An Expedition to Survey The Many-Bristled Crayfish Euastacus polysetosus (Riek 1951)

September 10, 2017RobertFeatured, News

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.

Paddys Creek, Barrington Tops

Paddys Creek, Barrington Tops

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.

Dilgry River, Barrington Tops

Dilgry River, Barrington Tops

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.

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Cheers

Rob

Euastacus vesper, a new Euastacus for NSW

March 27, 2017RobertFeatured, News

 

Euastacus vesper, from the Cudgegong River

Euastacus vesper, from the Cudgegong River

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 Zootaxa pp556-567.2017_Page_01

Euastacus vesper Zootaxa pp556-567.2017_Page_01

 

 

 

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

DOI: https://doi.org/10.11646/zootaxa.4244.4.6

 

 

 

 

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.

Euastacus vesper berried female - note the small size

Euastacus vesper berried female – note the small size

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.

Euastacus vesper

Euastacus vesper

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

The Cudgegong Giant Spiny Crayfish Euastacus vesper

The Cudgegong Giant Spiny Crayfish Euastacus vesper

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.

Cheers
Rob

REFERENCE
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

 

 

The small spiny crayfish Euastacus dangadi (Morgan 1997)

February 26, 2017RobertFeatured, News

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, Bellingen area

Euastacus dangadi, Bellingen area

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.

Euastacus dangadi

Euastacus dangadi

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.

Euastacus dangadi

Euastacus dangadi

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.

Cheers
Rob

Photos are of ACP Spec 5903, Kalang River, small male 33.42 gram, 39.30 mm OCL

The amazing variations in colours of the Lamington Crayfish Euastacus sulcatus

December 13, 2016RobertFeatured, News
Euastacus sulcatus, Lamington National Park, Qld

Euastacus sulcatus, Lamington National Park, Qld

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 small Euastacus sulcatus wandering the forest floor, Binna Burra, Qld

A small Euastacus sulcatus wandering the forest floor, Binna Burra, Qld

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.

Lamington National Park found a piece of animal intestines on the forest floor

This one from Lamington National Park found a piece of animal intestines on the forest floor

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.

Green Euastacus sulcatus, North Branch, Main Range National Park

Green Euastacus sulcatus, North Branch Creek, Main Range National Park

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.

Emu Creek, south branch, Emu Vale State Forest, Qld

Emu Creek, south branch, Emu Vale State Forest, Qld

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.

Euastacus sulcatus, Sheepstation Creek, Border Ranges National Park, NSW

Euastacus sulcatus, Sheepstation Creek, Border Ranges National Park, NSW

Further east in Sheepstation Creek, Border Ranges National Park (Richmond River drainage, NSW), brown, blue and green with larger white highlights.

Rusty red colouration of Euastacus sulcatus from Brindle Creek, NSW

Rusty red colouration of Euastacus sulcatus from Brindle Creek, NSW

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.

Euastacus sulcatus from Bean Creek, Yabbra State Forest (Clarence River drainage)

Euastacus sulcatus from Bean Creek, Yabbra State Forest (Clarence River drainage)

Further east in a tributary Bean Creek, Yabbra State Forest (Clarence River drainage), again we get the rusty red colouration with bright white highlights.

Florescent blue and white Euastacus sulcatus, Currumbin Creek, Qld

Fluorescent blue and white Euastacus sulcatus, Currumbin Creek, Qld

Currumbin Creek, Queensland the well known fluorescent blue and white colouration. This is mostly blue with little white colour.

Euastacus sulcatus, Mount Tamborine, Qld

Euastacus sulcatus, Mount Tamborine, Qld

Mount Tamborine, (Albert River drainage, Qld), this one has it all, brown, green, blue and white.

White Euastacus sulcatus, Nerang River drainage, Qld

White Euastacus sulcatus, Nerang River drainage, Qld

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.

Juvenile Euastacus sulcatus

Juvenile Euastacus sulcatus (Emu Creek, South Branch, Qld)

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.

