Giant Freshwater Crayfish (Tayatea, Astacopsis gouldi)

WB Gould, 'Freshwater crayfish', 1832 (ALMFA, SLT)

This remarkable member of Tasmania's freshwater fauna is the largest non-marine invertebrate in the world, growing to over 4 kg in weight and almost a metre in length. It lives in rivers and streams draining into Bass Strait, and in the Arthur River system. The species was first described by Gould in 1870, and later by Thomas Henry Huxley, but they did not distinguish it from the other stream-dwelling crayfish. It was not until 1936 that an Australian biologist, Ellen Clark, recognised it as a distinct species and named it. The species is now protected, but very large specimens are rare.

Alastair Richardson