View allAll Photos Tagged polymorph
*
The loggerhead sea turtle (Caretta caretta) is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around 90 cm (35 in) in carapace length when fully grown. The adult loggerhead sea turtle weighs approximately 135 kg (298 lb), with the largest specimens weighing in at more than 450 kg (1,000 lb). The skin ranges from yellow to brown in color, and the shell is typically reddish brown. No external differences in sex are seen until the turtle becomes an adult, the most obvious difference being the adult males have thicker tails and shorter plastrons (lower shells) than the females.
The loggerhead sea turtle is found in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean Sea. It spends most of its life in saltwater and estuarine habitats, with females briefly coming ashore to lay eggs. The loggerhead sea turtle has a low reproductive rate; females lay an average of four egg clutches and then become quiescent, producing no eggs for two to three years. The loggerhead reaches sexual maturity within 17–33 years and has a lifespan of 47–67 years.
The loggerhead sea turtle is omnivorous, feeding mainly on bottom-dwelling invertebrates. Its large and powerful jaws serve as an effective tool for dismantling its prey. Young loggerheads are exploited by numerous predators; the eggs are especially vulnerable to terrestrial organisms. Once the turtles reach adulthood, their formidable size limits predation to large marine animals, such as large sharks.
The loggerhead sea turtle has a cosmopolitan distribution, nesting over the broadest geographical range of any sea turtle. It inhabits the Atlantic, Indian, and Pacific Oceans and the Mediterranean Sea.
In the Atlantic Ocean, the greatest concentration of loggerheads is along the southeastern coast of North America and in the Gulf of Mexico. Very few loggerheads are found along the European and African coastlines. Florida is the most popular nesting site, with more than 67,000 nests built per year. Nesting extends as far north as Virginia, as far south as Brazil, and as far east as the Cape Verde Islands. The Cape Verde Islands are the only significant nesting site on the eastern side of the Atlantic. Loggerheads found in the Atlantic Ocean feed from Canada to Brazil.
In the Indian Ocean, loggerheads feed along the coastlines of Africa, the Arabian Peninsula, and in the Arabian Sea. Along the African coastline, loggerheads nest from Mozambique's Bazaruto Archipelago to South Africa's St Lucia estuary. The largest Indian Ocean nesting site is Oman, on the Arabian Peninsula, which hosts around 15,000 nests, giving it the second largest nesting population of loggerheads in the world. Western Australia is another notable nesting area, with 1,000–2,000 nests per year.
Pacific loggerheads live in temperate to tropical regions. They forage in the East China Sea, the southwestern Pacific, and along the Baja California Peninsula. Eastern Australia and Japan are the major nesting areas, with the Great Barrier Reef deemed an important nesting area. Pacific loggerheads occasionally nest in Vanuatu and Tokelau. Yakushima Island is the most important site, with three nesting grounds visited by 40% of all nearby loggerheads. After nesting, females often find homes in the East China Sea, while the Kuroshio Current Extension's Bifurcation region provides important juvenile foraging areas. Eastern Pacific populations are concentrated off the coast of Baja California, where upwelling provides rich feeding grounds for juvenile turtles and subadults. Nesting sites along the eastern Pacific Basin are rare. mtDNA sequence polymorphism analysis and tracking studies suggest 95% of the population along the coast of the Americas hatch on the Japanese Islands in the western Pacific. The turtles are transported by the prevailing currents across the full length of the northern Pacific, one of the longest migration routes of any marine animal. The return journey to the natal beaches in Japan has been long suspected, although the trip would cross unproductive clear water with few feeding opportunities. Evidence of a return journey came from an adult female loggerhead named Adelita, which in 1996, equipped with a satellite tracking device, made the 14,500 km (9,000 mi) trip from Mexico across the Pacific. Adelita was the first animal of any kind ever tracked across an ocean basin.
The Mediterranean Sea is a nursery for juveniles, as well as a common place for adults in the spring and summer months. Almost 45% of the Mediterranean juvenile population has migrated from the Atlantic. Loggerheads feed in the Alboran Sea and the Adriatic Sea, with tens of thousands of specimens (mainly sub-adult) seasonally present in the North-Eastern portion of the latter, above all in the area of the Po Delta. Greece is the most popular nesting site along the Mediterranean, with more than 3,000 nests per year. Zakynthos hosts the largest Mediterranean nesting with the second one being in Kyparissia Bay. Because of this, Greek authorities do not allow planes to take off or land at night in Zakynthos due to the nesting turtles. In addition to the Greek coast, the coastlines of Cyprus and Turkey are also common nesting sites.
