Dolphin

There are 40 species of dolphins, from Maui's dolphin, about the size of a person (1.7 m and 50 kg), to the orca, at 9.5 m and 10 tonnes. They are aquatic mammals from the toothed whale group, with a streamlined, fish-like body and front limbs that have turned into flippers. They communicate with high-pitched clicks and whistles and find their way by echolocation, that is, by the echo of the sounds they make.