This species is found in the south-west of Tasmania (TAS).Features:
This freshwater crayfish is the only species to possess multiple terminal spines on the tailfan. Apart from these spines the carapace and chelae (claws) are relatively smooth. Adults tend to be brown in colour, while juveniles are light brown to orange. They grow to a maximum length of approximately 80 mm. There is no difference between males and females in either their overall size or in the size of the chelaeEcology/Way of Life:
This is one of the many burrowing freshwater crayfish species found in Tasmania. Its burrows extend down to the water table, terminating in a water-filled chamber; these burrows may extend for more than two metres. Although it is occasionally found in rainforest and shrubby heath, this crayfish is more common in the buttongrass plains of south-western Tasmania. The peats in these regions can be very acidic (often as low as pH 4.0), Northern Hemisphere burrowing crayfish can not tolerate such acidic conditions. The crayfish burrows are important in such areas, as they have a significant impact on both the soil and the vegetation. Crayfish burrows affect water movement and increase the amount of oxygen available in the soil, encourage the growth of plant roots and fungi. Vegetation in areas that contain crayfish burrows is denser and taller than similar areas which do not contain burrows.
In this species of crayfish the females moult and produce young only every second year. Mating and spawning occurs between autumn and spring, and females carry the eggs from early winter. The eggs hatch in early summer, and the young remain attached to the female through two moults. The young are released in late summer and remain within the female's burrow system until her next hatchlings are released.Interaction with Humans/Threats:
It is unlikely that Aboriginal people made much use of these animals as a food source, as the only practical method for obtaining them is to excavate the burrows. They are relatively slow-growing, and reach a maximum size of only 80 mm. Their burrowing habit, slow growth rate and small size also make them unsuitable for intensive rearing through aquaculture. Large parts of the range of this species lie within the Tasmanian World Heritage Area, so while they may be vulnerable to land clearing, the species is 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/
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. & Richardson, A. M. M. (2001). Substantial allozyme diversity in the freshwater crayfish
Parastacoides tasmanicussupports extensive cryptic speciation. Invertebrate Taxonomy 15:667 – 679.
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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