, secondaries similar with outer webs edged with bright olive, the white bands less distinct. Wing coverts dark olive tinged with metallic bronze, edged with greenish-yellow. The pointed tail feathers, stiffened by a strong central shaft except for the shorter outer pair, are blackish-brown, with whitish bars at regular intervals. Chin, throat and breast dull brownish-olive. Belly, lower abdomen and vent dark brownish-buff, the feathers being pale centrally and broadly edged with olive on both sides, producing a heavily striped appearance.

 

Females are very similar but have the top of the head entirely black. In immature birds, the green of the upperparts is duller than in adults, the face more greyish-brown and extending to the sides of the nape. The underparts are paler, the stripes much less distinct. Nestlings of both sexes have black crowns, the young males often acquiring red on the crown while still being fed by the parents.

 

Soft parts: Iris wine-red, dark brown in young birds, eye-ring greenish-grey. Tarsus greenish-horn. Upper mandible black, sometimes marked with yellow and paler at tip, lower mandible yellow at base, darker at tip.

 

Similar species: This species very closely resembles the Streak-breasted Woodpecker Picus viridanus which is not found in Singapore but does occur in peninsular Malaysia.

 

Picus vittatus: Chin, throat and upper breast dull brownish-olive, with no streaks. Lower breast dark brownish-buff with fine lacy marks.

 

Picus viridanus: Throat greener, lightly streaked. Entire breast green, with bold scaly streaks.

 

Status, Habitat & Behaviour: A coastal species found in the casuarinas and mangrove belt from Perak down to Johore and Singapore, it is common on both sides of the Johore Straits but is rarely found inland (Robinson & Chasen 1939). While Burknill & Chasen (1927) considered it unlikely to be found in gardens or near town, the degree of forest clearance since then may have changed things somewhat.

 

Medway & Wells (1976) found it in mangrove and adjacent secondary growth to, at the most, 24 km inland in coconut plantations and village gardens. Wells (1999) found it common near the coast, less so inland, but noted its landward expansion, particularly since 1970's, into oil palm and rubber plantations, nearby wooded gardens and parkland up to 30 km from the sea, but strictly at plains level.

 

Since the early 1900's, there has been much debate, and confusion, over its taxonomy, as well as its status and relationships to very similar birds, such as the Streak-breasted Woodpecker Picus viridanus and the Streak-throated Woodpecker Picus xanthopygaeus, found in peninsular Malaya, Thailand and Myanmar. This debate still continues, and further taxonomic migration can be anticipated. As a result, very little of the early data, on its habits and behaviour, can safely be ascribed to this species.

 

Found singly, in pairs or in small family parties, it is not a shy bird. Most often, it is seen on tree trunks, its tail depressed and partly fanned out to support it against the bark, climbing upwards, often going round and round the trunk in short jerky movements, sometimes hopping backwards for a pace or two. Every now and again, it stops and, with its head cocked to one side, peers very intently at the tree bark, possibly to listen for activity beneath the bark, occasionally tapping tentatively at the bark with its bill. Whenever it suspects the presence of its prey, it starts pecking furiously away, vigorously enough to send wood chips flying all around it, then inserts its tongue into the cavity to extract food.

 

The bird frequently finds its food on the fallen trunks of trees, in tall grass, and can regularly be seen feeding on the ground, the tail pressed against the ground, the body held upright. The underparts of several museum specimens were sullied with mud, suggesting that the birds had fed on the ground or on the roots of mangrove (Burknill & Chasen 1927). In Perak, they were seen searching for food among the fallen leaves in a rubber estate (Edgar 1933). A pair was seen feeding on the ground in Singapore too (Kwong 2011).

 

Occasionally, it can be seen perched on tree trunks or stumps, sunning itself with one or both wings partly outstretched. When disturbed, it flies a short distance to land on the lower branches of a nearby tree. Its flight is strong and undulating.

 

Food: Like all woodpeckers, it feeds mainly on termites, ants and other small insects, including the larvae and eggs of wood-boring insects, hidden in decaying wood or within the hollow stems of various plants. It finds its prey by chiselling into the rotting wood. Then, using its long and greatly extensible tongue, the barbed tip covered with glutinous saliva, it probes deep into the cavity to extract the prey. In Singapore, a bird was seen on the ground, apparently eating worms (Jane 2010).

 

There is very little by way of detailed information specific to its diet but it has been known to eat fruit and berries. A congeneric species, the Streak-throated Woodpecker Picus xanthopygaeus, takes the nectar of flowers from the Erythrina and Salmalia trees, and drinks juice from date palms tapped for toddy (Ali & Ripley 1970). From Singapore, there are reports of this bird feeding at a durian tree Durio zibethinus (Goh et al 2006), and on an oil palm tree Elaeis guineensis (Chow 2011) - whether the bird was actually eating the fruit, drinking the sap or feeding on insects remains unclear. Additionally, there is an early record, from 1989, of this bird being seen "pecking and gobbling the juicy flesh of rambutans" but the actual source of this citation, however, remains elusive.

 

Voice and Calls: Its call is a high-pitched and fairly loud kek, repeated about a dozen times, every two to three seconds or so.

 

Breeding: In Singapore, nest building has been recorded from December to April and June, brooding in April and May, chicks in June, and young birds were seen in June and August (Wang & Hails 2007). In Perak, West Malaysia, nests were found from March to April (Edgar 1933). Medway & Wells (1976) have recorded nests between February and June.

 

Like all woodpeckers, it nests in holes excavated into tree trunks. Their nests, situated 1 to 9 m (3 to 30 feet) above the ground level, have been found on an "api-api' tree (Avicennia spp.), dead coconut trees Cocos nucifera, on a hog-plum tree Spondias spp, a dead mango tree Mangifera spp (Edgar 1933) and on a casuarina tree (Madoc 1956). Though it appears to nest mainly on dead trunks, some nests have been excavated into living trees (Wells 1999).

 

The normal clutch consists of four eggs, pinkish-white, fairly glossy, the average size varying from 26.4 x 19.1 mm. to 27.4 x 21.1 mm. (Edgar 1933). Both sexes help excavate the nest, incubate the eggs and feed the young. Very little is known of its courtship behaviour or its breeding biology.

 

Moult: In Genus Picidae, the primaries moult descendantly and sequentially, the secondaries from two centres, ascendantly from S1 (starting after P5), ascendantly and descendantly from S8 (starting with P3). Tail moult is centrifugal. Post-nuptial is complete. Post-juvenile moult is partial, of primaries, tail and body but not the secondaries, primary coverts or tertials though, sometimes, one or two tertials may be replaced. Occasionally, the outer primary coverts are also moulted, with contrast between the new and old feathers showing (Baker 1993).

 

On 26th August, a family party of two adults and an immature bird was caught at Ulu Pandan in Singapore. The male, with an ill-defined brood patch, was in post-nuptial moult. Wing: P1 to P4 = 5, P5 = 3, P6 = 1, rest = 0, S1 = 4, S2 to S5 = 0, S6 to S8 = 5. Tail: T1 = 0, T2 = 2, T3 = 1, rest = 0. The female, with a distinct brood patch, was also in post-nuptial moult. Wing: P1 to P3 = 5, P4 = 4, P5 = 2, rest = 0. S1 to S6 = 0, S7 to S8 = 5. Tail: T1 = 0, T2 = 1, rest = 0. The immature bird, a female, was undergoing post-juvenile moult. Wing: P1 to P2 = 5, P3 = 4, P4 = missing, rest = 0 (Wang 1999).

 

Miscellaneous: Generally speaking, birds are said to have very little sense of smell or taste. Whether woodpeckers have an acute sense of hearing which enables them to detect the movements of prey items hidden within the wood or whether tapping at the wood with the bill enables them to locate any prey in hidden hollows beneath the surface of the wood, is not entirely clear.

 

The bone structure in a woodpecker's skull is part of an evolutionary adaptation that enables it to hammer away into tree trunks without suffering damage to its brain. Its tongue, too, often more than twice the length of the bird's skull, is just as specialised. More information about this can be obtained from the ON Nature magazine, or the Wild Birds Unlimited site.

 

To discover how the development of the woodpecker's skull has helped inspire the development of shock absorbers, please visit this page published in the New Scientist. The original paper it cites, a highly technical and detailed effort, A mechanical analysis of woodpecker drumming and its application to shock-absorbing systems (Yoon & Park 2011), can be obtained at the IOPscience website.

 

Two adult birds ringed at Rantau Panjang were recaptured there 116 and 120 months later (Medway & Wells 1976).

  

[Credit: singaporebirds.net/]

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Jellyfish, also known sea jellies, are the medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria.

 

Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles, although a few are anchored to the seabed by stalks rather than being mobile. The bell can pulsate to provide propulsion for highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle. The medusa is normally the sexual phase, which produces planula larvae; these then disperse widely and enter a sedentary polyp phase, before reaching sexual maturity.

 

Jellyfish are found all over the world, from surface waters to the deep sea. Scyphozoans (the "true jellyfish") are exclusively marine, but some hydrozoans with a similar appearance live in freshwater. Large, often colorful, jellyfish are common in coastal zones worldwide. The medusae of most species are fast-growing, and mature within a few months then die soon after breeding, but the polyp stage, attached to the seabed, may be much more long-lived. Jellyfish have been in existence for at least 500 million years, and possibly 700 million years or more, making them the oldest multi-organ animal group.

 

Jellyfish are eaten by humans in certain cultures. They are considered a delicacy in some Asian countries, where species in the Rhizostomeae order are pressed and salted to remove excess water. Australian researchers have described them as a "perfect food": sustainable and protein-rich but relatively low in food energy.

 

They are also used in research, where the green fluorescent protein used by some species to cause bioluminescence has been adapted as a fluorescent marker for genes inserted into other cells or organisms.

 

The stinging cells used by jellyfish to subdue their prey can injure humans. Thousands of swimmers worldwide are stung every year, with effects ranging from mild discomfort to serious injury or even death. When conditions are favourable, jellyfish can form vast swarms, which can be responsible for damage to fishing gear by filling fishing nets, and sometimes clog the cooling systems of power and desalination plants which draw their water from the sea.

