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Leatherback Sea Turtle (Dermochelys coriacea)

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Leatherback Turtle Laying Eggs / Paul Mannix, Flickr

Leatherback sea turtle laying eggs on Turtle Beach, Tobago.

Courtesy Paul Mannix / Flickr

At a maximum length of over 6 feet and weight of 2,000 pounds, the leatherback sea turtle is the largest sea turtle. Impressively, it's also the world's largest living reptile.

Description:

The leatherback sea turtle (Dermochelys coriacea) is a in a class of its own. Rather, it is in its own family. Out of the 7 species of sea turtles, the leatherback is the only one in the family Dermochelys.

The leatherback's appearance is unmistakable. Adults are black with whitish-pink speckles on the carapace and head. Their name comes from their leather-like, oily carapace made up of connective tissue that covers bones.

Leatherbacks are also deep divers, capable of diving at least 3,900 feet (Source: NOAA) - meaning they could dive alongside some of the deepest-diving whales (More on leatherback diving)

Classification:

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Reptilia
  • Order: Testudines
  • Family: Dermochelyidae
  • Genus: Dermochelys
  • Species: coriacea

Habitat & Distribution:

Leatherback turtles have a wide range that stretches across all but the coldest parts of the Atlantic, Pacific and Indian Oceans. A large number of leatherbacks feed off the Eastern coast of Canada, but these same turtles may migrate as far as South America during the winter nesting season. Leatherbacks may be found in both pelagic and coastal areas.

Leatherbacks have adaptations that enable them to live in cold water, including the ability to shunt blood away from their flippers to avoid losing too much heat, and a circulation system that warms cold blood from the turtle's flippers before it gets to the body core.

Feeding:

Leatherback turtles eat soft prey like jellyfish and salps. Instead of teeth, they have sharp cusps to grab their prey, and spines in their throat and mouth to aid in getting their slippery prey down their throat. In addition to jellyfish and salps, they may eat other small invertebrates such as crustaceans, squid and urchins.

Migration:

Leatherbacks are world travelers, undertaking extreme migrations between feeding grounds and nesting grounds. One leatherback was tracked for 12,774 miles as it traveled from Indonesia to Oregon.

Reproduction:

Leatherbacks mate at sea, and females migrate to tropical beaches in the spring to nest. Primary nesting areas for the leatherback are in northern South America and West Africa. In the U.S., small numbers of leatherbacks nest in the U.S. Virgin Islands, Puerto Rico and southern Florida.

Females dig a nest onshore, then lay 80-100 eggs. She may lay eggs every 8-12 days during the nesting season. The sex of the hatchlings is, interestingly, determined by the nest temperature - higher temperatures produce females and lower temperatures produce males. Temperatures around 85 degrees produce a mix of both.

It takes about 2 months for the young turtles to hatch, at which time they are 2-3 inches long and weigh less than 2 ounces. The hatchlings head to the sea, where males will remain for life. Females will return to the same nesting beach where they hatched at around 6-10 years of age to lay their own eggs.

Conservation:

Leatherbacks are endangered in the U.S., and listed on the IUCN Red List as critically endangered. The Pacific Ocean leatherback population has experienced dramatic declines in nesting, while the population in the Atlantic Ocean appears more stable.

Threats to the leatherback include egg harvesting, entanglement in fishing gear, ship strikes, and ingestion and entanglement in marine debris.

New tagging and tracking studies, such as those conducted by the University of New Hampshire, are helping scientists learn more about leatherback turtles and their wide-ranging movements.

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