This species is restricted to the Lake Pedder region of central Tasmania. (TAS).Features:
This crayfish species is usually dark brown to olive green in colour, although juveniles tend to be paler. The rostrum is long, and, unlike other related species in the region, the species has only eight corneous denticles (teeth) on each mandible (jaw). Burrow entrances often have a distinct depression surrounding the entrance, perhaps allowing surface water to be directed into the burrow.Ecology/Way of Life:
As is usual with burrowing crayfish, when mating time approaches, males leave their burrows and search for females. Mating occurs within the female's burrow. Mating and spawning appear to be induced by decreasing water temperatures and occurs in autumn. The females carry the eggs (usually about 50, but can be up to 85) from April to November. The eggs hatch in early summer, and the young remain attached to the female through two moults. The young are released in early summer and remain in the female's burrow system until her next hatchlings are released. This means that it is sometimes possible to find up to three generations of this crayfish within a single female's burrow. In this species of crayfish the females moult and produce young only every second year. Males are always solitary, with only the single animal occupying a burrow. Males become sexually mature at a younger age and smaller size than females.
Most freshwater crayfish are omnivores, eating a variety of vegetable matter, detritus and some animal matter, although adult burrowing crayfish tend to have less animal matter in their diet than species that inhabit streams and lakes. The diet of this species consists mainly of detritus, buttongrass (both decaying and fresh material), plant roots, algae and a small amount of animal matter (usually worms and insects). Juvenile crayfish tend to have a higher proportion of animal matter in their diet than adults. Although animals in this species are usually found in areas of buttongrass plains, they are occasionally found in areas of wet forest or rainforest.Interaction with Humans/Threats:
Animals in this species are relatively slow-growing, and reach a maximum size of only 80 mm. Being burrowers, they are not suitable for intensive rearing through aquaculture. The range of this species extends into the Tasmanian World Heritage Area, the species is therefore well-protected.Other Comments:
Variations within the species are yet to be formally described. Refer to Hansen and Richardson (2002).Further Reading:
Crandall, K.A. & Fetzner, J.W. (2004). Crayfish Home Page. http://crayfish.byu.edu/
Growns, I. O. and Richardson, A. M. M. (1988). The diet and burrowing habits of the freshwater crayfish Parastacoides tasmanicus tasmanicus Clark (Decapoda: Parastacidae). Australian Journal of Marine and Freshwater Research 39, 525 – 534.
Hansen, B. and Richardson, A. M. M. (1999). Interpreting the geographic range, habitat and evolution of the Tasmanian freshwater crayfish genus Parastacoides from a museum collection. In: W. Ponder & D. Lunney, (eds) The Other 99% – the Conservation and Biodiversity of Invertebrates. Transactions of the Royal Society of New South Wales, Mosman. pp 210 – 218.
Hansen, B., Adams, M., Krasnicki, T. and Richardson, A. M. M. (2001). Substantial allozyme diversity in the freshwater crayfish Parastacoides tasmanicus supports extensive cryptic speciation. Invertebrate Taxonomy 15:667 – 679.
Hamr, P. (1994). Life history of Parastacoides tasmanicus tasmanicus Clark, a burrowing crayfish from south-western Tasmania. Australian Journal of Marine and Freshwater Research 45: 455 – 470.
Hansen, B. & Richardson, A.M.M. (2002). Geographic ranges, sympatry and the influence of environmental factors on the distribution of species of an endemic Tasmanian freshwater crayfish. Invertebrate Systematics. 16(4) pp621 – 629.
Text and distribution map by Brita Hansen. Photography by A.M.M. Richardson.Sponsorship welcomed:
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