This ever smiling creature may have once inspired mermaid myths. Dugongs are surprisingly more closely related to elephants than to other marine mammals such as whales and dolphins. Male dugongs age 12 even have a pair of tusk like teeth! Unlike most other marine mammals they cannot hold their breaths for long periods of time, so most dives last only around 1-3 minutes. These incredible animals belong to an ancient group called Sirenians which are conventionally divided into four families: two, the Prorastomidae and the Protosirenidae, are extinct, while the Dugongidae (dugongs) and Trichechidae (manatees) survive today. Until a few hundred years ago the dugong’s closest relative was Steller’s sea cow but it was hunted to extinction within 27 years of its discovery, and now manatees are the dugong’s closest living relatives.
Dugongs and manatees are the only herbivorous marine mammals living today. Because they feed almost exclusively on sea grass Dugongs are also called “sea cows.” Given their diet, this species occurs in the shallow coastal waters of tropical seas, where there is an abundance of sea grass: from East Africa to Australia, including the Red Sea, Indian Ocean, and Pacific waters. Long distance migration is unknown, although some individuals have been recorded swimming up to 600 km at certain times of year and they can live for more than 70 years in the wild.
The species has been traditionally hunted throughout much of its range for its meat, hide, oil and bones. Although commercial hunting is now banned, traditional hunting still occurs in parts of its range. Fishing nets have also resulted in the death of many dugongs given they are not able to hold their breath for long. Another major threat to the species is habitat loss and degradation since sea grass ecosystems are very sensitive to human activity and may be destroyed directly by mining or trawling, or lost as a result of dredging, land clearing and land reclamation.