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The pygmy killer whale (''Feresa attenuata'') is a small, rarely seen cetacean of the oceanic dolphin family (Delphinidae). It derives its common name from sharing some physical characteristics with the killer whale. It is the smallest species that has "whale" in its common name. In fact, "killer" may be more apt in the case of the pygmy killer whale than its larger relative; when a number of pygmy killers were brought into captivity in Hawaii and South Africa, they were extremely aggressive—even killing other poolmates. A pod captured in Japan did not display such aggression.〔Masa Ushioda, (“Pygmy Killer Whale” ), ”Cool Water Photo”, March 11, 2015〕 Although it had been described by John Gray in 1874, the pygmy killer whale, until the early 1950s, was known only from two skulls kept at the British Museum. In 1954, Japanese cetologist Munesato Yamada published accounts of a "rare porpoise" discovered in 1952 by whale hunters working from Honshū. He wrote that the individuals he examined had skulls matching those in the museum and that the body had features similar to the killer whale, and proposed the common name lesser (or pygmy) killer whale. Despite its name and features, the pygmy killer whale is of a different genus to the killer whale. The scientific species descriptor ''attenuata'' is Latin for 'tapering' and refers to the gradual narrowing from the head to the tail fin.〔Masa Ushioda, (“Pygmy Killer Whale” ), ”Cool Water Photo”, March 11, 2015〕 ==Description== The pygmy killer is an average-sized dolphin (a little larger and heavier than a grown man) and may easily be confused at sea with other species, in particular the melon-headed whale. The body is robust and dark-colored. The cape is particularly dark. The head is rounded without a beak. The sides are lighter and the belly is often white. Several individuals have been seen with a white lining around the mouth and chin. The dorsal fin is tall and slightly falcate.〔Gaia Guide, (“Pygmy Killer Whale” ), ”The Gaia Guy”, March 12, 2015〕 The pygmy avoids human contact. Some spy-hopping, breaching, and other active behaviors have been recorded, but it is not an acrobatic animal. 〔”Many different providers”, (“Feresa Attenuata” ), ”EOL, Encyclopedia of Life”, March 12, 2015〕 These dolphins always move in groups, usually of 10 to 30, but occasionally much larger.〔Pete Thomas, (“Marine Mammals” ), ”The Outdoor Guide”, March 12, 2015〕 Data from strandings, which seem to be common in the species, indicate a diet of cephalopods and small fish. They have been observed attacking, killing, and eating other cetacean species such as the common dolphin.〔Marinebio.org Inc, (“Pygmy Killer Whale, Feresa Attenuata” ), ”Marine Bio”, March 12, 2015〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pygmy killer whale」の詳細全文を読む スポンサード リンク
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