''Astacus'' (from the Greek , ', meaning "lobster" or "crayfish") is a genus of

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...

found in Europe and western Asia, comprising three

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

(living) species and three extinct fossil species. Due to the crayfish plague, crayfish of this genus have declined in many European regions, being replaced by the invasive species, invasive North American signal crayfish, which carries the plague but is unaffected by it.

Classification

''Astacus'' belongs to the family (biology), family Astacidae, one of the three families of Northern Hemisphere freshwater crayfish within the superfamily (biology), superfamily Astacoidea. The internal phylogeny of Astacidae can be shown in the cladogram below:

Extant species

*''Astacus astacus'' (Linnaeus, 1775) - known as the "European crayfish", "noble crayfish" or "broad-fingered crayfish" - it is distributed across Europe, in France throughout Central Europe, to the Balkans, Balkan Peninsula, and north as far as parts of the British Isles, Scandinavia, and the western parts of the former Soviet Union. It is the most common species of

in Europe, and a traditional foodstuff. Like other crayfish, ''A. astacus'' is restricted to freshwater, fresh water, living only in pollution, unpolluted streams, rivers, and lakes. Males may grow up to 16 cm long, and females up to 12 cm. *''Astacus balcanicus'' (Karaman, 1929) - found in the Vardar river basin, Lake Pamvotida (Greece) and Lake Ohrid (North Macedonia/eastern Albania) *''Astacus colchicus'' Kessler, 1876 - can be found in Rioni river basin (Georgia (country), Georgia)

Fossil species

*?''Astacus edwardsii'' Van Straelen, 1928 - France - proposed to new genus ''Emplastron'' in 2021 study *''Astacus laevissimus'' Fritsch & Kafka, 1887 - Czech Republic *''Astacus multicavatus'' Bell, 1863 - United Kingdom

References

{{Taxonbar, from=Q1942450 Astacidae Crustacean genera Taxa named by Johan Christian Fabricius