Manatees and dugongs are herbivores, meaning they eat only plants such as the water hyacinth in the picture. Seagrass beds are important feeding grounds for them. Although manatees and dugongs mainly eat larger aquatic plants, they also eat algae and crustacea such as barnacles which grow on these plants. They spend much of their day feeding and can eat up to 100 pounds of vegetation in one day! Manatees and dugongs spend more time feeding hist before winter because they need more energy to maintain their body temperature in colder water. A manatee and dugong mouth is different from ours. Its lower lip and jaw has horny pads that help it grasp plants. Its upper lip is split down the middle and each side can move independently. Its teeth are broad and flat, well suited for grinding up plants. As the teeth are worn away by the grit, sand, and sediment which can adhere to plants the animals eat, they are replaced by other teeth which grow in from behind. Manatees and dugongs have no front teeth.