During routine “Pure Research” as part of the Australian Crayfish Project we were attempting to map the distributions of known species in central western drainage of NSW. This involves opportunistic surveying of any available streams as we drive rural backroads attempting to head in a general direction.
You may think this is easy, but it’s not by any means. We have a general plan before we leave, mostly planned by google maps. When we are on the ground we are use our Hema GPS and Garmin GPS plus a number of other phone apps in the vehicle. Unfortunately, none of them are accurate, all our maps indicate the road continues but that’s not the fact. We will travel an hour up a back road but come to a locked gate, or the road ends, or it’s a private property, or a deep river crossing. We then need to back track an hour, travel 2 hours around to the other side of the road, survey it then head back to camp.
Most of western NSW is rural grazing properties and significantly habitat altered. This restricts our surveying efforts to the creek and river crossing on whichever road we end up on. Despite the difficulties, we persevere and have good results.
Surprisingly at a random creek crossing we found this animal. Now it does not like anything unusual or significant until you have a closer look. This crayfish has 4 mesial carpal spines which is very significant.
The majority of NSW crayfish with 4 mesial carpal spines are all restricted to the far north of the state in the rainforests. The species with 4 mesial carpal spines are Euastacus girurmalayn, Euastacus guruhgi, Euastacus jagaba, Euastacus maidae and Euastacus mirangudjin. All of these species are in eastern drainage.
Queensland has a mass of species with 4 spines but once you get below the NSW/Qld border area the species with 4 spines are restricted to just 2. In NSW in eastern drainage you have Euastacus reductus and in Victoria you have Euastacus diversus.
This new species represents the first species of Euastacus with 4 mesial carpal spines ever found in western drainage. Interestingly, the spines are in a relatively straight row, unlike the spines of the border range Euastacus. Among other things I’m researching Euastacus maidae from the upper Tweed and Currumbin Creek area . This is one I caught in early May 2019 (ACP6345), note the mesial carpal spines are not in a straight row, the first two spines are offset to the other two.
Its early days yet and we will now start a “Strategic Research Project” to describe this new species. This will be a slow process as Im just a volunteer doing all this research out of my own pocket with the help of some of you generous people that donate to the project. Every day in the field requires 2 days in the lab, processing specimens and writing up results and papers. Plus vehicle costs are astronomical with over 50,000 km/year travelled looking for crayfish. If anyone has some spare cash please contribute.
Describing a species is important, without a name and when no one knows that the species exists then any sort of conservation is impossible. Formal description of a species provides the information the management agencies need to help conserve the species and provides support to catchment and landcare groups that are concerned with riparian zone repair and stream health in which the crayfish species lives.
Research continues on Euastacus reductus, a true dwarf group crayfish from mid-eastern New South Wales. It can be found in a wide range of habitats from flowing streams to seepages and swamps. This is the most widespread and prolific dwarf group species in Australia, but despite its wide distribution, it’s an elusive species that most people never know occurs in their area.
A nocturnal species that is rarely captured in a trap. A typical dwarf group species inhabiting marginal areas away from the deep permanent water that other more aggressive and outgoing species occur. It’s these species that are typically captured in large numbers in traps.
An extensive burrower with multiple entrances and multiple chambers, with the individual immature and male crayfish seeming to have multiple burrows that they move between. Burrows extend deep into the forest floor, with numerous entrances well above water level. Much of this intricate and complex burrow system is high and dry, with these crayfish spending much of their time within dry burrow systems.
This road is a good 70 metres above the local creek, however its the south side of the mountain and damp conditions and seepages are common on south facing mountain sides.
There is seepage water in the drain beside the road but just damp conditions up the mountain side. This is very suitable habitat for E. reductus with none of the other species in the area wanting this marginal habitat area.
Capturing specimens is difficult, the area can be riddled with burrows entrances but it may be days, weeks or years before the crayfish would use that entrance/exit. We are currently experimenting with both mist net snares and modified Norrocky traps to capture crays.
