What is the world’s largest freshwater crayfish, native to Tasmania?

The Tasmanian giant freshwater crayfish is the world’s largest freshwater crayfish.

This species, also called the giant Tasmanian freshwater crayfish, lives in cool, flowing streams and rivers in northern and western Tasmania. Exceptional individuals can weigh more than 5 kilograms and measure over 80 centimetres long, making them among the largest freshwater invertebrates known.

The crayfish grows slowly and can live for many decades. It feeds on aquatic plants, terrestrial vegetation that falls into the water, and small animals or carrion. Its size and longevity make it particularly vulnerable to overfishing and habitat degradation.

The species is protected in Tasmania, where fishing restrictions apply. It should not be confused with the Murray crayfish, another large Australian freshwater crayfish found on the mainland, but not the world’s largest species.