Seaturtles: Cheloniidae

Physical characteristics: The green seaturtle is dark brown to black, with a whitish underside. This turtle gets its name from the color of its body fat, which is green from their diet of algae (AL-jee), or tiny, plantlike growths that live in water. The upper shell of this large turtle can measure 5 feet (1.5 meters) in length, and the turtle itself can weigh as much as 750 pounds (340 kilograms). It has large, flipper-like front legs, with which it swims, and a fairly flat upper shell, to slice more easily through the water. Compared with females, males have a long claw on the front flipper and a lengthier tail and narrower upper shell.

Geographic range: The green seaturtle lives in tropical and temperate seas around the world.

Habitat: Although they sometimes can be found in temperate saltwater areas or far out at sea, green seaturtles are much more common in shallow, sea-grass-covered coastlines and in the warmer waters of the tropics.

Diet: Adult green seaturtles spend much of the daylight hours munching on sea grasses and algae, which are the main items of their diet. Only rarely do they eat a bit of meat, such as a sponge or jellyfish. Some The upper shell of the green seaturtle can measure 5 feet (1.5 meters) in length, and the turtle itself can weigh as much as 750 pounds (340 kilograms). (©Dr. Paula A. Zahl/Photo Researchers, Inc. Reproduced by permission.) scientists believe that the young may eat much more meat, but there is no evidence that they do.

Behavior and reproduction: As a cold-blooded animal, or one that gets its body warmth from the surrounding environment, the seaturtle does different things to maintain a healthy body temperature, such as rising to the sunshine-drenched top of the water column. Unlike other saltwater-living turtles, this species will even crawl up on the shoreline to bask, or rest, in the sun. When winter cold arrives, some species hibernate (HIGH-bur-nayt), or become inactive, by dropping down to the bottom of the water and burying themselves in the mud. In the breeding season, when they reproduce, males and females may migrate more than 1,900 miles (3,058 kilometers) from their feeding grounds to their nesting sites. There, males try to attract the females by giving them little nips, nudges, and sniffs; the turtles mate in the water. A single female may mate with several males, and so the young in a female's clutch may have different fathers, some from matings that happened several years earlier. When she is ready to lay her eggs, the female will crawl up onto a dry coastline, dig a hole, and drop in fewer than a dozen to nearly 240 eggs, although 108 to 120 per nest is typical. She may lay two to five nests, and sometimes as many as seven, in a single season. The leathery, round eggs hatch in one to three months.

Green seaturtles and people: For centuries, humans have hunted green seaturtles for their meat and their eggs, which they eat for food.

Conservation status: The IUCN lists this species as Endangered. The U.S. Fish and Wildlife Service lists the breeding populations in Florida and the Pacific coast of Mexico as Endangered and all other populations as Threatened. Besides hunting and collecting, these turtles are in danger from the development of their nesting grounds into seafront resorts, from fishing nets that entangle them and often lead to their deaths by drowning, and from boaters who unknowingly run over them with their motor propellers. ∎