Loading profile...

Loading profile. Please wait . . .

Boxclaw Crayfish. Photo by Chris Lukhaup. Image may be subject to copyright.
range map button NatureServe button About button

Cambarus distans Rhoades, 1944

Boxclaw crayfish

Federal Protection: No US federal protection

State Protection: No Georgia state protection

Global Rank: G5

State Rank: S1

SWAP High Priority Species (SGCN): Yes

Element Occurrences (EOs) in Georgia: 2

Habitat Summary for element in Georgia: Clear cool streams under debris or clean slab rocks; streams can dry to isolated pools


Description

This a generally drab crayfish with overall colors of olive and tan. The carapace and abdomen have a mottled appearance and rostral margins darker than surrounding areas. The claws are brownish and there is a single row of well-developed tubercles along the mesial margin of the palm. The areola is wide and the rostrum is short and narrows quickly creating a short acumen. This species reaches a maximum total body length of about 65 mm (2.6 in).

Similar Species

This is the only species of crayfish collected within its range in Georgia.

Habitat

The Boxclaw Crayfish is found hiding beneath rocks and debris in stream and spring run habitats.

Diet

No studies of the Boxclaw 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

Stream dwelling crayfishes typically hide during the day and come out at night to feed. Reproduction usually occurs during the spring and fall, but males in reproductive condition may be found at any time during the year. When female crayfish are ready to lay eggs, they usually find a secure hiding place and hence are rarely encountered. When the eggs are released, the female attaches them to her swimmerets and is said to be “in berry.” Upon hatching, the juvenile crayfish are attached to the mother by a thread. After the juveniles molt for the second time, they are free of the mother, but stay close and will hold on to her for some time. Eventually they move off on their own. Crayfishes molt 6 or 7 times during their first year of life and most are probably able to reproduce by the end of that year. They molt once or twice a year for the remainder of their lives and live about 3 years. No information on breeding condition males or females is available for this species in Georgia.

Survey Recommendations

This species can be collected by carefully removing large rocks (or other debris) and either pinning the crayfish by hand or coaxing into a dipnet. The use of minnow traps set overnight would probably be effective as well.

Range

The range of the Boxclaw Crayfish barely penetrates Georgia. It is currently known only from a single stream (Murphy Hollow Creek) in Dade County in northwestern Georgia. This species is primarily distributed along the Cumberland Plateau in Tennessee and Kentucky (Hobbs 1981, 1989).

Threats

Although the species has no obvious threats, the fact that it is known from only one location in the state makes it vulnerable to extirpation from land use changes or the introduction of a non-native crayfish species.

Georgia Conservation Status

The species is highly endangered in Georgia based simply on the fact it is known from only a single location.

Conservation Management Recommendations

Conserving populations of the Boxclaw 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.

References

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 32:372–389.

Authors of Account

Christopher E. Skelton

Date Compiled or Updated

C. Skelton, 2012: original account

C. Skelton, January 2019: general update of account.