Distribution (Extract from The Spiny Freshwater Crayfish book)
This is the most widespread and prolific dwarf group species in Australia. Found from the Wilson–Maria River catchment in the north to the northern side of the Hunter River in the south in eastern flowing small streams and the marginal areas of larger streams and rivers. Drainages include the Hunter, Paterson, Williams, Karuah, Myall, Coolongolook, Wallamba, Manning, Hastings and Wilson rivers. They are a broad altitude species ranging from 30 to 900 m a.s.l., but are most common in the 150 to 500 m range. The most northern populations (Wilson River drainage) share the streams with E. dangadi. Further south they share with E. spinifer, E. polysetosus, E. spinichelatus, Euastacus sp. 3, Cherax setosus and Gramastacus lacus.
Research continues and eventually we will publish a paper documenting our results.
Euastacus polysetosus,called the Many-Bristled Crayfish by some are an intermediate group crayfish that rarely reaches above 70 grams and 56.6 mm OCL in size. They live in the high altitude, clear, clean, flowing mountain streams of the Barrington Tops Region of NSW. In September 2017 we visited the Barrington Tops region to survey this endangered species.
Euastacus polysetosus is a cool/cold-water species. They will not survive long in elevated water temperatures, being stressed at 22°C and dying rapidly at 26°C. Generally, they are restricted to the smaller tributary streams where they are relatively plentiful. The larger main rivers will have the odd large individual in the deeper pools and juveniles in the marginal habitat areas, but they are relatively rare in these habitats.
Horwitz and Richardson (1986) classified Australian crayfish burrows into three categories based on their relationship with the water-table (Types 1-3). Euastacus polysetosus constructs a burrow system in response to their location in the stream and the maturity of crayfish. Nevertheless, all burrows fit within the “Type 1” category as all burrows are in, or connected to open water.
To see the rest of this article and the collection data base you need to be a subscriber.
The first specimens of this Euastacus species were collected in 2008 by researchers of the Australian Crayfish Project, then over the next 9 years with the assistance of the Australian Museum research group the project continued, finally culminating in the publication of this new species description.
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. Zootaxa is a peer-reviewed international journal for rapid publication of high quality papers on any aspect of systematic zoology.
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
Both Euastacus armatus and Euastacus vesper occur in the upper Cudgegong River and this has led to much confusion in the past. Additionally, E. vesper resembles Euastacus spinifer that occurs in the adjoining eastern drainage of the Hunter and Hawkesbury rivers. Whiterod et al 2016 completed a study on the Murray Crayfish Euastacus armatus. In that study they found that the E. armatus population in the upper Cudgegong River is more than likely a translocated population.
Preliminary surveying of the area indicate the distribution of the new species is restricted to a relatively small area. This area has been dramatically altered by a series of dams, rampant land clearing and rural development extracting water. Add a translocated giant spiny competitive species and heavy recreational fishing pressure all ads up to extreme danger to the long term survival of this unique species.
The next project for Shane and I will be to complete a full survey of the whole area to define the exact distribution of this new species. Once that’s completed we can complete an accurate conservation assessment. Initially, we would expect a listing of Critically Endangered would be appropriate for this new species
In this study, we formally describe the new Euastacus species, increasing the number of species of Euastacus to 53. A number of other new Euastacus are currently in preparation so this number will rise in the near future, stay tuned.
Nick S. Whiterod, Sylvia Zukowski, Martin Asmus, Dean Gilligan and Adam D. Miller. 2016.Genetic analyses reveal limited dispersal and recovery potential in the large freshwater crayfish Euastacus armatus from the southern Murray–Darling Basin. Marine and Freshwater Research. http://dx.doi.org/10.1071/MF16006
On a recent ACP Survey of the lower north eastern coast of NSW we captured an amazing number of freshwater crabs, shrimps, fish, giant spiny crayfish and this intermediate crayfish. Euastacus dangadi is a relatively small, coastal, freshwater, intermediate crayfish with a large distribution in north eastern New South Wales. The species can grow to just over 200 grams in weight but typically animals in the 50-70 gram weight are the most common large crayfish. Most populations are easily identified by their orange/red claws. Being an intermediate crayfish they can occur with both dwarf crayfish and giant spiny crayfish.
