SREL Reprint #2029

Factors contributing to temporal and age-specific genetic variation in the freshwater turtle Trachemys scripta

Kim T. Scribner, Stephen J. Morreale, Michael H. Smith, and J. Whitfield Gibbons

Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802

Discussion: Few detailed genetic studies have been conducted on freshwater turtles. In the absence of detailed genetic characterizations of natural turtle populations, several aspects of their life history and ecology suggest a series of working hypotheses regarding expected temporal and age-specific variation. Despite extensive documentation of high longevity and of low adult population turnover, detailed studies by Gibbons and colleagues on the SRS suggest that T. scripta are highly susceptible to variation in environmental regimes, particularly in regard to changes in reproductive and movement ecology. Data for T. scripta from the SRS obtained during this study suggest that populations are not in genetic equilibrium but rather show dramatic annual variation in population genetic characteristics. The magnitude of year-to-year changes in interindividual genetic relationships within each population surveyed corroborate results for a related species C. picta (Scribner et al., 1993) and argue for the generality of these dynamic genetic changes in natural populations of many semiaquatic turtle species.

SREL Reprint #2029

Scribner, K.T., S.J. Morreale, M.H. Smith, and J.W. Gibbons. 1995. Factors contributing to temporal and age-specific genetic variation in the freshwater turtle Trachemys scripta. Copeia 1995:970-977.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).