ChordataReptilia

=Benji and Ben= =Phylum: Chordata (Reptilia)= =Species: Leatherback Sea Turtle (//Dermochelys coriacea//) =

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Leatherback Sea Turtles are unique to the world because of several features, which distinguish them from other turtles and reptiles. For starters they are the largest turtle in the world. They have a bilateral body symmetry. They can grow to an astounding six and a half feet and weigh up to 1,500 pounds. The largest one ever found was an astonishing 11 feet and 2,019 pounds. On top of having the 3rd largest body type among reptiles, they are the most hydrodynamic Reptile. This allows them to swim huge distances with little resistance from the water. This is thanks to ridges along their carapace, which give a more hydrodynamic structure. This helps in their ability to dive to depths of 4,200 feet deep, the deepest of any reptile. Their shell is one of its most notable features. The shell does not posses the common bony carapace and instead of scutes, or more commonly known as the shell, it has thick, leathery skin. Hence the "Leatherback Sea Turtle." The leathery skin is embedded with osteoderms. Osteoderms are the scales or bony parts of the skin that has been found on lizards and various species of extinct reptiles such as dinosaurs. Leatherback Sea Turtles have existed on earth in some form considering the fact they a common ancestor of the original Sea Turtle is 110 million years old. The circle of life for Leatherback Sea Turtles is quite interesting because they have seasonal mating patterns. These patterns include swimming great distances to return to the beach on which the individual turtle hatched on. They also mate at a certain time of year and just before climbing onto the beach they mate with a male who also returns to the same beach. They then climb onto the beach, dig a burrow, and lay their eggs which require a tropical temperature to incubate the eggs. Since Sea Turtle eggs are a delicasy in the human and animal world alike, the turtles lay large amounts of eggs to increase the chance of a hatchling making it into the ocean. Ocean dwelling birds are a primary predator of newborn Leatherback Sea Turtles. Another interesting fact about Leatherback Sea Turtles is their ability to regulate their body temperature unlike many reptiles. They are able to do this because of using a specialized fleet of adaptations that allows them to generate and also retain body heat. Some of these adaptations are their unique body size (large), a thick layer of blubber like fat underneath their skin, regulating swimming activity, and increasing or decreasing their blood flow with their specialized circulatory system that is unlike any other circulatory system in Reptiles.

Along with adapting to regulating their body temperature in cold waters they have also developed a unique mouth. Instead of teeth they posses sharp backward facing points all along the inside of its mouth and throat. Their diet mostly consists of jellyfish. The Leatherback has developed a thick "leathery" skin that is immune to the toxins found in the tentacles of jellyfish. The turtle has backwards facing spines on the inside of its esophagus to help pass gelatinous prey through its digestive system. The Leatherback also inhales oxygen above water like all other reptiles. This helps it capture and swallow their favorite food. Jellyfish. They are able to evade the jellyfishes sting because of their thick skin. 

They are ver y important to the ecosystem because they are a grand contributor of controlling the jellyfish population. This love of jellyfish has also endangered the Leatherback Sea Turtle. Because they are one of the widest global distributed vertebrates on the planet, they can be found everywhere. Leatherback Sea Turtles commonly mistake plastic for jellyfish and some have been found with 11 pounds of plastic in their stomach. This along with the fishing market laying huge nets across their habitat and their boats striking the majestic creatures has unintentionally taken out a huge chunk of the population. Another reason they are endangered along with the other eight types of Sea Turtles is because of their leathery skin, which is rich in oil. The oil and hide is used for many purposes. Lamps, purses, souvenirs, etc. Their lifespan is unknown, but recently they have been meeting an early death because of fatal human interaction. Evolutionary History: The Leatherback Sea Turtle, along with all other turtles, share the common ancestor known as Odontochelys. The Leatherback's ancestor had some of the basic characteristics expressed by the reptile today. Odontochelys had a premature solid carapace, contrary to many present day turtles, which have developed the common bony carapace. The Leatherback however, possesses a similar shell structure to that of its ancestor. The Leatherback Sea Turtle has developed a light, hydrodynamic "leathery" shell (previously mentioned) embedded with many osteoderms (also known as scales) instead of one, solid carapace.

Environment: The Leatherback's environment plays a huge role in why the reptile is an endangered species. Leatherback Sea Turtles are found in all oceans except the Arctic Ocean, and their vast migratory patterns spread the population into jellyfish filled coves and dangerous fishing areas. The turtles commonly mistake plastic for jellyfish and some have been found with 11 pounds of plastic in their stomach. Fishnets also accidently catch these animals unintentionally, which is another contributor that has taken out a huge chunk of the population. Another reason they are endangered along with the other eight types of Sea Turtles is because of their leathery skin, which is rich in oil. The oil and hide is used for many purposes. Lamps, purses, souvenirs, etc. Their lifespan is unknown, but recently they have been meeting an early death because of fatal human interaction.

Biome: (Terrestrial ; Marine) This animal spends much of its time in the Intertidal Zone (close to shore) and the Pelagic Zone (open ocean). Although these zones supply most, if not all, of the jellyfish for the turtles nutrition, it can go into the Benthic Zone (deep sea, but not quite abyss). The Intertidal Zone consists of waves, constantly moving mud, dirt, dead organisms, and seaweed. The Pelagic Zone is offshore and can vary in temperature, but is colder than the Intertidal Zone. -Temperature -Sunlight -Dead organisms -Sand -Rocks -Boats -Nets -Hooks -Ship Wrecks -Dolphins -Jellyfish -Whales -Fish -Plankton -Squid -Crustaceans -Other Sea Turtles -Sea snake -People -Sharks
 * Abiotic Factors:**
 * Biotic Factors:**

Relationships between abiotic and biotic factors

-The abundance of jellyfish in certain aquatic environment determines the migratory patterns of the Leatherback sea turtles. For example, the sea turtles migrate to the oceans off the coast of southern California to feed on jellyfish. -Leatherbacks have become an endangered species due to many human-made abiotic factors. Commercial fishing boats accidentally catch the turtles in their nets and on hooks. Humans themselves, a biotic factor, also hunt the turtles for their oil and rubbery hide. -The sea turtles environmental temperature has effected the evolutionary adaptations the animal has made. The reptile has developed a thick layer of oil under its skin to retain heat, which allows it to live in colder environments.

Bibliography

"Leatherback Turtle (Dermochelys Coriacea) - Office of Protected Resources - NOAA Fisheries." //NOAA :: National Marine Fisheries Service//. Web. 05 May 2011.

The Leatherback Turtle." //Turtle Trax//. Web. 05 May 2011. .