Marine algae are also consumed when seagrass is scarce. Dugongs are more closely related to elephants than to other marine mammals such as whales and dolphins, but their closest living aquatic relatives are the manatees. Manatees are aquatic mammals that live in freshwater rivers and coastal seas of West Africa, the Caribbean and America. Dugongs swim using their whale-like fluked tail and they use their front flippers for balance and turning. Their movements are often slow and graceful.
Dugongs look similar to a rotund dolphin or seal, although they are less streamlined.
They have a rounded head with small eyes and a large snout. As they are mammals, dugongs must surface to breathe. However, unlike other aquatic mammals, such as whales, dolphins and porpoises, dugongs cannot hold their breath underwater for more than a few minutes, especially if swimming fast. Australia's northern waters are one of the world's last strongholds for dugongs. Dugongs have poor eyesight but they find seagrass with the aid of coarse, sensitive bristles which cover their large and fleshy snout.