Cheers
Rob

REFERENCES

McCormack, R.B. 2012. A guide to Australia’s Spiny Freshwater Crayfish. CSIRO Publishing, Collingwood, Victoria. ISBN 978 0 643 10386 3

South eastern Queensland and far northern NSW projects continue

October 9, 2016RobertFeatured, News

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.

The Hinterland Crayfish Euastacus maidae from Mudgeeraba Creek

The Hinterland Crayfish Euastacus maidae from Mudgeeraba Creek

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.

The Strong Crayfish Euastacus valentulus from the upper Tweed River

The Strong Crayfish Euastacus valentulus from the upper Tweed River

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.

The cusped yabby Cherax cuspidatus

The cusped yabby Cherax cuspidatus

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.

Embezee’s Crayfish Euastacus binzayedi

Embezee’s Crayfish Euastacus binzayedi

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 fishing from the veranda

Paul fishing from the veranda

Paul managed to catch a bream off the cabins veranda.

Paul with the catch of the day

Paul with the catch of the day

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.

Cherax sp.

Cherax sp.

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.

The survey team in the upper Mudgeeraba Creek

The survey team in the upper Mudgeeraba Creek area

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.

Euastacus valentulus

Euastacus valentulus

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.

Cheers

Rob

Australian Parastacid Pioneer, Edgar Fredrick Riek dies aged 95

March 5, 2016RobertFeatured, News

Edgar Riek one of Australia pioneers in the freshwater crayfish field died on the 9th February after receiving a serious head injury from a fall. His death was a great loss; Edgar was an amazing man with a long and distinguished career in a wide range of subjects including, entomology, palaeontology, geology, biology, bacteriology, horticulture, trout fishing and wine making.

Although technically born in New Zealand in 1920, he was raised on a farm at Caboolture, Queensland from a baby. Attending Brisbane Grammar School then as a lab assistant in the Geology Department of Queensland University (QU) completing his undergraduate university as an evening student. Edgar obtained a B.Sc. (1944) and M.Sc. (1946 freshwater invertebrates) from QU. He obtained a D.Sc. (Qld) for his work on fossil insects in 1971. In Australian limnological circles he is remembered for his taxonomic work on mayfies, stoneflies and decapod crustaceans. Edgar was awarded an OAM in 1996 for his services to viticulture and to entomology.

On graduation, he became a demonstrator in the Department of Zoology. and it’s only from there, after the war, at the end of 45, that he went to Canberra and joined CSIRO. Edgar was the principal research scientist in the Division of Entomology at the CSIRO from 1945 through to 1978. During that time he worked on insects, fossils and our decapod crustacean. He was incredibly productive and described a mass of our freshwater crustaceans.

This is a list of the freshwater crayfish species he described:

Riek 1951
Euastacus cunninghami
Euastacus valentulus
Euastacus hystricosus
Euastacus sulcatus
Euastacus nobilis crassus
Euastacus polysetosus
Tenuibranchiurus glypticus
Engaeus parvulus
Parastacoides leptomerus
Parastacoides setosimerus
Cherax dispar
Cherax dispar elongates
Cherax dispar crassus
Cherax depressus
Cherax robustus
Cherax rotundus setosus
Cherax rhynchotus

Riek 1956
Euastacus spinosus,
Euastacus simplex
Euastacus neohirsutus
Genus Euastacoides,
Euastacoides setosus
Euastacoides maidae
Euastacoides urospinosus
Cherax esculus

Riek 1967
Engaewa subcoerulea
Engaewa reducta
Engaewa similis
Parastacoides sternalis
Parastacoides pulcher
Cherax crassimanus
Chevax glaber
Cherax glabrimanus
Cherax neocarinatus

Riek 1969
Australian Freshwater Crayfish
Engaeus urostrictus
Engaeus australis
Engaeus jumbunna
Engaeus connectus
Engaeus reductus
Engaeus aliensus
Euastacus diversus
Euastacus neodiversus
Euastacus claytoni
Euastacus kierensis
Euastacus aquilus
Euastacus clydensis
Euastacus brachythorax
Astacopsis fluviatilis
Cherax cuspidatus
Cherax neopunctatus
Cherax cairnsensis
Cherax wasselli
Cherax gladstonensis
Cherax urospinosus

Riek 1972
The Phylogeny of the Parastacidae
Genus Gramastacus
Gramastacus insolitus
Gramastacus gracilis

Riek's Crayfish Euastacus rieki

Riek’s Crayfish Euastacus rieki

Riek’s Crayfish Euastacus rieki was named by Gary Morgan in 1997 in respect of the pioneering parastacid systematic works of E.F. Riek.

