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The common yabby (''Cherax destructor'') is an Australian freshwater crustacean in the Parastacidae family. It is listed as a vulnerable species〔 Listed as Vulnerable (VU A1de v2.3).〕 of crayfish by the World Conservation Union (IUCN), though the validity of this listing is questionable; wild yabby populations remain strong, and have expanded into new habitats created by reservoirs and farm dams.〔(【引用サイトリンク】title=Yabby )〕 Its common name of "yabby" is also applied to many other Australian ''Cherax'' species of crustacean (as well as to marine ghost shrimp of the infra-order Thalassinidea). Yabbies occasionally reach up to 30 cm (12 in) in length but are more commonly 10–20 cm (4–8 in) long.〔(【引用サイトリンク】title=''Cherax destructor'' )〕 Colour is highly variable and depends on water clarity and habitat; yabbies can range from black, blue-black or dark brown in clear waters to light brown, green-brown or beige in turbid waters.〔(【引用サイトリンク】title=''Cherax destructor'' )〕 Yabbies specifically bred to be a vibrant blue colour are now popular in the aquarium trade in Australia. ==Ecology== Yabbies are common in Victoria and New South Wales, although the species also occurs in southern Queensland, South Australia and throughout parts of the Northern Territory, making it the most widespread Australian crayfish. It has been introduced to Western Australia, where it is an invasive species and poses a threat to other ''Cherax'' crayfish species native to the region, such as gilgies (''Cherax quinquecarinatus''). Yabbies are found in swamps, streams, rivers, reservoirs and farm dams at low to medium elevations. It appears that yabbies were largely restricted to lower altitude habitats in inland areas of south-eastern Australia including the Murray-Darling Basin before European settlement, with the ''Euastacus'' spiny crayfish species found in higher altitude habitats and the coastal river systems. High altitude yabby populations in Lakes Eucumbene and Jindabyne, on the upper reaches of the coastal Snowy River system, are unusual and may be translocated. Yabbies are found in many ephemeral waterways, and can survive dry conditions for long periods of time (at least several years) by aestivating (lying dormant) in burrows sunk deep into muddy creek and swamp beds. Yabbies are primarily nocturnal detritivores, feeding primarily on algae and plant remains at night, but also opportunistically feeding on any fish or animal remains they encounter at any time of day. In Southern Australia, it is commonly accepted that yabbies are active and thereby available to catch during the warmer months. (Colloquially any month with the letter "R" in it.) When temperatures fall below , they enter a state of reduced metabolic activity, or "partial hibernation".〔 Yabbies are an important dietary item for Australian native freshwater fish such as Murray cod and golden perch. 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「common yabby」の詳細全文を読む スポンサード リンク
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