Euastacus dangadi is relatively widespread and prolific, currently listed as “Least concern” on the IUCN Red List. It is found in coastal mountain streams of New South Wales from north of Coffs Harbour to Telegraph Point in the south and Rolland Plains, Dorrigo and Nymboida in the west. Generally, the smaller more intermittent streams or flowing streams in the upper catchments have the largest populations. The shallower feeder streams with few eels are the preferred habitat. They are a lowland species found from 50 m to 550 m a.s.l. Drainages include the Clarence, Nambucca, Bellingen, Macleay and Wilson river systems.
These are from the Bellingen area from small, clear, flowing side streams feeding the main river. In the main rivers throughout the area you will not find them in the large deep pools, they are mostly restricted to the margins, shallow riffle areas and feeder streams, to avoid the predators like eels, turtles and bass that infest the main rivers.
All small Euastacus species are protected by default in New South Wales as they do not reach the minimum recreational size limit of 9 cm OCL that is in place for all New South Wales species. Anyone found with this species in their possession is in breach of the Fisheries Management Act and will be subject to prosecution. Look-photograph-but NEVER TAKE.
Photos are of ACP Spec 5903, Kalang River, small male 33.42 gram, 39.30 mm OCL
The Lamington Crayfish (also known as the Mountain or Skeletal Crayfish) Euastacus sulcatus, is best known from its type locality in Lamington National Park, Queensland.
A member of the Giant Spiny Group of crayfish (McCormack 2012) they grow to a large size and are fearless. Typically in the Lamington NP area they are a vivid blue and bright white colouration making a spectacular crayfish to photograph. They are large, strong and fearless and actively wander the forest floor scavenging and are regularly seen by bushwalkers in the area.
Usually, when you see a photo of a Lamington crayfish it is this typical blue and white colouration, but colour should never be used to identify a species. Euastacus sulcatus is a widespread, well distributed species occurring in both NSW and Qld.
Extract from “A Guide to Australia’s Spiny Freshwater Crayfish”
Distribution: Found along the New South Wales–Queensland border region with a large scattered distribution from 100 m to over 1000 m a.s.l. To the west, on the north branch of Glengallan Creek (Condamine–Darling rivers) and Gap Creek, a tributary of Warrill Creek (Brisbane River). To the east is Mt Tambourine (Queensland) and Mt Warning and Yabbra Range (New South Wales). Drainages include the Tweed, Clarence and Richmond rivers of New South Wales and the Nerang, Albert, Logan, Brisbane and Condamine rivers and Mudgeeraba, Tallebudgera and Currumbin creeks, Queensland.
Across this vast distribution and different drainages, the general colour of the species varies considerably.
In the far west of their distribution in the Main Range, Queensland. In the North Branch Creek of Glengallen Creek (Condamine–Darling river drainage, Qld) they are a darker green colour with very pale white colourations in spines and claws.
Further south Steamers Creek a tributary of Emu Creek south branch, Emu Vale State Forest (Condamine-Balonne-Darling River drainage, Qld). These E. sulcatus have more brown in their colouration with small white highlights.
Further east in Sheepstation Creek, Border Ranges National Park (Richmond River drainage, NSW), brown, blue and green with larger white highlights.
Then nearby in Brindle Creek, Border Ranges National Park (Richmond River drainage NSW), we get a rusty red colouration with the large bright white highlights.
Further east in a tributary Bean Creek, Yabbra State Forest (Clarence River drainage), again we get the rusty red colouration with bright white highlights.
Currumbin Creek, Queensland the well known fluorescent blue and white colouration. This is mostly blue with little white colour.
Mount Tamborine, (Albert River drainage, Qld), this one has it all, brown, green, blue and white.
Finally, this Euastacus sulcatus from Cave Creek, Natural Bridge, Springbrook National Park, (Nerang River drainage, Qld). This is the rare, pure white variation. You are very lucky if you see one of these.
Euastacus sulcatus prefers rainforest stream that are clear and clean and nearly always flowing, they have gravel, sand and rock bottoms with lots of boulders and a sediment layer that is fine and black from the surrounding rain forests. Large crays will be found in the main permanent streams but juveniles will be forced to the margins and found in the marginal areas away from permanent flowing water. Like all juveniles of the giant spiny group of crayfish E. sulcatus juveniles have the bands on the 1st and 6th somites. The band on the first somite fades by the first year but the 6th lingers longer (August), claw tips remain cream.
