As C. destructor has the ability to switch trophic positions, when an otherwise abundant, high protein food sources (i.e. fish) becomes limited (as was the case in winter in the Hutt River), it was able to co-exist with C. cainii. Furthermore, the ability of C. destructor to switch from a diet of fish in summer to a predominantly herbaceous/detrital diet in winter suggests that it may compete for food resources with the other smaller native freshwater crayfishes (such as C. quinquecarinatus) in the small unproductive lotic and lentic systems common to south-western Australia, which often lack fish during summer