Euastacus brachythorax 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Arthropoda Malacostraca Decapoda Parastacidae

Scientific Name: Euastacus brachythorax Riek, 1969

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(iii) ver 3.1
Year Published: 2010
Date Assessed: 2010-06-01
Assessor(s): Furse, J. & Coughran, J.
Reviewer(s): Collen, B. & Richman, N.
Contributor(s): Livingston, F., Livingston, F., Soulsby, A.-M., Batchelor, A., Dyer, E., Whitton, F., Milligan, H.T., Smith, J., Lutz, M.L., De Silva, R., McGuinness, S., Kasthala, G., Jopling, B., Sullivan, K. & Cryer, G.
Euastacus brachythorax has been assessed as Endangered B1ab(iii). This species has an estimated extent of occurrence (EOO) of 2,000 km2, has a severely fragmented distribution, and is likely undergoing a continuing decline in habitat quality due to destruction by invasive species. In addition, to which poaching of individuals has been reported. This species' habitat is anticipated to undergo a decline in quality as a result of temperature extremes, droughts and increased frequency of forest fires. Further research and monitoring of the population numbers, life history characteristics, thermal tolerance, and habitat status is required to better understand key parameters for its conservation.

Geographic Range [top]

Range Description:

This species is endemic to Australia. Its range is known to extend from the Brown Mountains area west of Bemboka, 25 km south along the mountains to near Mount Darragh, northwest of Wyndham in New South Wales (Morgan 1997). A specimen found near Timbillica, a further 60 km south indicates that the species extends to near the Victorian border, though the distribution may be patchy (Morgan 1997). It has been collected from streams between 240 m and 1,000 m above sea level. The extent of occurrence of the species is in the vicinity of 2,000 km2, although it is known from only four localities within that range, representing headwaters of various different drainages. The species can thus be considered severely fragmented across its range due to the barrier effects of mountain ridges and unsuitable habitat in the intervening lowlands (Morgan 1997, Ponniah and Hughes 2006).

Countries occurrence:
Australia (New South Wales)
Additional data:
Number of Locations:4
Lower elevation limit (metres):240
Upper elevation limit (metres):1000
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:There is no population data available for this species however as this species is extremely susceptible to over exploitation (J. M. Furse and J. Coughran pers. comm. 2008).
Current Population Trend:Unknown
Additional data:
Population severely fragmented:Yes

Habitat and Ecology [top]

Habitat and Ecology:

This species is found in highland streams in granite dominated country. Light temperate rainforest or tree ferns are found along the stream banks, with dry sclerophyll on ridges above providing good shade (Morgan 1997). The species is sympatric with Euastacus yanga and Euastacus claytoni at some sites (Morgan 1997).

The slow growth rate and low fecundity of many Euastacus renders them less resilient to reduction in population numbers through habitat destruction and catastrophic events (Van Praagh 2003).

Continuing decline in area, extent and/or quality of habitat:Unknown

Threats [top]

Major Threat(s): The species is extremely susceptible to localized impacts, including bush fires, forest management practices, habitat destruction and over-exploitation by collectors.

Climate change, including increasing temperature, alteration to hydrological regimes, severe weather events, loss of suitable rain forest and increased potential for bushfires also threaten this species (Chiew and McMahon 2002, Howden 2003, Hughes 2003, Pittock 2003, Hennessy 2006, Westoby and Burgman 2006, IPCC 2007).

Exotic species (cats, foxes, pigs, goats) that have generally been found to impact on crayfish (e.g. Green and Osbourne 1981; Horwitz 1990; Merrick 1995; Eyre et al. 1997, ACT Government 2007, O'Brien 2007), also occur in this species' range (DEH 2004a,b,c,d). These exotic species could have localised impacts on this species which given the fragmented distribution of this species, could contribute to declines in distribution and/or local abundance.

Conservation Actions [top]

Conservation Actions:

There are no species-specific conservation measures in place for this species. Further research should be initiated to include population assessment and monitoring, biological and life history information, habitat requirements, and investigations into thermal tolerance.

In New South Wales, a minimum recreational size limit of 90 mm OCL is in place for any spiny crayfish (NSW DPI 2007). This species does not attain that size, and so is indirectly protected by this restriction.

Citation: Furse, J. & Coughran, J. 2010. Euastacus brachythorax. The IUCN Red List of Threatened Species 2010: e.T153615A4520692. . Downloaded on 19 September 2018.
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