They are called green turtles because of the color of the flesh. Chelonia mydas are one of the largest turtles ranging from 30 to 60 inches. They can weigh up to 200 pounds. They have limbs that are paddle-like, which are used to swim. Their heads seem small compared to their body size. Males are larger than females and the tail is longer, extending well beyond the shell. The carapace can be olive to brown, or sometimes black, depending on the geographic location of the species. Green turtles cannot pull their heads inside of their shells.

Green sea turtles live in tropical waters all over the world. The only time they emerge from the water is when they are nesting. The only time males are not at sea is when they were first born. C. m. agassizii are sometimes found with seals and albatrosses basking on the beach. When it is time to mate they migrate from several hundred to over a thousand miles across the ocean to where they hatched. Female green turtles use the same beaches to nest as their mothers and grandmothers.

Green turtles live in warm tropical waters from New England to South Africa and in the Pacific from Western Africa to the Americas.

Males and females mature between 10 and 24 years. The breeding season depends on the latitude. Internal fertilization takes place when the male and female copulate. This is the only time there is vocalization. Like many species, there is male competition. One male may try to bite another male who is copulating with a female. Mating occurs underwater or on the surface about one kilometer from the shore. Sometimes the female will retain enough sperm to nest several times that year. Nesting occurs every three to six years. When the female is ready to lay her eggs, she leaves the water, crawls onto the sand and starts digging for hour and hours until her flippers will not allow her to dig deeper. She then lays 100 to 200 eggs. This group of eggs is called a clutch. She covers them with sand to protect them from the sun, heat, and predators. Pacific green turtles lay fewer eggs than Atlantic green turtles. The gestation period is 40 to 72 days, depending on the location.

Green turtles are mostly herbivorous. They spend most of their time feeding on algae in the sea and the grass that grow in shallow waters. As juveniles, they eat plants and other organisms such as: jellyfish, crabs, sponges, snails, and worms. As adults, they are strictly herbivorous.

Baby turtles use their egg tooth when they hatch to break the shell of the egg. Females lay so many eggs because the chance for their survival is very low. Sometimes animals such as raccoons, foxes, coyotes, ants, and even people will dig up the eggs and eat them. But if the eggs are successful, when they hatch they start moving their flippers. When they do this, the sand starts to fall below them, pushing them up out of the hole so they can start making their way to the sea. As soon as they get to the sea, they start to drift off. They spend a few years floating at sea eating plankton at the surface. During this time, their shell is soft and they are very subject to predation by fish. After a few years of eating plankton, they move to shallow waters to feed on sea grasses.

To avoid predation, they dive and swim away. Young green turtles that have just hatched are the most vulnerable. They may get eaten from the time they hatch, crossing the sand on their way to the ocean, and during the first couple of years at sea. Predators in the sand include ghost crabs, ants, snakes, gulls, opossums, rats, and vultures. There are many more in the water such as sharks, dolphin fish, kingfish, needlefish, and bottle-nosed dolphins.

Green turtles are an endangered species because they have so many predators--including humans. Even though a female can lay over 200 eggs in on clutch, some will not hatch, and many will be eaten. Even if they do hatch, they get eaten on their way to the water, and in the water. So only a few will survive if any. If the they do survive, they can live to be over 100 years old. Sometimes eggs are laid on a public beach. When this happens conservationists come and move them to a safer place. In the United States, green turtles are protected by the Endangered Species Act.

McKeown, Sean. A Field Guide to Reptiles and Amphibians in the Hawaiian Islands. Diamond Head Publishing Company, 1996