*Wikipedia
The Meadow Brown, Maniola jurtina, is a butterfy found in the Palearctic ecozone. Its range includes Europe south of 62 N, Russia eastwards to the Urals, Asia Minor, Iraq, Iran, North Africa and the Canary Islands.The larvae feed on grasses.
Similar species are Gatekeeper (which prefers to rest with its wings open) and Small Heath (which is smaller).
There is marked sexual dimorphism in this species. Males are less colorful, with smaller eyespots and much reduced orange areas on the upper forewings. They are also much more active and range far about, while females fly less and often may not away from the area where they grew up.
A variable number of smaller eyespots are usually found on the hindwing undersides. These may number up to 12 per individual butterfly, with up to 6 on each wing. The factors that govern polymorphism in this trait are not resolved, although a number of theories have been proposed (Stevens 2005). On the other hand, the evolutionary significance of the upperwing eyespots is more obvious: The more active males have a markedly more cryptic upperside pattern, whereas the females have more often opportunity to present their eyespots in a sudden display of colors and patterns that presumably make neophobic predators hesitate so that the butterfly has better chances of escaping.
A species which is variable in flower colour and leaf spotting. Cambourne seems to have almost the full range of colour combinations.
Canon EOS 50D, Canon EF 100-400mm f/4,5-5,6 L IS USM, development in Lightroom.
Photographed on a birdwatchers' boat trip to the Farne Islands, Northumberland.
Uria aalge - Common Guillemot (Common Murre) - Trottellumme - Zeekoet - Guillemot de Troïl - Arao común - Uria - Sillgrissla - Lomvie - Nurzyk zwyczajny - . . .
Wikipedia (edited): "The common murre or common guillemot (Uria aalge) is a large auk. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to breed on rocky cliff shores or islands.
Guillemots are fast in direct flight but are not very agile. They can manoeuvre better underwater, where they typically dive to depths of 30–60m. They breed in colonies at high densities; nesting pairs may be in bodily contact with their neighbours. They make no nest; their single egg is incubated on a bare rock ledge on a cliff face.
Some individuals in the North Atlantic, known as "bridled guillemots", have a white ring around the eye extending back as a white line. This is not a distinct subspecies, but a polymorphism that becomes more common the farther north the birds breed."
en.wikipedia.org/wiki/Farne_Islands
potentille du printemps
Plante vivace de 5-20 cm., verte, velue ou pubescente, à souche très rameuse ; tiges latérales, faibles, étalées, dépassant peu ou point les feuilles, à poils ordinairement étalés-dressés ; feuilles inférieures digitées, à 5-7 folioles obovales, velues, dentées dans le haut, à dent terminale plus petite ; stipules radicales étraitement linéaires, les caulinaires lancéolées ; fleurs jaunes, assez grandes, en cymes lâches pauciflores ; pédicelles fructifères ascendants ou à peine courbés ; calicule à lobes plus petits que ceux du calice ; pétales émarginés, dépassant le calice ; carpelles lisses. Plante polymorphe.
Visit www.julieboyd.co.uk for all things D&T (especially textiles). Includes free resources, weekly newsletter & courses
Ring based on my synesthetic response to the bassline from Stockholm Syndrome by Muse. Ferro-Fluid like bassline with clear drips forming as pulled by some invisible force and carnelian and tourmaline guitar distortion. Polymorph thermoplastic, Auto-Air Colours, resin.
The Meadow Brown, Maniola jurtina, is a butterfly found in European meadows, where its larvae feed on grasses, such as Sheep's Fescue.
Similar are the Gatekeeper (which prefers to rest with its wings open) and Small Heath (which is smaller).
There is marked sexual dimorphism in this species. Males are less colorful, with smaller eyespots and much reduced orange areas on the upper forewings. They are also much more active and range far about, while females fly less and often may not away from the area where they grew up.
A variable number of smaller eyespots are usually found on the hindwing underside - up to 6 on each wing. The factors that govern polymorphism in this trait are not resolved, although several theories have been proposed. On the other hand, the evolutionary significance of the upperwing eyespots is more obvious: The more active males have a markedly more cryptic upperside pattern, whereas the females have more often opportunity to present their eyespots in a sudden display of colors and patterns that presumably make neophobic predators hesitate so that the butterfly has better chances of escaping.
(Wikipedia)
A species which is variable in flower colour and leaf spotting. Cambourne seems to have almost the full range of colour combinations.
*
Turtle Eggs ready to be moved to a secure enclosure for hatching. Volunteers monitor the beaches for turtles laying then retrieve the eggs and place them in a caged off enclosure a few meters away.
