Leatherback Sea Turtle

Conservation status: VULNERABLE
Common name: Leattherback sea turtle, lute turtle, leathery turtle, luth
Scientific name: Dermochelys coriacea
Type: Reptile
Diet: Jellyfish, tunicates, cephalopods
Length: 1.83~ 2.2m
Weight: 250~750Kg

The leatherback sea turtle (Dermochelys coriacea), sometimes called the lute turtle or leathery turtle or simply the luth, 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 by skin and oily flesh. Dermochelys is the only extant genus of the family Dermochelyidae.

Leatherback turtles 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. Like other sea turtles, the leatherback has flattened fore limbs adapted for swimming in the open ocean. Claws are absent from both pairs of flippers. The leatherback’s flippers are the largest in proportion to its body among extant sea turtles. Leatherback’s front flippers can grow up to 2.7 m (8.9 ft) in large specimens, the largest flippers (even in comparison to its body) of any sea turtle.

The leatherback has several characteristics that distinguish it from other sea turtles. Its most notable feature is the lack of a bony carapace. Instead of scutes, it has thick, leathery skin with embedded minuscule osteoderms. Seven distinct ridges rise from the carapace, 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 colored dark grey to black, with a scattering of white blotches and spots. Demonstrating countershading, the turtle’s underside is lightly colored. Instead of teeth, the leatherback turtle has points on the tomium 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.

People around the world still harvest sea turtle eggs. Asian exploitation of turtle nests has been cited as the most significant factor for the species’ global population decline. In Southeast Asia, egg harvesting in countries such as Thailand and Malaysia has led to a near-total collapse of local nesting populations. In Malaysia, where the turtle is practically locally extinct, the eggs are considered a delicacy. In the Caribbean, some cultures consider the eggs to be aphrodisiacs.

They are also a major jellyfish predator, which helps keep populations in check. This bears importance to humans, as jellyfish diets consist largely of larval fish, the adults of which are commercially fished by humans.

References

1.  Wallace, B.P.; Tiwari, M. & Girondot, M. (2013). “Dermochelys coriacea“. The IUCN Red List of Threatened Species. IUCN. 2013: e.T6494A43526147
2.  “Species Fact Sheet: Leatherback Sea Turtle”. Caribbean Conservation Corporation & Sea Turtle Survival League. Caribbean Conservation Corporation.
3.  “WWF – Leatherback turtle – Ecology & Habitat”. Marine Turtles. World Wide Fund for Nature. 
4.  “WWW – Leatherback Turtle – Threats”. Marine Turtles. World Wide Fund for Nature.