Cherax rotundus is presently known from very few localities. It is known from the Barmah forest near Echuca and has been collected from the upper Goulburn river valley. It has been recorded from Queensland but this may be an error. Cherax rotundus may be more widespread but its secretive way of life may mean that it is rarely observed and collected. (VIC, QLD?).
Cherax rotundus is one of the larger and least known freshwater crayfish in Australia. The species has an even olive-green colouration and the claws are massive, the widest of any known member of the smooth yabby family (genus: Cherax). The species has a small head, a smooth shell with two rounded ridges behind the eyes and it lacks prominent spines.
Ecology/Way of Life:
Cherax rotundus appears to be a very strong burrowing species that only rarely appears in larger water bodies. It can be caught in shallow water holes and in inundated forests (ie Barmah) during late winter after flooding. Almost nothing is known about its ecology and life history other than that the species appears to be able to complete most of its life cycle within its large burrow systems. Like other freshwater crayfish females have reproductive openings at the base of the middle pair of walking legs, and males have their genital papillae at the base of the last pair of legs closest to the tail. The male deposits a spermatophore (sperm packet) between the female's legs and she incubates the eggs on short appendages (pleopods) under the tail.
Interaction with Humans/Threats:
Very occasionally this species is trapped by recreational fisher fishing for Yabbies in natural water bodies. Although a large species, reaching up to 200 grams, the broad claw is not farmed, because it is so difficult to collect and poorly known. The major threats to this species relate to its limited distribution and our ignorance regarding its ecology, distribution and habitat requirements.
Cherax rotundus, named by Clark 1941.
Crandall, K. A. & Fetzner, J.W. (2004) Crayfish Homepage. http://crayfish.byu.edu/
Austin, C.M, (996) Systematics of the freshwater crayfish genus Cherax Erichson (Decapoda: Parastacidae) in northern and eastern Australia: electrophoretic and morphological variation. Australian Journal of Zoology 44, 259–96.
Fallu, R. (1992). Yabbies for fun, fishing and farming. Department of Food and Agriculture.
Olszewski, P. (1980). A salute to the humble yabby. Angus & Robertson.
Text by Chris Austin & Thuy Nguyen, map by Chris Austin and photography by Paul Jones.
Please Contact ABRS if you wish to discuss sponsoring this or other pages.
|Images and Multi-media:|
|Distribution of Cherax rotundus|