Common Name: WHITE TUBERCLED CRAYFISH
Scientific Name: Procambarus (Pennides) spiculifer (LeConte)
Rarity Ranks: G5/S5
State Legal Status: None
Federal Legal Status: None
Description: The overall appearance of the White Tubercled Crayfish is brownish to bluish with dark markings. As the name implies, the claws are dark with whitish tubercles; the claws can be quite large on males in reproductive condition. The carapace typically has a dark saddle near its rear edge that extends forward on either side of the carapace as two “horns”. The most obvious pigmentation characteristics are the discrete reddish or purplish spots along the margins of the abdomen. The rostrum is long and sharply pointed and there are two distinctive cervical spines on either side of the carapace. Adult White Tubercled Crayfish may reach a maximum total body length of over 100 mm (>4 in).
Similar Species: The presence of two cervical spines separates the White Tubercled Crayfish from all Georgia species except other members of the subgenus Pennides. The Disjunct Crayfish, Procambarus raneyi, is very similar and may occur with the White Tubercled Crayfish in the Broad and Ocmulgee river systems. However, the palms of the Disjunct Crayfish are light with dark tubercles rather than dark with light tubercles. There are also differences in the male reproductive structure which must be examined using magnification. The White Tubercled Crayfish could also occur (however unlikely) with the Muckalee Crayfish (P. gibbus) in the mainstem Flint River. Details of the first pleopods of first form males are required to separate these two species.
Habitat: The White Tubercled Crayfish is found in a wide array of flowing water habitats across its range. Depending on the substrates available it can be found hiding beneath rocks, within woody debris or leaf litter, and beneath undercut banks.
Diet: No studies of the White Tubercled Crayfish diet 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: Males in reproductive condition have been collected in all months except January. Hobbs (1981) listed numbers of eggs for seven ovigerous females between 22 and 363. He suggested that eggs had been lost from the female with the lower number. These females were collected in April, May, and August. White Tubercled Crayfish are probably mature after their first year of life and live a maximum of about three years (Hobbs 1981).
Survey Recommendations: In rocky streams most easily collected by holding a net perpendicular to the current downstream of a large rock, then lifting the rock and disturbing the substrate beneath it. If a crayfish is hiding underneath the rock, it will likely move into the net. Use the same technique in streams with woody debris or aquatic plants. Shocking downstream into a seine net with a backpack electroshocker is also effective. Collections in spring or fall are more likely to produce males in reproductive condition which can be helpful with identifications.
Range: The White Tubercled Crayfish is found from the upper Savannah River system in South Carolina, south and west to the Mobile Basin in Alabama (Hobbs 1989). It is the most widespread and arguably the most common crayfish in Georgia. Until recently, is known from all major river systems in Georgia except the Chattooga (Coosa), the Ogeechee, and the lower Savannah (Hobbs 1981).
Threats: This species is considered secure although it is apparently being replaced in the lower Flint River system by the Creole Painted Crayfish, Orconectes palmeri creolanus (Sargent et al. 2011)
Conservation and Management Recommendations: General watershed level protection measures will help secure the continued existence of the White Tubercled 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.
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.
Sargent, L.W., S.W. Golladay, A.P. Covich, and S.P. Opsahl. 2011. Physicochemical habitat association of a native and a non-native crayfish in the lower Flint River, Georgia: implications for invasion success. Biological Invasions 13:499–511.
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