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The Tasmanian giant freshwater crayfish (''Astacopsis gouldi''), also called Tasmanian giant freshwater lobster, is the largest freshwater invertebrate in the world. The species is only found in Tasmania (an Australian island), and is listed as an endangered species due to habitat loss and over fishing. It is also severely threatened by siltation and de-snagging of streams as decaying wood forms the favourite part of its diet. It is not known if the animals are nourished by the wood, the bacteria, algae or invertebrates living in the rotting logs. They also eat leaves, fish and other meat, including other freshwater invertebrates. Individuals of over in weight and over long have been known in the past, but now, even individuals over are rare. The species is only found in Tasmanian rivers flowing north into the Bass Strait below above sea level, and is listed as an endangered species on the IUCN Red List. The specific epithet ''gouldi'' commemorates the naturalist John Gould. ''A. gouldi'' is very long-lived, surviving for up to 40 years. Their main predators are humans, platypus, river blackfish and rakali. ==Biology== ''Astacopsis gouldi'' is territorial. Males maintain a harem of several females. Hatchlings are a mere 6 mm long, and mature extremely slowly, living for up to 40 years.〔(【引用サイトリンク】title=The Giant Tasmanian Freshwater Lobster )〕 Reproductive maturity occurs at around nine years in males and 14 years in females, with females breeding just once every two years. Mating occurs in autumn and the eggs, attached to the female’s swimming legs during development, hatch the following summer, remaining attached to the swimming legs as hatchlings for another month. Such a long reproductive process means that females spend much of their life with their young attached to their legs – a good strategy as fully grown adults have no natural predators.〔 However, fishing of adult crayfish by humans results in the removal of not only the adults but all their young as well.〔(【引用サイトリンク】title=Threatened species and ecological communities publications - Biodiversity )〕 The giant freshwater crayfish is omnivorous, eating primarily rotting wood and animal flesh, as well as leaves and insects that fall into the water. Juveniles tend to hide in shallow water where they are less at risk from their large predators including other crayfish, fish, and platypus. Adults hide under submerged logs in deep pools where they appear to tolerate each other, despite being aggressive elsewhere.〔 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「Tasmanian giant freshwater crayfish」の詳細全文を読む スポンサード リンク
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