Marine mammals form a fascinating group of animals including whales, dolphins, seals and the dugong, also known as the sea cow. Being mammals, they are more closely related to elephants, leopards, bats and hares than they are to sharks and other fish. There are some 120 species of marine mammal to be found in the world, and a fourth of these may be found in India and adjacent countries.Dugongs are one of the ancient living creatures underwater and are most interesting aquatic mammals.