Manatees are herbivores and are typically found in shallow rivers, where they feed on sea grass and algae. They can weigh up to 1,200 pounds and consume about 10 percent of their body weight each day.
Manatees are mammals, so they must return to the surface of the water every three to five minutes in order to breathe. They are able to spend longer periods of time underwater when they need to, and can hold their breath for up to 20 minutes.
Dugongs are a type of manatee that is typically found in the coastal waters of the Indian and western Pacific oceans. They are salt-water mammals and do not venture into fresh water. They closely resemble manatees except for their whale-like fluke; manatees have much more rounded tails.
Manatees are sometimes called sea cows, but in actuality they evolved from the same land mammal as elephants about 50 million years ago, making elephants their closest living relatives today. Manatees, like their elephant cousins, are able to continuously replace any teeth that they may lose.
Unlike human brains that have cortical folds, manatee brains are completely smooth. They also have the lowest ratio of brain to body size of any mammal.
A female manatee is pregnant for 12 months, and the calf is born underwater. The mother then assists the calf to the surface so that it can breathe. The manatee calf is able to swim within an hour after its birth.