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
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 very different from other manatees. They can only survive in freshwater, and are found in the Amazon river basin. They are rarely seen and thus, their exact population is unknown. They prefer lagoons and backwater lakes, which are known for their 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.