Leatherback sea turtles (Dermochelys coriacea) are the only living members of the Dermochelyidae family. They are the largest among sea turtles, and the fourth largest reptile. They have many distinct features, like absence of the top bony shell, and the long front flippers without claws and scales.
Though leatherback sea turtles resemble other turtle species, the former is different in various aspects. One of the main distinguishing features is the rubbery skin on the dorsal part of their body. So, these turtles lack carapace.
As the name rightly suggests, this skin is similar to leather, and has embedded bony plates. They also have seven ridges on the back, starting from the anterior end, and converging at the posterior end. The dorsal skin is dark gray to black in color, with many white spots on it.
Another feature of these turtles is their long front flippers, which are longer than that of any other living turtle. In some individuals, these flippers can be as long as 2.7 meters. Their flippers do not have claws or scales. They lack teeth, but have sharp-edged jaws with tooth-like points. They possess spines in the throat, which help in swallowing food.
An average adult leatherback sea turtle can grow to a length of around one to two meters, and their weight ranges between 250 to 700 kilograms. A specimen of leatherback turtle, found on the west coast of Wales in the North Atlantic, weighed about 916 kilograms, and had a body length of three meters.
Habitat and Range
Leatherback sea turtles are seen in the open ocean, usually in the vicinity of land. They can dive to a depth of 1,280 meters. They cover long distances in search of food, or for nesting. Generally, they mate in water along the nesting beaches and migratory corridors.
They are widely distributed and are found in all tropical, subtropical and temperate waters. These turtles can be seen in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean Sea. It is believed that these sea turtles can adapt well in the Arctic Circle too.
Coasts of northern South America and west Africa are among the main nesting grounds for these turtles, but the major part of their nesting occurs in the beaches of United States.
These turtles never leave water, except for the females, who move to the beach for nesting. Leatherback turtles nest every two to three years, but annual nesting has also been observed. They like beaches with soft sand and shallow edges, for nesting. They make pits, and lay around 100 eggs in each pit.
They can nest several times, at an interval of 8 to 12 days, during a nesting season. On an average, a female leatherback sea turtle can lay around nine clutches of eggs (one clutch means approximately 100 eggs).
It takes almost 60 to 65 days for the eggs to hatch, and the hatchlings have white stripes on the dorsal part of the body (along the ridges), and on the margin of the flippers. The front flippers are longer, and the body length may vary between 2 to 3 inches. Each hatchling weighs around 40 to 50 grams.
The lifespan of leatherback sea turtles is still unknown, as most of them become victims of human activities, pollution, and predation, during the early stages of their life. Many of them die due to ingestion of plastic bags, mistaking them for jellyfish, which is their favorite food.
Hence, this turtle is now an endangered species, and efforts are underway to protect them. It is necessary to create awareness among the public, regarding conservation of these beautiful creatures.