The most significant Atlantic nesting sites are in Suriname, French Guiana and Trinidad and Tobago in the Caribbean and Gabon in Central Africa. Off the Atlantic coast of Canada, leatherback turtles feed in the Gulf of Saint Lawrence near Quebec and as far north as Newfoundland and Labrador. However, only a few beaches on both sides of the Atlantic provide nesting sites. Unlike other sea turtles, leatherback feeding areas are in colder waters, where there is an abundance of their jellyfish prey, which broadens their range. They range as far north as the North Sea and to the Cape of Good Hope in the south. These declining numbers have energized efforts to rebuild the species, which currently is critically endangered.The leatherback turtle population in the Atlantic Ocean ranges across the entire region. Recent estimates of global nesting populations are that 26,000 to 43,000 females nest annually, which is a dramatic decline from the 115,000 estimated in 1980. While nesting beaches have been identified in the region, leatherback populations in the Indian Ocean remain generally unassessed and unevaluated. The Atlantic ''Dermochelys'' population is separate from the ones in the eastern and western Pacific, which are also distinct from each other.hieroglyph snipped. There are three major, genetically distinct populations. The leatherback is found in all tropical and subtropical oceans, and its range extends well into the Arctic Circle. coriacea'' has the widest distribution, reaching as far north as Alaska and Norway and as far south as the Cape of Good Hope in Africa and the southernmost tip of New Zealand. Of all the extant sea turtle species, ''D. The leatherback turtle is a species with a cosmopolitan global range. ''Dermochelys coriacea'' exhibits a suite of anatomical characteristics believed to be associated with a life in cold waters, including an extensive covering of brown adipose tissue, temperature independent swimming muscles, counter-current heat exchangers between the large front flippers and the core body, as well as an extensive network of counter-current heat exchangers surrounding the trachea. That specimen was found on a beach on the west coast of Wales. The largest ever found, however, was over 3 metres from head to tail, including a carapace length of over 2.2 metres, and weighed 916 kilograms. ''Dermochelys coriacea'' adults average 1–1.75 metres in carapace length, 1.83–2.2 metres in total length and weigh 250 to 700 kilograms. Instead of teeth, the leatherback turtle has points on the tomium of its upper lip, with backwards spines in its throat to help it swallow food. Demonstrating countershading, the turtle's underside is lightly colored. The entire turtle's dorsal surface is colored dark grey to black, with a scattering of white blotches and spots. Leatherbacks are unique among reptiles in that their scales lack β-keratin. Seven distinct ridges rise from the carapace, crossing from the anterior to posterior margin of the turtle's back. Instead of scutes, it has thick, leathery skin with embedded minuscule osteoderms. Its most notable feature is the lack of a bony carapace. The leatherback has several characteristics that distinguish it from other sea turtles. Leatherback's front flippers can grow up to 2.7 metres in large specimens, the largest flippers of any sea turtle. The leatherback's flippers are the largest in proportion to its body among extant sea turtles. Claws are absent from both pairs of flippers. Like other sea turtles, the leatherback's flattened forelimbs are adapted for swimming in the open ocean. A large pair of front flippers power the turtles through the water. Leatherback turtles have the most hydrodynamic body design of any sea turtle, with a large, teardrop-shaped body.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |