Dugong, large marine mammal that inhabits the tropical waters of the Indian and western Pacific oceans. It is commonly called a sea cow. The dugong's massive body is about 2.4 to 2.7 m (about 8 to 9 ft) long and tapers to a forked, horizontally flattened tail. The forelimbs are rounded flippers; no hindlimbs remain. Large, muscular lips (the upper one cleft) are used for tearing off water plants. Molars and hard pads at the front of the jaws grind the food; the male also has two small, tusklike incisors. Feeding mainly at night, the dugong commonly travels in pairs or in small groups. After a gestation of about 13 to 14 months, the young, usually a single offspring, is born in the water and suckles at the mother's pectoral teats.

This harmless sea animal has long been hunted for its meat, blubber, oil, and hide, and today the world population of dugongs is believed to be reduced to less than 40,000. They are now classified as endangered. Dugongs were sometimes viewed by early voyagers as mermaids and were identified with the Sirens of mythology. See also Manatee.

Scientific classification: The dugong makes up the family Pugongidae in the order Sirenia. It is classified as Dugong dugon.