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The Alaska pollock or walleye pollock (''Gadus chalcogrammus'',〔Eschmeyer, W. (2015) (''chalcogrammus, Gadus ) Catalog of Fishes, Calicornia Academy of Sciences, accessed 5 June 2015)〕〔http://www.afsc.noaa.gov/Quarterly/OND2013/divrptsRACE1.htm〕 formerly ''Theragra chalcogramma'') is a marine fish species of the cod family Gadidae. Alaska pollock is a semipelagic schooling fish widely distributed in the North Pacific with largest concentrations found in the eastern Bering Sea.〔 〕 While belonging to the same family as the Atlantic pollock, the Alaska pollock is not a member of the same ''Pollachius'' genus. Alaska pollock was long put in its own genus ''Theragra'', but more recent research has shown it is rather closely related to the Atlantic cod and should be moved back to genus ''Gadus'' in which it was originally described. Furthermore, Norwegian pollock (''Theragra finnmarchica''), a rare fish of Norwegian waters, is likely the same species as the Alaska pollock.〔 ==Ecology and behaviour== The speckled colouring of Alaska pollock makes it more difficult for predators to see them when they are near sandy ocean floors. They are a relatively fast-growing and short-lived species, currently representing a major biological component of the Bering Sea ecosystem.〔 It has been found that catches of Alaska pollock go up three years after stormy summers. The storms stir up nutrients, and this results in phytoplankton being plentiful for longer, which in turn allows more pollock hatchlings to survive. The Alaska pollock has well-developed drumming muscles that the fish use to produce sounds during courtship, like many other gadids. 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「Alaska pollock」の詳細全文を読む スポンサード リンク
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