What are the peculiarities of the movements of these living things : Dolphins

Explanation

Dolphin is an inhabitant of seas. It can efficiently swim with the help flippers and streamlined body. Since it is a mammal, it cannot breathe in the water and thus for every inhalation and exhalation it rises to the surface of water. It looks like as it is trying to jump out. One can easily notice a jumping dolphin when the sea is calm.