Manatees, often referred to as “sea cows,” are large, gentle marine mammals. These herbivores are known for their slow, graceful movements and distinct appearance, featuring whiskered faces and paddle-like tails.
The Three Species of Manatees
There are three recognized living species of manatees, all belonging to the genus Trichechus: the Amazonian manatee (Trichechus inunguis), the West Indian manatee (Trichechus manatus), and the African manatee (Trichechus senegalensis).
Distinguishing Features and Habitats
The Amazonian manatee (Trichechus inunguis) is the smallest of the three species, weighing between 264 and 595 pounds and measuring 63 to 91 inches long. This species is found exclusively in freshwater habitats within the Amazon Basin, including rivers, lakes, and lagoons across Brazil, Colombia, Ecuador, and Peru. Its skin is thin and wrinkled, often brownish or gray, and it can be identified by a unique white or pink patch on its chest or abdomen. Amazonian manatees are fully aquatic and never leave the water, relying on a low metabolic rate and fat reserves to endure dry seasons when food is scarce.
The West Indian manatee (Trichechus manatus) is the largest manatee species, measuring 9 to 15 feet long and weighing between 440 and 1,320 pounds. Females are larger than males. West Indian manatees inhabit warm coastal waters, estuaries, and rivers, ranging from the southeastern United States to the Caribbean, Central America, and northern Brazil. This species includes two recognized subspecies: the Florida manatee (Trichechus manatus latirostris) and the Antillean manatee (Trichechus manatus manatus), found in the Caribbean and parts of Central and South America. They are gray with sparse hairs and a round, paddle-shaped tail.
The African manatee (Trichechus senegalensis) is found along the west coast of Africa, from Senegal to Angola. It occupies shallow coastal waters, estuaries, lagoons, and freshwater rivers. The African manatee resembles the West Indian manatee in appearance, though it is less studied. It has a body that is widest in the middle. It can be found in both fresh and saltwater environments, avoiding waters below 18°C (64°F).
Manatees vs. Dugongs: A Related Marine Mammal
Manatees are confused with dugongs, another large herbivorous marine mammal belonging to the same taxonomic order, Sirenia, but a different family (Dugongidae). A primary distinction lies in their tails: manatees have a horizontal, paddle-shaped tail, resembling a beaver’s tail. In contrast, dugongs possess a fluked tail, similar to that of a whale or dolphin.
Another difference is their snout shape and feeding habits. Manatees have a shorter, rounded snout with a divided upper lip, allowing them to feed on aquatic plants at or near the water’s surface. Dugongs feature a longer, downward-pointing snout that helps them graze on seagrass beds on the ocean floor. While manatees can inhabit both fresh and saltwater, dugongs are exclusively found in saltwater environments, primarily in the Indo-Pacific region.