  

Names

The name jellyfish, in use since 1796, has traditionally been applied to medusae and all similar animals including the comb jellies (ctenophores, another phylum). The term jellies or sea jellies is more recent, having been introduced by public aquaria in an effort to avoid use of the word "fish" with its modern connotation of an animal with a backbone, though shellfish, cuttlefish and starfish are not vertebrates either. In scientific literature, "jelly" and "jellyfish" have been used interchangeably. Many sources refer to only scyphozoans as "true jellyfish".

 

A group of jellyfish is called a "smack" or a "smuck".

 

Definition

The term jellyfish broadly corresponds to medusae, that is, a life-cycle stage in the Medusozoa. The American evolutionary biologist Paulyn Cartwright gives the following general definition:

 

Typically, medusozoan cnidarians have a pelagic, predatory jellyfish stage in their life cycle; staurozoans are the exceptions [as they are stalked].

 

The Merriam-Webster dictionary defines jellyfish as follows:

 

A free-swimming marine coelenterate that is the sexually reproducing form of a hydrozoan or scyphozoan and has a nearly transparent saucer-shaped body and extensible marginal tentacles studded with stinging cells.

 

Given that jellyfish is a common name, its mapping to biological groups is inexact. Some authorities have called the comb jellies and certain salps jellyfish, though other authorities state that neither of these are jellyfish, which they consider should be limited to certain groups within the medusozoa.

 

The non-medusozoan clades called jellyfish by some but not all authorities (both agreeing and disagreeing citations are given in each case) are indicated with on the following cladogram of the animal kingdom:

 

Jellyfish are not a clade, as they include most of the Medusozoa, barring some of the Hydrozoa. The medusozoan groups included by authorities are indicated on the following phylogenetic tree by the presence of citations. Names of included jellyfish, in English where possible, are shown in boldface; the presence of a named and cited example indicates that at least that species within its group has been called a jellyfish.

 

Taxonomy

The subphylum Medusozoa includes all cnidarians with a medusa stage in their life cycle. The basic cycle is egg, planula larva, polyp, medusa, with the medusa being the sexual stage. The polyp stage is sometimes secondarily lost. The subphylum include the major taxa, Scyphozoa (large jellyfish), Cubozoa (box jellyfish) and Hydrozoa (small jellyfish), and excludes Anthozoa (corals and sea anemones). This suggests that the medusa form evolved after the polyps. Medusozoans have tetramerous symmetry, with parts in fours or multiples of four.

 

The four major classes of medusozoan Cnidaria are:

Scyphozoa are sometimes called true jellyfish, though they are no more truly jellyfish than the others listed here. They have tetra-radial symmetry. Most have tentacles around the outer margin of the bowl-shaped bell, and long, oral arms around the mouth in the center of the subumbrella.

Cubozoa (box jellyfish) have a (rounded) box-shaped bell, and their velarium assists them to swim more quickly. Box jellyfish may be related more closely to scyphozoan jellyfish than either are to the Hydrozoa.

Hydrozoa medusae also have tetra-radial symmetry, nearly always have a velum (diaphragm used in swimming) attached just inside the bell margin, do not have oral arms, but a much smaller central stalk-like structure, the manubrium, with terminal mouth opening, and are distinguished by the absence of cells in the mesoglea. Hydrozoa show great diversity of lifestyle; some species maintain the polyp form for their entire life and do not form medusae at all (such as Hydra, which is hence not considered a jellyfish), and a few are entirely medusal and have no polyp form.

Staurozoa (stalked jellyfish) are characterized by a medusa form that is generally sessile, oriented upside down and with a stalk emerging from the apex of the "calyx" (bell), which attaches to the substrate. At least some Staurozoa also have a polyp form that alternates with the medusoid portion of the life cycle. Until recently, Staurozoa were classified within the Scyphozoa.

There are over 200 species of Scyphozoa, about 50 species of Staurozoa, about 50 species of Cubozoa, and the Hydrozoa includes about 1000–1500 species that produce medusae, but many more species that do not.

 

Fossil history

Since jellyfish have no hard parts, fossils are rare. The oldest unambiguous fossil of a free-swimming medusa is Burgessomedusa from the mid Cambrian Burgess Shale of Canada, which is likely either a stem group of box jellyfish (Cubozoa) or Acraspeda (the clade including Staurozoa, Cubozoa, and Scyphozoa). Other claimed records from the Cambrian of China and Utah in the United States are uncertain, and possibly represent ctenophores instead.

 

Anatomy

The main feature of a true jellyfish is the umbrella-shaped bell. This is a hollow structure consisting of a mass of transparent jelly-like matter known as mesoglea, which forms the hydrostatic skeleton of the animal. 95% or more of the mesogloea consists of water, but it also contains collagen and other fibrous proteins, as well as wandering amoebocytes which can engulf debris and bacteria. The mesogloea is bordered by the epidermis on the outside and the gastrodermis on the inside. The edge of the bell is often divided into rounded lobes known as lappets, which allow the bell to flex. In the gaps or niches between the lappets are dangling rudimentary sense organs known as rhopalia, and the margin of the bell often bears tentacles.

  

Anatomy of a scyphozoan jellyfish

On the underside of the bell is the manubrium, a stalk-like structure hanging down from the centre, with the mouth, which also functions as the anus, at its tip. There are often four oral arms connected to the manubrium, streaming away into the water below. The mouth opens into the gastrovascular cavity, where digestion takes place and nutrients are absorbed. This is subdivided by four thick septa into a central stomach and four gastric pockets. The four pairs of gonads are attached to the septa, and close to them four septal funnels open to the exterior, perhaps supplying good oxygenation to the gonads. Near the free edges of the septa, gastric filaments extend into the gastric cavity; these are armed with nematocysts and enzyme-producing cells and play a role in subduing and digesting the prey. In some scyphozoans, the gastric cavity is joined to radial canals which branch extensively and may join a marginal ring canal. Cilia in these canals circulate the fluid in a regular direction.

  

Discharge mechanism of a nematocyst

The box jellyfish is largely similar in structure. It has a squarish, box-like bell. A short pedalium or stalk hangs from each of the four lower corners. One or more long, slender tentacles are attached to each pedalium. The rim of the bell is folded inwards to form a shelf known as a velarium which restricts the bell's aperture and creates a powerful jet when the bell pulsates, allowing box jellyfish to swim faster than true jellyfish. Hydrozoans are also similar, usually with just four tentacles at the edge of the bell, although many hydrozoans are colonial and may not have a free-living medusal stage. In some species, a non-detachable bud known as a gonophore is formed that contains a gonad but is missing many other medusal features such as tentacles and rhopalia. Stalked jellyfish are attached to a solid surface by a basal disk, and resemble a polyp, the oral end of which has partially developed into a medusa with tentacle-bearing lobes and a central manubrium with four-sided mouth.

 

Most jellyfish do not have specialized systems for osmoregulation, respiration and circulation, and do not have a central nervous system. Nematocysts, which deliver the sting, are located mostly on the tentacles; true jellyfish also have them around the mouth and stomach. Jellyfish do not need a respiratory system because sufficient oxygen diffuses through the epidermis. They have limited control over their movement, but can navigate with the pulsations of the bell-like body; some species are active swimmers most of the time, while others largely drift. The rhopalia contain rudimentary sense organs which are able to detect light, water-borne vibrations, odour and orientation. A loose network of nerves called a "nerve net" is located in the epidermis. Although traditionally thought not to have a central nervous system, nerve net concentration and ganglion-like structures could be considered to constitute one in most species. A jellyfish detects stimuli, and transmits impulses both throughout the nerve net and around a circular nerve ring, to other nerve cells. The rhopalial ganglia contain pacemaker neurones which control swimming rate and direction.

 

In many species of jellyfish, the rhopalia include ocelli, light-sensitive organs able to tell light from dark. These are generally pigment spot ocelli, which have some of their cells pigmented. The rhopalia are suspended on stalks with heavy crystals at one end, acting like gyroscopes to orient the eyes skyward. Certain jellyfish look upward at the mangrove canopy while making a daily migration from mangrove swamps into the open lagoon, where they feed, and back again.

 

Box jellyfish have more advanced vision than the other groups. Each individual has 24 eyes, two of which are capable of seeing colour, and four parallel information processing areas that act in competition, supposedly making them one of the few kinds of animal to have a 360-degree view of its environment.

 

Box jellyfish eye

The study of jellyfish eye evolution is an intermediary to a better understanding of how visual systems evolved on Earth. Jellyfish exhibit immense variation in visual systems ranging from photoreceptive cell patches seen in simple photoreceptive systems to more derived complex eyes seen in box jellyfish. Major topics of jellyfish visual system research (with an emphasis on box jellyfish) include: the evolution of jellyfish vision from simple to complex visual systems), the eye morphology and molecular structures of box jellyfish (including comparisons to vertebrate eyes), and various uses of vision including task-guided behaviors and niche specialization.

 

Evolution

Experimental evidence for photosensitivity and photoreception in cnidarians antecedes the mid 1900s, and a rich body of research has since covered evolution of visual systems in jellyfish. Jellyfish visual systems range from simple photoreceptive cells to complex image-forming eyes. More ancestral visual systems incorporate extraocular vision (vision without eyes) that encompass numerous receptors dedicated to single-function behaviors. More derived visual systems comprise perception that is capable of multiple task-guided behaviors.

 

Although they lack a true brain, cnidarian jellyfish have a "ring" nervous system that plays a significant role in motor and sensory activity. This net of nerves is responsible for muscle contraction and movement and culminates the emergence of photosensitive structures. Across Cnidaria, there is large variation in the systems that underlie photosensitivity. Photosensitive structures range from non-specialized groups of cells, to more "conventional" eyes similar to those of vertebrates. The general evolutionary steps to develop complex vision include (from more ancestral to more derived states): non-directional photoreception, directional photoreception, low-resolution vision, and high-resolution vision. Increased habitat and task complexity has favored the high-resolution visual systems common in derived cnidarians such as box jellyfish.