The loggerhead sea turtle (Caretta caretta) is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around 90 cm (35 in) in carapace length when fully grown. The adult loggerhead sea turtle weighs approximately 135 kg (298 lb), with the largest specimens weighing in at more than 450 kg (1,000 lb). The skin ranges from yellow to brown in color, and the shell is typically reddish brown. No external differences in sex are seen until the turtle becomes an adult, the most obvious difference being the adult males have thicker tails and shorter plastrons (lower shells) than the females.
The loggerhead sea turtle is found in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean Sea. It spends most of its life in saltwater and estuarine habitats, with females briefly coming ashore to lay eggs. The loggerhead sea turtle has a low reproductive rate; females lay an average of four egg clutches and then become quiescent, producing no eggs for two to three years. The loggerhead reaches sexual maturity within 17–33 years and has a lifespan of 47–67 years.
The loggerhead sea turtle is omnivorous, feeding mainly on bottom-dwelling invertebrates. Its large and powerful jaws serve as an effective tool for dismantling its prey. Young loggerheads are exploited by numerous predators; the eggs are especially vulnerable to terrestrial organisms. Once the turtles reach adulthood, their formidable size limits predation to large marine animals, such as large sharks.
The loggerhead sea turtle has a cosmopolitan distribution, nesting over the broadest geographical range of any sea turtle. It inhabits the Atlantic, Indian, and Pacific Oceans and the Mediterranean Sea.
In the Atlantic Ocean, the greatest concentration of loggerheads is along the southeastern coast of North America and in the Gulf of Mexico. Very few loggerheads are found along the European and African coastlines. Florida is the most popular nesting site, with more than 67,000 nests built per year. Nesting extends as far north as Virginia, as far south as Brazil, and as far east as the Cape Verde Islands. The Cape Verde Islands are the only significant nesting site on the eastern side of the Atlantic. Loggerheads found in the Atlantic Ocean feed from Canada to Brazil.
In the Indian Ocean, loggerheads feed along the coastlines of Africa, the Arabian Peninsula, and in the Arabian Sea. Along the African coastline, loggerheads nest from Mozambique's Bazaruto Archipelago to South Africa's St Lucia estuary. The largest Indian Ocean nesting site is Oman, on the Arabian Peninsula, which hosts around 15,000 nests, giving it the second largest nesting population of loggerheads in the world. Western Australia is another notable nesting area, with 1,000–2,000 nests per year.
Pacific loggerheads live in temperate to tropical regions. They forage in the East China Sea, the southwestern Pacific, and along the Baja California Peninsula. Eastern Australia and Japan are the major nesting areas, with the Great Barrier Reef deemed an important nesting area. Pacific loggerheads occasionally nest in Vanuatu and Tokelau. Yakushima Island is the most important site, with three nesting grounds visited by 40% of all nearby loggerheads. After nesting, females often find homes in the East China Sea, while the Kuroshio Current Extension's Bifurcation region provides important juvenile foraging areas. Eastern Pacific populations are concentrated off the coast of Baja California, where upwelling provides rich feeding grounds for juvenile turtles and subadults. Nesting sites along the eastern Pacific Basin are rare. mtDNA sequence polymorphism analysis and tracking studies suggest 95% of the population along the coast of the Americas hatch on the Japanese Islands in the western Pacific. The turtles are transported by the prevailing currents across the full length of the northern Pacific, one of the longest migration routes of any marine animal. The return journey to the natal beaches in Japan has been long suspected, although the trip would cross unproductive clear water with few feeding opportunities. Evidence of a return journey came from an adult female loggerhead named Adelita, which in 1996, equipped with a satellite tracking device, made the 14,500 km (9,000 mi) trip from Mexico across the Pacific. Adelita was the first animal of any kind ever tracked across an ocean basin.
The Mediterranean Sea is a nursery for juveniles, as well as a common place for adults in the spring and summer months. Almost 45% of the Mediterranean juvenile population has migrated from the Atlantic. Loggerheads feed in the Alboran Sea and the Adriatic Sea, with tens of thousands of specimens (mainly sub-adult) seasonally present in the North-Eastern portion of the latter, above all in the area of the Po Delta. Greece is the most popular nesting site along the Mediterranean, with more than 3,000 nests per year. Zakynthos hosts the largest Mediterranean nesting with the second one being in Kyparissia Bay. Because of this, Greek authorities do not allow planes to take off or land at night in Zakynthos due to the nesting turtles. In addition to the Greek coast, the coastlines of Cyprus and Turkey are also common nesting sites.
