Biology, distribution and conservation of a dwarf-group crayfish, Euastacus spinichelatus Morgan, 1997 (Decapoda: Astacidea: Parastacidae), a freshwater crayfish from the Great Dividing Range, New South Wales, Australia

We present the outcomes of two conservation initiatives, namely 'The Australian Crayfish' and 'Saving the Spinys' projects, which have substantially contributed to enhancing our understanding of E. spinichelatus concerning its distribution, habitat, biology, and conservation status. We extend the range of E. spinichelatus to encompass the headwater reaches of the Namoi River within the Murray-Darling Basin. The use of molecular taxonomy analyses identified divergent lineages that acted to remove the southeastern tributaries of the Hastings River and the most western tributary of the Manning River from the range of E. spinichelatus. The species has suffered significant population declines in recent years, with it appearing to be highly susceptible to anthropogenic changes, drought and/or high-severity bushfires. Results advocate for the classification of E. spinichelatus as an endangered species, recognizing its distinctive ecological niche and its status as a climate refugee, aiming to protect this rare species from anthropogenic and climate-related challenges. We also present a taxonomic key differentiating E. spinichelatus from other members of Parastacidae in the region.