Characteristics of a Leatherback Sea Turtle
by Suzanne McCullough White
The largest turtle in the world, the leatherback sea turtle (Dermochelys coriacea) is also the world's largest living reptile. These giant animals have been listed as endangered since 1970, and multiple conservation plans are in place to save them. One of the biggest threats to leatherbacks is fishing nets, in which they become entangled and die. They can also be killed by eating floating plastic and other debris that they think is their favorite food: jellyfish.
Adult leatherback sea turtles can reach 6 1/2 feet in length and can weigh up to 1 ton. Their name comes from their soft, leathery shell (carapace)--all other sea turtles have hard shells. The shells have prominent vertical ridges going their entire length, which serve to make them more hydrodynamic, and they taper at the end. Leatherbacks are usually black, with pinkish white undersides. Their heads have white and pink spots.
Leatherback sea turtle in the sand.
Leatherbacks migrate the farthest (up to 3,700 miles each way) and have one of the widest distributions of all reptiles and possibly of any vertebrate. They are found everywhere from the icy Atlantic Ocean near Newfoundland to the warm waters of the Caribbean.
After mating at sea, the female leatherback turtle comes ashore to lay clutches of about 100 eggs in the sand of beaches, digging a hole, depositing the eggs and then covering them with sand before making her way back to the water. The turtles do this several times during the nesting season. The baby turtles hatch after about 60 to 65 days.
Leatherback turtle hatchling.
Leatherbacks don't have the hard, crushing jaws of other sea turtles. Instead, they have jaws with razor-sharp edges and small teeth-like structures, both good adaptations for a diet of soft-bodied prey such as jellyfish. It isn't known how leatherbacks survive on this diet, because jellyfish are mostly water and contain few nutrients.
Head of a leatherback sea turtle.
In addition to their specially adapted mouths, leatherback sea turtles have several adaptations that allow them to live in such diverse locations. They are able to maintain a core body temperature higher than surrounding icy waters because of a specially adapted heat-exchange system, a high body fat content and large body size. Temperature inside their nests determines the sex of leatherback hatchlings: at around 85 degrees F, there is a mixture of males and females, while higher temperatures produce females and lower temperatures produce males.