*Wikipedia
EXPOSITION
06.09.2017 - 29.10.2017
MAISON EUROPÉENNE DE LA PHOTOGRAPHIE
Anne et Patrick Poirier développent une œuvre polymorphe dans laquelle la photographie occupe, dès leurs débuts en 1967, une place aussi centrale que méconnue, au même titre que la sculpture ou l’installation. Au fil des ans et de leurs expérimentations, ils n’ont cessé de développer un corpus d’œuvres, explorant sans a priori et sans limite les possibilités du médium photographique. Cette exposition, qui réunit près de 200 tirages, en propose la première rétrospective.
PROVISIONAL text. I have found great variation and contradiction in paper & online sources. Your comments would be appreciated.
In particular, last 3 lines about layer 3 are based on my examination of the disposition of the layers and on reasoning unsupported by any source that I can find. Please say if you see any flaws in my interpretation (also of layer 2).
The Alden reference at the end doesn’t appear especially authoritative, do you know of a better one that supports or disagrees with what he says about oceans?
A troubling thought is the glaze deposited on the body whorl to form the parietal lip of this and many other gastropods. It can only be deposited by the mantle skirt when the animal is not retracted. Is it another pre-2 layer that gets covered by layer 2 as it advances??
TEXT:
The following structure of layers is common to all Littorina species of Europe’s Atlantic coast. Other taxa vary.
Periostracum on outer surface is thin and indiscernible, or eroded away.
1: outer layer 1 is of calcite morph of calcium carbonate with irregular-prismatic structure. Whitish and rufous on this specimen. Deposited only by mantle-edge on aperture-margin in micro-growth bands corresponding to tidal cycles. Layer is thin on spire whorls formed when animal small, increasing in thickness on later whorls with growth of animal.
2: dark brown layer 2 is of aragonite morph of calcium carbonate with crossed-lamellar structure. Primary lamellae arranged perpendicular to aperture margin. Deposited by visceral mass over entire inner surface of layer 1, except for wide band within aperture rim where mantle skirt, not viscera, in contact with shell when animal extended, and uncovered when animal retracted. Layer 2 is fairly uniform in thickness throughout the shell.
3: white (or pale) layer 3 is of aragonite with crossed-lamellar structure. Thickest in older, early whorls, acting as spire-filler; compensates there for thinness of calcite layer 1.
Layer 3 dwindles to imperceptible in larger whorls. It, like layer 2, is deposited by surface of viscera. Because of its disposition, it seems that layer 3 is deposited by the posterior of the visceral mass, moving over layer 2 (that was deposited by the anterior viscera) as the animal grows.
4: columella made of brown layer 2 thickly coated with white translucent layer 3.
Properties of aragonite and calcite.
Shell layers are of calcium carbonate in a fenestrated matrix of proteinaceous conchiolin which affects their properties. Data are averages for the pure minerals.
Hardness on Moh scale: aragonite, 3.5 – 4, harder than calcite, 3.
Specific gravity: aragonite, 2.95, denser than calcite, 2.71.
Solubility: both have retrograde solubility i.e. more soluble in cold sea water than in warm sea water. Calcite is 35% less soluble than aragonite.
Comment
As aragonite is denser and harder, it should resist crushing by predators and accident better than calcite. Over geological time the oceans have fluctuated between aragonite and calcite rich water, each favouring species that use what is most easily available. For the last 40 million years the oceans have been aragonite rich ( Alden, 2014). For these reasons one might expect aragonite to be the commoner mineral morph in seashells. However, D. Reid (1996) states,
“In most gastropod shells calcium carbonate is present in the mineral polymorph aragonite, whereas calcite is of much more restricted occurrence (Bøggild, 1930). In two species of Littorina [sub-tropical] - - - the shell is entirely aragonitic, whereas in all remaining species there is an outer layer of calcite. - - - Taylor and Reid (1990) pointed out that, in the Littorinidae as a whole [includes other genera], groups with calcitic shells are found only in temperate and higher latitudes. They suggested that intertidal animals are particularly exposed to the danger of shell dissolution, because of accumulation of carbon dioxide during the night in inshore seawater. Dissolution of calcium carbonate is most likely to occur in cold water, in which it is more soluble. Since calcite is less soluble than aragonite, they argued that shells with an outer calcite layer should be more resistant to dissolution.”
Alden, A. Calcite v aragonite
geology.about.com/od/minerals/fl/calcite-vs-aragonite.htm
No full account yet of this species. Sets of OTHER SPECIES at:
www.flickr.com/photos/56388191@N08/collections/7215763361...
*
Turtle Eggs ready to be moved to a secure enclosure for hatching. Volunteers monitor the beaches for turtles laying then retrieve the eggs and place them in a caged off enclosure a few meters away.