They are a hissing species like most spiny group crayfish. Anything over 70 gram will happily hiss away at you, as they try to attack you with their raised claws. These little critters do not take any lip from anybody, they are generally very aggressive. They are a predatory species and will take baits so are relatively easily captured, making them extremely vulnerable to capture and theft. All Euastacus sulcatus all sizes in both Queensland and New South Wales are protected and it is illegal to have one in your possession. Please, do your bit to help preserve this vulnerable species. Look, enjoy and take a photo, but don’t take them.
McCormack, R.B. 2012. A guide to Australia’s Spiny Freshwater Crayfish. CSIRO Publishing, Collingwood, Victoria. ISBN 978 0 643 10386 3
Are you aware that illegal exotic Dwarf Mexican Crayfish are currently being clandestinely sold in Australia! All exotic freshwater crayfish are banned from Australia due to the potential for carrying “Crayfish Plague” and the potential to become pest species upsetting the natural balance. All exotic crayfish species are prohibited from Australia.
Crayfish plague is a serious disease of freshwater crayfish, and Australian crayfish are highly susceptible. Crayfish plague has the potential to destroy the Australian Crayfish Aquaculture Industries in all States. Redclaw, Marron and Yabbies are all highly susceptible as are all other native Australian freshwater crayfish. Freshwater crayfish are keystone species with a disproportionately large effect on the whole catchment relative to their abundance. They play a critical role in maintaining the structure of the whole ecological community, their prosperity and abundance affecting many other organisms in the ecosystem and helping to determine the types and numbers of these other species in the catchment. As keystone species, their removal from the creeks, rivers and lakes of Australia would detrimentally alter the ecology of Australia.
It was the 12th July 2016 when I heard that this clandestine trade was occurring and unscrupulous people were selling them on facebook and trying to hide their trails. Seemingly, everyone knew they were doing something illegal but these crayfish were being sold for $30-$200 each so very lucrative. My immediate concern was to alert the authorities so I immediately contacted the Department of Agriculture and Water Resources (DAWR) and then wrote to the Deputy Prime Minister Barnaby Joyce who is also the Minister for DAWR. This department is responsible for Australia’s biosecurity and their job to keep exotic species out of the country.
Well what a waste of my time that exercise was. Over the months I kept hounding the department for answers as to why nothing is happening, week after week went by, I kept sending in more and more information as more and more of these dangerous exotic crayfish were being distributed throughout the community. Yet nothing from the department except they are investigating. Its not as if DAWR doesn’t know the risk they even listed it in Emergency Animal Disease Bulletin – No 112
The Department of Agriculture and Water Resources, 2005 created AQUAVETPLAN – Disease Strategy Manual – Crayfish Plague. This disease strategy manual is an integral part of the Australian Aquatic Veterinary Emergency Plan (AQUAVETPLAN).
The manual sets out the disease control principles for use in response to a suspected or confirmed incursion of crayfish plague in Australia.
National environment law is covered by the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). This legislation covers the import of all live animals. For the imports of live plants and animals the legislation: establishes a list of specimens suitable for live import. Only fish listed on the list of specimens taken to be suitable for live import (the live import list) can be imported into Australia. You should be aware that species not listed on the live import list are prohibited imports.
No freshwater crayfish are on the list so all freshwater crayfish are prohibited from Australia.
The EPBC Act refers to illegal imports.
On the website it states: Some of the exotic animals available in Australia have been imported illegally despite Australia’s strict import laws. Possessing illegally imported animals (or their offspring) is an offence under national environment law. The penalty for illegal possession under national environment law is gaol of up to five years and/or a fine of up to $110,000.
Despite legislation to stop this illegal trade nothing is heard from the Department of Department of Agriculture and Water Resources for 15 weeks whilst they supposedly investigate. Then on the 26/9/16 this turns up on Facebook!
