The Cambaridae are the largest of the four

families Family (from ) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictability, structure, and safety as ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

crayfish 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 spe ...

, with over 400

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

. 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 Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...

and

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. It is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Ocean at the Gulf of Fonseca, ...

. Three live on the island of

Cuba Cuba, officially the Republic of Cuba, is an island country, comprising the island of Cuba (largest island), Isla de la Juventud, and List of islands of Cuba, 4,195 islands, islets and cays surrounding the main island. It is located where the ...

. The species in the genus ''

Cambaroides ''Cambaroides'' is a genus of freshwater crayfish from eastern Asia (eastern Russia, northeastern China, Korean Peninsula and Japan). Together with ''Pontastacus ''Pontastacus'' is a genus of freshwater crayfish native to eastern Europe and w ...

'' are only found outside North America, as they are restricted to eastern Asia. A few species, including the invasive ''

Procambarus clarkii ''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 introduc ...

'' and ''

Faxonius rusticus The rusty crayfish (''Faxonius rusticus'') is a large, aggressive species of freshwater crayfish which is native to the United States, in the Ohio River Basin in parts of Ohio, Kentucky, and Indiana. Its range is rapidly expanding across much of ...

'', have been introduced to regions far outside their native range (both in North America and other continents). Conversely, many species have tiny ranges and are seriously threatened; a few are already extinct. A 2006 molecular study suggested that the family Cambaridae may be

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

, with the family

Astacidae Astacidae is a family (biology), family of freshwater crayfish native to Europe, western Asia and western North America. The family is made up of four extant taxon, extant (living) genera: The genera ''Astacus'' (which includes the European crayf ...

nested within it, and the status of the genus ''Cambaroides'' remains unclear. The oldest fossils of the family are known from the

Late Jurassic The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...

Morrison Formation The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltston ...

of western North America.

References

External links

* * Crayfish Decapod families Taxa named by Horton H. Hobbs Jr. {{Crayfish-stub