 

Basal visual systems observed in various cnidarians exhibit photosensitivity representative of a single task or behavior. Extraocular photoreception (a form of non-directional photoreception), is the most basic form of light sensitivity and guides a variety of behaviors among cnidarians. It can function to regulate circadian rhythm (as seen in eyeless hydrozoans) and other light-guided behaviors responsive to the intensity and spectrum of light. Extraocular photoreception can function additionally in positive phototaxis (in planula larvae of hydrozoans), as well as in avoiding harmful amounts of UV radiation via negative phototaxis. Directional photoreception (the ability to perceive direction of incoming light) allows for more complex phototactic responses to light, and likely evolved by means of membrane stacking. The resulting behavioral responses can range from guided spawning events timed by moonlight to shadow responses for potential predator avoidance. Light-guided behaviors are observed in numerous scyphozoans including the common moon jelly, Aurelia aurita, which migrates in response to changes in ambient light and solar position even though they lack proper eyes.

 

The low-resolution visual system of box jellyfish is more derived than directional photoreception, and thus box jellyfish vision represents the most basic form of true vision in which multiple directional photoreceptors combine to create the first imaging and spatial resolution. This is different from the high-resolution vision that is observed in camera or compound eyes of vertebrates and cephalopods that rely on focusing optics. Critically, the visual systems of box jellyfish are responsible for guiding multiple tasks or behaviors in contrast to less derived visual systems in other jellyfish that guide single behavioral functions. These behaviors include phototaxis based on sunlight (positive) or shadows (negative), obstacle avoidance, and control of swim-pulse rate.

 

Box jellyfish possess "proper eyes" (similar to vertebrates) that allow them to inhabit environments that lesser derived medusae cannot. In fact, they are considered the only class in the clade Medusozoa that have behaviors necessitating spatial resolution and genuine vision. However, the lens in their eyes are more functionally similar to cup-eyes exhibited in low-resolution organisms, and have very little to no focusing capability. The lack of the ability to focus is due to the focal length exceeding the distance to the retina, thus generating unfocused images and limiting spatial resolution. The visual system is still sufficient for box jellyfish to produce an image to help with tasks such as object avoidance.

 

Utility as a model organism

Box jellyfish eyes are a visual system that is sophisticated in numerous ways. These intricacies include the considerable variation within the morphology of box jellyfishes' eyes (including their task/behavior specification), and the molecular makeup of their eyes including: photoreceptors, opsins, lenses, and synapses. The comparison of these attributes to more derived visual systems can allow for a further understanding of how the evolution of more derived visual systems may have occurred, and puts into perspective how box jellyfish can play the role as an evolutionary/developmental model for all visual systems.

 

Characteristics

Box jellyfish visual systems are both diverse and complex, comprising multiple photosystems. There is likely considerable variation in visual properties between species of box jellyfish given the significant inter-species morphological and physiological variation. Eyes tend to differ in size and shape, along with number of receptors (including opsins), and physiology across species of box jellyfish.

 

Box jellyfish have a series of intricate lensed eyes that are similar to those of more derived multicellular organisms such as vertebrates. Their 24 eyes fit into four different morphological categories. These categories consist of two large, morphologically different medial eyes (a lower and upper lensed eye) containing spherical lenses, a lateral pair of pigment slit eyes, and a lateral pair of pigment pit eyes. The eyes are situated on rhopalia (small sensory structures) which serve sensory functions of the box jellyfish and arise from the cavities of the exumbrella (the surface of the body) on the side of the bells of the jellyfish. The two large eyes are located on the mid-line of the club and are considered complex because they contain lenses. The four remaining eyes lie laterally on either side of each rhopalia and are considered simple. The simple eyes are observed as small invaginated cups of epithelium that have developed pigmentation. The larger of the complex eyes contains a cellular cornea created by a mono ciliated epithelium, cellular lens, homogenous capsule to the lens, vitreous body with prismatic elements, and a retina of pigmented cells. The smaller of the complex eyes is said to be slightly less complex given that it lacks a capsule but otherwise contains the same structure as the larger eye.

 

Box jellyfish have multiple photosystems that comprise different sets of eyes. Evidence includes immunocytochemical and molecular data that show photopigment differences among the different morphological eye types, and physiological experiments done on box jellyfish to suggest behavioral differences among photosystems. Each individual eye type constitutes photosystems that work collectively to control visually guided behaviors.

 

Box jellyfish eyes primarily use c-PRCs (ciliary photoreceptor cells) similar to that of vertebrate eyes. These cells undergo phototransduction cascades (process of light absorption by photoreceptors) that are triggered by c-opsins. Available opsin sequences suggest that there are two types of opsins possessed by all cnidarians including an ancient phylogenetic opsin, and a sister ciliary opsin to the c-opsins group. Box jellyfish could have both ciliary and cnidops (cnidarian opsins), which is something not previously believed to appear in the same retina. Nevertheless, it is not entirely evident whether cnidarians possess multiple opsins that are capable of having distinctive spectral sensitivities.

 

Comparison with other organisms

Comparative research on genetic and molecular makeup of box jellyfishes' eyes versus more derived eyes seen in vertebrates and cephalopods focuses on: lenses and crystallin composition, synapses, and Pax genes and their implied evidence for shared primordial (ancestral) genes in eye evolution.

 

Box jellyfish eyes are said to be an evolutionary/developmental model of all eyes based on their evolutionary recruitment of crystallins and Pax genes. Research done on box jellyfish including Tripedalia cystophora has suggested that they possess a single Pax gene, PaxB. PaxB functions by binding to crystallin promoters and activating them. PaxB in situ hybridization resulted in PaxB expression in the lens, retina, and statocysts. These results and the rejection of the prior hypothesis that Pax6 was an ancestral Pax gene in eyes has led to the conclusion that PaxB was a primordial gene in eye evolution, and that the eyes of all organisms likely share a common ancestor.

 

The lens structure of box jellyfish appears very similar to those of other organisms, but the crystallins are distinct in both function and appearance. Weak reactions were seen within the sera and there were very weak sequence similarities within the crystallins among vertebrate and invertebrate lenses. This is likely due to differences in lower molecular weight proteins and the subsequent lack of immunological reactions with antisera that other organisms' lenses exhibit.

 

All four of the visual systems of box jellyfish species investigated with detail (Carybdea marsupialis, Chiropsalmus quadrumanus, Tamoya haplonema and Tripedalia cystophora) have invaginated synapses, but only in the upper and lower lensed eyes. Different densities were found between the upper and lower lenses, and between species. Four types of chemical synapses have been discovered within the rhopalia which could help in understanding neural organization including: clear unidirectional, dense-core unidirectional, clear bidirectional, and clear and dense-core bidirectional. The synapses of the lensed eyes could be useful as markers to learn more about the neural circuit in box jellyfish retinal areas.

 

Evolution as a response to natural stimuli

The primary adaptive responses to environmental variation observed in box jellyfish eyes include pupillary constriction speeds in response to light environments, as well as photoreceptor tuning and lens adaptations to better respond to shifts between light environments and darkness. Interestingly, some box jellyfish species' eyes appear to have evolved more focused vision in response to their habitat.

 

Pupillary contraction appears to have evolved in response to variation in the light environment across ecological niches across three species of box jellyfish (Chironex fleckeri, Chiropsella bronzie, and Carukia barnesi). Behavioral studies suggest that faster pupil contraction rates allow for greater object avoidance, and in fact, species with more complex habitats exhibit faster rates. Ch. bronzie inhabit shallow beach fronts that have low visibility and very few obstacles, thus, faster pupil contraction in response to objects in their environment is not important. Ca. barnesi and Ch. fleckeri are found in more three-dimensionally complex environments like mangroves with an abundance of natural obstacles, where faster pupil contraction is more adaptive. Behavioral studies support the idea that faster pupillary contraction rates assist with obstacle avoidance as well as depth adjustments in response to differing light intensities.

 

Light/dark adaptation via pupillary light reflexes is an additional form of an evolutionary response to the light environment. This relates to the pupil's response to shifts between light intensity (generally from sunlight to darkness). In the process of light/dark adaptation, the upper and lower lens eyes of different box jellyfish species vary in specific function. The lower lens-eyes contain pigmented photoreceptors and long pigment cells with dark pigments that migrate on light/dark adaptation, while the upper-lens eyes play a concentrated role in light direction and phototaxis given that they face upward towards the water surface (towards the sun or moon). The upper lens of Ch. bronzie does not exhibit any considerable optical power while Tr. cystophora (a box jellyfish species that tends to live in mangroves) does. The ability to use light to visually guide behavior is not of as much importance to Ch. bronzie as it is to species in more obstacle-filled environments. Differences in visually guided behavior serve as evidence that species that share the same number and structure of eyes can exhibit differences in how they control behavior.

 

Largest and smallest

Jellyfish range from about one millimeter in bell height and diameter, to nearly 2 metres (6+1⁄2 ft) in bell height and diameter; the tentacles and mouth parts usually extend beyond this bell dimension.

 

The smallest jellyfish are the peculiar creeping jellyfish in the genera Staurocladia and Eleutheria, which have bell disks from 0.5 millimetres (1⁄32 in) to a few millimeters in diameter, with short tentacles that extend out beyond this, which these jellyfish use to move across the surface of seaweed or the bottoms of rocky pools; many of these tiny creeping jellyfish cannot be seen in the field without a hand lens or microscope. They can reproduce asexually by fission (splitting in half). Other very small jellyfish, which have bells about one millimeter, are the hydromedusae of many species that have just been released from their parent polyps; some of these live only a few minutes before shedding their gametes in the plankton and then dying, while others will grow in the plankton for weeks or months. The hydromedusae Cladonema radiatum and Cladonema californicum are also very small, living for months, yet never growing beyond a few mm in bell height and diameter.

 

The lion's mane jellyfish, Cyanea capillata, was long-cited as the largest jellyfish, and arguably the longest animal in the world, with fine, thread-like tentacles that may extend up to 36.5 m (119 ft 9 in) long (though most are nowhere near that large). They have a moderately painful, but rarely fatal, sting. The increasingly common giant Nomura's jellyfish, Nemopilema nomurai, found in some, but not all years in the waters of Japan, Korea and China in summer and autumn is another candidate for "largest jellyfish", in terms of diameter and weight, since the largest Nomura's jellyfish in late autumn can reach 2 m (6 ft 7 in) in bell (body) diameter and about 200 kg (440 lb) in weight, with average specimens frequently reaching 0.9 m (2 ft 11 in) in bell diameter and about 150 kg (330 lb) in weight. The large bell mass of the giant Nomura's jellyfish can dwarf a diver and is nearly always much greater than the Lion's Mane, whose bell diameter can reach 1 m (3 ft 3 in).

