Pilot whale is one of the largest types of dolphins. The animal may grow 14 to 21 feet (4 to 6 meters) long and weigh 3/4 to 2 1/2 tons (0.7 to 2.3 metric tons). A pilot whale is black, with a white streak down its underside. Its head has an organ called a melon that is made of fatty tissue. The melon helps the animal locate objects in the water (see Dolphin (The bodies of dolphins) ). Pilot whales swim in groups called schools. Large numbers of pilot whales often strand themselves on beaches. Scientists are not certain what causes this behavior. Pilot whales are sometimes called blackfish, a name that also refers to various kinds of true fish and to the killer whale (see Killer whale ).
Pilot whale
