Green turtles are one of the most widespread species of marine turtle, found in tropical and subtropical waters throughout the globe.
Two subspecies (C.m.mydas and C.m.agassizii).
They are one of the largest marine turtles, reaching between 0.7-1.5m in shell length and weighing up to 200kg.
Named for the greenish colour of their fat, green turtles have a small head, which they cannot retract into the shell. The greenish-brown upper shell is wide and smooth and the limbs are paddle-like for swimming. The tail in the male extends well beyond the carapace.
Green turtles inhabit the waters and coasts of Atlantic, Pacific and Indian oceans.
They are found in warm, coastal waters emerging on to land to nest or to bask occasionally.
Green turtles are primarily herbivorous, feeding mainly on marine grasses and algae, except as juveniles when they eat small marine creatures, such as jellyfish, molluscs and sponges.
Green turtles are streamlined and powerful swimmers. They sometimes emerge on to land to bask in the sun. Though they may be vocal when mating, they are otherwise silent. Competition between males occurs during the breeding season.
Internal fertilisation takes place during underwater or surface mating about 1km offshore. The female stores sperm, which may last through several nestings in one year. Nesting occurs every 3-6 years. 100-200 eggs are laid in burrows dug out by the female on isolated sandy beaches, and covered with sand to protect them from the sun. The young hatch after 6-8 weeks and make a desperate dash for the sea, but many are eaten by crabs and seabirds before they get there.
The IUCN Red List 2002 ranks green turtles as endangered.