The giant freshwater crayfish is the world’s largest freshwater crustacean. The species has been reported to attain weights of up to 6 kg, however in recent years the majority of the larger specimens recorded weigh between 2-3 kg. The species is slow-growing and long-lived. Colour varies considerably among individuals, with adults ranging from dark brown-green to black or blue. The species is spiny and has large distinct chelae (front pincers), walking legs, carapace and abdomen ending in a tail fan. Males have larger pincers than females. Astacopsis gouldi is the largest of the three Astacopsis species. Juvenile A. gouldi can be differentiated from the other two species (A. franklinii and A. tricornis) by the presence of a raised ridge in the middle of its forehead (rostrum).
Giant Freshwater Crayfish, Tasmanian Giant Freshwater Lobster |
Status: Vulnerable on the EPBC Act list
Government evidence of impact of climate change:
Australian Government, Conservation Advice, Astacopsis gouldi
Current threats to the species include habitat loss and disturbance and sedimentation of waterways; modifications to water flow; illegal fishing and climate change.
Climate change Changes to suspected Climate change is a significant overarching threat that may streamflow and current result in alterations to stream flow and temperature; and temperature catchment vegetation (DotE; 2015).
The extreme weather events predicted under climate change may have significant effects on entire local crayfish populations (TSS; 2006).
Within Australia climate mediated threats are putting the conservation status of two thirds of all freshwater crayfish species at risk (Richman et al.; 2015).