An Assessment of the Distribution, Biology, Threatening Processes and Conservation Status of the Freshwater Crayfish, Genus Euastacus (Decapoda, Parastacidae), in Continental Australia. I. Biological Background and Current Status

Abstract

Of the 10 Australian crayfish genera, Euastacus is the largest with 49 species described, including some of the largest, and some of the rarest, species in the World. Many species are slow growing, late maturing, and the lifespan of some exceeds 30 years. The distribution of the genus encompasses most of the east coast of Continental Australia, a latitudinal range of approximately 23? (a distance of over 2500 km). Euastacus also has the widest altitudinal range of all Australian genera, occurring from sea level to over 1500 m above sea level. Due to these broad geographical and altitudinal ranges, Euastacus inhabit most of the climatic zones in Australia, and are found in a wide range of habitats including large temperate lowland rivers, high altitude rainforest gullies and Alpine streams. We review the distribution, habitat, population data, and biology for these crayfish, and their current conservation status where available. Sixteen species were listed on the IUCN Red List in 1996, and there have been increasing concerns regarding the conservation status of the genus since then. The current review was undertaken in order to allow, 1) assessment of the conservation status of all species against current IUCN Red List Criteria, and, 2) a discussion of research, conservation and management imperatives for the genus, presented in two accompanying papers.