Berried Euastacus rieki from Namadgi National Park, ACT

Berried Euastacus rieki from Namadgi National Park, ACT

Research on Riek’s Crayfish Euastacus rieki continues today with the ACT Aquatic Team  from the ACT Government’s Conservation Planning and Research Unit recording the first breeding record in 2014. http://www.aabio.com.au/rieks-crayfish-euastacus-rieki-first-breeding-record/  They are currently heading out into the field (2016) to increase our knowledge base on this unique species.

 

References and further reading:

50 years of history Australian Society for Limnology http://www.asl.org.au/assets/ASL/ASL-50-Year-Compilation.pdf

Orbost Spiny Crayfish Euastacus diversus http://www.aabio.com.au/tag/spiny-crayfish/ 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 Euastacus diversus. Since that day this crayfish has remained a rare and elusive species.

The Canberra Times http://www.canberratimes.com.au/act-news/canberra-wine-district-pioneer-edgar-riek-dies-aged-95-20160210-gmqa1q.html

National Library of Australia, Edgar Riek interviewed by Heather Rusden http://nla.gov.au/nla.oh-vn255039

Morgan, G. J. 1997. Freshwater crayfish of the genus Euastacus Clark (Decapoda: Parastacidae) from New South Wales, with a key to all species of the genus. Records of the Australian Museum Supplement 23: 1-110.

Riek’s Crayfish Euastacus rieki (first breeding record) http://www.aabio.com.au/rieks-crayfish-euastacus-rieki-first-breeding-record/

 

The Otway’s Cray, Geocharax gracilis

November 28, 2015RobertFeatured, News

Clark 1936 described the species from the Gellibrand River south of Colac, Victoria. Its a relatively common species in the Otway’s and south of the Colac region. A recent expedition  (November 2015) to the area found them to be widespread and when present abundant. Many places we captured both Cherax albidus and Geocharax gracilis together. Other place only one or the other species. Interestingly, sites we had caught Geocharax at previously (3 years) and no Cherax, only had Cherax this time.

Geocharax gracilis

Geocharax gracilis

Geocharax gracilis is a species commonly used as bait for recreational fishers. Referred to as “Black Yabbies” they make great bait but they are just not as prolific as Cherax so their numbers take a lot longer to recover after heavy bait collection. Perhaps that’s why Cherax are now in their previous areas, they have just outbreed/out competed them.

Geocharax gracilis

Geocharax gracilis

We sampled over a thousand G. gracilis over several days by both net and trap. Typically, males far outnumbered females:

Trapping = approx. 92% males

Scooping = approx. 75-80% males

We never recorded a female with eggs despite it being November and within the breeding season.

Geocharax gracilis

Geocharax gracilis

Geocharax gracilis is endemic to southern Victoria, King Island and far north west Tasmania, Australia. It has been assessed as Least Concern. While this species is known to be impacted by agriculture practices, this is likely to be a localised threat only. This species is known from a broad geographic range with an estimated extent of occurrence of 20,000 km2 (IUCN 2015).

Geocharax gracilis

Geocharax gracilis

Typically, they would have 2-3 surface entrances, 2 deep burrows, 350-450 mm deep into water table. Burrows are along the banks of streams and dams may connect to the stream but others further away do not. They will colonize low lying swampy areas

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Western Burrowing Cray, Engaeus merosetosus

November 26, 2015RobertFeatured, News
Engaeus merosetosus

Engaeus merosetosus

Engaeus crayfish are known as the burrowing or terrestrial crayfish. They are all small species usually under 70 mm head to tail and some species can be found well away from water in suburban lawns or the sides of mountains. There are 35 species found in Australia with 23 of those found in Victoria.

