The average adult manatee is 10 feet long and weighs 1,000 - 1,200 pounds. However, manatees can grow to reach a length of 13 feet and a weight of approximately 3,000 pounds. Up to six to eight hours each day is spent in the seagrass bed feeding. They consume about ten percent of their body weight daily, or about 60 to 100 pounds. Manatees are herbivores, and eat a large variety of submerged, emergent, and floating plants.
Female manatees reach sexual maturity when they are about four-seven years old.
Once they are sexually mature, they give birth to one calf every two to five years. Their gestation period is approximately thirteen months. Newborn manatee calves are 4 to 4.5 feet long and weigh about 70 pounds. The main source of nourishment for calves comes from their mother's milk, although they are able to nibble on plants within a few weeks of birth because they are born with premolars and molars. The calves nurse underwater for three minutes at a time from nipples located underneath the mother's flippers.