The manatee, also known as the sea cow, is my favorite marine mammal. They are probably called the "sea cow" because of their awesome shape, friendliness, and way of life. All that these friendly slow critters do is grub on seaweed and other types of plant-life that are present on the sea-floor. These animals are known to not be smart, but recent studies have shown that they have a long-term memory. What's sad is the amount of manatees and dugongs being killed by humans. These cute things are always getting tangled up in fishing lines and other man-made objects and then being killed by boat engine propellers. At one time they were hunted near Africa, but most of it has stopped in modern times.