Dugong (Dugong dugon)
The order Sirenia contains two families: the Trichechidae, found in the Americas, and the Dugongidae in Africa, Asia and Australasia. Like the Cetaceans, they are adapted to a life completely in the water, but they appear to be have evolved separately. Sirenians live in shallow coastal seas, feeding only on plant material. The fore-limbs are flippers and there is a tail flipper or fluke, but no dorsal fin. In adult Dugongs there is only one pair of tusk-like incisors in the upper jaw and none in the lower jaw. There are no canines or premolars, but a total of 10 to 12 molars, only some of which are visible at one time; the deeper ones replace the top ones as they wear out.
Measurements: TL 2.5-30 m. Wt 150-250 kg.
Identification: Coloration usually dull brownish-grey. Has a few sparsely scattered hairs on body and stiff bristles on upper lip. Head broad and rounded, with the mouth on the underside. Unlike most cetaceans of similar size, the Dugong has two nostrils and no dorsal fin. Less active than most small cetaceans.
Ecology and Habitat: Usually rests during the day in deep water and feeds on sea grasses and other vegetation in shallow waters at night. Usually found in small groups, which are believed to travel long distances between feeding areas.
Distrbution: Borneo - Recorded near Lawas in Sarawak (though not recently); very few recent records, and possibly extinction in Borneo.