Date of Award





Earth and Space Science - Environmental Science Track


Earth & Space Science

First Advisor

George E. Stanton


Two crayfish species, whose conservation status was of concern, Procambarus (Pennides) gibbus Hobbs and Procambarus (Pennides) versutus Hagen, and one relatively common crayfish, Procambarus (Pennides) spiculifer LeConte were studied at nine creek sites in Marion County, Georgia. Major objectives of the yearlong study were to 1) compare the habitats of these species, looking for environmental differences that might account for their isolated distributions within the county and 2) assess the current conservation status of P. gibbus and P. versutus. Each study site was characterized by a one-time assessment of floodplain width, stream width, water velocity, stream depth and assessment of bed substrate and dissolved solids. Water was tested bimonthly to measure temperature, specific conductivity, turbidity, pH, and dissolved oxygen. Results indicate that Procambarus versutus habitat is clearly different from the habitats of the sister species by virtue of its lower pH and turbidity. Procambarus gibbus habitat is distinguished from those of the other two species with regard to substrate (higher gravel and coarse sand content) and higher conductivity. Wire traps baited with canned cat food were checked weekly to monitor crayfish populations. Captures indicated year-round activity from healthy populations of each species, but P. gibbus merits conservation because it is essentially endemic to Muckalee Creek. P. versutus merits conservation attention in Georgia because its range is quite restricted in the state and most, if not all of it range lies within the Fort Benning Military Reservation, where it may receive special attention but also may be subject to habitat modification dictated by issues of national security.