Common Name: COMMON CRAYFISH
Scientific Name: Cambarus (Cambarus) bartonii bartonii (Faxon)
Rarity Ranks: G5/No State Ranking
State Legal Status: None
Federal Legal Status: None
Description: The Common Crayfish is probably one of the most variable in North America. The overall color of the Common Crayfish can vary from tan to dark brown or olive with darker blotches. In some populations the rear margins of the abdominal segments can be reddish. The tips of the fingers may be orangish. Usually with a single row of flattened tubercles along the mesial margin of the palm (rarely two rows). The areola is wide and the rostrum is typically short and wide with no marginal spines or tubercles. This species reaches a maximum total body length of about 100 mm (3.9 in).
Similar Species: The Common Crayfish is most likely to be confused with the Little Tennessee Crayfish, Cambarus georgiae; Hiwassee Crayfish, C. hiwasseensis; and Hiwassee Headwater Crayfish, C. parrishi. The claws of both the Hiwassee Crayfish and Hiwassee Headwater Crayfish have two rows of tubercles along the mesial margin of the palm, while those of Common Crayfish typically have a single row. The Little Tennessee Crayfish has marginal spines on the rostrum and a well developed cervical spine; the Common Crayfish possesses neither characteristic.
Habitat: The Common Crayfish inhabits nearly all areas of small streams including flowing areas and pools. It is typically found beneath rocks or woody debris, but will also tunnel along the banks of streams among rocks or under logs.
Diet: No studies of the Common Crayfish are known. Crayfishes are considered opportunistic omnivores and likely feed on live and decaying vegetation, aquatic insect larvae, small fishes, and dead animal matter.
Life History: Male Common Crayfish in reproductive condition have been collected in all months except December, January, and February. Several females with eggs were collected in April and June and a single female with young was found in August. The smallest breeding male known is about 40 mm (1.6 in) and the smallest female with eggs is about 38 mm (1.5 in) in length (Hobbs 1981).
Survey Recommendations: Flipping larger rocks in just about any habitat in a stream should turn up this species. The animal can be pinned by hand or gently driven into a dipnet. Excavating burrows along banks may also yield specimens.
Range: The Common Crayfish is most commonly found in the Blue Ridge physiographic province from northeastern Georgia to Quebec, Canada. In Georgia it primarily inhabits upland streams in the north-central and northeastern portion of the state in the Hiwassee, Chattahoochee, Little Tennessee, and Savannah drainages. There are a few records from the upper Conasauga and Etowah river systems, widely scattered populations in the upper Oconee and Broad river systems, and a single record from the Little River in Wilkes County (Eversole and Jones 2004; Hobbs 1981; 1989).
Threats: This species is apparently secure across its range.
Conservation and Management Recommendations: Conserving populations of the Common Crayfish will require general watershed level protection measures, including the protection of riparian zones, control of sediment and nutrient runoff from farms and construction sites, and limiting the amount of impervious cover (e.g., pavement) within occupied watersheds. Non-native crayfishes should never be used for bait; instead, anglers should use crayfishes collected from the river system where they will be fishing. Unused bait of any kind should not be released back into Georgia waters.
Eversole, A. G. and D. R. Jones. 2004. Key to the Crayfish of South Carolina. US Forest Service Publication. 79 p.
Hobbs, H. H., Jr. 1981. The crayfishes of Georgia. Smithsonian Contributions to Zoology 318:1-549.
Hobbs, H.H., Jr. 1989. An Illustrated Checklist of the American Crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Contributions to Zoology 480:1-236.
Taylor, C. A., G. A. Schuster, J. E. Cooper, R. J. DiStefano, A. G. Eversole, P. Hamr, H. H. Hobbs III, H. W. Robison, C. E. Skelton, and R. F. Thoma. 2007. A reassessment of the conservation status of crayfishes of the United States and Canada after 10+ years of increased awareness. Fisheries 32(8):372-389.
Date Compiled or Updated: August 2012