Once I saw this I immediately contacted DAWR and the Minister as I could not believe that this was true. But sure enough someone claiming to be from DAWR rang me and advised they had finished their investigation, they had tested one crayfish and it was plague free, that the crayfish being sold are offspring of imported crayfish, the departments only interest is imported crayfish, as these aren’t imported, they don’t care and nothing they can do.
You can imagine this was not what I wanted to hear and I advised; Im not interested in listening to hearsay over the phone I want all that in writing. In response he advised this was a Monday and the whole Department had the day off and there was no one there that day so it would be a few days before I would receive conformation in writing. Going on past performance I’m sure you can all guess there was no written confirmation within the next few days. It wasn’t till the 18th October (24 days later) that I finally received a very disturbing response from Barnaby Joyce. SHAME! SHAME! SHAME! is an understatement. For a copy of the Minister’s unpalatable response to this Biosecurity Threat to Australia “Click here”.
He states the exotic Mexican crayfish were legally brought into Australia. How can an illegal species be legally brought into Australia?????????????? Then only 1 crayfish tested for plague, what level of accuracy or protection does that give us???????????????
I’ve requested the Minister advise, who legally imported them and when; plus who is responsible for allowing this import. As yet no response but I have heard on the grape vine that legally imported is a typo and it should have been illegal. Who knows-Ill update when the Minister responds-going on past performances, that’s no time soon.
In my opinion the Deputy Prime Minister, Barnaby Joyce has categorically failed in his duty of care to the people of Australia, the Aquaculture Industry of Australia and the Ecology of Australia. He is unconcerned with exotic crayfish being bred and distributed throughout Australia.
Now, thanks to the Minister and his Department the clandestine trade has moved out of Facebook and into main stream media. These environmental vandals are now openly trading their illegal produce on mainstream media. Thanks to Barnaby Joyce the trade has moved onto Gumtree.
There is current Legislation to solve this problem and discourage further black market profiteering from illegal exotic crayfish. Unfortunately, efforts with the Minister for Agriculture and Water Resources the Hon Barnaby Joyce, have been unsuccessful and the Minister has approved the proliferation of this exotic species in Australia. Those who were previously dealing clandestinely on Facebook are now marketing openly on Gumtree touting they have the approval of the Department of Agriculture and Water Resources.
Distinguishing between an exotic crayfish newly illegally imported carrying crayfish plague or an exotic crayfish supposedly breed from illegal imports without plague is impossible. All exotic crayfish should be prohibited from Australia. Offspring from illegally imported species should also be illegal, it is unacceptable that Barnaby Joyce considers them legal. Those now propagating offspring of those illegal crayfish are profiting from a crime with the full support of the Deputy Prime Minister, the Hon Barnaby Joyce.
There are many other varieties/species of Mexican Dwarf Crayfish. For example the orange dwarf Mexican crayfish (Cambarellus patzcuarensis) may sell for well over $2000/crayfish when it is illegally imported into Australia. Make NO Mistake the aquarium crayfish industry is huge with hundreds of species traded worldwide. For example in America the aquarium pet crayfish industry trades $100 million USD/year.
The incentive and demand for unique crayfish species is huge. The huge sums of money to be made from the illegally importing of more exotic crayfish species into Australia and the condoning of the sale of the progeny from this black market trade by the Department of Agriculture and Water Resources is placing the ecology of Australia at extreme risk. Lack of action on this first illegal import gives the GREEN LIGHT for further illegal imports of exotic freshwater crayfish.
This issue is far from over, here in NSW we have far more efficient and professional Government Departments than DAWR. NSW DPI is well aware of the risks.
The NSW Department of Primary Industry states: Many European countries have had their crayfish stocks destroyed by the so-called “crayfish plague”, caused by fungus Aphanomyces astaci. It originated in the United States and spread to Europe with introduced crayfish. This fungus is not present in Australia, but tests have shown that if it were to reach Australia it would destroy many of our crayfish stocks. To stop this fungus destroying our unique crayfish fauna, the import of crayfish into Australia has been prohibited.
I have generated a report for the NSW Aquaculture Association on this Issue and the Risks. For a copy of that report “Click here”. Hopefully, these crayfish will soon be prohibited in NSW and anyone with them in their possession will be prosecuted. We will continue to push for the same in all states and continue to harass the Federal Government to pick up their game and protect the ecology of Australia. I urge you all to join with us and add your voice and question the Government Departments as to what they are going to do to resolve this extreme biosecurity risk to Australia.
