Common Name: AMBIGUOUS CRAYFISH
Scientific Name: Cambarus (Depressicambarus) striatus Hay
Rarity Ranks: G5/S5
State Legal Status: None
Federal Legal Status: None
Description: Depending on the population encountered, the Ambiguous Crayfish may exhibit a striped or non-striped color pattern. The overall color ranges from olive or light brown, to orangish brown. Striped individuals have paired dark longitudinal stripes on the abdomen which may carry forward onto the carapace. The areola is very narrow, almost obliterated. The rostrum is wide, relatively short and does not have marginal spines or tubercles. There are two rows of tubercles along the mesial margin of the palm. A small, single cervical tubercle is rarely present. This species reaches a maximum total body length of about 120 mm (4.7 in).
Similar Species: Across its range, the Ambiguous Crayfish is most similar to the Variable Crayfish, Cambarus latimanus. According to Hobbs (1981) the two are sometimes impossible to separate. The areola on the Variable Crayfish is typically not as narrow and rostrum is longer and narrower than Ambiguous Crayfish. Careful study will be required for positive identification where the two species overlap.
Habitat: In some parts of its range in Georgia, the Ambiguous Crayfish is a secondary burrower and can often be found in flowing streams (e.g. Conasauga River system). Farther south the species is rarely found in open water and acts more like a primary burrower. In streams it is usually found beneath rocks or within woody debris.
Diet: No studies of the Ambiguous 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 Ambiguous Crayfish in reproductive condition have been collected in all months except February, July, and August. Three females carrying eggs were found in April (Bouchard 1978). The smallest breeding male known is about 48 mm (2.5 in) in length (Camp et al. 2011) and no females with eggs have been collected. The largest female specimen collected is about 90 mm (3.5 in) in length (Bouchard 1978).
Survey Recommendations: In the Conasauga River system, flipping rocks within streams should reveal this species. In other portions of the range, the species is apparently restricted to burrows which will have to be excavated or trapped.
Range: The Ambiguous Crayfish is a widespread species found from Mississippi to western South Carolina and north to Kentucky. In Georgia it is most commonly found in the northwestern portion of the state with scattered populations south and east. It is found all the way to the Florida state line in the Chattahoochee and Flint river systems but has not been found farther south than the Altamaha in river systems that flow to the Atlantic Ocean (Hobbs 1981; 1989).
Threats: This species is apparently secure across its range.
Conservation and Management Recommendations: General watershed level protection measures will help secure the continued existence of the Ambiguous Crayfish in Georgia. These include 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 they will be fishing in and should never release unused bait crayfish back into Georgia waters. If possible areas with burrows should be protected from land disturbing activities and activities that could alter groundwater resources. Environmental education programs should include information about burrowing crayfishes and encourage protection of burrows.
Bouchard, R. W. 1978. Taxonomy, ecology, and phylogeny of the subgenus Depressicambarus, with the description of a new species from Florida and redescriptions of Cambarus graysoni, Cambarus latimanus, and Cambarus striatus (Decapoda: Cambaridae). Alabama Museum of Natural History Bulletin, 3:26-60.
Camp, M.A., C.E. Skelton, and C.B. Zehnder. 2011. Population dynamics and life history of the Ambiguous Crayfish (Cambarus striatus). Freshwater Crayfish 18(1):75-81.
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