|Scientific Name:||Euastacus robertsi|
|Species Authority:||Monroe, 1977|
|Red List Category & Criteria:||Critically Endangered B1ab(iii) ver 3.1|
|Assessor(s):||Coughran, J. & Furse, 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 robertsi has been assessed as Critically Endangered under the criteria B1ab(iii). The extent of occurrence for this species is less than 100 km2 and it is known from only two severely fragmented localities. 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.
This species is endemic to Australia. It is known only from two sites (approximately 40 km apart), the type locality (Mount Finnigan) and Thornton Peak, South of Cooktown, North Queensland (Morgan 1988). Both sites are above 1,000 m above sea level, and should be considered as severely fragmented given that intervening lowland areas are barriers to dispersal (Morgan 1997, Ponniah and Hughes 2006). This species has an extent of occurrence of less than 100 km2 (J. Coughran and J.M. Furse pers.comm. 2009).
|Range Map:||Click here to open the map viewer and explore range.|
There is no population information available for this species.
|Habitat and Ecology:||
This species inhabits cool, clear, fast-flowing waters in areas of tropical rainforest (Morgan 1988). It is found in streams and pools where it burrows in the bank or shelters in natural crevices for shelter (Monroe 1977). Specimens have been collected during the day from under rocks or in leaf litter, and at night this species has been observed just inside the burrow entrance (Monroe 1977). The burrows of this species have been observed to have one or two entrances (Monroe 1977).
|Major Threat(s):||Euastacus robertsi has low dispersal capabilities through non-continuous rainforest which will result in problems in the future as more and more and more of the surrounding rainforest is harvested (Ponniah and Hughes 1998). This species also has a very limited range which means the effects of habitat degradation will be more pronounced. Agriculture within their range and a loss of riparian vegetation is also having a detrimental effect on the species (Horwitz 1990, 1995). In addition the species is susceptible to the following potential threats:1. Given its highly restricted range, the species is extremely susceptible to localized impacts, including bush fires, forest management practices, habitat destruction and over exploitation by collectors; 2. Climate change, including increasing temperature, alterations to hydrological regimes, severe weather events, loss of suitable rainforest habitat, increased potential for bushfires (Hilbert et al. 2001, Chiew and McMahon 2002, Howden 2003, Hughes 2003, Pittock 2003, Hennessy 2006, Westoby and Burgman 2006, IPCC 2007, Laurance and Curran 2008); 3. There is a potential large scale threat from Cane Toads (Rhinella marina) (DEH 2004a) although there are no specific data on impacts for this species. Other exotic species (cats and pigs) that have generally been found to impact on crayfish (e.g. Horwitz 1990, Merrick 1995, Eyre et al. 1997, ACT Government 2007, O’Brien 2007) also occur in this species’ range (DEH 2004b,c) and given this species highly restricted distribution and rarity, could have serious impacts on E. robertsi by contributing to declines in its distribution and/or abundance.|
There are no species specific conservation measures in place for this species. However its distribution coincides with a number of protected areas including the Northern Queensland World Heritage Area, Cape Tribulation National Park and Cedar Bay National Park (J. Coughran and J.M. Furse pers. comm. 2009). 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 (J. Coughran and J.M. Furse pers. comm. 2009).
Further research should be initiated to include population assessment and monitoring, biological and life history information, habitat requirements, investigations into thermal tolerance and the impacts of threats within its range (J. Coughran and J.M. Furse pers. comm. 2009).
|Citation:||Coughran, J. & Furse, J. 2010. Euastacus robertsi. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 05 July 2015.|