 

The rarely encountered deep-sea jellyfish Stygiomedusa gigantea is another candidate for "largest jellyfish", with its thick, massive bell up to 100 cm (3 ft 3 in) wide, and four thick, "strap-like" oral arms extending up to 6 m (19+1⁄2 ft) in length, very different from the typical fine, threadlike tentacles that rim the umbrella of more-typical-looking jellyfish, including the Lion's Mane.

 

Desmonema glaciale, which lives in the Antarctic region, can reach a very large size (several meters). Purple-striped jelly (Chrysaora colorata) can also be extremely long (up to 15 feet).

 

Life history and behavior

Life cycle

Jellyfish have a complex life cycle which includes both sexual and asexual phases, with the medusa being the sexual stage in most instances. Sperm fertilize eggs, which develop into larval planulae, become polyps, bud into ephyrae and then transform into adult medusae. In some species certain stages may be skipped.

 

Upon reaching adult size, jellyfish spawn regularly if there is a sufficient supply of food. In most species, spawning is controlled by light, with all individuals spawning at about the same time of day; in many instances this is at dawn or dusk. Jellyfish are usually either male or female (with occasional hermaphrodites). In most cases, adults release sperm and eggs into the surrounding water, where the unprotected eggs are fertilized and develop into larvae. In a few species, the sperm swim into the female's mouth, fertilizing the eggs within her body, where they remain during early development stages. In moon jellies, the eggs lodge in pits on the oral arms, which form a temporary brood chamber for the developing planula larvae.

 

The planula is a small larva covered with cilia. When sufficiently developed, it settles onto a firm surface and develops into a polyp. The polyp generally consists of a small stalk topped by a mouth that is ringed by upward-facing tentacles. The polyps resemble those of closely related anthozoans, such as sea anemones and corals. The jellyfish polyp may be sessile, living on the bottom, boat hulls or other substrates, or it may be free-floating or attached to tiny bits of free-living plankton or rarely, fish or other invertebrates. Polyps may be solitary or colonial. Most polyps are only millimetres in diameter and feed continuously. The polyp stage may last for years.

 

After an interval and stimulated by seasonal or hormonal changes, the polyp may begin reproducing asexually by budding and, in the Scyphozoa, is called a segmenting polyp, or a scyphistoma. Budding produces more scyphistomae and also ephyrae. Budding sites vary by species; from the tentacle bulbs, the manubrium (above the mouth), or the gonads of hydromedusae. In a process known as strobilation, the polyp's tentacles are reabsorbed and the body starts to narrow, forming transverse constrictions, in several places near the upper extremity of the polyp. These deepen as the constriction sites migrate down the body, and separate segments known as ephyra detach. These are free-swimming precursors of the adult medusa stage, which is the life stage that is typically identified as a jellyfish. The ephyrae, usually only a millimeter or two across initially, swim away from the polyp and grow. Limnomedusae polyps can asexually produce a creeping frustule larval form, which crawls away before developing into another polyp. A few species can produce new medusae by budding directly from the medusan stage. Some hydromedusae reproduce by fission.

 

Lifespan

Little is known of the life histories of many jellyfish as the places on the seabed where the benthic forms of those species live have not been found. However, an asexually reproducing strobila form can sometimes live for several years, producing new medusae (ephyra larvae) each year.

 

An unusual species, Turritopsis dohrnii, formerly classified as Turritopsis nutricula, might be effectively immortal because of its ability under certain circumstances to transform from medusa back to the polyp stage, thereby escaping the death that typically awaits medusae post-reproduction if they have not otherwise been eaten by some other organism. So far this reversal has been observed only in the laboratory.

 

Locomotion

Jellyfish locomotion is highly efficient. Muscles in the jellylike bell contract, setting up a start vortex and propelling the animal. When the contraction ends, the bell recoils elastically, creating a stop vortex with no extra energy input.

Using the moon jelly Aurelia aurita as an example, jellyfish have been shown to be the most energy-efficient swimmers of all animals. They move through the water by radially expanding and contracting their bell-shaped bodies to push water behind them. They pause between the contraction and expansion phases to create two vortex rings. Muscles are used for the contraction of the body, which creates the first vortex and pushes the animal forward, but the mesoglea is so elastic that the expansion is powered exclusively by relaxing the bell, which releases the energy stored from the contraction. Meanwhile, the second vortex ring starts to spin faster, sucking water into the bell and pushing against the centre of the body, giving a secondary and "free" boost forward. The mechanism, called passive energy recapture, only works in relatively small jellyfish moving at low speeds, allowing the animal to travel 30 percent farther on each swimming cycle. Jellyfish achieved a 48 percent lower cost of transport (food and oxygen intake versus energy spent in movement) than other animals in similar studies. One reason for this is that most of the gelatinous tissue of the bell is inactive, using no energy during swimming.

 

Ecology

Diet

Jellyfish are, like other cnidarians, generally carnivorous (or parasitic), feeding on planktonic organisms, crustaceans, small fish, fish eggs and larvae, and other jellyfish, ingesting food and voiding undigested waste through the mouth. They hunt passively using their tentacles as drift lines, or sink through the water with their tentacles spread widely; the tentacles, which contain nematocysts to stun or kill the prey, may then flex to help bring it to the mouth. Their swimming technique also helps them to capture prey; when their bell expands it sucks in water which brings more potential prey within reach of the tentacles.

 

A few species such as Aglaura hemistoma are omnivorous, feeding on microplankton which is a mixture of zooplankton and phytoplankton (microscopic plants) such as dinoflagellates. Others harbour mutualistic algae (Zooxanthellae) in their tissues; the spotted jellyfish (Mastigias papua) is typical of these, deriving part of its nutrition from the products of photosynthesis, and part from captured zooplankton. The upside-down jellyfish (Cassiopea andromeda) also has a symbiotic relationship with microalgae, but captures tiny animals to supplement their diet. This is done by releasing tiny balls of living cells composed of mesoglea. These use cilia to drive them through water and stinging cells which stun the prey. The blobs also seems to have digestive capabilities.

 

Predation

Other species of jellyfish are among the most common and important jellyfish predators. Sea anemones may eat jellyfish that drift into their range. Other predators include tunas, sharks, swordfish, sea turtles and penguins. Jellyfish washed up on the beach are consumed by foxes, other terrestrial mammals and birds. In general however, few animals prey on jellyfish; they can broadly be considered to be top predators in the food chain. Once jellyfish have become dominant in an ecosystem, for example through overfishing which removes predators of jellyfish larvae, there may be no obvious way for the previous balance to be restored: they eat fish eggs and juvenile fish, and compete with fish for food, preventing fish stocks from recovering.

 

Symbiosis

Some small fish are immune to the stings of the jellyfish and live among the tentacles, serving as bait in a fish trap; they are safe from potential predators and are able to share the fish caught by the jellyfish. The cannonball jellyfish has a symbiotic relationship with ten different species of fish, and with the longnose spider crab, which lives inside the bell, sharing the jellyfish's food and nibbling its tissues.

 

Main article: Jellyfish bloom

Jellyfish form large masses or blooms in certain environmental conditions of ocean currents, nutrients, sunshine, temperature, season, prey availability, reduced predation and oxygen concentration. Currents collect jellyfish together, especially in years with unusually high populations. Jellyfish can detect marine currents and swim against the current to congregate in blooms. Jellyfish are better able to survive in nutrient-rich, oxygen-poor water than competitors, and thus can feast on plankton without competition. Jellyfish may also benefit from saltier waters, as saltier waters contain more iodine, which is necessary for polyps to turn into jellyfish. Rising sea temperatures caused by climate change may also contribute to jellyfish blooms, because many species of jellyfish are able to survive in warmer waters. Increased nutrients from agricultural or urban runoff with nutrients including nitrogen and phosphorus compounds increase the growth of phytoplankton, causing eutrophication and algal blooms. When the phytoplankton die, they may create dead zones, so-called because they are hypoxic (low in oxygen). This in turn kills fish and other animals, but not jellyfish, allowing them to bloom. Jellyfish populations may be expanding globally as a result of land runoff and overfishing of their natural predators. Jellyfish are well placed to benefit from disturbance of marine ecosystems. They reproduce rapidly; they prey upon many species, while few species prey on them; and they feed via touch rather than visually, so they can feed effectively at night and in turbid waters. It may be difficult for fish stocks to re-establish themselves in marine ecosystems once they have become dominated by jellyfish, because jellyfish feed on plankton, which includes fish eggs and larvae.

 

As suspected at the turn of this century, jellyfish blooms are increasing in frequency. Between 2013 and 2020 the Mediterranean Science Commission monitored on a weekly basis the frequency of such outbreaks in coastal waters from Morocco to the Black Sea, revealing a relatively high frequency of these blooms nearly all year round, with peaks observed from March to July and often again in the autumn. The blooms are caused by different jellyfish species, depending on their localisation within the Basin: one observes a clear dominance of Pelagia noctiluca and Velella velella outbreaks in the western Mediterranean, of Rhizostoma pulmo and Rhopilema nomadica outbreaks in the eastern Mediterranean, and of Aurelia aurita and Mnemiopsis leidyi outbreaks in the Black Sea.

 

Some jellyfish populations that have shown clear increases in the past few decades are invasive species, newly arrived from other habitats: examples include the Black Sea, Caspian Sea, Baltic Sea, central and eastern Mediterranean, Hawaii, and tropical and subtropical parts of the West Atlantic (including the Caribbean, Gulf of Mexico and Brazil).

 

Jellyfish blooms can have significant impact on community structure. Some carnivorous jellyfish species prey on zooplankton while others graze on primary producers. Reductions in zooplankton and ichthyoplankton due to a jellyfish bloom can ripple through the trophic levels. High-density jellyfish populations can outcompete other predators and reduce fish recruitment. Increased grazing on primary producers by jellyfish can also interrupt energy transfer to higher trophic levels.

