They can move freely between freshwater and saltwater habitats. The Amazonian manatee is restricted to the freshwater Amazon basin. All manatees are herbivores. The Florida manatee feeds on more that 60 varieties of grasses and plants. A manatee's only teeth are molars, for grinding vegetation.
Some research suggests that manatees periodically require fresh water.
West Indian manatees have been seen congregating at river mouths and drinking from hoses, culverts, and sewage outfalls. A female manatee, called a cow, gives birth about once every three years. Gestation lasts about 12 months. A calf nurses from teats under the mother's pectoral flippers. But human activities pose a much greater threat to manatees.