South African Wildlife Pictures - Dolphins

Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin.  

Dolphins are considered to be amongst the most intelligent of animals and their often friendly appearance and seemingly playful attitude have made them popular in human culture.

Dolphins have a streamlined fusiform body, adapted for fast swimming. The tail fin, called the fluke, is used for propulsion, while the pectoral fins together with the entire tail section provide directional control. The dorsal fin, in those species that have one, provides stability while swimming. Teeth can be very numerous (up to two hundred and fifty) in several species. Dolphins breathe through a blowhole located on top of their head, with the trachea being anterior to the brain.

Most dolphins have acute eyesight, both in and out of the water, and their perception of sound extends ten times or more above the upper limit of adult human hearing.