 

During blooms, jellyfish significantly alter the nutrient availability in their environment. Blooms require large amounts of available organic nutrients in the water column to grow, limiting availability for other organisms. Some jellyfish have a symbiotic relationship with single-celled dinoflagellates, allowing them to assimilate inorganic carbon, phosphorus, and nitrogen creating competition for phytoplankton. Their large biomass makes them an important source of dissolved and particulate organic matter for microbial communities through excretion, mucus production, and decomposition. The microbes break down the organic matter into inorganic ammonium and phosphate. However, the low carbon availability shifts the process from production to respiration creating low oxygen areas making the dissolved inorganic nitrogen and phosphorus largely unavailable for primary production.

 

These blooms have very real impacts on industries. Jellyfish can outcompete fish by utilizing open niches in over-fished fisheries. Catch of jellyfish can strain fishing gear and lead to expenses relating to damaged gear. Power plants have been shut down due to jellyfish blocking the flow of cooling water. Blooms have also been harmful for tourism, causing a rise in stings and sometimes the closure of beaches.

 

Jellyfish form a component of jelly-falls, events where gelatinous zooplankton fall to the seafloor, providing food for the benthic organisms there. In temperate and subpolar regions, jelly-falls usually follow immediately after a bloom.

 

Habitats

Most jellyfish are marine animals, although a few hydromedusae inhabit freshwater. The best known freshwater example is the cosmopolitan hydrozoan jellyfish, Craspedacusta sowerbii. It is less than an inch (2.5 cm) in diameter, colorless and does not sting. Some jellyfish populations have become restricted to coastal saltwater lakes, such as Jellyfish Lake in Palau. Jellyfish Lake is a marine lake where millions of golden jellyfish (Mastigias spp.) migrate horizontally across the lake daily.

 

Although most jellyfish live well off the ocean floor and form part of the plankton, a few species are closely associated with the bottom for much of their lives and can be considered benthic. The upside-down jellyfish in the genus Cassiopea typically lie on the bottom of shallow lagoons where they sometimes pulsate gently with their umbrella top facing down. Even some deep-sea species of hydromedusae and scyphomedusae are usually collected on or near the bottom. All of the stauromedusae are found attached to either seaweed or rocky or other firm material on the bottom.

 

Some species explicitly adapt to tidal flux. In Roscoe Bay, jellyfish ride the current at ebb tide until they hit a gravel bar, and then descend below the current. They remain in still waters until the tide rises, ascending and allowing it to sweep them back into the bay. They also actively avoid fresh water from mountain snowmelt, diving until they find enough salt.

  

Parasites

Jellyfish are hosts to a wide variety of parasitic organisms. They act as intermediate hosts of endoparasitic helminths, with the infection being transferred to the definitive host fish after predation. Some digenean trematodes, especially species in the family Lepocreadiidae, use jellyfish as their second intermediate hosts. Fish become infected by the trematodes when they feed on infected jellyfish.

 

Relation to humans

Jellyfish have long been eaten in some parts of the world. Fisheries have begun harvesting the American cannonball jellyfish, Stomolophus meleagris, along the southern Atlantic coast of the United States and in the Gulf of Mexico for export to Asia.

 

Jellyfish are also harvested for their collagen, which is being investigated for use in a variety of applications including the treatment of rheumatoid arthritis.

 

Aquaculture and fisheries of other species often suffer severe losses – and so losses of productivity – due to jellyfish.

 

Products

Main article: Jellyfish as food

In some countries, including China, Japan, and Korea, jellyfish are a delicacy. The jellyfish is dried to prevent spoiling. Only some 12 species of scyphozoan jellyfish belonging to the order Rhizostomeae are harvested for food, mostly in southeast Asia. Rhizostomes, especially Rhopilema esculentum in China (海蜇 hǎizhé, 'sea stingers') and Stomolophus meleagris (cannonball jellyfish) in the United States, are favored because of their larger and more rigid bodies and because their toxins are harmless to humans.

 

Traditional processing methods, carried out by a jellyfish master, involve a 20- to 40-day multi-phase procedure in which, after removing the gonads and mucous membranes, the umbrella and oral arms are treated with a mixture of table salt and alum, and compressed. Processing makes the jellyfish drier and more acidic, producing a crisp texture. Jellyfish prepared this way retain 7–10% of their original weight, and the processed product consists of approximately 94% water and 6% protein. Freshly processed jellyfish has a white, creamy color and turns yellow or brown during prolonged storage.

 

In China, processed jellyfish are desalted by soaking in water overnight and eaten cooked or raw. The dish is often served shredded with a dressing of oil, soy sauce, vinegar and sugar, or as a salad with vegetables. In Japan, cured jellyfish are rinsed, cut into strips and served with vinegar as an appetizer. Desalted, ready-to-eat products are also available.

 

Biotechnology

The hydromedusa Aequorea victoria was the source of green fluorescent protein, studied for its role in bioluminescence and later for use as a marker in genetic engineering.

Pliny the Elder reported in his Natural History that the slime of the jellyfish "Pulmo marinus" produced light when rubbed on a walking stick.

 

In 1961, Osamu Shimomura extracted green fluorescent protein (GFP) and another bioluminescent protein, called aequorin, from the large and abundant hydromedusa Aequorea victoria, while studying photoproteins that cause bioluminescence in this species. Three decades later, Douglas Prasher sequenced and cloned the gene for GFP. Martin Chalfie figured out how to use GFP as a fluorescent marker of genes inserted into other cells or organisms. Roger Tsien later chemically manipulated GFP to produce other fluorescent colors to use as markers. In 2008, Shimomura, Chalfie and Tsien won the Nobel Prize in Chemistry for their work with GFP. Man-made GFP became widely used as a fluorescent tag to show which cells or tissues express specific genes. The genetic engineering technique fuses the gene of interest to the GFP gene. The fused DNA is then put into a cell, to generate either a cell line or (via IVF techniques) an entire animal bearing the gene. In the cell or animal, the artificial gene turns on in the same tissues and the same time as the normal gene, making a fusion of the normal protein with GFP attached to the end, illuminating the animal or cell reveals what tissues express that protein—or at what stage of development. The fluorescence shows where the gene is expressed.

 

Aquarium display

Jellyfish are displayed in many public aquariums. Often the tank's background is blue and the animals are illuminated by side light, increasing the contrast between the animal and the background. In natural conditions, many jellies are so transparent that they are nearly invisible. Jellyfish are not adapted to closed spaces. They depend on currents to transport them from place to place. Professional exhibits as in the Monterey Bay Aquarium feature precise water flows, typically in circular tanks to avoid trapping specimens in corners. The outflow is spread out over a large surface area and the inflow enters as a sheet of water in front of the outflow, so the jellyfish do not get sucked into it. As of 2009, jellyfish were becoming popular in home aquariums, where they require similar equipment.

 

Stings

Jellyfish are armed with nematocysts, a type of specialized stinging cell. Contact with a jellyfish tentacle can trigger millions of nematocysts to pierce the skin and inject venom, but only some species' venom causes an adverse reaction in humans. In a study published in Communications Biology, researchers found a jellyfish species called Cassiopea xamachana which when triggered will release tiny balls of cells that swim around the jellyfish stinging everything in their path. Researchers described these as "self-propelling microscopic grenades" and named them cassiosomes.

 

The effects of stings range from mild discomfort to extreme pain and death. Most jellyfish stings are not deadly, but stings of some box jellyfish (Irukandji jellyfish), such as the sea wasp, can be deadly. Stings may cause anaphylaxis (a form of shock), which can be fatal. Jellyfish kill 20 to 40 people a year in the Philippines alone. In 2006 the Spanish Red Cross treated 19,000 stung swimmers along the Costa Brava.

 

Vinegar (3–10% aqueous acetic acid) may help with box jellyfish stings but not the stings of the Portuguese man o' war. Clearing the area of jelly and tentacles reduces nematocyst firing. Scraping the affected skin, such as with the edge of a credit card, may remove remaining nematocysts. Once the skin has been cleaned of nematocysts, hydrocortisone cream applied locally reduces pain and inflammation. Antihistamines may help to control itching. Immunobased antivenins are used for serious box jellyfish stings.

 

In Elba Island and Corsica dittrichia viscosa is now used by residents and tourists to heal stings from jellyfish, bees and wasps pressing fresh leaves on the skin with quick results.

 

Mechanical issues

Jellyfish in large quantities can fill and split fishing nets and crush captured fish. They can clog cooling equipment, having disabled power stations in several countries; jellyfish caused a cascading blackout in the Philippines in 1999, as well as damaging the Diablo Canyon Power Plant in California in 2008. They can also stop desalination plants and ships' engines.

If one considers blog software as a "lightweight content management" system or a template driven web publishing platform, the possibilities are only bounded by our creativity.

 

Key questions:

 

* Once past the land of "blogs as diaries", what is there?

* What are the essential characteristics of blog software, and how can their applications be extended?

 

Hand coding HTML for web pages works fine for a few "pages", but loses effectiveness when the numbers hit 3 or 4 decimal places. What blog software provides for anyone publishing web content include:

 

* separation of content (stored in a database) from formatting (more and more web-standard designed templates)

* built in keyword search

* built in creation of RSS feeds

* built in commenting

* flexible organization via ctaegories defined by users

* editing via a simple web browser interface, w/o need for special software

* a shift to focus on the content from the formatting

* extensibility of functions via plug-ings

 

In April 2001 Dave Winer foresaw the Read/Write Web-- The Web is a Writing Environment-- In the meantime, the one revolution that the Internet has totally delivered is a fundamental change in the way written information and ideas flow. As people get more comfortable with networking technology, and as engineers learn how to do easier user interfaces, there will be more people writing on the Web.

  

See Also...

