Marine mammal Dugong dugong of the order Sirenia (sea cows), found in the Red Sea, the Indian Ocean, and western Pacific Ocean. It can grow to 3.6 m/11 ft long, and has a tapering body with a notched tail and two fore-flippers. All dugongs are listed on the Convention on International Trade in Endangered Species (CITES) Appendix 1, which bans all trade in the species.
The addition of dugongs to CITES Appendix 1 followed a decision made in May 2000 to add Australia's coastal dugongs to the list despite the fact that they are not endangered, to facilitate protection of other dugong populations.
The dugong has a very long hind gut (30 m/98 ft in adults) which functions similarly to the rumen in ruminants. It feeds mostly on sea grasses and seaweeds, and is thought to have given rise to the mermaid myth. The dugong was thought to be the only truly herbivorous marine mammal until Australian research in 1995 showed that some eat sea squirts. These invertebrate creatures were shown to make up 25.5% of the wet weight of faeces from dugongs in Moreton Bay, eastern Australia.
Dugongs are slow breeders: the gestation period is 13 months, with up to three years between pregnancies. Coastal dugongs are in decline. The population along the Great Barrier Reef fell from 3,479 in 1987 to 1,682 in 1994. A survey released in 1997 revealed that gill nets used by commercial fishermen kill many dugongs, and polluted river water running into the ocean may be another cause of their decline.
1. an aquatic herbivorous mammal, Dugong dugon, of the order Sirenia, having forelimbs adapted as flippers, no hind limbs, and a horizontal lobed
Dugong (Dugong dugon). Credit:Encyclopædia Britannica, Inc. Large marine mammal (Dugong dugon, the sole living member of the family Dugongidae)