The West Indian manatee , also known as the North American manatee, is a large, aquatic mammal native to warm coastal areas of the Caribbean, from the eastern US to northern Brazil. Living alone or in herds, it feeds on underwater plants and uses its whiskers to navigate. It is divided into two endangered subspecies, the Florida manatee in the US and the Antillean manatee in the Caribbean, both of which face pressure from habitat loss, pollution, and other human activity. The West Indian manatee is the largest living member of the sirenians , a group of large aquatic mammals that includes the dugong, other manatees, and the extinct Steller's sea cow.