Green sea turtle (Chelonia mydas)

Green sea turtle
(Chelonia mydas)

TAXONOMY AND NAMING

Class : Reptilia
Order : Testudines
Family : Cheloniidae
Genus/species : Chelonia
Common names :
English : Green sea turtle
Spanish : Tortuga verde
French : Tortue verte

Green sea turtle (Chelonia mydas)©Xanthe Rivett

ANATOMY AND MORPHOLOGY

The green sea turtle (Chelonia mydas) refers to the usually green fat found beneath its carapace, not to the color of its carapace, which is olive to black. The dorsoventrally flattened body has a pair of large, paddle-like flippers. It is usually lightly colored. Adult green turtles grow to 1.5 metres (5 ft) long. The average weight of mature individuals is 68–190 kg (150–419 lb) and the average carapace length is 78–112 cm (31–44 in).

The carapace of the turtle has various color patterns that change over time. Hatchlings of Chelonia mydas, like those of other marine turtles, have mostly black carapaces and light-colored plastrons. Carapaces of juveniles turn dark brown to olive, while those of mature adults are either entirely brown, spotted or marbled with variegated rays.

DISTRIBUTION AND LIFE HISTORY

The green turtle range extends throughout tropical and subtropical seas around the world, with two distinct populations in the Atlantic and Pacific Oceans, but it is also found in the Indian Ocean. Each population is genetically distinct, with its own set of nesting and feeding grounds within the population’s known range. Within their geographical range, the green sea turtles generally stay near continental and island coastlines. Near the coastlines, the green sea turtles live within shallow bays and protected shores.

C. mydas is mostly herbivorous. Like other sea turtles, green sea turtles migrate long distances between feeding grounds and hatching beaches. Many islands worldwide are known as Turtle Island due to green sea turtles nesting on their beaches. Females crawl out on beaches, dig nests, and lay eggs during the night. Later, hatchlings emerge, and scramble into the water. Those that reach maturity may live to 80 years in the wild. In the Caribbean, major nesting sites have been identified on Aves Island, the U.S. Virgin Islands, Puerto Rico, the Dominican Republic, and Costa Rica. In recent years, there are signs of increased nesting in the Cayman Islands. One of the region’s most important nesting grounds is in Tortuguero in Costa Rica.

Green sea turtle (Chelonia mydas) geographic range©IUCN red list

THREATS

Green turtles are in danger due to human activity. In some countries, turtles and their eggs are still hunted for food. Pollution indirectly harms turtles at both population and individual scales. Many turtles die after being caught in fishing nets. In addition, real estate development often causes habitat loss by eliminating nesting beaches.

ECOLOGICAL IMPORTANCE

Green sea turtles play an essential role in the ecosystem in which they live. In the seagrass beds, the turtles feed on the seagrass by trimming only the top and leaving the roots of the plant. Through their feeding technique, the turtles help to improve the health and growth of the seagrass beds. Furthermore, in their coral reef habitat, the green sea turtles have a symbiotic interaction with reef fish, including the yellow tang.

PROTECTION AND CONSERVATION STATUS

The species is recognized as endangered on the IUCN Red List. The green sea turtle is subject to differing conservation laws in various countries. Several Caribbean countries also started conservation efforts.

CITES : yes _ Annex I

SPAW Protocol : yes since 1991 _ Annex II

Sea turtle national protection status in SPAW parties ©SPAW RAC

Sea turtle national protection status in SPAW parties

Bibliography

Connolly, Norma (2011). "More turtles nesting in Cayman". Caymanian Compass. Archived from the original on September 23, 2015. Retrieved April 9, 2012. (Quoted Ebanks-Petrie, Gina and Blumenthal, Janice of the Department of the Environment, Cayman Islands).
Ferri, Vincenzo (2002). Turtles & Tortoises. Buffalo, New York : Firefly Books. ISBN 978-1-55209-631-4.
"Green Sea Turtle – Chelonia mydas japonica". Turtles of Pakistan. Wildlife of Pakistan. 2003. Retrieved February 21, 2007.
Kindersley, Dorling (2005). Animal. New York City : DK Publishing. ISBN 978-0-7894-7764-4.
Ruckdeschel, C. and Shoop, C. R. 2006. Sea Turtles of the Atlantic and Gulf Coasts of the United States. A Wormsloe Foundation nature book ; Wormsloe Foundation nature book. Athens : University of Georgia Press.
Spotila, J. (2004). Sea Turtles : A Complete Guide to their Biology, Behavior, and Conservation. Baltimore, MD : Johns Hopkins University Press.