Crayfishes
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© Judie Shore; Chimney Crayfish (Fallicambarus fodiens) |
Quick facts
Background
Richness and diversity in Canada
Species spotlight - Chimney Crayfish
Species spotlight - Virile Crayfish
Status of knowledge in Canada
Results of general status assessment
Threats to Canadian crayfishes
Conclusion
Further information
References
Crayfish: Freshwater crayfishes are a globally common and diverse crustacean group, occurring naturally on all continents except for Africa and Antarctica. Hamr 1998.
Quick facts
There are more than 540 species of crayfishes worldwide, of which 11 are found in Canada.
Almost two-thirds (64%) of Canadian crayfishes have Canada General Status Ranks (Canada ranks) of Secure, while 18% have Canada ranks of Sensitive, and none have Canada ranks of At Risk or May Be At Risk.
Two crayfishes species have Canada ranks of Exotic, the Rusty Crayfish and the Obscure Crayfish. Both were introduced into Ontario as fish bait and now also occur in Quebec. The Rusty Crayfish has spread rapidly in Ontario and has eliminated native crayfishes from many lakes and rivers. Little is known about the Obscure Crayfish in Canada.
One-third of native crayfish species in the United States are Endangered or Threatened, according to the American Fisheries Society Endangered Species Committee.
Citation for species list
Crayfishes
Hamr, P. 1998. Conservation status of Canadian freshwater crayfishes. World Wildlife Fund Canada and the Canadian Nature Federation, Toronto. 87 pp
Hobbs, H. H. 1989. An illustrated checklist of the American crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Institution Press, Washington, D.C.
Helfrich , L. A. , and R. J. DiStefano 2003. Sustaining America's Aquatic Biodiversity: Crayfish Biodiversity and Conservation Publication , Virginia Cooperative Extension Note number 420-524.
Tayler , C.A., M.L. Warren, Jr. , J.F. Fitspatrick, Jr., H.H.Hobbs, III, R.F. Jezeriknac, W.L. Pfieger and H.W. Robison.(1996). Conservation Status of Crayfishes of the United States and Canada. Fisheries 21: 25-38.
