Leatherback Sea Turtle (Dermochelys coriacea)
Photos from iStock unless otherwise noted
Description: Leatherback sea turtles are the largest of all living turtles. It is also one of the largest living reptiles, surpassed only by some species of crocodiles. Adults range from 53-74 in. (135-189 cm). Leatherbacks typically weigh between 650 and 1,200 pounds (295-544 kg). The largest leatherback ever recorded weighed 2,016 pounds. The carapace and plastron of the leatherback is covered by a smooth, rubbery skin that is grey-black, dark-blue, or bluish black in color. Patchy spots of white or pink can appear almost anywhere on the turtle, but are most common on the plastron, front flippers, and head. Males have a more concave plastron and longer tails than females. The cloaca on males extends outside of the shell. In addition to their enormous size and shell which lacks scutes, leatherbacks can be distinguished from other sea turtles by the seven longitudinal ridges on the carapace. The plastron also has five ridges. Leatherbacks have delicate yet scissor-like jaws for eating soft-bodied animals.
Range and Habitat: The leatherback is a highly pelagic species and is found throughout the Atlantic, Pacific, and Indian oceans. Their primary habitat is the upper reaches of the open ocean, but they often dive to depths up to 1650 feet in search of food. These turtles move to coastal waters only during the breeding season or to follow large concentrations of jellyfish. In eastern North America, leatherbacks nest in southeastern Florida, Culebra, Puerto Rico, and St. Croix.
Habits: Leatherbacks feed almost exclusively on jellyfish, but also eat tunicates and seaweed. The mouth and esophagus have backward-pointing spines that aid in swallowing jellyfish. Leatherbacks also have the ability to maintain their body temperature at a slightly higher temperature than the surrounding water. This feature allows these turtles to range as far north as Greenland where water temperature range from 30-40 degrees. Another unique feature of leatherbacks is that since they have no shell they can dive to depths over 1000 meters in search of food without succumbing to the enormous pressure. Leatherbacks nest on sandy beaches in tropical regions. Females probably nest once every several years. Because they live in the open ocean, relatively little is known about the biology of this species.
Conservation Status: The U.S. Federal government has listed the leatherback as endangered worldwide. Internationally, leatherbacks are listed as Critically Endangered by the International Union for Conservation of Nature and Natural Resources. Threats to the existence of leatherbacks include entanglement in commercial fishing gear, injury due to propellers, habitat loss of their nesting environment, and ingestion of marine debris that resembles food such as plastic that resembles a jellyfish. Recent population estimates show about 34,000 nesting females worldwide.
Pertinent References:
James, Michael C. 2004. Body temperatures of leatherback turtles in temperate waters. Canadian Journal of
Zoology. 82(8): 1302-1306.
Troeng, Sebastian. 2004. Possible decline in leatherback turtle nesting. Oryx. 38(4): 395-403.
Account Author: Benjamin Morrison, University of Georgia – edited by J.D. Willson