West Indian manatee  (Trichechus manatus)

Biology

These aquatic animals may live for over 50 years and exhibit a slow reproduction rate; they reach sexual maturity at three to five years old and at most they produce a single calf every two years. Pregnancy lasts for 11 to 14 months and the calf remains dependent on its mother for up to two years (5) (9). There is no distinct breeding season but when a female is receptive, many males may surround her in a mating herd and she will often mate with more than one male (6).

Manatees mainly feed on aquatic vegetation and can consume ten to fifteen percent of their body weight a day (6). Manatees in North America carry out seasonal migrations. They move to natural and industrial warm water sources in central and southern Florida in the winter, but can be found as far north as Virginia and the Carolinas when temperatures increase in the summer (6). Sirenians (manatees and dugongs) produce a large volume of gas, which is given off during the digestion of plant material and this makes them particularly buoyant, so much so that their bones are dense in order to compensate (10).