The manatee, often called the sea cow, is the only exclusively herbivorous marine mammal. It grazes on all kinds of aquatic plants, especially marine sea grasses, assisted by its large prehensile lips, which are studded with bristles.
During the day, it is frequently found close to the surface, sleeping within the top three to ten feet (1 to 3 m). Occasionally it swims down to thirty feet (10 m), propelling itself along with the aid of its large flat tail, which it also uses as a rudder.
When feeding, which it usually does at night, it walks along the bottom using its fore limbs.
It is restricted to tropical and subtropical waters because it has an unusually low metabolic rate for a large mammal and rapidly loses body heat to the surrounding water.
Because it was overhunted in the past and — despite its current protected status — continues to be caught in fishing gear and hit by speed boats, the West Indian manatee is endangered.
Name: West Indian Manatee (Trichechus manatus)
Family: Trichechidae (Manatees)
Range: Florida to northeastern Brazil, including islands
Habitat: Rivers, estuaries, and coastal waters
Diet: Seagrass and other aquatic plants
Total Length: 8 to 13 feet (2.4 to 4 m)
Weight: 440 to 1,300 pounds (200 to 600 kg)
Life Cycle: Mating year-round; gestation 385 to 400 days, one (sometimes two) calves born
Description: Gray to gray-brown skin; small eyes; whiskered snout; absence of external ear flaps; two large flippers; flat, paddle-like tail
Conservation Status: Vulnerable
Major Threat: Human interference