Manatees are representatives of a detachment of sirens, relatives of mammals of the eastern hemisphere called dugoni. It is believed that manatees evolved from four-pronged terrestrial mammals about 60 million years ago.
Although manatees live in water, they are closer to elephants and damans than to sea lions and whales. Manatees are never selected from the water to land, although like all marine mammals, they are periodically forced to swim to the surface to inhale air. A resting manatee can hold its breath for up to 15 minutes, but during the voyage should inhale the air every 3-4 minutes.
In length, the manatees reach an average of 4 meters and can weigh up to 590 kilograms. They have front paws, similar to the scapula with fingernails. Apparently such a structure of the limbs was given to manatees from their distant land ancestors.
Usually manatees swim at the usual pace at a speed of 5-8 kilometers per hour, but if necessary they can speed up to 30 kilometers per hour for a short time. They are quite mobile and constantly move in different directions.
Manatees can produce a large number of sounds that are used to communicate with each other, especially for communication between the mother and the baby. Adult individuals use sounds to maintain contact and during sexual and other games. In addition to sounds, manatees also use touch, smells and so on for communication.
The manatees have rather small eyes, although they have excellent eyesight. They have a special membrane that protects the eyes. The hearing in manatees is also very good, despite the absence of the structures of the external ear. Instead, they have large bones in the inner ear.
All their time manatees are busy with food, travel and leisure.
Despite their impressive size, the manatees have little fat, they are sorts of a subtropical belt and are very sensitive to cold.
The teeth of manatees change their whole lives, as they eat quite rough food.
The manatees have only 6 vertebrae. Most mammals, including a giraffe, have seven vertebrae. Because of this structure of the spine, manatees can not turn their heads to the sides. To look at the line, they need to turn their whole body.
