Orconectes virilis (crustacean)

Ecology Distribution Management Info Impact Info References and Links Contacts

General Impact Orconectes virilis may have a variety of impacts on introduced ecosystems that include direct and indirect impacts on habitat, competition with and displacement of native species, and other ecological interactions. O. virilis is known to alter and reduce macrophyte biomass and diversity (Chambers et al, 1990; Davidson et al, 2010; Olden et al, 2009). It may displace native crayfish as in the case of the endangered Pacifastacus nigrescens in California (Light et al, 1995); Orconectes obscurus and Cambarus bartonii in North Carolina (Cooper et al, 1998); and Orconectes limosus and Cambarus bartonii bartonii in Maryland (USA) (Schwartz et al, 1963). Field and laboratoy observations indicate that is may compete with and/or cause the decline of native fish species such as juvenile desert suckers (Catostomus clarkii), the Sonora sucker (Catostomus insignis), and the federally threatened Little Colorado spinedace (Lepidomeda vittata) in Arizona (Davidson et al, 2010; Bryan et al, 2002); the flannelmouth sucker (Catostomus latipinnis) in Colorado (Carpenter, 2005); and the White Sands pupfish (Cyprinodon tularosa) in New Mexico (Rogowski & Stockwell, 2006). It has been reported to contribute to the decline of the Chiricahua leopard frog (Rana chiricahuensis) in Arizona (Davidson et al, 2010). O. virilis is also known to cause the decline of native snails (ANSIS, 2007), as in the case of three forks spring snail (Pyrgulopsis trivialis) in Arizona (Davidson et al, 2010) and Canadian native snails Stagnicola elodes and Physa gyrina in laboratory studies (Hanson et al, 1990). Additional impacts associated with O. virilis include the reduction of insects and other macroinvertebrates (Davidson et al, 2010; Hanson et al, 1990), the alteration of the structure and composition of littoral zones (Chambers et al, 1990), the increase in turbidity of waters (Davidson et al, 2010), and impacts to irrigation networks and levees as a result of their burrowing near head gates and weir boxes (Godfrey, 2002).          Location Specific Impacts: Netherlands   Ecosystem change: Orconectes virilis is believed to have a negative impact on freshwater ecology in introduced locations of the Netherlands (Holdrich et al, 2009; Filipova et al, 2009). Arizona (United States (USA))   Ecosystem change: Orconectes virilis have cleared streams of vegetation, eliminated insects and other organisms, and increased turbidity in small streams (Davidson et al, 2010). Reduction in native biodiversity: Orconectes virilis is a problematic invasive in Arizona where it is known to cause the reduction of native species. It is reported to contribute to the decline of the 'Vulnerable (VU)' Chiricahua leopard frog (see Lithobates chiricahuensis in IUCN Red List of Threatened Species); juvenile desert suckers- a 'Wildlife Species of Concern' (see Catostomus clarkii); the threatened Sonora sucker (see Catostomus insignis), the threatened Little Colorado spinedace (see Lepidomeda vittata), and the Three Forks spring snail (see Pyrgulopsis trivialis) a species in decline(in Davidson et al, 2010). Threat to endangered species: Orconectes virilis is a problematic invasive in Arizona where it is known to cause the reduction of native species. It is reported to contribute to the decline of the 'Vulnerable (VU)' Chiricahua leopard frog (see Lithobates chiricahuensis in IUCN Red List of Threatened Species); juvenile desert suckers- a 'Wildlife Species of Concern' (see Catostomus clarkii); the threatened Sonora sucker (see Catostomus insignis), the threatened Little Colorado spinedace (see Lepidomeda vittata), and the Three Forks spring snail (see Pyrgulopsis trivialis) a species in decline(in Davidson et al, 2010). California (United States (USA))   Reduction in native biodiversity: Orconectes virilis has invaded the endemic range of the 'Critically endangered (CR)' Shasta crayfish (see Pacifastacus fortis in IUCN Red List of Threatened Species) and is believed to be a contributing factor to its decline (Light et al, 1995). Threat to endangered species: Orconectes virilis has invaded the endemic range of the 'Critically endangered (CR)' Shasta crayfish (see Pacifastacus fortis in IUCN Red List of Threatened Species) and is believed to be a contributing factor to its decline (Light et al, 1995). Maryland (USA) (United States (USA))   Competition: Orchonectes virilis is believed to have displaced native crayfish Orconectes limosus and Cambarus bartonii bartonii from the Patapsco River (Schwartz et al, 1963). New Mexico (United States (USA))   Reduction in native biodiversity: A laboratory experiment indicates that Orconectes virilis has a significant effect on reducing the population size of 'Vulnerable (VU)' White Sands pupfish (see Cyprinodon tularosa in IUCN Red List of Threatened Species) in New Mexico (Rogowski & Stockwell, 2006). Threat to endangered species: A laboratory experiment indicates that Orconectes virilis has a significant effect on reducing the population size of 'Vulnerable (VU)' White Sands pupfish (see Cyprinodon tularosa in IUCN Red List of Threatened Species) in New Mexico (Rogowski & Stockwell, 2006). North Carolina (United States (USA))   Competition: Orconectes virilis is reported to have displaced native crayfish Orconectes obscurus and Cambarus bartonii in the Catawba River (Cooper et al, 1998).