The Leatherback sea turtle is the only remaining species of the Dermochelidae Family. This turtle is the longest surviving reptile on Earth! Leatherbacks live between 30 to 125 years — maybe longer. It is estimated that leatherback populations once numbered in the tens of millions during the Jurassic period. When dinosaurs perished in the ice ages, the hearty leatherbacks adapted and survived. This fact speaks volumes when one considers that leatherbacks have not been able to survive threats caused by human activity in the last 40 years
As the surviving species among some 250 similar species and of 12 families of turtles, the leatherback is the largest marine turtle in the world and perhaps, by weight, the largest reptile. Adult female leatherbacks are about 6 feet in length; 3 feet thick and up to 9 feet wide including the flippers. Females average 1,000 pounds in weight. Adult male leatherbacks are considerably larger, up to 9 feet in length and over 2,000 pounds. During its lifespan, leatherbacks will increase their weight 10,000 to 20,000 times over depending on the sex.
Sexual maturity is reached between 15 and 20 years after hatching. Females mate with a different male each nesting season to ensure a better distribution of the fragile gene pool to increase the survival of this species. Females return to specific nesting beaches every 3-5 years to lay eggs under about 4 feet of warm tropical sand. The hatchlings weigh about 1.5 ounces at birth and measure about 4 inches long. The nesting impulse drives females across the Pacific Ocean along a semi-circular route from California/Central America to the remote beaches in Irian Jaya.
The Eastern Pacific families forage and travel a reverse route and/or migrate down the Central American coast. These leatherbacks are the most pelagic of any turtle species. Leatherbacks feed in the open ocean, rather than on reefs as most other turtle species. Male leatherbacks spend their entire life deep in the oceans (at 3,000 ft. or less) at sea and only come ashore if they are injured or about to die.
Leatherbacks do not have a hard shell like other sea turtle species. The name “leatherback” is thought to have been derived from its soft leathery skin, which is very soft to the touch. There are 7 longitudinal ridges on the back. Leatherbacks are a dark gray to black color with mottled white spots, which can be used to identify individuals. Their soft, flexible skin helps them dive quite deep (over 3,000 feet) in search of food. The soft shell allows for expansion of the lungs for a greater intake of air so that they can dive to deeper depths.
NOAA satellite tracking has established leatherbacks as the marine creatures with the widest of migration habits, including the whales. Leatherbacks in the Pacific family have been observed (by satellite) to forage from the warm beaches of Indonesia to the cold waters off California and as far North as Alaska; from latitudes of 71 degrees North to 47 degrees South.
There are 2 principle remaining groups of leatherbacks. One roams the Atlantic and the other is Pacific-based. Each group touches all the shore lines of every continent as they forage on squid, jellyfish, tunicates (sea squirts, salps and pyrosomas) and soft marine creatures. The Leatherback families that once inhabited the Indian Ocean have disappeared since 1990. They were last seen in Sri Lanka waters in 1994 and in Malaysia in 2005.
When female leatherbacks exit from the sea to lay eggs, it is on the night high tide. She hauls her enormous bulk (1,000 pounds or more) up the beach to a location to where she was hatched.. She then digs her nest with her back flippers using them as shovels to scoop up the sand and flip it to the front flippers to be scattered. Once her eggs are deposited, she pats the sand firm with her body and flippers and follows her instincts back to the sea on a low tide when the sea is calmest.
A mature female leatherback will deposit 100 +/- eggs at each nesting. Baseline hatch out rates were low, a problem that S.O.L.O. has worked to solve. Kill one female and lose about 700 eggs/baby turtles in just one season.
Hatchlings return to sea and swim for about 6 days and nights before they begin to feed.The yolk of the egg the turtles is hatched from is absorbed into its tiny body at birth. The yolk provides sufficient energy for the hatchling to locate bio plankton foods within this six day period. During this time their internal guidance system becomes active and imprints the place where they originated and the cardinal directions for self navigation across the entire width of the Pacific Ocean. The awareness is automatic in this species and is thought to be related to the earth's magnetic field. Once feeding begins they must consume jellyfish in weights that parallel their weight as the energy required to constantly swim is huge. They forage to great depths to seek jellyfish, Portuguese man-of-war and many other soft species. The jellyfish contain a full supply of vitamins and minerals for turtles. As the turtles feed, the jellyfish are compacted into a feeding tube within its body that leads to the stomach. The turtle is able to pack in the food while expelling the sea water that is taken in. The food is processed and released to the stomach as needed.
Dermochelys coriacea, Leatherback Sea Turtle - MarineBio.org. Retrieved Tuesday, January 1, 2008, from http://marinebio.org/species.asp?id=287.
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