Green Turtle

Chelonia mydas, or the green turtle, is common marine reptile in tropical waters.  Their common names do not come from their color, but rather the color of their fatty tissue.  They generally have yellowish brown to dark brown shells mixed with shades of olive.  Unlike the loggerhead turtle, the green turtle's first costal plate does not touch the nuchal (see the loggerhead post for explanation of costal and nuchal plates).  Additionally, green turtles have two small plates between the eyes which help separate them from hawksbill turtles who have the same shell pattern.  Although green turtles do not get as large as loggerhead turtles, they can still reach four feet in length and between 250-450 pounds.

These organisms belong to the phylum Chordata and are in the class Reptilia.  All reptiles breath air, lay eggs, have scales, and are ectotherms.  Obviously, they also belong to the order Testudines, or turtles.  This order is characterized by a hard shell that surrounds the body of the organism.  The shell is composed of two main parts: the carapace, the hard top of the shell, and the plastron, or bottom shell.  Another part of the shell called the bridge connects the two main parts.

An averaged sized Green Turtle

Like loggerhead turtles, green sea turtles are found throughout the world's tropical waters.  The various life stages of these marine turtles occupies inshore bays, lagoons, estuaries, offshore reefs, and even the open ocean.  Adults can often be found grazing on reefs or resting under reef ledges.  Green turtles start are primarily herbivores that feed on seagrasses and algae.  From time to time, however, green turtles love to munch on a delicious jellyfish or crustacean.

Like all sea turtles, their life cycle begins on a beach.  After adult green turtles copulate out at sea, females crawl onto sandy beaches at night to lay their eggs.  After a 60 day gestation period, roughly 110 babies hatch and crawl back to the ocean.  The juvenile turtles then take to the ocean currents where they end up in the Azores and Canary Islands.  After reaching sexual maturity, green turtles return to the same reefs and beaches where their parents spawn and lay their eggs; repeating the same process.

The green sea turtle is listed as endangered by the United States Fish and Wildlife Service.  This turtle is highly prized for its shell and in many other countries its meat and eggs.  Up until 1974 there was a green turtle fishery in Florida as well as harvesting their eggs.  Green sea turtles face additional human problems including habitat degredation, boat colisions, marine garbage, entangelment, and bycatch.  Shrimp trawlers account for the majority of accidental green turtle deaths.  Since it takes more than 20 years for these turtles to reach sexual maturity, even a little environmental stress carries a long way.  Hopefully under the protection of the Endangered Species Act and the requirement of the federal government to establish a recovery plan for endangered species, one day green turtles will again be numerous on the reefs of Florida, the Caribbean, and the world.

References: Humann, Paul, and Ned DeLoach. Reef Fish Identification: Florida, Caribbean, Bahamas. Jacksonville, FL: New World Publications, 2002. 481. Print.; "Green Turtle." Smithsonian Marine Station (SMS) at Fort Pierce. Web. 26 Jan. 2011. <http://www.sms.si.edu/irlspec/chelon_mydas.htm>.