Research Project 100007 initiated in 2008 has finally been completed. This project has been ongoing for the last 10 years, but has at last culminated in the publication of a description of a NEW Euastacus species for the western drainage of New South Wales, Australia.
The Cudgegong Giant Spiny Crayfish Euastacus vesper is described from the upper reaches of the Cudgegong River, east of Kandos NSW. The description was published in May 2017 in the international journal Zootaxa.
Euastacus vesper sp. nov., a new giant spiny crayfish (Crustacea, Decapoda, Parastacidae) from the Great Dividing Range, New South Wales, Australia
ROBERT B. MCCORMACK & SHANE T. AHYONG
This new species seemingly has a very small distribution and faces a large range of serious threats. The next Project will to systematically survey the surrounding area and accurately define the exact distribution of the species and then publish a paper of its conservation status, something we consider based on the available information, would be “Critically Endangered”.
Research Project 100084 has been generated to designate a conservation status for this new Euastacus species.
Project: 100007 started back in 2008 final draws to a closure. The project that started out as an unidentified Euastacus crayfish species has been found in western drainage of NSW has been finalized with the completion of the project going to press.
A scientific manuscript title; Euastacus sp. nov., a new giant spiny crayfish (Crustacea, Decapoda, Parastacidae) from the Great Dividing Range, New South Wales, Australia, by Robert B. McCormack & Shane T. Ahyong has been completed and submitted to the journal Zootaxa.
The new species is described from the upper Cudgegong River, New South Wales, Australia This new species occurs in the western drainage of the Great Dividing Range, and is most closely related to E. spinifer (Heller, 1865), which occurs on the eastern side of the range. The new species differs from E. spinifer by its considerably smaller maximum size, greater degree of thoracic spination loosely arrayed in three instead of two rows, genetic sequence divergence in COI and unusual colour variations.
Both Euastacus armatus and the new Euastacus species occur in the upper Cudgegong River and this has led to much confusion in the past. Recent research by Whiterod et al., 2016 indicates that the E. armatus population in the upper Cudgegong is a translocated population.
In our present study, we formally describe this new Euastacus species, increasing the number of species of Euastacus to 53.
Started in 2005 the quest to rediscover the Orbost Spiny Crayfish Euastacus diversus has been a long and intriguing journey cumulating in the publication of this paper.
This story began back in 1959 when one of Australia’s foremost expert on freshwater crayfish at that time, Edgar Riek, discovered this small freshwater crayfish species in the east Gippsland region of Victoria. Then in 1969 he described the species and named it Euastacusdiversus. Since that day this crayfish has remained a rare and elusive species.
In 1986, the then current expert on the genus Euastacus, Gary Morgan, searched for this species but was unable to find any in the wild. As a consequence he redescribed the handful of original specimens collected by Riek in 1959 that are held at the Australian Museum. Gary Morgan’s detailed description, published in the Memoirs of the Museum of Victoria 30th May 1986, was the latest scientific publication on this species and forms the basis of all current information and opinions until now.
In 2005, the Australian Crayfish Project (ACP) was started, involving one of the largest projects researching freshwater crayfish ever seen in Australia. Between 2005 and 2007 we also failed to find any specimens of Euastacus diversus for the type locality general area 40 miles north of Orbost. Then in 2007 we changed our methods and successfully started finding more and more specimens. Up to 2011 a considerable number of E. diversus and other Euastacus species were found in the wild. The project has been very successful in finding this and other crayfish species, and large areas of southern NSW and eastern Victoria were systematically biologically surveyed specifically for freshwater crayfish. We found Euastacus specimens everywhere and most did not match the description for the known species leading to much confusion. However, genetic analysis by the Carnegie Museum of Natural History in the USA helped clarify the situation resulting in the thorough redescription of E. diversus and the discover of a number of new species.
The research culminated in this paper titled “Re-description of the Orbost Spiny Crayfish, Euastacus diversus Riek 1969 (Decapoda: Parastacidae), in Eastern Victoria, Australia” published in the journal “Freshwater Crayfish”. The paper redescribes Euastacus diversus to include the Bonang River crayfish (previously thought to be a new species).
The Bonang taxon represent a morphologically distinct population of Euastacus diversus that is genetically 1.95% divergent from the E. diversus type locality populations.
The research extends the distribution of the species to the Brodribb, Yalmy, Rodger and Bonang River drainages at elevations ranging from 350 – 950 m a.s.l., with an overall Extent of Occurrence of 465 km2. Research continues on E. diversus which will surely increase the Extent of Occurrence. Research also continues on the new Euastacus species and hopefully the first of the new species descriptions will be published later this year.
Coughran J, McCormack RB and Fetzner Jr. JW (2015). Re-description of the Orbost spiny crayfish, Euastacus diversus Riek 1969 (Decapoda: Parastacidae), in eastern Victoria, Australia. Freshwater Crayfish 21(1): 185-197.
We have finally finished our aquatic surveys of the lower Clyde River, NSW. It’s an exciting area with mostly pristine clear flowing streams full of aquatic life. The results of the survey have been extremely interesting and have resulted in some significant findings. We have identified 3 different freshwater crayfish species in the lower Clyde River and they all match the known descriptions for all three species. Interestingly, the specimens of Euastacus crayfish previously collected from the upper Clyde are generally morphologically different to those in the lower Clyde. Eventually we will get the genetics done on all the specimens collected and then work out whether the upper Clyde specimens are a morphological variation or a separate species. Stay tuned for further updates. The full results of the aquatic biological surveys will be complied into a report and issued to the Southern Rivers Catchment Management Authority.
We surveyed 57 sites and at 43 of those we captured freshwater crayfish. A total of 149 Euastacus yanga were captured, examined, weighed, measured, and released during this survey. Euastacus yanga has the third largest distribution of any Euastacus species in Australia after E. spinifer and E. armatus. Found in south-eastern New South Wales from Robertson all the way south to north-eastern Victoria. It’s distribution extends from the Shoalhaven River in the north, then south through the Clyde, Deua, Tuross, Brogo, Murrah, Bega, Towamba, Womboyn, Wallagaraugh and Genoa rivers, as well as all the smaller coastal rivers and creeks running into all the inlets, lakes and bays down the coast. Found from 50 m to 895 m a.s.l it is a widespread and abundant species.
We observed Euastacus yanga to commence breeding in mid May in water temperatures between 11.3-12.1°C. The berried females nurtured their eggs and young till mid November to mid December when they released their brood into the streams. A huge amount of information was gathered as part of the surveys and this will be compiled into a peer reviewed scientific manuscript.