The loggerhead sea turtle (Caretta caretta) is a species of oceanic turtle distributed throughout the world. It is a marine reptile, belonging to the family Cheloniidae. The average loggerhead measures around 90 cm (35 in) in carapace length when fully grown. The adult loggerhead sea turtle weighs approximately 135 kg (298 lb), with the largest specimens weighing in at more than 450 kg (1,000 lb). The skin ranges from yellow to brown in color, and the shell is typically reddish brown. No external differences in sex are seen until the turtle becomes an adult, the most obvious difference being the adult males have thicker tails and shorter plastrons (lower shells) than the females.
The loggerhead sea turtle is found in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean Sea. It spends most of its life in saltwater and estuarine habitats, with females briefly coming ashore to lay eggs. The loggerhead sea turtle has a low reproductive rate; females lay an average of four egg clutches and then become quiescent, producing no eggs for two to three years. The loggerhead reaches sexual maturity within 17–33 years and has a lifespan of 47–67 years.
The loggerhead sea turtle is omnivorous, feeding mainly on bottom-dwelling invertebrates. Its large and powerful jaws serve as an effective tool for dismantling its prey. Young loggerheads are exploited by numerous predators; the eggs are especially vulnerable to terrestrial organisms. Once the turtles reach adulthood, their formidable size limits predation to large marine animals, such as large sharks.
The loggerhead sea turtle has a cosmopolitan distribution, nesting over the broadest geographical range of any sea turtle. It inhabits the Atlantic, Indian, and Pacific Oceans and the Mediterranean Sea.
In the Atlantic Ocean, the greatest concentration of loggerheads is along the southeastern coast of North America and in the Gulf of Mexico. Very few loggerheads are found along the European and African coastlines. Florida is the most popular nesting site, with more than 67,000 nests built per year. Nesting extends as far north as Virginia, as far south as Brazil, and as far east as the Cape Verde Islands. The Cape Verde Islands are the only significant nesting site on the eastern side of the Atlantic. Loggerheads found in the Atlantic Ocean feed from Canada to Brazil.
In the Indian Ocean, loggerheads feed along the coastlines of Africa, the Arabian Peninsula, and in the Arabian Sea. Along the African coastline, loggerheads nest from Mozambique's Bazaruto Archipelago to South Africa's St Lucia estuary. The largest Indian Ocean nesting site is Oman, on the Arabian Peninsula, which hosts around 15,000 nests, giving it the second largest nesting population of loggerheads in the world. Western Australia is another notable nesting area, with 1,000–2,000 nests per year.
Pacific loggerheads live in temperate to tropical regions. They forage in the East China Sea, the southwestern Pacific, and along the Baja California Peninsula. Eastern Australia and Japan are the major nesting areas, with the Great Barrier Reef deemed an important nesting area. Pacific loggerheads occasionally nest in Vanuatu and Tokelau. Yakushima Island is the most important site, with three nesting grounds visited by 40% of all nearby loggerheads. After nesting, females often find homes in the East China Sea, while the Kuroshio Current Extension's Bifurcation region provides important juvenile foraging areas. Eastern Pacific populations are concentrated off the coast of Baja California, where upwelling provides rich feeding grounds for juvenile turtles and subadults. Nesting sites along the eastern Pacific Basin are rare. mtDNA sequence polymorphism analysis and tracking studies suggest 95% of the population along the coast of the Americas hatch on the Japanese Islands in the western Pacific. The turtles are transported by the prevailing currents across the full length of the northern Pacific, one of the longest migration routes of any marine animal. The return journey to the natal beaches in Japan has been long suspected, although the trip would cross unproductive clear water with few feeding opportunities. Evidence of a return journey came from an adult female loggerhead named Adelita, which in 1996, equipped with a satellite tracking device, made the 14,500 km (9,000 mi) trip from Mexico across the Pacific. Adelita was the first animal of any kind ever tracked across an ocean basin.
The Mediterranean Sea is a nursery for juveniles, as well as a common place for adults in the spring and summer months. Almost 45% of the Mediterranean juvenile population has migrated from the Atlantic. Loggerheads feed in the Alboran Sea and the Adriatic Sea, with tens of thousands of specimens (mainly sub-adult) seasonally present in the North-Eastern portion of the latter, above all in the area of the Po Delta. Greece is the most popular nesting site along the Mediterranean, with more than 3,000 nests per year. Zakynthos hosts the largest Mediterranean nesting with the second one being in Kyparissia Bay. Because of this, Greek authorities do not allow planes to take off or land at night in Zakynthos due to the nesting turtles. In addition to the Greek coast, the coastlines of Cyprus and Turkey are also common nesting sites.
*Wikipedia