Manatees (genus Trichechus ) are found on both sides of the tropical Atlantic Ocean. They are sluggish, largely nocturnal bottom feeders and consume up to 100 lb (45 kg) of vegetation daily. They must surface for air every 15 or 20 min. They are usually 7 to 12 ft (2.1–3.6 m) long and weigh about 500 lb (225 kg), although males sometimes grow much larger. Their paddlelike tail fin is nearly circular. Both parents care for the young, one holding it while the other dives for food. The West Indian manatee, Trichechus manatus, lives in offshore waters, bays, estuaries, and river mouths in Florida, Central America, and the West Indies. It is protected by law in Florida. The Amazonian manatee, T. inunguis, is found in rivers of NE South America, ascending the Amazon as far as Ecuador. Both are listed as endangered species. The West African manatee, T. senegalensis, lives in the coastal rivers and lagoons of W Africa.