Manatees are large marine mammals, which are completely aquatic in nature. They are also known as 'sea cows' owing to their striking resemblance to cows. The Amazonian manatee (Trichechus inunguis), West African manatee (Trichechus senegalensis), and the West Indian manatee (Trichechus manatus) are the three extant species of manatee.
The West Indian manatee belongs to the order Sirenia, and is divided in two subspecies: the Florida manatee and Antillean or Caribbean Manatee. The other two don't have any subspecies.
Facts about Their Habitat
West Indian manatees are usually seen in rivers, canals, estuaries, bays, and coastal areas where there is ample seagrass and vegetation. The specialty of the species is that they can survive in freshwater as well as saline or salt water. They can also adapt to brackish water as their bodies are accustomed to any aquatic conditions. They are usually found at the depth of 3.25-feet, though they prefer to stay connected to the coast. These manatees thrive in waters where the temperature exceeds 70°F. Rarely are Florida manatees seen in the deep ocean; the only exception being when they are traveling long distances. The West African manatee also has a similar habitat.
Amazonian manatees are known to be very different from other manatees. They can only survive in freshwater, and are usually found in the Amazon river basin. They are rarely seen and thus, their exact population is unknown. In the Amazon basin, they prefer lagoons and backwater lakes, which are known for their rich vegetation and aquatic plant life. These herbivores are voracious feeders who are known to eat about 12 percent more than their total body weight. They require a surrounding where the temperature ranges between 77°F to 86°F.
Though there is no concrete evidence as such, yet another species, the Dwarf manatee (Trichechus pygmaeus), is believed to be found in the Aripuanã River―a tributary of the Amazon.