Procambarus clarkii

Electrophoretic phylogenetic analysis revealed the five southeastern species of the subgenus Scapulicambarus revealed two cl;ades, one containing P. clarkii and P. troglodytes, and the other containing P. howellae, P. paeninsulanus, and P. okaloosae (Busack 1989).

Native range extends from the Mississippi-Ohio confluence down the Mississippi River floodplain to Louisiana, and along the Gulf coastal Plain southwest to Alabama, to the Rio Grande basin in south New Mexico and north Mexico. It was widely introduced in many places throughout Africa, Asia, and Europe, and also outside its native range in North America.

Native range extends from the Mississippi-Ohio confluence down the Mississippi River floodplain to Louisiana, and along the Gulf coastal Plain southwest to Alabama, to the Rio Grande basin in south New Mexico and north Mexico. Mexican distribution includes Baja California, Baja California Sur, Chihuahua, Sonora, Sinaloa, Durango, Coahuila, Nuevo Leon, and Tamaulipas (Hernandez et al., 2008). It was widely introduced in many places throughout Africa, Asia, and Europe, and also outside its native range in North America (see Hobbs, 1989). Genetic variation in introduced European populations found to be high enough to uniquely fingerprint most of the surveyed individuals (Barbaresi et al., 2003) and a similar situation exists in Asia (Yue et al., 2010). In the United States, established non-native populations now occur in California, Nevada, Idaho, Illinois, New York, North Carolina, Ohio, Oregon, and Washington (Taylor and Schuster, 2004).

The species has been introduced to Massachusetts (University of Massachusetts campus pond, Amherst) and Rhode Island (University of Rhode Island campus pond, Kingston) (Smith, 2000). Recently it was found at a single in the Catawba River in North Carolina (Alderman, 2005). It has been introduced to all North Carolina river basins in the Piedmont Plateau and Coastal Plain (Cooper and Armstrong, 2007; Simmons and Fraley, 2010). It has been introduced in a variety of aquatic habitats in lentic areas in South Carolina across much of the state (Eversole and Jones, 2004).In Georgia, it has been introduced into a single stream in downtown Athens and a highly disturbed urban stream in Gwinnett Co. and an urban stream in the Etowah River system (Skelton, 2010). In the Cumberland Plateau it occurs from introductions in the Black Warrior River system in Jefferson Co., Alabama. (Bouchard, 1974). In Kentucky, it has a distribution almost identical to Procambarus viaeviridis; known from the floodplains of the extreme lower Tennessee, lower Ohio, and Mississippi Rivers and from tributaries of the Mississippi River in the extreme western portion of the state (Taylor and Schuster, 2004). In Indiana, it was collected in 2000 from Lake Michigan in Indiana and it has spread into the West Branch of the Grand Calamet River (Simon, 2001) and more recently in East Branch Calumet River in Lake Co. (Simon et al., 2005). In Ohio, it was introduced in the western end of Sandusky Bay, a fish hatchery at Denison University, and the Grand River upstream of Harpersfield Dam (Thoma and Jezerinac, 2000). In Missouri, it occurs widely in the Lowland Faunal Region (Pflieger, 1996). In Illinois it is known from lowland habitats in the extreme southern Illinois counties of Alexander, Jackson, massac, Pope, Pulaski, and Union (Page, 1985) and recently the North branch Chicago River in Chicago, Cook Co.; hundreds of km north (Taylor and Tucker, 2005). In Alabama, it is known from the Tennessee, Mobile, Black Warrior, Cahaba, Coosa, Tallapoosa, and Escambia River systems (Schuster and Taylor, 2004) as well as Alabama, Pascagoula, and Tombigbee drainages (Schuster et al., 2008). In Texas, the natural range is throughout the eastern portion along the coastal plain and upstream within rivers thatr flow from the Edwards Plateau into the Gulf (Johnson and Johnson, 2008). This species has been documented in Cuatro Cienegas, Coahuila, Mexico (Dinger et al., 2005).

The red swamp crayfish is a highly invasive species which is under no threat. It is a major threat to other crayfish and to freshwater ecosystems in general. In an anomalous instance, P. acutus replaced P. clarkii in experimental culture ponds in South Carolina in <10 years (Eversole et al., 2006).