Tasmanian Giant Freshwater Crayfish

The Tasmanian giant freshwater crayfish lives only in cool, well oxygenated rivers and streams of northern Tasmania, Australia, and is recognized as the largest freshwater invertebrate in the world. Large individuals can weigh several kilograms and grow to a length far exceeding that of any other freshwater crayfish species. It grows and matures slowly, with individuals living for many decades in the wild, which makes populations especially slow to recover once reduced. Historic overharvesting for food sharply reduced numbers across its range during the twentieth century, and the species has since been protected from fishing and listed as vulnerable to extinction. It depends on cool, clean, well shaded streams, so land clearing and water pollution in the rivers it inhabits remain ongoing threats to its survival. Conservation efforts in Tasmania now focus on protecting streamside vegetation and river habitat quality across its limited natural range.