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| unranked_subordo = Cetacea | unranked_superfamilia = Mysticeti | familia=Balaenopteridae | genus=''Balaenoptera'' | species=''B. musculus '' | binomial=''Balaenoptera musculus'' | binomial_authority=(Linnaeus, 1758) | subdivision_ranks=Subspecies | subdivision= * ''B. m. brevicauda'' Ichihara, 1966 * ?''B. m. indica'' Blyth, 1859 * ''B. m. intermedia'' Burmeister, 1871 * ''B. m. musculus'' Linnaeus, 1758 | range_map=Cypron-Range Balaenoptera musculus.svg | range_map_caption=Blue whale range (in blue) | synonyms= * ''Balaenoptera gibbar'' Scoresby, 1820 * ''Pterobalaena gigas'' Van Beneden, 1861 * ''Physalus latirostris'' Flower, 1864 * ''Sibbaldius borealis'' Gray, 1866 * ''Flowerius gigas'' Lilljeborg, 1867 * ''Sibbaldius sulfureus'' Cope, 1869 * ''Balaenoptera sibbaldii'' Sars, 1875 }} The blue whale (''Balaenoptera musculus'') is a marine mammal belonging to the baleen whales (Mysticeti).〔 At in length and 〔(【引用サイトリンク】 publisher = Smithsonian National Zoological Park )〕 or more in weight, it is the largest extant animal and is the heaviest known to have existed. Long and slender, the blue whale's body can be various shades of bluish-grey dorsally and somewhat lighter underneath.〔(【引用サイトリンク】 publisher = Fisheries and Aquaculture Department, Food and Agriculture Organization, United Nations )〕 There are at least three distinct subspecies: ''B. m. musculus'' of the North Atlantic and North Pacific, ''B. m. intermedia'' of the Southern Ocean and ''B. m. brevicauda'' (also known as the pygmy blue whale) found in the Indian Ocean and South Pacific Ocean. ''B. m. indica'', found in the Indian Ocean, may be another subspecies. As with other baleen whales, its diet consists almost exclusively of small crustaceans known as krill. Blue whales were abundant in nearly all the oceans on Earth until the beginning of the twentieth century. For over a century, they were hunted almost to extinction by whalers until protected by the international community in 1966. A 2002 report estimated there were 5,000 to 12,000 blue whales worldwide, in at least five groups. More recent research into the Pygmy subspecies suggests this may be an overestimate. Before whaling, the largest population was in the Antarctic, numbering approximately 239,000 (range 202,000 to 311,000). There remain only much smaller (around 2,000) concentrations in each of the eastern North Pacific, Antarctic, and Indian Ocean groups. There are two more groups in the North Atlantic, and at least two in the Southern Hemisphere. As of 2014, the Californian blue whale population has rebounded to nearly its pre-hunting population.〔(【引用サイトリンク】title=California Blue Whales Bounce Back From Whaling )〕 ==Taxonomy== Blue whales are rorquals (family Balaenopteridae), a family that includes the humpback whale, the fin whale, Bryde's whale, the sei whale, and the minke whale.〔 The family Balaenopteridae is believed to have diverged from the other families of the suborder Mysticeti as long ago as the middle Oligocene (28 Ma ago). It is not known when the members of those families diverged from each other. The blue whale is usually classified as one of eight species in the genus ''Balaenoptera''; one authority places it in a separate monotypic genus, ''Sibbaldus'', but this is not accepted elsewhere.〔 DNA sequencing analysis indicates that the blue whale is phylogenetically closer to the sei whale (''Balaenoptera borealis'') and Bryde's whale (''Balaenoptera brydei'') than to other ''Balaenoptera'' species, and closer to the humpback whale (''Megaptera'') and the gray whale (''Eschrichtius'') than to the minke whales (''Balaenoptera acutorostrata'' and ''Balaenoptera bonaerensis''). If further research confirms these relationships, it will be necessary to reclassify the rorquals. There have been at least 11 documented cases of blue-fin hybrid adults in the wild. Arnason and Gullberg describe the genetic distance between a blue and a fin as about the same as that between a human and a gorilla. Researchers working off Fiji believe they photographed a hybrid humpback-blue whale〔(Amazing Whale Facts Archive ). Whale Center of New England (WCNE). Retrieved on 2008-02-27.〕 including the case of discovery through DNA analyzing from a meat sample found on Japanese market.〔Ogino M. (2005)『クジラの死体はかく語る』, Kodansha〕 The first published description of the blue whale comes from Robert Sibbald's ''Phalainologia Nova'' (1694). In September 1692, Sibbald found a blue whale that had stranded in the Firth of Forth—a male -long—which had "black, horny plates" and "two large apertures approaching a pyramid in shape".〔 The specific name ''musculus'' is Latin and could mean "muscle", but it can also be interpreted as "little mouse". Carl Linnaeus, who named the species in his seminal ''Systema Naturae'' of 1758, would have known this and may have intended the ironic double meaning.〔(【引用サイトリンク】 publisher = New York State Department of Environmental Conservation )〕 Herman Melville called this species "sulphur-bottom" in his novel ''Moby-Dick'' due to an orange-brown or yellow tinge on the underparts from diatom films on the skin. Other common names for the blue whale have included "Sibbald's rorqual" (after Sibbald, who first described the species), the "great blue whale" and the "great northern rorqual". These names have now fallen into disuse. The first known usage of the term "blue whale" was in Melville's ''Moby-Dick'', which only mentions it in passing and does not specifically attribute it to the species in question. The name was really derived from the Norwegian ''blåhval'', coined by Svend Foyn shortly after he had perfected the harpoon gun; the Norwegian scientist G. O. Sars adopted it as the Norwegian common name in 1874. Authorities classify the species into three or four subspecies: ''B. m. musculus'', the northern blue whale consisting of the North Atlantic and North Pacific populations, ''B. m. intermedia'', the southern blue whale of the Southern Ocean, ''B. m. brevicauda'', the pygmy blue whale found in the Indian Ocean and South Pacific,〔Ichihara T. (1966). The pygmy blue whale ''B. m. brevicauda'', a new subspecies from the Antarctic in ''Whales, dolphins and porpoises'' Page(s) 79–113.〕 and the more problematic ''B. m. indica'', the great Indian rorqual, which is also found in the Indian Ocean and, although described earlier, may be the same subspecies as ''B. m. brevicauda''.〔 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「blue whale」の詳細全文を読む スポンサード リンク
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