Manatees are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living species in the order Sirenia: the Amazonian manatee, the West Indian manatee, and the West African manatee. They measure up to 4.0 metres long, weigh as much as 590 kilograms (1,300 lb), and have paddle-like tails.
Manatee
A skeleton of a manatee and calf, the Museum of Osteology, Oklahoma City
Skull of a West Indian manatee, the Museum of Osteology, Oklahoma City
Endangered Florida manatee (Trichechus manatus)
Marine mammals are mammals that rely on marine (saltwater) ecosystems for their existence. They include animals such as cetaceans, pinnipeds, sirenians, sea otters and polar bears. They are an informal group, unified only by their reliance on marine environments for feeding and survival.
A humpback whale (Megaptera novaeangliae)
A leopard seal (Hydrurga leptonyx)
A polar bear (Ursus maritimus), a member of family Ursidae
A sea otter (Enhydra lutris), a member of family Mustelidae