Cheers Rob McCormack
The ACP has a number of projects going in this freshwater crayfish hotspot and in August 2016 a team got together to further investigate.
a) Project 100057 The Hinterland crayfish Euastacus maidae (Decapod: Parastacidae) with notes on biology, distribution and conservation status. Robert B. McCormack and Paul Van der Werf
This project is nearing completion with final surveying being conducted this trip to help define the species distribution in NSW and Qld.
b). Project 100066 The ecology, distribution and conservation status of Euastacus valentulus (decapoda: parastacidae), a giant freshwater spiny crayfish from south eastern Queensland, Australia Robert B McCormack
This project has been ongoing for quite a while and this trip was just further defining the distribution and fecundity of the species.
c). Project 100067 Taxonomy, distribution and ecology of the cusped yabby Cherax cuspidatus (Riek 1969). Robert B McCormack, Peter J F Davie and Dean R Jerry
This project has been nearly completed for some time. We know the species occurs south of the Tweed River and another species occurs from Currumbin creek north, it’s the Tweed and associated creeks that we needed to find out whats in them. Interestingly this trip we didn’t find any Cherax in the main Tweed River but heaps in the tributaries of Terranora Creek.
d). Project 100073 The distribution, ecology and conservation status of Embezee’s Crayfish Euastacus binzayedi Coughran et al, 2013 (Crustacea: Decapoda: Parastacidae), a dwarf freshwater crayfish from the Gondwana Rainforests, south-eastern Queensland Robert B. McCormack, Paul Van der Werf, Chris Van der Wyk and Craig N Burnes
This project is completed and just awaiting the completion of the E. maidae paper as both will be published together.
Base camp for this expedition was Kira Beach Caravan Park at Coolangatta. We had a couple of cabins and these were base camp for our daily expeditions.
Paul managed to catch a bream off the cabins veranda.
Day one started in the upper Bilambil and Duroby Creek area of northern NSW. This is a very interesting area, mostly an undescribed species of Cherax crayfish and Euastacus valentulus. There are another 2 species of Euastacus crayfish in the area and these were the main target of our research.
Day 2 saw us in the National Parks of NSW, Wollumbin, Mebbin, Limpinwood and Numinbah, etc. All basically the upper Tweed River drainage. Our thanks to Lance Tarvey of NSW National Parks for all his help and assistance with guidance and access to the management trails. Paul, Nathan and I caught so many Euastacus valentulus it was ridiculous.
Day 3 back into Queensland and the upper Mudgeeraba Creek. Paul Donatiu the Coastal Catchments Southern Area Manager was our guide for the day. Our thanks to Paul for taking the time to show us this amazing area and arrange access to the numerous private properties we surveyed. We built up quite a team for this expedition with Isaac, Kirby and Dave joining both Pauls and myself to trudge the creeks seeking critters. The upper Mudgeeraba Creek was an amazing area with abundant crayfish everywhere. We found Cherax sp., Euastacus sulcatus, Euastacus maidae and Euastacus valentulus throughout the area.
Day 4 in Queensland the Natural Bridge area to start with and then back through NSW doing upper Crystal, Numinbah and Couchy Creeks. Met a real wackjob when were in the upper Crystal Creek area, we were parked on a public road, in the public creek beside the road when we were accosted by this obnoxious local. Seems he thinks that the whole area is his and no one else is allowed in the area. He has no idea what species occur in his creek, he doesn’t care whats in his creek, how dare anyone even look in his creek, just get the F#*@ out of the area. A real charmer with a real bad attitude. Luckily, we are not the types to take offense when we meet the local weirdo, however, others may not be as forgiving, let hope a bunch of recreational fishers legally having a fish in the creek don’t encounter him.
Day 5 saw us packing up and heading home. It was a great expedition with a wealth of information gathered. My thanks to all those that helped in the gathering of all that information.
