The animal's name can therefore be interpreted as meaning "a 'fish' with a womb". The name is originally from Greek δελφίς ( delphís), "dolphin", which was related to the Greek δελφύς ( delphus), "womb". The most common dolphin species in captivity is the bottlenose dolphin, while there are around 60 killer whales in captivity. Dolphins are sometimes kept in captivity and trained to perform tricks. Dolphins occasionally feature in literature and film, as in the film series Free Willy. Dolphins have been depicted in various cultures worldwide. Besides drive hunting, they also face threats from bycatch, habitat loss, and marine pollution. Dolphins produce a variety of vocalizations, usually in the form of clicks and whistles.ĭolphins are sometimes hunted in places such as Japan, in an activity known as dolphin drive hunting. Mothers of some species fast and nurse their young for a relatively long period of time. Calves are typically born in the spring and summer months and females bear all the responsibility for raising them. Male dolphins typically mate with multiple females every year, but females only mate every two to three years. Dolphins feed largely on fish and squid, but a few, like the killer whale, feed on large mammals, like seals. They have a layer of fat, or blubber, under the skin to keep warm in the cold water.Īlthough dolphins are widespread, most species of them prefer the warmer waters of the tropic zones, but some, like the right whale dolphin, prefer colder climates. Some species are well adapted for diving to great depths. They have well-developed hearing which is adapted for both air and water and is so well developed that some can survive even if they are blind. Dolphins use their conical shaped teeth to capture fast-moving prey. Though not quite as flexible as seals, some dolphins can travel at speeds 29 kilometres (18 mi) per hour for short distances. They have streamlined bodies and two limbs that are modified into flippers. Several species of dolphins exhibit sexual dimorphism, in that the males are larger than females. Dolphins can sometimes leap about 30 feet (9.1 m). There are 40 extant species named as dolphins.ĭolphins range in size from the relatively small 1.7-metre-long (5 ft 7 in) long and 50-kilogram (110-pound) bodied Maui's dolphin to the 9.5 m (31 ft 2 in) and 10-tonne (11-short-ton) killer whale. The term dolphin usually refers to the extant families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the brackish dolphins), and the extinct Lipotidae (baiji or Chinese river dolphin). For other uses, see Dolphin (disambiguation).Ĭladistically included but traditionally excluded taxaĭolphin is the common name of aquatic mammals within the infraorder Cetacea. This article is about the marine mammals.
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