Euastacus coughrani sp. nov., A New Intermediate Spiny Crayfish (Crustacea: Decapoda: Parastacidae) from Forested Perennial Streams of East Gippsland, Victoria, Australia

Abstract A new species of freshwater crayfish, Euastacus coughrani sp. nov., is described from the Bemm, Brodribb and Queensborough River catchments in eastern Victoria, Australia. Euastacus coughrani sp. nov. inhabits perennial, small to medium, cool-flowing streams through a range of forest ecosystems including ancient wet eucalypt forests, cool and warm temperate rainforests at elevations between 251 m and 1050 m. The species’ restricted extent of occurrence (422 km²) supports a conservation status of Endangered. Morphologically, E. coughrani sp. nov. is closely related to E. diversus and E. bidawalus and represents a genetically distinct population distributed between the two. This new species can be distinguished from its congeners by the morphology of the thorax, abdomen, chelae and gastric mill. Detailed insights into the species’ ecology, biology, and conservation status are provided herein to facilitate and guide future conservation and management endeavors.