Glenelg Spiny Freshwater Crayfish, Pricklyback
Euastacus bispinosus occur from Western Victoria (Glenelg River system) north to the Grampians and across to eastern South Australia. (Vic, SA)Features:
Euastacus bispinosus are usually deep green, greenish-blue or greenish-brown in colour with paler spines on the claws and abdomen. Their total body length (including the abdomen) is about 265mm; the carapace may be up to 135mm long. Males and females are similar. When startled the claws are raised and outstretched above the head.Ecology/Way of Life:
The Glenelg River crayfish live in small to medium-sized streams. Adults are most active in the cooler months (May-November) and at night. Like other members of the family it is thought to be an opportunistic feeder, eating a wide range of foods when they are available.
The adults are territorial (staying in one small area of the stream) for many years. Males are usually mature when 120mm long, but females may be up to 170mm in length and 8–11 years old before they start to breed. They have an annual breeding cycle with mating occurring in autumn. Females produce between 65 and 810 oval-shaped eggs, larger females producing more eggs then smaller females. The eggs are incubated under the tail for about 4 months, before hatching in early spring. The young remain attached to the swimmerets for about 4 weeks before release in October. There is no parental care.Interaction with Humans/Threats:
For some time the Glenelg crayfish has been recognized as threatened due to a combination of recreational fishing, changes to stream habitats and clearance of surrounding areas for forestry. Some fragmentation of populations has occurred and surveys suggest that wild stocks can only cope with minimal fishing. Fishing is now regulated and the survival of remaining populations depends on conservation action, especially control of water quality and habitat changes.Further Reading:
Honan, J.A. & Mitchell, B.D. (1995a). Reproduction of Euastacus bispinosus Clark (Decapoda: Parastacidae), and trends in the reproductive characteristics of freshwater crayfish. Marine and Freshwater Research. Vol. 46, pp. 485–499.
Honan, J.A. & Mitchell, B.D. (1995b). Catch characteristics of the large freshwater crayfish Euastacus bisinosus Clark (Decapoda: Parastacidae), and implications for management. Freshwater Crayfish, Vol. 10, pp. 57–69.
Jones, D.S. & Morgan, G.J. (1994). A Field Guide to Crustaceans of Australian Waters. Reed and Western Australian Museum. 216 pp.
Text and Distribution map by J.R. Merrick. Photograph by J. Hoey.Sponsorship welcomed:
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