* Weblogging: Another kind of website by Chris Ashley, IST—Interactive University. One day in mid-March of last year, Raymond Yee of the Interactive University (IU) [1] thought it would be a good idea to buy and experiment with Manila, a web server application capable of supporting literally thousands of weblog websites. A bargain-priced education license was purchased, and Catherine Yoes (then at IU) downloaded and installed it on a rather ordinary NT server. Within weeks the IU experienced a revolutionary change in thinking about what a website is, how they're hosted, what they're used for, how they're built, and who owns them. A year and a half later, all of the IU's websites are being produced using weblog technology, our team communications and sharing have been vitally enhanced, and a number of our team members are regularly writing on the web, as are many of our University/K-12 projects and the K-12 teachers we work with. (emphasis added)

* Weblogs, part II: A Swiss Army website? Chris Ashley, IST–Interactive University. This second article is an overview of a number of areas in which weblog software and the weblog model of content production and platform interoperability are proving to be increasingly useful and powerful, pushing and inspiring innovative developments for, and uses of, the Web. These areas include: content, information, and knowledge management; community building; publishing and journalism; teaching, learning, and collaboration; and course management systems (CMS).

* The blog as resume and autobiography (Jon Udell) The idea would be to explore the professional blog as a literary form that grows out of, and extends, two traditional forms: the resume and the autobiography.

* What Blogs Are: A Collaborative, Open Model For Information Exchange Robin Good, MasterNewMedia

* Using WordPress as a CMS (Ruminate) lists a few examples

* Beyond the Blog (The Prequel) A screencast (43 MB QuickTime) that demonstrates some educational blogs that push the common perceptions of what a weblog does. See also the companion wiki.

 

Education Support / Department Sites

* LEAP- a student support resource site at UBC

* Bowie State University School of Education site (WordPress)

* Building a School Web Site One Blog At a Time Rob Wall describes using WordPress to create the CELTC School Announcement System . See Several more examples in the comments:

 

** School Library System Genesee School District

** Grandview Elemenary School Library

** Ms Hunnicut's English Homework Page (Middle School)

 

Journals, Newsletters, Books

* MCLI iForum - online publication at Maricopa Community Colleges (published in WordPress). See technical details.

* Culture Corner Horace Mann Elementary School (MovableType)

* Classroom Notes at Lewis Elementary School . Using a Weblog to Facilitate Paper Publishing Tim Lauer describes how his Elementary School uses MovableType to assemble stories from teachers for publishing in electronic and print format.

* Pulse The Coming of Age of Systems and Machines Inspired by Living Things by Robert Frenay"This is a networked book. We’re releasing the full text of Pulse to the public via RSS, email, and on this blog. You can even get a from-the-beginning feed if you come late. In a first, the text is fully linked and tagged."

 

Resource Sites

* Wisdom Quotes a reference/resource site (MovableType)

* Low Threshold Applications (MovableType)

* Into the Blogosphere (University of Minnesota) "This online, edited collection explores discursive, visual, social, and other communicative features of weblogs. Essays analyze and critique situated cases and examples drawn from weblogs and weblog communities. Such a project requires a multidisciplinary approach, and contributions represent perspectives from Rhetoric, Communication, Sociology, Cultural Studies, Linguistics, and Education, among others."

 

Activism / Citizen Journalism

* WikiPedia definition

* J-Learning "your how-to site for community journalism"

* The Thunderbird UBC's blog-powered School of Journalism online publication.

* iTalkNews

* Philly Future - Philadelphia Blogs - "The News YOU Write

* The 11 Layers of Citizen Journalism PoynterOnline

* We the Media "grassroots journalism by the people, for the people"

* Stormwatchers citizen journalists covering hurrican Rita

* I, Reported

Presentation Medium

* Staying Ahead of Your Patrons With Weblogs and RSS by Steven Cohen (Blogger). See his notes, www.librarystuff.net/2005/02/presentation-about-weblogsin...

* More Than Cat Diaries: Publishing With Weblogs by Alan Levine (Blogger)

 

See more examples and resources in the notdiaries tag stream.

 

Image Credits: Mock-up of SciFi book cover created by Alan Levine, derived from Creative Commons licensed flickr image by "Spatial Mongrel"

  

«« Back: My Life, My Blog, My Diary

»» Next The Blogs That Ate My Campus

 

Prototype of the Mercury, an infinitely extensible, open camera system that I developed over the past two years, with some help from others. This one is shown configured for 6x9 medium format.

A wild tangent inspired by Dominik Strzelec's Processing demo of catenary curves in Toxiclibs.

 

I was curious about the simulation aspect and how it might relate to parametric modeling, but then I added some basic color shading and promptly forgot about everything else. Sketches like these don't really have a defined place in my current practice and I usually only get to show them in lectures, so by now I have a growing elephant graveyard of code sketches like these.

 

I'm embarrassed to say this is the first time I've seriously used Toxiclibs for more than 20 minutes. It really is a thing of beauty and contains some very powerful tools once you figure out Karsten's code structure. Most coders tend towards idiosyncracy and Karsten is no exception, but his manifests itself in the form of well-thought out and extensible code structures while mine are far less elegant.

 

I plan to post a version of my sketch on OpenProcessing as a nod to Dominik for using his code. The physical simulation is still Toxiclibs, but I've moved all rendering, GUI and meshing to Modelbuilder for my own convenience's sake.

Friendly Notice:

The listing is for THREE different colors. The monopod tripod and bluetooth booth in Blue, Black and Red color. Pleasae bid it carefully.

Features:

Monopod tripod:

 

Telescopic length :22 – 95cm

  

Main material: steel

Expansion joints: 6

Length...

 

telephone.pascherenchine.com/products/bleu-noir-rouge-3-e...

www.mueblesartesanos.es

This interesting picture, courtesy of the US Navy, I have posted with a fairly high pixel level so it can be seen very clearly.

     

The Remote Minehunting System (RMS) and an AN/AQS-20 are brought onboard USS Independence (LCS 2) from the Gulf of Mexico waters on Jan. 7, 2012 during mine countermeasure mission module developmental testing. The two organic mine warfare capabilities were captured by a Twin Boom Extensible Crane (TBEC) onboard the littoral combat ship.

 

Rondant pel sud de la província de Soria, tot i que les referències que teníem no eren del tot entusiastes però per allò d’aprofundir en les arrels gastronòmiques locals, vam voler dinar a Virrey Palafox que és considerat un dels restaurant veterans i més clàssics de la zona.

 

Vam entrar només obrir les portes i ens trobem dins d’un menjador de generoses dimensiones amb una decoració rústica bastant recarregada i un munt de taules ben a punt, algunes d’elles preparades per atendre a grups nombrosos, la qual cosa anticipava una mica de soroll. I en efecte; de seguida vam començar a entrar grups de persones que ràpidament vam omplir el menjador i l’ambient es va alterar bastant. Val a dir que era un migdia laborable i que la majoria de persones que omplien el menjador semblaven atretes pel seu menú de migdia ofert a 15€; és de suposar que durant el cap de setmana o per les nits l'ambient pot ser força diferent. O no.

 

Nosaltres vam optar per dinar a la carta. I bé, en el seu conjunt el dinar no va estar malament però vam veure una cuina bastant corrent i una mica irregular que no ens va impressionar. En qualsevol cas, tampoc va estar malament i no ens penedim d’haver-lo conegut però ja està vist i no crec que hi tornem. Per acabar, val a dir que la persona que ens va atendre va estar molt amable, empàtica i ens va fer sentir a gust i que al final ens va convidar als cafès, una gentilesa que, pel que vam veure, feien extensible a les altres taules que havien optat per prescindir del menú, imaginem que com a compensació per suportar el soroll ambiental. Un detall.

 

El que més ens va agradar: els torreznos; la perdiu; les natilles; el vi

El que menys ens va agradar: el remenat

 

Satisfacció: @@@

 

Virrey Palafox

Universidad, 7

42300 El Burgo de Osma (Soria)

Telèfon: 975 341 311

 

Tanca diumenges nit i dilluns.

Una nova incursió a Elkano ens referma, una vegada més, que aquest rostidor mariner de Getaria és una “casa de menjars” imprescindible. I la titllem com a “casa de menjars” perquè el tarannà de l’Aitor Arregui a la sala (extensible també a la resta de l’equip, encara que en menor grau) és d’allò tan summament hospitalari, servicial i educat que –literalment- et fa sentir com a casa. Un luxe de tracte al que no li coneixem equivalents.

 

D’altra banda, l’espai, pulcre i refinat, garanteix el màxim confort per poder gaudir amb garanties de la qualitat de tot el que arriba damunt la taula, des de les peces grans de peix fins a l’excel·lent pa i oli de l’inici, tot és bo o molt bo. Un gran restaurant guipuscoà. Un clàssic.

 

El que més ens va agradar: la qualitat del conjunt

El que menys ens va agradar: que els preus no incloguin l’IVA

El que recomanem: deixar-se aconsellar per establir un menú a la mida de les apetències

 

Satisfacció: @@@@

 

Elkano

Herrerieta, 2

20808 Getaria (Guipúzcoa)

Telèfon: 943 140 024

 

Tanca les nits de dilluns, dimecres i diumenge i dimarts tot el dia.

Teníem alguna referència del Nou Moderno i també molt present un recent i engrescador reportatge que d’aquest restaurant familiar van publicar recentment a la revista Cuina. Tot aprofitant que rondàvem per la zona vam dirigir les nostres pases fins a la localitat de Vilalba dels Arcs per dinar.

 

El restaurant forma part de les instal·lacions de l’hotel homònim. Un menjador ampli d’estil clàssic, una mica massa “vintage” pel nostre gust, però acurat i ben condicionat. Ens van ubicar en una taula d’un racó on vam estar còmodes i molt ben atesos. En aquest sentit cal destacar l’amabilitat i bona predisposició per part d’en Josep Maria, que va accedir amb franca voluntat de servei a tots els requeriments i suggeriments que li vam fer, una amabilitat també extensible a la resta de components del servei de sala. Molt bé fins aquí.

 

Sense carta, s’oferien fins a tres menús de diferent format i composició i finalment ens vam decantar pel més bàsic o estàndard anomenat “Menú fi de setmana” (era un diumenge), on es podien escollir varis plats entre diferents opcions, algunes no escrites i cantades a peu de taula. Pintava bé i en el conjunt de l’àpat ens van arribar un parell de plats realment bons però la resta considerem que no va estar a l’alçada. Sap greu dir-ho però un plat completament fallit i alguns detalls que revelen descuit o mala gestió del producte ens van fer arrufar el nas i vam sortir d’allà amb una certa sensació de decepció. Una llàstima.

