Crayfish

thumb|Rearing white-clawed crayfish at Cynrig hatchery, Wales. Establishing a breeding population from introduced captive-bred animals. thumb|Cajun style crayfish thumb|Dried crayfish at an African market

Astacidae is a family of freshwater crayfish native to Europe, western Asia and western North America. The family is made up of four extant (living) genera: The genera Astacus (which includes the European crayfish), Pontastacus (which includes the Turkish crayfish), and Austropotamobius are all found throughout Europe and parts of western Asia, while Pacifastacus (which includes the signal crayfish) is native to western United States and British Columbia, but has also been introduced elsewhere.

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.

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 to 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 only found outside North America, as they are restricted to eastern Asia.

crayfish disease caused by Aphanomyces astaci

Astacoidea is superfamily of freshwater crayfish that live in the Northern Hemisphere. The other superfamily of crayfish, Parastacoidea, lives in the Southern Hemisphere. Astacoidea consists of three families: Astacidae (from Europe and western North America), Cambaridae (from eastern North America), and Cambaroididae (from eastern Asia). Crayfish are closely related to lobsters, as shown in the simplified cladogram below.

species of Malacostraca

Parastacus is a genus of southern crawfish in the family Parastacidae. There are about 15 described species in Parastacus, found in South America. In addition, there are some preserved specimens from Australia that are possibly members of this genus. thumb|Parastacus brasiliensis, Brazil

species of Malacostraca

thumb|Cambaroides dauricus

species of Malacostraca

species of Malacostraca