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| image = Cetorhinus maximus by greg skomal.JPG | status = VU | status_system = iucn3.1 | status_ref = | regnum = Animalia | phylum = Chordata | classis = Chondrichthyes | subclassis = Elasmobranchii | superordo = Selachimorpha | ordo = Lamniformes | familia = Cetorhinidae | familia_authority = T. N. Gill, 1862 | genus = ''Cetorhinus'' | genus_authority = Blainville, 1816 | species = ''C. maximus'' | binomial = ''Cetorhinus maximus'' | binomial_authority = (Gunnerus, 1765) | range_map = Cypron-Range Cetorhinus maximus.svg | range_map_caption = Range of the basking shark | synonyms = ''Cetorhinus blainvillei'' Capello, 1869 ''Cetorhinus maximus infanuncula'' Deinse & Adriani, 1953 ''Cetorhinus normani'' Siccardi, 1961 ''Hanovera aurata'' van Beneden, 1871 ''Halsydrus pontoppidiani'' * Neill, 1809 ''Polyprosopus macer'' Couch, 1862 ''Scoliophis atlanticus'' * Anonymous, 1817 ''Selachus pennantii'' Cornish, 1885 ''Squalis gunneri'' * Blainville, 1816 ''Squalis shavianus'' * Blainville, 1816 ''Squalus cetaceus'' Gronow, 1854 ''Squalus elephas'' Lesueur, 1822 ''Squalus gunnerianus'' Blainville, 1810 ''Squalus homianus'' Blainville, 1810 ''Squalus isodus'' Macri, 1819 ''Squalus maximus'' Gunnerus, 1765 ''Squalus pelegrinus'' Blainville, 1810 ''Squalus rashleighanus'' Couch, 1838 ''Squalus rhinoceros'' * DeKay, 1842 ''Squalus rostratus'' Macri, 1819 ''Tetraoras angiova'' * Rafinesque, 1810 ''Tetroras angiova'' * Rafinesque, 1810 ''Tetroras maccoyi'' Barrett, 1933 ---- * ambiguous synonym }} The basking shark (''Cetorhinus maximus'') is the second largest living fish, after the whale shark, and one of three plankton-eating sharks besides the whale shark and megamouth shark. It is a cosmopolitan migratory species, found in all the world's temperate oceans. It is a slow-moving filter feeder and has anatomical adaptations for filter feeding, such as a greatly enlarged mouth and highly developed gill rakers. Its snout is conical and the gill slits extend around the top and bottom of its head. The gill rakers, dark and bristle-like, are used to catch plankton as water filters through the mouth and over the gills. The basking shark is usually greyish-brown, with mottled skin. The caudal (tail) fin has a strong lateral keel and a crescent shape. The teeth of the basking shark are very small and numerous, and often number one hundred per row. The teeth have a single conical cusp, are curved backwards, and are the same on both the upper and lower jaws. Adults typically reach in length. Basking sharks are believed to overwinter in deep waters. They may be found in either small schools or alone. Small schools in the Bay of Fundy and the Hebrides have been seen swimming nose to tail in circles in what may be a form of mating behaviour. Despite their large size and threatening appearance, basking sharks are not aggressive and are harmless to humans. It has long been a commercially important fish, as a source of food, shark fin, animal feed, and shark liver oil. Overexploitation has reduced its populations to the point where some have disappeared and others need protection. ==Taxonomy== This shark is called the "basking" shark because it is most often observed when feeding at the surface and appears to be basking in the warmer water there. It is the only member of the family Cetorhinidae, part of the mackerel shark order Lamniformes. Gunnerus was the first to describe and name the species ''Cetorhinus maximus'' from a specimen found in Norway. The genus name ''Cetorhinus'' comes from the Greek ''ketos'' which means marine monster or whale and ''rhinos'' meaning nose; the species name ''maximus'' is from Latin and means "greatest". In the following centuries there were more attempts at naming: ''Squalus isodus'', in 1819 by Macri; ''Squalus elephas'', by Lesueur in 1822; ''Squalus rashleighanus'', by Couch in 1838; ''Squalus cetaceus'', by Gronow in 1854; ''Cetorhinus blainvillei'' by Capello in 1869; ''Selachus pennantii'', by Cornish in 1885; ''Cetorhinus maximus infanuncula'', by Deinse and Adriani in 1953; and finally ''Cetorhinus maximus normani'', by Siccardi in 1961. Other names include bone shark, elephant shark, hoe-mother (sometimes contracted to ''homer''), sail-fish, and sun-fish.〔Yarrell, William. (1836). (''A History of British Fishes''. Volume II. ) John Van Voorst, London. (p. 397 ).〕 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「Basking shark」の詳細全文を読む スポンサード リンク
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