The Tasmanian Giant Freshwater Lobster Astacopsis gouldi is the planets largest freshwater invertebrate. It’s been known to grow up to 6 kg, theses days however, animals weighing 2–3 kg are considered large and anything over 4 kg as gigantic.
On a recent trip to Tasmania a four man Australian Crayfish Project (ACP) team joined the foremost expert on the species Mr Todd Walsh to assist him and his assistant with their research on this river giant. Todd and his assistant Michelle were great value and took us to one of their regular survey sites.
The research project involves capturing giant freshwater crayfish and microchipping them. Small microchips the same as you would use for your dog or cat is implanted into the crayfish. Microchips are what is known as an RFID device (Radio Frequency Identification Device). They are approximately the size of a grain of rice and implanted into the crayfish. The tiny microchip is completely inert, it doesn’t have a power source and it is not activated until a scanner is run over it. The scanner reads the unique identification number of the microchip and displays it on the screen.
Each crayfish is micro tagged, sexed, weighed and measured. Its location is recorded and over many years Todd will compile very accurate and important information on the species growth and activity.
We helped Todd captured over 20 large crayfish that day and about half were new animals and half already tagged. The tagged animals are very important as Todd can look back through his records and see where it was caught last and how much it has grown over that period.
The crayfish were relatively easy to catch, being the top invertebrate predator in the river, they are fearless and happily wandered the creeks and rivers during the day. I could walk along through the river and just pick one up. They are a species that was traditionally recreationally fished for, but, back in 2000 all fishing was banned. Unfortunately, illegal fishing still seriously impacts this species which is very slow growing.
They are opportunistic feeders. I was walking along the bank of the river and spotted what looked like an eel some 40 m away in the river on the other side. I called Paul over and said, that likes like an eel, and that large black shape looks like a big cray – “I think that looks like a cray eating a live eel.” Paul reckoned I was right and he called Todd over and sure enough Todd agreed and they both slide down the bank some 6 m or so into the water, raced across the river and Todd grabbed a 1.3 kg crayfish. Todd and Paul were happy they caught another crayfish, the crayfish was unhappy as it lost its eel meal, got a microchip shoved into it before release, but the eel escaped so I expect it was happy. It was an interesting observation that they can catch and eat large live eels.
They are river-dwelling crayfish preferring pristine creeks and rivers. Unfortunately, large portions of their habitat areas have been heavily modified with disastrous results for the species.
They are a species that is slow-growing, slow colonising, large-sized, easily caught, with relatively low fecundity. Being May it was within the known breeding season yet we didn’t find any berried females. Surprisingly, the females don’t berry every year and it may be 2 or more years between mating.
The juveniles live under rocks in the river and are very slow growing so they would be very vulnerable to predation by eels, galaxias and trout, plus cannibalism from other crayfish. We surveyed some of last years juvenile crayfish, but they were under 10-12 mm OCL so still very small.
Our sincerest thanks to Todd and Michelle for taking the time to share their vast knowledge with us. A very memorable time for us all and we hope to be back soon to do it all over again.
If you would like more information on our Tassie adventure, see: http://www.aabio.com.au/the-australian-crayfish-project-team-visits-tasmania/
The East Gippsland region of Victoria is a difficult region to survey with a limited window of opportunity. In summer it’s too hot and subject to bushfires and closed forests. In winter it’s too cold with the crayfish retiring to their burrows and difficult to access. This leaves the spring and autumn crayfishing seasons.
The new research season in East Gippsland, Victoria commenced in March 2016 when the ACP teams commenced surveying. The first survey was of the upper Murray River and tributaries of the upper Snowy River (The Little, Suggan Buggan and Buchan Rivers). Team members Rob McCormack and Craig Burnes surveyed these rivers with great success. We were collecting specimens of a species we lovingly refer to as Euastacus neocrassus. It’s very similar to Euastacus crassus found further north.
The object of our research is to collect specimens and compare the genetics. We have specimens of Euastacus crassus from further north and the ACT plus the new population we discovered in the Shoalhaven River drainage. Add in these new ones from the upper Murray and the Upper Snowy and Tambo rivers will make an interesting DNA analysis and may lead to the redescription of E crassus or the description of new species. Stay tuned for further updates.