Waurn Ponds Creek, Victoria

Waurn Ponds Creek, Victoria

Pierre Horwitz in 1990 described Engaeus merosetosus with the holotype from Waurn Ponds in Victoria. The species occurs predominantly in the Geelong-Ballarat region, Victoria, Australia. It has been found in the upper reaches of the Werribee River and just across the Great Dividing Range in the upper reaches of the Loddon and Tullaroop drainages (Horwitz 1990).

Western Burrowing Cray Engaeus merosetosus

Western Burrowing Cray Engaeus merosetosus

Engaeus merosetosus has been assessed as Least Concern by the IUCN. This species is relatively broadly distributed, and there is no evidence that it is experiencing declines at the present time. This species has an estimated extent of occurrence of 5,292 km2 (IUCN 2015).

Berried Female Engaeus merosetosus

Berried Female Engaeus merosetosus

Horwitz 1990 did not record any berried females so the discovery of this berried female (44 eggs, 5.31 grams, 17.22 mm OCL) from Waurn Ponds Creek was a lucky find. The creek was low with just scattered puddles. Burrows were abundant most quite deep and all seemed water filled at least 200 mm down.

Engaeus merosetosus burrow

Engaeus merosetosus burrow

 

References and Further Reading

Horwitz, P. (1990). A taxonomic revision of species in the freshwater crayfish genus Engaeus Erichson (Decapoda: Parastacidae). Invertebrate Taxonomy 4: 427‐614.

IUCN Citation: Doran, N. and Horwitz, P. 2010. Engaeus merosetosus. The IUCN Red List of Threatened Species 2010: e.T153749A4540433. http://dx.doi.org/10.2305/IUCN.UK.2010-3.RLTS.T153749A4540433.en. Downloaded on 23 November 2015.

 

The Burrowing Crayfish Engaeus lyelli

November 26, 2015RobertFeatured, News

Engaeus crayfish are known as the burrowing or terrestrial crayfish which are generally all very small species usually under 70 mm head to tail. Engaeus lyelli has a widespread distribution and is considered the largest of all the Engaeus species. The large size and taxonomy of the species has led to much consternation and various authors have disagreed with its designation and affinities. Gan et al 2014 ran he complete mitogenome of the Australian land crayfish Engaeus lyelli to help clarify the situation.

Engaeus lyelli Spec 2875 Eildon, Vic

Engaeus lyelli Spec 2875 Eildon, Vic.

Thirty five described Engaeus species are found in Australia with twenty three of those found in Victoria. The Australian Crayfish Project (ACP) is researching all these species and E. lyelli has been under research for the last 8 years.

Engaeus lyelli Spec 2261 Nilahcootie, Vic

Engaeus lyelli Spec 2261 Nilahcootie, Vic

Horwitz 1990 redescribed the species and stated: The largest male found was 28.7 mm carapace length. Mature females ranged from 18.8 to 32.4 mm carapace length. The largest non-reproductive female was 27.7 mm carapace length. Horwitz 1990 did not record any berried females so the discovery by the ACP of females with eggs greatly increases the knowledge base on this species. This female from the Seymour area in November 2015 has 114 eggs, weighs 16.66 grams with an OCL 30.45 mm has eggs 2.5 mm long and 1.9 mm wide.

Engaeus lyelli, Spec 5629, Pukapunyal, Vic

Engaeus lyelli, Spec 5629, Pukapunyal, Vic

Engaeus lyelli has been assessed as Least Concern by the International Union for the Conservation of Nature and Natural Resources (IUCN). Although this species has a relatively restricted range, with an estimated extent of occurrence 11,200 km2, it is not impacted upon by any major threat processes. Monitoring of the population is suggested as habitat loss and degradation occurs within parts of its range, and climate change may pose a significant future threat to this specie. (IUCN 2015)

Engaeus lyelli, Spec 5633, Pukapunyal, Vic

Engaeus lyelli, Spec 5633, Pukapunyal, Vic

The IUCN states under distribution: This species is endemic to Victoria, Australia. It is most commonly found north of the Great Dividing Range from the Grampian Ranges in the west to near Myrtleford in the east, and it does not appear to extend far from the foothills of the Great Dividing Range in Victoria (although its northwards range has not been thoroughly investigated). The distribution is characterized by distinct gaps in its range, with gaps occurring between Moyston and Beaufort, in the Lerderderg River drainage region, between Ballarat and Daylesford, and in the Seymour-Yea region (although this gap may be due to insufficient sampling) (Horwitz 1990).

