When we were at the Sydney Aquarium we had a chance to see one of their star attractions, the dugong. Sirenia (commonly referred to as sea cows) are an order of aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. Four species are living, in two families and genera. These are the dugong (one species, Dugong dugong) and manatees (three species; Amazonian manatee (Trichechus inunguis), West Indian manatee (Trichechus manatus), and West African manatee (Trichechus senegalensis)). Sirenia, commonly sirenians, are also referred to by the common name sirens, deriving from the sirens of Greek mythology. This comes from a legend about their discovery, involving lonely sailors mistaking them for mermaids. “Sea cow” (seekoei) is also the name for a hippopotamus in Afrikaans. In Germanic languages, the word Sea can mean either a body of fresh or salt water, so this follows from the hippopotamus inhabiting lakes in southern Africa rather than the sea itself. Australia is home to the largest population of dugongs, stretching from Shark Bay in Western Australia to Moreton Bay in Queensland. The population of Shark Bay is thought to be stable with over 10,000 dugongs.