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Type: Article
Published: 2022-12-20
Page range: 285-297
Abstract views: 307
PDF downloaded: 48

Redescription of Euastacus clydensis Riek, 1969 (Crustacea: Parastacidae), a valid species of spiny crayfish from southern New South Wales, Australia

1School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia.
2Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW 2000, Australia, and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
1School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia.
1School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia.
Australian Crayfish Project, c/- Australian Aquatic Biological Pty Ltd, P.O. Box 3, Karuah, NSW 2324, Australia, and Research Associate, Carnegie Museum of Natural History, Section of Invertebrate Zoology, 4400 Forbes Avenue, Pittsburgh, PA 15213-4080 USA.
Crustacea Astacidea Decapoda Euastacus freshwater crayfish Australia


The Giant Sydney Crayfish (Euastacus spinifer (Heller, 1865)) was thought to have a wide range in New South Wales, Australia, spanning some 600 km north–south. A recent extensive molecular phylogenetic and population genomic analysis of E. spinifer across its geographical range revealed strong population structure corresponding to several major geographically correlated clades, the southernmost clade being the most genetically divergent and clearly a separate species. This southern clade corresponds to the junior synonym E. clydensis Riek, 1969 and is sister to the clade comprising the remaining populations of E. spinifer and Euastacus vesper. We formally remove E. clydensis from the synonymy of E. spinifer, increasing the recognised number of species of Euastacus to 54. Euastacus clydensis is redescribed based on type and other material, and is distinguished from E. spinifer by differences in abdominal spination and the form of the antennal scaphocerite. Euastacus clydensis has a restricted southern New South Wales range in the Shoalhaven and Jervis Bay–Clyde River catchments, from Moss Vale south to the vicinity of Clyde Mountain; much of the known range of E. clydensis was burnt in the 2019–2020 eastern Australian megafires.



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