It feeds underwater, but must surface periodically to breath. Manatees are herbivores, meaning they eat only plants. But they eat a great variety of aquatic plant species, including water hyacinth and hydrilla. Manatees must eat 4 to 9 percent of their body weight each day. To do this, they spend 5 to 8 hours a day eating.
Manatees spend their lives moving between freshwater, brackish, and saltwater environments.
They prefer large, slow- moving rivers, river mouths, and shallow coastal areas such as coves and bays. Great distances may be covered as the animals migrate between winter and summer grounds. During the winter, manatees congregate around warm springs and power plants that discharge warm water. During summer months, they have occasionally been seen as far north as Maryland and Rhode Island. Manatees reach breeding maturity between 3 and 10 years of age.