Sea Cows Dugongs and Manatees: Sirenia

Dugongs, sea cows, and manatees are mammals that vary in length from 9.8 feet (3 meters) to 32.8 feet (10 meters) and weigh anywhere from 992 pounds (450 kilograms) to more than 9,920 pounds (4,500 kilograms). Sirenians (sye-REEN-ee-unz), members of the order Sirenia, are nearly hairless and skin texture varies from smooth to rough. They have no back limbs, only short, flexible forelimbs that they use to help them swim. The tail of the manatee is paddle-shaped while that of the dugong and sea cow is fluked with long, horizontal fins, like a whale. Eyes are small, and their ears are not visible. Sirenians vary in color from gray to brown. The manatee has both upper and lower molars, flat teeth suitable for chewing, which are replaced on a regular basis throughout its lifetime. Male dugongs have tusks, and all dugongs have molars that are not replaced. Sea cows were toothless. All appear to have whiskers.