Green Sea TurtleCheloniamydas By Jennifer Bengele
Green Sea Turtle Taxonomy Kingdom Animalia Phylum Chordata Class Reptilia Order Testudines Family Cheloniidae Genus Chelonia species mydas (www.nmfs.noaa.gov/pr/species/turtles/green)
Physical Description Green sea turtles have light colored skin tinted green from a diet comprised entirely of algae and sea grass. They have a shell which varies in color from black to yellow on top called a carapace which is divided into sections called scutes. The hard tissue that forms on the bottom of the shell covering their bellies is called a plastron. Green sea turtles are sexually dimorphic since the males have longer, thicker tails than the females (www.hsus.org).
Green Sea Turtle Stats Length: 3 - 4 feet average Weight: 300-350 pound average Lifespan: between 40 and 100 years or even more Reproduction age: 20-30 years Gestation: 7-10 weeks Number of offspring: about 100 eggs
Nesting of the Green Turtle Female green turtles travel to shore and lay their eggs in the sand on warm beaches. These nesting grounds are called rookeries. The temperature of the sand determines the gender of the hatchlings. Warm temperatures produce females and cooler temperatures result in males. Out of the 100 or so eggs laid, only 1 or 2 of the hatchlings will make it to adulthood (http://library.thinkquest.org).
Biome Habitat Green Sea Turtles are found in the tropical and temperate regions of ocean throughout the world. Therefore, they play a role in the food web of the marine biome. Females will leave the water to lay their eggs on beaches found in tropical places such as Hawaii and Florida. Males remain in the ocean their entire lives (www.marinebio.com).
The Niche of the Green Sea Turtle Green sea turtles, unlike their relatives, are exclusively herbivorous as adults, favoring sea grass and algae. This is very important to maintaining sea grass beds. As juveniles, green turtles also consume animal material including sponges, jellyfish, snails, worms, and mollusks. Turtle eggs are often preyed upon by raccoons, ants, & crabs. Hatchlings are eaten by sea birds and crabs, and occasionally, an adult turtle will be consumed by a shark. (www.earlham.edu)
Niche (Con’t.) The debris from hatched eggs enriches the sand with much needed nutrients for dune plants which strengthens the beach ecosystem (www.adoptaseaturtle.org). Green sea turtles are migratory animals, and, as the fastest of the sea turtles, may travel up to 300 miles in just 10 days (http://www.hsus.org). Scientists believe that females use light to find their way to beaches for nesting. In addition, the earth’s magnetic field has been shown to play a role in aiding the turtles in their migration routes to and from their feeding and breeding grounds.
Symbiotic Relationships • Mutualism • Algae-eating cleaner fish on reefs, such as damselfish and angelfish (www.sailhawaii.com) • Parasitism (http://veterinaryrecord.bvapublications.com) • Cardiovascular flukes • Leeches on skin surface • Virus that causes tumors
Why Green Turtles are Endangered? • A viral infection which causes fibropapilloma tumors • Consumption of garbage, especially plastics, dumped in the ocean • Harvesting of turtle eggs which are considered a delicacy • Accidental entrapment in fishing gear, such as nets • Habitat destruction • Hunting for turtle meat under plastron • Increased human activity at beaches
Value to Humans • Human consumption of eggs, skin, meat, and calipee which is the cartilage cut from the plastron (www.turtles.org) • Shells for decorations such as jewelry • Some retailers in the Carribean even sell whole stuffed turtles for profit • Breeding grounds (beaches) are desirable to humans
Conservation Measures • Education programs • Using TED’s in commercial fishing nets • Reintroduction programs • Legislation • CITES • US Endangered Species Act
A Few Things We Can Do • Avoid beach activities during the nesting season • Dispose of garbage responsibly • Pick up litter from others • Report poachers to authorities • Do not plant trees, especially non-native species, in beach areas • Don’t buy turtle products
Optimum Aquarium Conditions • A large tank (about 200,000 gallons of salt water) • A reef – either real or manmade • Appropriate diet based on mostly vegetables such as cabbage, lettuce, brussel sprouts, and squid
Other Interesting Facts • Nearsighted while on land • Excellent sense of smell • Use the earth’s magnetic field for navigation • Unable to pull head into carapace • Evolved from land turtles
Literature Cited http://library.thinkquest.org http://veterinaryrecord.bvapublications.com www.adoptaseaturtle.org www.earlham.edu www.hsus.org www.marinebio.com www.nmfs.noaa.gov/pr/species/turtles/green www.sailhawaii.com www.turtles.com