 

El que més ens va agradar: els fideus, la presa, el vi; el bon tracte

El que menys ens va agradar: les olives negres, el plat d’orada, el fricandó, les nous

 

Satisfacció: @@+

 

Nou Moderno

Sant Llorenç, 17

43782 Vilalba dels Arcs

Telèfon: 977 43 82 04 – 977 43 80 12

 

Tanca diumenge nit i dilluns.

(1)

Connectome

connectomes.org/

 

In their words:

"A connectome is a synapse-resolution mapping of connections between

all neurons in a model organism's brain. In other words, a

synapse-resolution circuit diagram of the brain. Current approaches to

mapping the connectomes of model organisms employ serial block face

scanning electron microscopy (SBF-SEM) and transmission electron

microscopy (TEM). The only connectome that has been mapped out to date

has been from the flatworm, C. elegans, which has only around 300

neurons."

 

(2)

ConnectomeViewer

www.connectomeviewer.org/

 

In their words:

"The field of Connectomics research benefits from recent advances in

structural neuroimaging technologies on all spatial scales. The need

for software tools to visualize and analyse the emerging data is

urgent. ... The Connectome Viewer application was developed to meet

the needs of basic and clinical neuroscientists, as well as complex

network scientists, providing an integrative, extensible platform to

visualize and analyze Connectomics data.With the Connectome File

Format, interlinking different datatypes such as networks, surface

data, and volumetric data is easy and might provide new ways of

analyzing and interacting with data."

 

In addition to the viewer, this site also provides quite a variety of

datasets

that can be used to test different features and functions.

 

(3)

Human Connectome Project

humanconnectome.org/

 

In their words:

"The HCP will map the human connectome as accurately as possible in a

large number of normal adults and will make this data freely available

to the scientific community using a powerful, user-friendly

informatics platform."

"Successful charting of the human connectome in normal adults will be

enormously informative. Even more importantly, it will pave the way

for studies that reveal how brain circuitry changes during development

and aging and how it differs in numerous neurological and psychiatric

disorders. In short, it will transform our understanding of the human

brain in health and disease."

 

(4)

BrainMaps

brainmaps.org/

 

In their words:

"Brain atlases have traditionally been one resolution and

non-interactive. The next-generation brain atlas is multiresolution,

highly interactive, and fully integrated with the latest research

literature. This is BrainMaps.org, a complete online brain atlas

founded on the principle that a brain atlas is a dynamic, interactive,

multiresolution research and didactic tool that facilitates brain

exploration and knowledge discovery."

 

As if that isn't enough, BrainMaps also has an API for

developers and and open source /

OpenGL-based 3D

viewer!

 

(5)

BrainMeta

brainmeta.com/

 

In their words:

"BrainMeta was established for the purpose of accelerating the

development of neuroscience through web-based initiatives, which

include the development, implementation and support of a wide range of

neuroinformatics tools, services, and databases."

 

(6)

Allen Institute for Brain Science: Brain Atlas

www.brain-map.org/

 

In their words:

"A growing collection of online public resources integrating extensive

gene expression and neuroanatomical data, complete with a novel suite

of search and viewing tools."

 

(7)

Brain Museum: Comparative Mammalian Brain Collections

www.brainmuseum.org/index.html

 

In their words:

"This web site provides browsers with images and information from one

of the world's largest collection of well-preserved, sectioned and

stained brains of mammals. Viewers can see and download photographs of

brains of over 100 different species of mammals (including humans)

representing over 20 Mammalian Orders."

 

(8)

MSU: Brain Biodiversity Bank

www.msu.edu/~brains/index.html

 

In their words:

"The Brain Biodiversity Bank refers to the repository of images of and

information about brain specimens contained in the collections

associated with the National Museum of Health and Medicine at the

Armed Forces Institute of Pathology in Washington, DC. These

collections include, besides the Michigan State University Collection,

the Welker Collection from the University of Wisconsin, the

Yakovlev-Haleem Collection from Harvard University, the Meyer

Collection from the Johns Hopkins University, and the Huber-Crosby and

Crosby-Lauer Collections from the University of Michigan.

Our purpose here is to provide some examples of ways in which images

and information from the Collections, in digital format, can be used

in educational, research and commercial enterprises. Millions of

beautifully stained sections from hundreds of different brains,

assembled in many locations over the past century can be made

available for a broad variety of purposes."

 

Want more pics?

 

Wikipedia: List of neuroscience databases

en.wikipedia.org/wiki/List_of_neuroscience_databases

 

Want more neuro imaging software?

 

UCLA: Laboratory of Neuro-Imaging

www.loni.ucla.edu/

(1)

Connectome

connectomes.org/

 

In their words:

"A connectome is a synapse-resolution mapping of connections between

all neurons in a model organism's brain. In other words, a

synapse-resolution circuit diagram of the brain. Current approaches to

mapping the connectomes of model organisms employ serial block face

scanning electron microscopy (SBF-SEM) and transmission electron

microscopy (TEM). The only connectome that has been mapped out to date

has been from the flatworm, C. elegans, which has only around 300

neurons."

 

(2)

ConnectomeViewer

www.connectomeviewer.org/

 

In their words:

"The field of Connectomics research benefits from recent advances in

structural neuroimaging technologies on all spatial scales. The need

for software tools to visualize and analyse the emerging data is

urgent. ... The Connectome Viewer application was developed to meet

the needs of basic and clinical neuroscientists, as well as complex

network scientists, providing an integrative, extensible platform to

visualize and analyze Connectomics data.With the Connectome File

Format, interlinking different datatypes such as networks, surface

data, and volumetric data is easy and might provide new ways of

analyzing and interacting with data."

 

In addition to the viewer, this site also provides quite a variety of

datasets

that can be used to test different features and functions.

 

(3)

Human Connectome Project

humanconnectome.org/

 

In their words:

"The HCP will map the human connectome as accurately as possible in a

large number of normal adults and will make this data freely available

to the scientific community using a powerful, user-friendly

informatics platform."

"Successful charting of the human connectome in normal adults will be

enormously informative. Even more importantly, it will pave the way

for studies that reveal how brain circuitry changes during development

and aging and how it differs in numerous neurological and psychiatric

disorders. In short, it will transform our understanding of the human

brain in health and disease."

 

(4)

BrainMaps

brainmaps.org/

 

In their words:

"Brain atlases have traditionally been one resolution and

non-interactive. The next-generation brain atlas is multiresolution,

highly interactive, and fully integrated with the latest research

literature. This is BrainMaps.org, a complete online brain atlas

founded on the principle that a brain atlas is a dynamic, interactive,

multiresolution research and didactic tool that facilitates brain

exploration and knowledge discovery."

 

As if that isn't enough, BrainMaps also has an API for

developers and and open source /

OpenGL-based 3D

viewer!

 

(5)

BrainMeta

brainmeta.com/

 

In their words:

"BrainMeta was established for the purpose of accelerating the

development of neuroscience through web-based initiatives, which

include the development, implementation and support of a wide range of

neuroinformatics tools, services, and databases."

 

(6)

Allen Institute for Brain Science: Brain Atlas

www.brain-map.org/

 

In their words:

"A growing collection of online public resources integrating extensive

gene expression and neuroanatomical data, complete with a novel suite

of search and viewing tools."

 

(7)

Brain Museum: Comparative Mammalian Brain Collections

www.brainmuseum.org/index.html

 

In their words:

"This web site provides browsers with images and information from one

of the world's largest collection of well-preserved, sectioned and

stained brains of mammals. Viewers can see and download photographs of

brains of over 100 different species of mammals (including humans)

representing over 20 Mammalian Orders."

 

(8)

MSU: Brain Biodiversity Bank

www.msu.edu/~brains/index.html

 

In their words:

"The Brain Biodiversity Bank refers to the repository of images of and

information about brain specimens contained in the collections

associated with the National Museum of Health and Medicine at the

Armed Forces Institute of Pathology in Washington, DC. These

collections include, besides the Michigan State University Collection,

the Welker Collection from the University of Wisconsin, the

Yakovlev-Haleem Collection from Harvard University, the Meyer

Collection from the Johns Hopkins University, and the Huber-Crosby and

Crosby-Lauer Collections from the University of Michigan.

Our purpose here is to provide some examples of ways in which images

and information from the Collections, in digital format, can be used

in educational, research and commercial enterprises. Millions of

beautifully stained sections from hundreds of different brains,

assembled in many locations over the past century can be made

available for a broad variety of purposes."

 

Want more pics?

 

Wikipedia: List of neuroscience databases

en.wikipedia.org/wiki/List_of_neuroscience_databases

 

Want more neuro imaging software?

 

UCLA: Laboratory of Neuro-Imaging

www.loni.ucla.edu/

A medium format rangefinder. The name results in confusion with the much later and quite modern Mamiya 6 with a plastic body and an extensible tube lens and no bellows.

 

It has a sharp 4 element 7.5cm (75mm, lol) Zuiko lens. That equates to a slight wide angle lens. A "normal" lens should be about the length of the diagonal between corners on the film. For a 6x6 cm that would be the square root of 72 or about 8.5 cm.

 

There's an small tear in the bellows that's repairable [repaired now], and a problem with the shutter cocking linkage -- it doesn't cock when the camera is wound but it can be cocked manually [still not right but I'll live with it by cocking manually]. [Edit: this was pretty easy to fix and I actually fixed it some time ago.]

 

If I can get this working [it's repaired now and shutter cleaned], I'll shoot it.

 

I originally stated these were made in the 1960's, but actually they were made from 1955 to 1958 or so when it was replaced by the Automat II -- information is sketchy and I've now simply dated it 1955 for it's inception date)

 

Please visit the Entropic Remnants website or my Entropic Remnants blog -- THANKS!

 

Mesa:

Largo: 180 cm

Min. largo: 140 cm

Max. largo: 220 cm

Ancho: 84 cm

Alto: 74 cm

Tiene dos planchas para extenderla.

 

Usada, en muy buen estado.

4500 pesos

  

Sillas: 1500 pesos cada una

Fueron retapizadas de cuero sintetico de color crema, muy facil de limpiar.

Feia temps que volíem anar a petar al Restaurante 33, especialitzat en verdures i hortalisses, però sempre ens ha pillat a contrapeu i ho hem anat deixant fins que, aquest estiu, hem planificat un viatge fent parada a la ciutat de Tudela expressament per dinar allà.

