The ACT Aquatic Team from the ACT Government’s Conservation Planning and Research Unit sent me this photo of a berried Euastacus rieki and I just had to share it with you all. It’s the first female with eggs recorded and a tremendous leap towards filling the huge knowledge gaps on this cryptic species.
The Aquatic Team from the ACT Government’s Conservation Planning and Research Unit have been surveying subalpine bogs as well as creeks and rivers in the ACT to determine potential methods for a broader distribution survey of two species of spiny crayfish.
The current project is stage 1 to test methods for a program to determine the distribution and relative abundance of Euastacus crassus and Euastacus rieki. Despite being the type location for Euastacus rieki, very little is known on the distribution or habits of these two species in the ACT or elsewhere.
Among the more than 50 crayfish collected the team discovered two berried E. rieki (42 & 53mm OCL) with 100, 3.5mm orange eggs. Both crays were collected in a subalpine bog (approximately 1600m a.s.l) in Namadgi National Park.
The project was directed by ecologists from the Environment and Sustainable Development Directorate of the ACT Government. The work has been supported through ACT Government climate change funding.
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.
A Guide to Australia’s Spiny Freshwater Crayfish wins a coveted Whitley Award. The winners were announced by the Royal Zoological Society of NSW at a ceremony held in the foyer of the Australian Museum in Sydney on Friday 11th of October 2013. The Whitley Awards are for outstanding publications dealing with the promotion and conservation of Australasian fauna.
We were successful in receiving an award for our latest book. A Guide to Australia’s Spiny Freshwater Crayfish published by CSIRO Publishing was awarded a Certificate of Commendation for Best Book in its Category, Invertebrate Guide. This was a great honour and we thank all those that nominated the book and voted for it to win the award.
To purchase a copy go to: http://www.aabio.com.au/products-page/
A new Euastacus species has been described from NSW. Jason Coughran and Kathryn Dawkins have described the new species from the Border Ranges National Park of north eastern, NSW. It is a dwarf species that is cryptic in nature and seemingly exceptionally rare.
The species is described from just one specimen collect in 2002 by Jason and he has never found another since. Then back in 2010 during routine biological surveys as part of the Australian Crayfish Project, Paul Van der Werf and myself found a solitary specimen and to the best of our knowledge these are the only two specimens in existence. At this time that makes this species the rarest Euastacus species in Australia.
It is very similar to other dwarf crayfish species found in the region except it has a laterally compressed carapace giving it the narrow or slender look and a small expodite on 3rd maxilliped. The specimen in the photos are of a male 11 gram in weight and 28.02 mm OCL, this represents the largest specimen on record. To date no females of this species are recorded.
Surveys in April 2013 of creeks in the Blue Mountains of NSW in partnership with Blue Mountains City Council have been very productive. Among other species we have been researching the Sydney Crayfish Euastacus australasiensis from the Leura area.
Euastacus australasiensis is a protected crayfish and it is illegal to have one in your possession. They are only for looking at and photographing rather than collecting and eating. Overfishing, illegal collection and translocation of invasive species are usually a result of lack of knowledge-people just have no idea they are doing anything wrong. Better education of general public is what’s needed and we will continue to strive towards better education.
We found them to be abundant in the local streams and our research increased the knowledge base on the species. Previously the largest specimen we the Australian Crayfish Project had on record was 130 gram and 60 mm OCL. That was just larger than that recorded by Morgan (1997) at OCL of 59.4 mm OCL.
From Leura Creek we recorded an Euastacus australasiensis of 143 gram and 64.75 mm OCL. That’s a new record for the Australian Crayfish Project for now, but we know from the size of the burrows we have seen that larger individuals must occur. The trouble is that these huge adults are 20 plus years old and some indications they may be over 50 years old. They have been just too smart to be captured by us (hopefully we will get smarter or luckier and catch a monster).