Georgia Wildlife Web

Home Glossary Classification Conservation Status Regions of Georgia Fishes of Georgia Make a Donation

Species Description

Dougherty Plain Cave Crayfish

Cambarus (Jugicambarus) cryptodytes


Classification

Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Family: Cambaridae

Description

Cambarus cryptodytes is a cave-dwelling crayfish with several modifications to live in the pools of cold, dark caves. The Dougherty Plain Cave Crayfish is albino or translucent (nearly clear) in appearance. It has small, unpigmented eyes and long, slender chelae (claws) with 1 or 2 rows of tubercles (small bumps). The rostrum is long and lacks both spines and tubercles. The carapace length is usually measures less than 30 mm (1.2 in) and the total body length is less than 60 mm (2.4 in). The areola is broad and approximately 5 times as long as it is wide.

Life Cycle

As with most cave crayfish, little is known about the life cycle of this species. The only available data about its life history is based upon past collections. First form (sexually mature) males have been collected in September and October. Females with eggs or immature young have not been found. The life cycle of this species may follow the general life cycle of other crayfish described below, but specific details about breeding season duration and development are not presently known. Copulation usually occurs between autumn and spring, for many crayfish. This process involves a sexually mature male crayfish grabbing a female and depositing sperm packages (spermatophores) into the seminal receptacle on the abdomen of a receptive female crayfish. Usually during the spring, females secrete a sticky substance on the underside of their abdomen and pleopods in order to attach their eggs. The eggs and sperm (from the seminal receptacle) are then released upon the sticky surface and fertilization occurs. A female carrying eggs on her abdomen and legs is said to be "in berry." Embryos usually develop and hatch on the underside of females in 2-20 weeks, likely depending upon species and temperature. The immature hatchlings molt (shed their exoskeleton to allow growth) and remain attached to their mother. These first-stage immature crayfish look fairly similar to typical crayfish, but have disproportionately large heads and eyes. Another molting takes place in about 1-2 weeks. These second-stage immature crayfish look even more like adult crayfish. Second-stage or third-stage immature crayfish leave their mother's surface and become independent. These young crayfish continue molting and growing and are usually sexually mature by their second or third autumn. Sexually mature males and females are believed to mate between autumn and late spring and many usually die within 3 years of hatching. There is speculation that cave species may have a longer lifespan that is correlated with their slower metabolism.

Natural History

Relatively little is known about the biology of this species of crayfish. It is limited to subterranean pool areas of caves in Georgia and Florida . Like all cave crayfish, this species appears to be adapted to its dark habitat. It is albino in appearance, has small eyes and large sensory antennae to help find its way around the clear, cool waters of caves. Cave crayfish are opportunistic scavengers. They feed upon any available food source in their secluded habitat, which is sometimes limited to organic material that drifts into the cave pools from outside. Because food is often scarce, they have reduced metabolic rates and may live longer than other types of crayfish. This species is often found associated with the Georgia Blind Salamander (Haideotriton wallacei).

Range

The Dougherty Plain Cave Crayfish is known only from several caves in Jackson County, Florida and Climax Cave in Decatur County , Georgia . Its range lies within the aquifer of the Dougherty Plain in the Apalachicola River basin .

Conservation Status

This species is listed as Rare and Critically Imperiled in Georgia . Very little is known about this species and studies should be conducted to better understand the general biology and life history of this rare crayfish. The Dougherty Plain Cave Crayfish has a very limited range and habitat in Georgia . It is likely quite susceptible to water quality degradation, pollution, unregulated spelunking (cave exploration) and other factors which would impact its fragile habitat.

Similar Species

Cambarus cryptodytes is a rare and unusual crayfish that is limited to one cave in Georgia and has not been found in association with other crayfish.