Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. 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.
The signal crayfish is a North American species of crayfish. It was introduced to Europe in the 1960s to supplement the North European Astacus astacus fisheries, which were being damaged by crayfish plague, but the imports turned out to be a carrier of that disease. The signal crayfish is now considered an invasive species across Europe, Japan, and California, ousting native species there.
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 Scandinavia and Finland, and Eastern Europe. Males may grow up to 16 cm long, and females up to 12 cm.
Pontastacus leptodactylus, the Danube crayfish, Galician crayfish, Turkish crayfish or narrow-clawed crayfish, is a relatively large and economically important species of crayfish native to fresh and brackish waters in eastern Europe and western Asia, mainly in the Pontic–Caspian region, among others including the basins of the Black Sea, and the Danube, Dnieper, Don and Volga rivers, as well as aquatic systems in Turkey. It has spread widely beyond its native range, beginning in the 1700s when it spread via canals constructed in western Russia and since the 1900s through introducions to many regions for human consumption. Today it is widespread throughout much of Europe.
The common yabby is an Australian freshwater crustacean in the Parastacidae family. It is listed as a vulnerable species of crayfish by the International Union for Conservation of Nature (IUCN), though the wild yabby populations remain strong, and have expanded into new habitats created by reservoirs and farm dams.
The Cambaridae are the largest of the four families of freshwater crayfish, with over 400 species. Most of the species in the family are native the United States east of the Great Divide and Mexico, but fewer range north to Canada, and south to Guatemala and Honduras. Three live on the island of Cuba. The species in the genus Cambaroides are the only found outside North America, as they are restricted to eastern Asia.
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.
Pacifastacus nigrescens, the sooty crayfish, is an extinct species of crayfish in the family Astacidae. It was originally described in 1857 by William Stimpson from the area around San Francisco, where it was once common in the creeks surrounding San Francisco Bay. The signal crayfish, Pacifastacus leniusculus was introduced to California, probably in the 19th century, and since then, no sightings of P. nigrescens have been made; it is now believed to be extinct. Intensive searches of its former habitat have found that every site where it once occurred is now occupied by either the signal crayfish or Procambarus clarkii.
Procambarus is a genus of crayfish in the family Cambaridae, all native to North and Central America. It includes a number of troglobitic species, and the marbled crayfish (marmorkrebs), which is parthenogenetic. Originally described as a subgenus for four species, it now contains around 161 species.
The marbled crayfish or Marmorkrebs is a parthenogenetic crayfish that was discovered in the pet trade in Germany in 1995. Marbled crayfish are closely related to the "slough crayfish", Procambarus fallax, which is widely distributed across Florida. No natural populations of marbled crayfish are known. Information provided by one of the original pet traders as to where the marbled crayfish originated was deemed "totally confusing and unreliable". The informal name Marmorkrebs is German for "marbled crayfish".
Faxonius virilis is a species of crayfish known as the virile crayfish, northern crayfish,eastern crayfish, and lesser known as the lake crayfish or common crawfish. Faxonius virilis was reclassified in August 2017, and the genus was changed from Orconectes to Faxonius. It is native to the central United States, east to tributaries of Lake Erie, Lake Ontario, Lake Champlain and the St. Lawrence River in New York and to much of Canada.
Procambarus zonangulus, the white river crawfish, white river crayfish or southern white river crayfish, is a species of freshwater crayfish. It is a distinct but closely related species from Procambarus acutus, which is also known as white river crayfish and has a wider range.
Biomphalaria pfeifferi is a species of air-breathing freshwater snail, an aquatic animal pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Potamon ibericum is a Eurasian species of freshwater crab. It is an omnivore that feeds on land, but returns regularly to the water, and can survive short periods of drought in burrows and under stones. Its natural range stretches from north-eastern Greece, around both sides of the Black Sea and to beyond the Caspian Sea; populations have also been introduced to southern France. It is included as a near threatened species on the IUCN Red List, and is included in the Red Data Book for Ukraine.
Crayfish are eaten all over the world. Like other edible crustaceans, only a small portion of the body of a crayfish is edible. In most prepared dishes, such as soups, bisques and étouffées, only the tail portion is served. At crawfish boils or other meals where the entire body of the crayfish is presented, other portions, such as the claw meat, may be eaten.
Alviela River is a river in Portugal. It is 51.16 kilometres (31.79 mi) long. The Alviela spring is one of the deepest in the world and is locally connected to a cave complex that represents the most significant fluvio-karstic phenomena in Portugal, one which supports several bat colonies with more than 5,000 bats in total. In 2007, a population of troglomorphic Procambarus clarkii, an invasive crayfish species, was recorded in the Alviela spring, raising concerns about their potential effect on native stygobitic fauna. These crayfish lack all body pigment, although pigmented specimens were recorded in nearby surface waters.
Procambarus acutus, the white river crayfish, is a species of crayfish in the family Cambaridae. It is found in North America and Europe.
Cambarus monongalensis, the blue crayfish or Monongahela crayfish, is a species of burrowing crayfish native to Pennsylvania and West Virginia. It has also been found recently in Ohio. The common name refers to the Monongahela River, with the first specimens being collected from Edgewood Park, Allegheny County, Pennsylvania. It is included on the IUCN Red List as a species of Least Concern.
