T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Turtle (Leatherback) Dermochelys coriacea

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testudines
Suborder: Cryptodira
Family: Dermochelyidae
Genus: Dermochelys
Species: D. coriacea
Binomial name: Dermochelys coriacea
Synonym: Testudo coriacea
Common name: Leatherback sea turtle, Lute turtle, Leathery turtle, Luth, Trunkback Turtle, Trunk Turtle, Coffin-back.

Dermochelys coriacea is an oceanic, deep-diving marine turtle inhabiting tropical, subtropical, and subpolar seas.
Dermochelys coriacea is one of the five species of turtles that visit New Zealand’s waters. The other four species are Caretta caretta (Loggerhead),  Dermochelys mydas (Hawksbill), Chelonia mydas (Green) and,  Lepidochelys olivacea (Olive ridley). Leatherbacks only come inshore to breed; those of the Pacific breed in Australia and the Solomon Islands.
After laying eggs they  return swiftly to feeding grounds in cooler waters, such as New Zealand. They are widely spread around New Zealand and have been recorded as far south as Fiordland. Satellite tracking studies indicate that the waters around North Cape and the eastern coast of Northland are favoured foraging grounds.

Dermochelys coriacea is the largest of all living turtles and is the fourth-heaviest modern reptile behind three crocodilians. It is the only living species in the genus Dermochelys and family Dermochelyidae. It can easily be differentiated from other modern sea turtles by its lack of a bony shell, hence the name. Instead, its carapace is covered with thick, leathery skin with embedded minuscule osteoderms (bony deposits forming scales). The carapace has seven distinct ridges, crossing from the cranial to caudal margin of the turtle's back. Leatherbacks are unique among reptiles in that their scales lack β-keratin. The entire turtle's dorsal surface is coloured dark grey to black, with a scattering of white blotches and spots. The plastron (the lower shell) is lightly coloured.
Leatherback adults have a length of over two metres and an estimated weight of 800 kilograms. The adults are a dark-brown or bluish-black above, spotted or blotched with pale yellowish or pale bluish-white about the throat, flippers and on part of the carapace. 
They have the most hydrodynamic body design of any sea turtle, with a large, teardrop-shaped body. A large pair of front flippers powers the turtles through the water. Claws are absent from both pairs of flippers. Instead of teeth, the leatherback turtle has points on the tomium (sharp cutting edge of the beak) of its upper lip, with backwards spines in its throat (oesophagus) to help it swallow food and to stop its prey from escaping once caught. They are known to dive to 1300m.
Leatherbacks can maintain core body temperatures up to 18°C warmer than the surrounding water, enabling them to survive in water that is much too cold for other marine turtles.

Leatherback sea turtles are IUCN listed as Endangered (population decreasing). The main causes of their decline as a bycatch in the pelagic longline fisheries, net entanglement, vessel collisions and the ingesting plastic bags. In their breeding areas, leatherback eggs and animals are taken for human use (i.e. consumption and commercial products), eggs are also eaten by domestic animals (e.g. dogs).
In New Zealand, sea turtles, are protected under the Wildlife Act 1953. This means it is illegal to kill or harass any species of sea turtle within New Zealand's Territorial Sea or Exclusive Economic Zone. It is also illegal to possess a sea turtle, or any part of a sea turtle without a permit issued under the Wildlife Act, or evidence that it was legally imported into New Zealand or was in your possession prior to the commencement of the Wildlife Act (1 April 1954).





Spiny throat and oesophagus of a Leatherback showing spines to retain prey.

Diagram of an adult Leatherback Sea Turtle showing its distinguishing features.

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/

http://www.terrain.net.nz/uploads/images/Te%20Henui/Faunatwo/1-Leatherback_sea_turtle_.jpg