Common Name: BROAD RIVER BURROWING CRAYFISH
Scientific Name: Distocambarus devexus Hobbs
Rarity Ranks: G1/S1
State Legal Status: Threatened
Federal Legal Status: None
Description: The overall color of the Broad River Burrowing Crayfish is tan to brownish with dark mottling. The areola is fairly narrow and the rostrum is wide, gradually converging anteriorly to a blunt point. The moveable fingers of the claws are about the same length as the mesial margins of the palm of the claws. The abdomen appears narrower than the cephalothorax. This species reaches a maximum total body length of about 75 mm (3 in).
Similar Species: Small individuals of the Broad River burrowing crayfish may be confused with small individuals of the Variable Crayfish (Cambarus latimanus). Juveniles of the latter usually have red-tipped claws, and a more sharply pointed rostrum. In addition, the moveable fingers of the claws are about 1.5 times the length of the mesial margin of the palm rather than about equal in length as in the Broad River Burrowing Crayfish.
Habitat: Simple and complex burrows adjacent to streams or in low areas where the water table is near the surface of the ground. A single specimen was collected from a burrow that did not penetrate the water table and was only damp in the bottom. This species (particularly juveniles) is frequently collected in temporary pools and ephemeral streams.
Diet: No studies of the Broad River Burrowing Crayfish are known and the diet of burrowing crayfishes in general is poorly understood. Crayfishes are considered opportunistic omnivores and likely feed on a variety of items, both plant and animal, living or dead. Burrowing crayfishes may forage around the mouths of their burrows, eat organisms that crawl or fall into the burrow, or eat worms that inadvertently tunnel through a burrow wall.
Life History: Males in reproductive condition have been collected in April and a female with large, bright orange eggs was observed in May. On two occasions, a male and female Broad River Burrowing Crayfish were found in the same burrow.
Survey Recommendations: Burrowing crayfishes may be collected by direct excavation of their burrows, by trapping, and during night surveys. Excavating burrows is time consuming and can be very difficult. It also results in destruction of the animals’ burrow. Traps made with PVC pipes or mist nets can be effective. Burrowing crayfishes are sometimes captured around the openings of their burrows on damp nights. Active burrows are found from about mid-March to mid-November if the water table is within about two feet of the surface of the ground.
Range: The Broad River Burrowing Crayfish is currently known from about seven locations in the Broad River system (Savannah River drainage) in northeastern Georgia in Wilkes, Washington, and Elbert counties. It has recently been found in Lincoln County in tributaries to impounded portions (Clark’s Hill Reservoir) of the Little and Savannah rivers.
Threats: The small range of this species makes it vulnerable to land disturbing activities around streams and wetlands.
Conservation and Management Recommendations: If possible, areas with burrows should be protected from land disturbing activities. Additional surveys and life history studies are needed to better define the range of the Broad River Burrowing Crayfish to help predict its response to environmental change. Environmental education programs should include information about burrowing crayfishes and encourage protection of burrows.
Hobbs, H. H., Jr. 1981. The crayfishes of Georgia. Smithsonian Contributions to Zoology 318:1-549.
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: September 2012