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Euastacus hystricosus

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Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA ARTHROPODA MALACOSTRACA DECAPODA PARASTACIDAE

Scientific Name: Euastacus hystricosus
Species Authority: Riek, 1951

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.
Justification:
Euastacus hystricosus has been assessed as Endangered B1ab(iii).  It has an estimated extent of occurrence of 3,000 km², and a severely fragmented distribution. It is only found in the headwaters of streams in mountainous areas, and is impacted by illegal fishing pressure, despite protection by a no take policy. This has the potential to remove large numbers of mature individuals and cause a reduction in the amount of reproductively viable adults which has already been observed in areas where there has been a single weekend of heavy fishing pressure. There has been a continuing decline in the quality of habitat due to the destructive nature of a number of exotic species in the area, some of which also predate upon this species. There is also destruction of suitable rainforest habitat in parts of its range. This species also faces the consequences of global temperature rise. As a restricted range species, dependent on cool, clear headwater streams, a slight increase in temperature could rapidly extirpate this species. Research should be initiated to include population assessment and monitoring, biological and life history information, habitat requirements, and resilience to effects of exotic species.
History:
1996 Vulnerable (Baillie and Groombridge 1996)
1996 Vulnerable
1994 Rare (Groombridge 1994)

Geographic Range [top]

Range Description: This species is endemic to Australia. It is known from the Maleny Plateau and streams flowing from it, in the upper reaches of Yabba Creek, and from a tributary of the upper Brisbane River, Queensland (Morgan 1988). Furthermore, this species is known only from sites approximately 475 m above sea level (Morgan 1988, Smith et al. 1998). This species has an estimated extent of occurrence of 3,000 km2. The distribution and habitat are limited (Morgan 1988), and all sites fall within 0.5° latitude and 0.5° longitude. There are few places within this EOO that are above 475m, so the area of occupancy is likely to be very low (J. Coughran and J.M. Furse pers. comm. 2009). Though this species occurs in a number of streams, the distribution is restricted to headwater reaches above 475 m, and therefore the distribution is severely fragmented as intervening lowland areas have been identified as barriers to dispersal (Morgan 1997, Ponniah and Hughes 2006).
Countries:
Native:
Australia (Queensland)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population:

There is no population information available for this species. Smith et al. (1998) recorded details about growth, habitat and abundance of juveniles in two creek catchments in the ConondaleRanges. The distribution of this species is severely fragmented as intervening lowland areas have been identified as barriers to dispersal (Morgan 1997, Ponniah and Hughes 2006).

Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology:

This species inhabits cool, clear, flowing headwaters in montane areas, in both wet sclerophyll and rainforest (Morgan 1988). Like other species of Euastacus, this species prefers heavily shaded, well oxygenated waters where it can burrow under logs and rocks. Smith et al. (1998) recorded the species in deep pools, runs, riffles and glides.

Systems: Freshwater

Use and Trade [top]

Use and Trade: This species is impacted by illegal fishing pressure, despite protection by a no take policy. This has the potential to remove large numbers of mature individuals and cause a reduction in the amount of reproductively viable adults.

Threats [top]

Major Threat(s): Given its highly restricted range, this species is extremely susceptible to localized threats, including bush fires, forest management practices, habitat destruction and over-exploitation by collectors (J. Coughran and J.M. Furse pers. comm. 2009). This species is also susceptible to climate change, including increasing temperature, alterations to hydrological regimes, severe weather events and loss of suitable highland habitat (Chiew and McMahon 2002, Howden 2003, Hughes 2003, Pittock 2003, Hennessy 2006, Westoby and Burgman 2006, IPCC 2007).

There is a potential large scale threat from Cane Toads (Bufo marinus) (DEH 2004b) although there is no specific data on the impact of this threat on this species. Other introduced exotic species (cats, foxes, pigs, goats) that have generally been found to impact on crayfish (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,c,d,e) and given this species highly restricted distribution, could have serious impacts by contributing to declines in its distribution and/or abundance (J. Coughran and J.M. Furse pers. comm. 2009).

Due to the narrow thermal tolerance of this species, and its restricted range (restricted to cool, headwater streams in forested catchments), global temperature increase has resulted in range contraction. This species is further compromised by the presence of exotic species (feral pigs, foxes, Cane Toads and cats) which are known to predate on crayfish and degrade riparian habitat; while the precise effects of these threats on this species are not yet well understood, they are believed to be significantly impacting the long term viability of the population (J. Furse and J. Coughran pers. comm. 2010).

Euastacus hystricosus is a large species that would be appealing to recreational fishers. Illegal harvesting is a potential threat (Smith et al. 1998). Morgan (1983) observed evidence of heavy fishing activities in the Conondale region, and noted that populations of Euastacus could be heavily impacted in a single weekend of heavy fishing pressure. Recreational fishing (in particular the taking of large adults) has the capacity to lead to serious and far reaching impacts on population structure (i.e. the stunted population phenomenon (Huner and Lindqvist 1985, Tulonen et al. 2008)), including impairment of reproductive success in females (Tulonen et al. 2008).

Conservation Actions [top]

Conservation Actions:

There are no species-specific conservation measures in place for this species, however its distribution coincides with several national parks and stateforests. Furthermore, All 'spiny crayfish' (Euastacus) species in Queensland are officially no take species under the Fisheries Act 1994 and must be released if captured (DPIF 2007). There is no information available on the levels of compliance, although evidence of illegal poaching is frequently observed. Research should be initiated to include population assessment and monitoring, biological and life history information, habitat requirements, investigations into thermal tolerance and resilience to exotic species.  


 



Citation: Furse, J. & Coughran, J. 2010. Euastacus hystricosus. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 25 October 2014.
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