Cherax destructor has become established in many wild aquatic systems in Western Australia in the past decade. The ability of C. destructor to withstand relatively extreme physicochemical conditions would help to facilitate this establishment. Life history traits described for C. destructor in the Hutt River are typical of an invasive, r-strategist crayfish species, i.e., an extended breeding period with multiple spawning events, a high spawning frequency, a rapid growth rate and the attainment of maturity at the end of its first year of life. These traits are likely to have facilitated the proliferation of this species in the Hutt River and also aided its establishment in other Western Australian systems. Furthermore, the comparison of life-history traits of C. destructor determined in the present study with those recently described for the endemic congeners C. cainii and C. quinquecarinatus, suggests that it has the potential to become the most abundant species of crayfish once established in an aquatic system that houses these endemics. Given the uniqueness of the freshwater crayfish fauna of the Southwest
Coast Drainage Division of Western Australia, the recent spread of C. destructor into wild aquatic systems in the region is of serious concern