Procambarus

The well-known and widespread Procambarus clarkii

The bright blue aquarium strain of Procambarus alleni

The majority of the diversity is found in the southeastern United States, but the genus extends as far south as Guatemala and Honduras, and on the Caribbean island of Cuba.[2][3] After United States, the highest diversity is in Mexico with about 45 species. Only two are native to Guatemala (P. pilosimanus and P. williamsoni), one to Belize (P. pilosimanus), one to Honduras (P. williamsoni) and three to Cuba (P. atkinsoni, P. cubensis and P. niveus).[3]

Subgenus Ortmannicus was the most widespread, with the range of Procambarus acutus extending as far north as the Great Lakes and New England, as well as south into northeastern Mexico; the subgenus Girardella also extended from the Great Lakes to Mexico, but was distributed further west than Ortmannicus.[4] Scapulicambarus and Pennides were widespread in the southeastern United States, further west (Texas and Louisiana) than Leconticambarus which was centered on Florida and neighbouring states. The subgenus Austrocambarus had the most southerly distribution, being found in Cuba and parts of Central America from Mexico to Belize, Guatemala and Honduras. The other subgenera are more restricted in their distributions, including three endemic to central Mexico, and six endemic to small areas in the United States.[2][3][4]

A few species of Procambarus have been introduced to regions outside their native range, both in North America and other continents. They are frequently categorized as invasive species, representing a threat to natives, including rarer crayfish species.[3][5][6]

Larva

Procambarus can be distinguished from other genera of crayfish by the form of the first pleopod in males, which typically has three or more processes at the tip, compared to two or fewer in Faxonius and Cambarus.[7]

Procambarus vazquezae is found only in Laguna Catemaco in Mexico

Most Procambarus species live in various above-ground waters such as rivers, streams, lakes, ponds and swamps, but several are troglobitic, living in caves, particularly in karstic areas. In the United States, these include both species in subgenus Lonnbergius (P. acherontis and P. morrisi).[8] Other cave-dwellers in the United States with various levels of troglomorphic adaptions are P. attiguus, P. erythrops, P. franzi, P. leitheuseri, P. lucifugus, P. milleri and P. orcinus, but these are all members of subgenera that also include species from above-ground waters. In Cuba, P. niveus is a cave-dweller. In Mexico, many species have been recorded in caves, but most of these have also been recorded from above-ground waters; only P. cavernicola, P. oaxacae, P. rodriguezi and P. xilitlae are strict cave-dwellers and troglomorphic.[9] In 2007, troglomorphic specimens of P. clarkii were found in caves in Portugal and Italy.[10]

The marbled crayfish (marmorkrebs) is parthenogenetic

Procambarus was originally described by Arnold Edward Ortmann in 1905 as a subgenus of a wider genus Cambarus, and originally contained only four species (P. williamsoni, P. digueti, P. mexicanus and P. cubensis).[11] The subgenus was elevated in 1942 to the taxonomic rank of genus by Horton H. Hobbs Jr., who later erected most of the subgenera fornerly recognised within the genus, in his 1972 monograph The subgenera of the crayfish genus Procambarus (Decapoda: Astacidae).[4] However, more recently the subgenera have been eliminated, and while it is recognized that Procambarus is not monophyletic, later literature does not make further taxonomic changes suggesting that more species sampling is required.[12]

• Media related to Procambarus at Wikimedia Commons
• Data related to Procambarus at Wikispecies
• Key to the subgenera of Procambarus