Crayfish are freshwater crustaceans resembling small lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mudbugs, or yabbies. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some species are found in brooks and streams, where fresh water is running, while others thrive in swamps, ditches, and paddy fields. Most crayfish cannot tolerate polluted water, although some species, such as Procambarus clarkii, are hardier. Crayfish feed on animals and plants, either living or decomposing, and detritus.
Astacus astacus, the European crayfish, noble crayfish, or broad-fingered crayfish, is the most common species of crayfish in Europe, and a traditional food source. Like other true crayfish, A. astacus is restricted to fresh water, living only in unpolluted streams, rivers, and lakes. It is found from France throughout Central Europe, to the Balkan Peninsula, and north as far as parts of the British Isles, Scandinavia and Finland, and Eastern Europe. Males may grow up to 16 cm long, and females up to 12 cm.
The Parastacidae are the family of freshwater crayfish found in the Southern Hemisphere. The family is a classic Gondwana-distributed taxon, with extant members in South America, Madagascar, Australia, New Zealand, and New Guinea, and extinct taxa also in Antarctica.
Cherax quadricarinatus is an Australian freshwater crayfish.
The Tasmanian giant freshwater crayfish, also called Tasmanian giant freshwater lobster, is the largest freshwater invertebrate and the largest freshwater crayfish species in the world. The species is only found in the rivers below 400 metres (1,300 ft) above sea level in northern Tasmania, an island-state of Australia. It is listed as an endangered species on the IUCN Red List due to overfishing and habitat degradation, and it has been prohibited to catch the crayfish since 1998.
Procambarus clarkii, known variously as the red swamp crayfish, Louisiana crawfish or mudbug, is a species of cambarid crayfish native to freshwater bodies of northern Mexico, and southern and southeastern United States, but also introduced elsewhere, where it is often an invasive pest.
Austropotamobius pallipes is an endangered European freshwater crayfish, and the only crayfish native to the British Isles. Its common names include white-clawed crayfish and Atlantic stream crayfish.
The blue crayfish, sometimes called the electric blue crayfish, the sapphire crayfish, or the Florida crayfish, is a species of freshwater crayfish endemic to Florida in the United States. Its natural range is the area east of St. Johns River and all of Florida from Levy County and Marion County southwards, as well as on some of the Florida Keys. It is included on the IUCN Red List as a species of Least Concern. The blue crayfish is frequently kept in freshwater aquaria. In the wild, this species varies from brown-tan to blue, but the aquarium strain has been selectively bred to achieve a brilliant cobalt blue color.
Cherax quinquecarinatus is a small freshwater crayfish endemic to the south-west corner of Australia. It is one of two species known as gilgie, or jilgi, which is a seasonal food source for people of the region. Gilgies are found throughout a biogeographically isolated region of the coastal south of Western Australia and are significant in the ecology of aquatic systems of that bioregion.
The Betsileo short-tailed rat is a species of rodent in the family Nesomyidae. It is found only in Madagascar. Its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland.
Astacoides is a genus of freshwater crayfish endemic to Madagascar. The first specimens were brought to Europe in 1839, and seven species are now recognised, most of which are considered as threatened on the IUCN Red List. They are large and slow-growing, and are threatened by habitat loss, overexploitation by local people and by spread of introduced non-indigenous marbled crayfish. They are only found in a relatively small part of the island, mostly in undisturbed upland areas. They belong to the Gondwana-distributed family Parastacidae, but their nearest relatives live in Australasia, there being no native crayfish in mainland Africa or India.
Astacoides caldwelli is a species of crustacean in family Parastacidae. It is endemic to Madagascar. A. caldwelli is mostly found in rivers draining forested areas at elevations between 600 - 800m. The populations are threatened by habitat loss as well as predation by introduced species and harvesting at a subsistence level from local fishermen.
Astacoides crosnieri is a species of crustacean in family Parastacidae. It is endemic to Madagascar, being widespread in the former Province Fianatantsoa. A. crosnieri inhabits swampy areas at an elevation between 500 – 1000 m above sea level.
Astacoides granulimanus is a species of southern crawfish in the family Parastacidae.
Astacoides madagascarensis is a species of southern crawfish in the family Parastacidae.
Astacoides petiti is a species of southern crawfish in the family Parastacidae.
Procambarus zonangulus, the white river crawfish, white river crayfish or southern white river crayfish, is a species of freshwater crayfish.
Astacopsis is a genus of crayfish endemic to the island of Tasmania. There are three extant species, Astacopsis gouldi, Astacopsis franklinii, and Astacopsis tricornis. All are threatened by illegal harvesting, and A. gouldi is protected by law. A. franklinii is found in the eastern half of the island, with A. tricornis taking its place in the west. A. gouldi is found only in rivers draining into the Bass Strait, except for the Tamar River.