 

Un cop dins ens vam trobar un menjador confortable i ben condicionat (feia una calor extrema al carrer i seure sota l’aire condicionat va resultar tota una benedicció ☺). El tracte amable i molt implicat per part del propietari, també extensible a la resta del servei, va contribuir a que la nostra estada resultés còmoda i molt satisfactòria.

 

I pel que fa a la teca, vam anar directes al menú degustació de verdures que ens va presentar alguns platets molt rellevants i molt ben executats, d’aquells que reclamen una ració per campions ☺, combinats amb altres més normals i, fins i tot, algun de fluixet. En el seu conjunt va estar força bé però, ara que ja sabem de que va la cosa, la pròxima vegada obviarem el menú i tirarem de carta. A modus d’anècdota, vam sentir dir al propietari, amb certa tristor i com lamentant-se, que estaven estirant el menú de verdures perquè la temporada ja s’acabava i ara venia una època més magra (¡!), com si les úniques verdures idònies per a completar un menú vegetal fossin les d’hivern/primavera. No sé, però creiem que, amb els tomàquets, els carbassons, les albergínies, els pebrots, les mongetes tendres i altres, es pot fer un menú espectacular a l’estiu. Però, en fi, sembla que la cosa va així en aquella terra perquè vam sentir la mateixa cantarella en un altre afamat restaurant de la zona ☹.

 

El que més ens va agradar: la patata duquessa, les carxofes, les “pochas”

El que menys ens va agradar: el format i contingut de la carta de vins

El que recomanem: sembla un bon lloc per menjar verdures i hortalisses, millor a la carta i fora del degustació

 

Satisfacció: @@@+

 

Restaurante 33

Pablo Sarasate, 7

31500 Tudela

Telèfon: 948 82 76 06 / 948 91 60 72

 

Tanca els dimarts i les nits de diumenge i dilluns.

(1)

Connectome

connectomes.org/

 

In their words:

"A connectome is a synapse-resolution mapping of connections between

all neurons in a model organism's brain. In other words, a

synapse-resolution circuit diagram of the brain. Current approaches to

mapping the connectomes of model organisms employ serial block face

scanning electron microscopy (SBF-SEM) and transmission electron

microscopy (TEM). The only connectome that has been mapped out to date

has been from the flatworm, C. elegans, which has only around 300

neurons."

 

(2)

ConnectomeViewer

www.connectomeviewer.org/

 

In their words:

"The field of Connectomics research benefits from recent advances in

structural neuroimaging technologies on all spatial scales. The need

for software tools to visualize and analyse the emerging data is

urgent. ... The Connectome Viewer application was developed to meet

the needs of basic and clinical neuroscientists, as well as complex

network scientists, providing an integrative, extensible platform to

visualize and analyze Connectomics data.With the Connectome File

Format, interlinking different datatypes such as networks, surface

data, and volumetric data is easy and might provide new ways of

analyzing and interacting with data."

 

In addition to the viewer, this site also provides quite a variety of

datasets

that can be used to test different features and functions.

 

(3)

Human Connectome Project

humanconnectome.org/

 

In their words:

"The HCP will map the human connectome as accurately as possible in a

large number of normal adults and will make this data freely available

to the scientific community using a powerful, user-friendly

informatics platform."

"Successful charting of the human connectome in normal adults will be

enormously informative. Even more importantly, it will pave the way

for studies that reveal how brain circuitry changes during development

and aging and how it differs in numerous neurological and psychiatric

disorders. In short, it will transform our understanding of the human

brain in health and disease."

 

(4)

BrainMaps

brainmaps.org/

 

In their words:

"Brain atlases have traditionally been one resolution and

non-interactive. The next-generation brain atlas is multiresolution,

highly interactive, and fully integrated with the latest research

literature. This is BrainMaps.org, a complete online brain atlas

founded on the principle that a brain atlas is a dynamic, interactive,

multiresolution research and didactic tool that facilitates brain

exploration and knowledge discovery."

 

As if that isn't enough, BrainMaps also has an API for

developers and and open source /

OpenGL-based 3D

viewer!

 

(5)

BrainMeta

brainmeta.com/

 

In their words:

"BrainMeta was established for the purpose of accelerating the

development of neuroscience through web-based initiatives, which

include the development, implementation and support of a wide range of

neuroinformatics tools, services, and databases."

 

(6)

Allen Institute for Brain Science: Brain Atlas

www.brain-map.org/

 

In their words:

"A growing collection of online public resources integrating extensive

gene expression and neuroanatomical data, complete with a novel suite

of search and viewing tools."

 

(7)

Brain Museum: Comparative Mammalian Brain Collections

www.brainmuseum.org/index.html

 

In their words:

"This web site provides browsers with images and information from one

of the world's largest collection of well-preserved, sectioned and

stained brains of mammals. Viewers can see and download photographs of

brains of over 100 different species of mammals (including humans)

representing over 20 Mammalian Orders."

 

(8)

MSU: Brain Biodiversity Bank

www.msu.edu/~brains/index.html

 

In their words:

"The Brain Biodiversity Bank refers to the repository of images of and

information about brain specimens contained in the collections

associated with the National Museum of Health and Medicine at the

Armed Forces Institute of Pathology in Washington, DC. These

collections include, besides the Michigan State University Collection,

the Welker Collection from the University of Wisconsin, the

Yakovlev-Haleem Collection from Harvard University, the Meyer

Collection from the Johns Hopkins University, and the Huber-Crosby and

Crosby-Lauer Collections from the University of Michigan.

Our purpose here is to provide some examples of ways in which images

and information from the Collections, in digital format, can be used

in educational, research and commercial enterprises. Millions of

beautifully stained sections from hundreds of different brains,

assembled in many locations over the past century can be made

available for a broad variety of purposes."

 

Want more pics?

 

Wikipedia: List of neuroscience databases

en.wikipedia.org/wiki/List_of_neuroscience_databases

 

Want more neuro imaging software?

 

UCLA: Laboratory of Neuro-Imaging

www.loni.ucla.edu/

(1)

Connectome

connectomes.org/

 

In their words:

"A connectome is a synapse-resolution mapping of connections between

all neurons in a model organism's brain. In other words, a

synapse-resolution circuit diagram of the brain. Current approaches to

mapping the connectomes of model organisms employ serial block face

scanning electron microscopy (SBF-SEM) and transmission electron

microscopy (TEM). The only connectome that has been mapped out to date

has been from the flatworm, C. elegans, which has only around 300

neurons."

 

(2)

ConnectomeViewer

www.connectomeviewer.org/

 

In their words:

"The field of Connectomics research benefits from recent advances in

structural neuroimaging technologies on all spatial scales. The need

for software tools to visualize and analyse the emerging data is

urgent. ... The Connectome Viewer application was developed to meet

the needs of basic and clinical neuroscientists, as well as complex

network scientists, providing an integrative, extensible platform to

visualize and analyze Connectomics data.With the Connectome File

Format, interlinking different datatypes such as networks, surface

data, and volumetric data is easy and might provide new ways of

analyzing and interacting with data."

 

In addition to the viewer, this site also provides quite a variety of

datasets

that can be used to test different features and functions.

 

(3)

Human Connectome Project

humanconnectome.org/

 

In their words:

"The HCP will map the human connectome as accurately as possible in a

large number of normal adults and will make this data freely available

to the scientific community using a powerful, user-friendly

informatics platform."

"Successful charting of the human connectome in normal adults will be

enormously informative. Even more importantly, it will pave the way

for studies that reveal how brain circuitry changes during development

and aging and how it differs in numerous neurological and psychiatric

disorders. In short, it will transform our understanding of the human

brain in health and disease."

 

(4)

BrainMaps

brainmaps.org/

 

In their words:

"Brain atlases have traditionally been one resolution and

non-interactive. The next-generation brain atlas is multiresolution,

highly interactive, and fully integrated with the latest research

literature. This is BrainMaps.org, a complete online brain atlas

founded on the principle that a brain atlas is a dynamic, interactive,

multiresolution research and didactic tool that facilitates brain

exploration and knowledge discovery."

 

As if that isn't enough, BrainMaps also has an API for

developers and and open source /

OpenGL-based 3D

viewer!

 

(5)

BrainMeta

brainmeta.com/

 

In their words:

"BrainMeta was established for the purpose of accelerating the

development of neuroscience through web-based initiatives, which

include the development, implementation and support of a wide range of

neuroinformatics tools, services, and databases."

 

(6)

Allen Institute for Brain Science: Brain Atlas

www.brain-map.org/

 

In their words:

"A growing collection of online public resources integrating extensive

gene expression and neuroanatomical data, complete with a novel suite

of search and viewing tools."

 

(7)

Brain Museum: Comparative Mammalian Brain Collections

www.brainmuseum.org/index.html

 

In their words:

"This web site provides browsers with images and information from one

of the world's largest collection of well-preserved, sectioned and

stained brains of mammals. Viewers can see and download photographs of

brains of over 100 different species of mammals (including humans)

representing over 20 Mammalian Orders."

 

(8)

MSU: Brain Biodiversity Bank

www.msu.edu/~brains/index.html

 

In their words:

"The Brain Biodiversity Bank refers to the repository of images of and

information about brain specimens contained in the collections

associated with the National Museum of Health and Medicine at the

Armed Forces Institute of Pathology in Washington, DC. These

collections include, besides the Michigan State University Collection,

the Welker Collection from the University of Wisconsin, the

Yakovlev-Haleem Collection from Harvard University, the Meyer

Collection from the Johns Hopkins University, and the Huber-Crosby and

Crosby-Lauer Collections from the University of Michigan.

Our purpose here is to provide some examples of ways in which images

and information from the Collections, in digital format, can be used

in educational, research and commercial enterprises. Millions of

beautifully stained sections from hundreds of different brains,

assembled in many locations over the past century can be made

available for a broad variety of purposes."

 

Want more pics?

 

Wikipedia: List of neuroscience databases

en.wikipedia.org/wiki/List_of_neuroscience_databases

 

Want more neuro imaging software?

 

UCLA: Laboratory of Neuro-Imaging

www.loni.ucla.edu/

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