Engaeus lyelli, Spec 892, Granpians, Vic

Engaeus lyelli, Spec 892, Granpians, Vic

Engaeus lyelli is a riparian zone species found along the sides of creeks, billabongs and dams. It is also found in close proximity to other Genera like Cherax, Geocharax and juvenile Euastacus freshwater crayfish. Specimens are typically collected from their burrows by digging, however when no other crayfish species are present they can be collected by scoop net from ponds and dams in relatively high numbers. Burrows have an open entrance, usually 2-3 surface entrances along the sides of the water body, entrances are typically above the water line but these are in high water level fluctuation areas, have several subsurface burrows that travel down into the water table and all burrows contained water at the bottom. Most burrows sampled were relatively new burrows with fresh material at the surface, however most animals were captured 350-500 mm deep so not exceptionally deep on the scheme of things.

Engaeus lyelli pond, Pukapunyal, Vic

Engaeus lyelli pond, Pukapunyal, Vic

Engaeus lyelli burrows along edge of pond Pukapunyal, Vic

Engaeus lyelli burrows along edge of pond Pukapunyal, Vic

References & Further Reading

Doran, N. and Horwitz, P. 2010. Engaeus lyelli. The IUCN Red List of Threatened Species 2010: e.T153693A4532851. http://dx.doi.org/10.2305/IUCN.UK.2010-3.RLTS.T153693A4532851.en. Downloaded on 22 November 2015.

Horwitz, P. (1990). A taxonomic revision of species in the freshwater crayfish genus Engaeus Erichson (Decapoda: Parastacidae). Invertebrate Taxonomy 4: 427‐614.

DOI:10.3109/19401736.2014.908361Han Ming Gana*, Mun Hua Tana, Yin Peng Leea, Mark B. Schultzb & Christopher M. Austin. The complete mitogenome of the Australian land crayfish Engaeus lyelli (Clark 1936) (Crustacea: Decapoda: Parastacidae)

ACP DATA BASE

Collection GPS Coordinates and specimem information is only available to ACP Members to

view the collection data base for E. lyelli “CLICK HERE”  

Excel database spreadsheet

 

Engaeus quadrimanus from Cann River, Victoria

September 30, 2015RobertFeatured, News
Engaeus quadrimanus

Engaeus quadrimanus

Engaeus quadrimanus Clark 1936 is a relatively widespread and locally abundant species. It’s a lowland species generally found under 250 m a.s.l. from just north of Melbourne, east along the coast to just before the NSW border.

Engaeus quadrimanus

Engaeus quadrimanus

Found along permanent creek and stream margins, swamps, seepages, drains and ephemeral creek beds. Found under dense scrub/forest to roadside drains and open sky backyards.

Engaeus quadrimanus

Engaeus quadrimanus

A very robust and adaptable species that usually has large colonies with the area being riddled with burrows. Typically, burrows are round to oval in shape and open with excavated material at the entrance. Many areas don’t have excavated material at the entrance as its been washed away with flood waters.

Engaeus quadrimanus

Engaeus quadrimanus

The species is extremely active during flood events and uses the creeks to migrate and find mates, etc. These specimens are from the Cann River region of Victoria.

Cheers

Rob McCormack

If you have enjoyed this article and our research please contribute financially to the research. Over $300 in fuel for the survey vehicles was expended on this project-we freely give our time but assistance with costs would help-even just a few dollars is gratefully accepted. To contribute less than $10 just change the quantity from 1 to say 0.5 for $5, if however, you have a spare $10K that would be enough to finish this research project and very gratefully accepted. To contribute “CLICK HERE”