WESTERN AUSTRALIAS FRESHWATER CRAYFISH
Hairy Marron - Mossyback (Cherax Tenuimanus)
Hairy Marron or Mossybacks as they are known to their native region, for their distinct hair-like tufts on their shell. These monsters can grow to more than 450 mm in total length. They are one of the largest freshwater crayfish species in the world with specimens having been recorded in excess of 2kg! Hairies were predominantly found in the Albany-Fraser orogen and stretched across the lower part of the Perth basin, prior to the smooth marron being introduced into nearby private dams and quickly spread. This led to interbreeding with our local Mossyback species. While adults are readily identified from the Smooth Marron (Cherax cainii), hybrids do occur and are more difficult to identify.
Good thing to look for is the thickness of the claw.
Hairy Marron have a narrow cheliped and have very prominent swimmerets, not to mention they are HAIRY.
MALE OR FEMALE, ALWAYS PUT A HAIRY MARRON BACK!
Always document the location and contact us on 0456 249 606 so we can protect its breeding ground.
Smooth Marron (Cherax Cainii)
The restaurant favourite! Growing to dinner plate size and larger, the Smooth Marron were introduced into the natural habitat
of the Hairy Marron in the early to mid
1980s and are currently found at all known population sites for the Hairy Marron. With their thicker claws and smooth body appearance these lip-smackers won the attention of the French and other overseas restaurants quite quickly, leaving very little availability to the general public unless purchased at a restaurant, Marron season only lasts from 1-2 weeks with limited bagging numbers. The Smooth Marron love permanent water sources and have been found walking across gravel roads out in the middle of nowhere making their way to the next water body as if by some sixth sense. Stories have been told of 40 Marron walking neatly single file through dry, gravel rock areas of the South-West, thanks to the water bladder the Marron have under their carapace.
Koonac (Cherax Preissii & Cherax Glaber)
The widespread Koonac Cherax preissii (Moore River to just east of Albany) & the Restricted Koonac Cherax glaber (Dunsborough to Windy Harbour), up to 250mm in length. Koonacs can be seen as the Marron's heavyweight (but smaller) relative. Their chelipeds are quite large and robust. They are serrated on the inside with quite a prominent nub on the inside of each claw, being pinched by one of these would leave an imprint in any child's memory for the remainder of their lives (personal memory). These crays spend times of drought burrowed into the mud & will stay there for months at a time waiting for the next downpour. Koonacs heads have four keels, two standing more prominent than the other two. With no spines or bumps on their carapace and telson, it gives the Koonac a 'sleek-black bullet' look that can make it easily mistaken for a large Yabby. These beasts have ruled the creeks of Western Australia well before the introduction of Yabbys in 1932.
Gilgie (Cherax Quinquecarinatus & Cherax Crassimanus
The widespread Gilgie Cherax quinquecarinatus (Moore River to just east of Albany), the Restricted Gilgie Cherax crassimanus (Margaret River to Denmark region). Gilgies are the cleaners of most streams, rivers and irrigation dams throughout the South-West, and can sometimes find themselves at the bottom
of your Marron net or in that empty Coke can at the edge of the road in the water run-offs. Gilgies burrow into the bank walls though out droughts and are very versatile to the river ways and washouts it calls home.
As kids, most people of the region will have stories of going down to the creek at the bottom of the street and moving a few rocks in search of these little ones. Gilgies quite normally get mistaken for baby Marron, but are in fact, very different.. Gilgies also have five keels on their heads like Marron, but only two pairs of spines on their rostrum.
Another great way to tell them apart is the claws, Smooth Marron claws are wider and the Gilgie have very distinct speckles on their claws.
An adult Gilgie can only reach up to 130mm, just longer than a bank card.
Yabby (Cherax Destructor)
Yabbies are an introduced species to WA.
Originally native to New South Wales, Victoria and South Australia, they were stocked into farm dams in WA in 1932. Yabbies can now be found in some of the south-west rivers and dams.
Unlike Marron their heads have four keels, two being more prominent and no spines on the rostrum. The inner edges of the claws have a layer of obvious hairs not found on other crayfish species native to WA.
As much as Yabbies are smaller than Marron they make up for it in numbers (see page 11). They are fast breeders and their name 'Destructor' says it all, rightfully named by Ellen Clark in 1936, these crayfish are highly territorial and aggressive towards pretty well anything they come across. They destroy river weed crops and natural vegetation is quickly demolished, due to the vast numbers this species can generate in a just a few years.
The Yabby is very popular in pet shops for its durability to water quality levels and ease of breeding.
Dil / Freshwater Burrowing Crayfish
(Engaewa Pseudoreducta & Engaewa Walpolea & Engaewa Reducta)
These little bug-gers are very hard to find. At full size they grow to only 5cm with a semi translucent carapace, purple claws and a reddish tail. One of the most distinctive features of the Burrowing Crayfish species is its one large claw that makes it look like a one handed arm wrestler. It uses its claw to burrow into the river bank and to get through the vegetated tributaries of each of their areas, where they search for any dead decaying plant and organic matter they need to eat.
As mentioned earlier in the book, the Burrowing Crayfish Engaewa species are ALL CRITICALLY ENDANGERED and the swampy head water creek habitats where they live; Margaret River, Walpole and Dunsborough, being substantially altered by clearing of native vegetation, cattle grazing, draining, afforestation practices and small dam constructions.
Now, with little funding to protect these mini mud-bugs, sadly the Burrowing Crayfish of either species is a rare find indeed!
If you find a pocket of our little Dil friend. Please document the area and contact us so we can protect their breeding home.