Meeting Abstract

132.3  Tuesday, Jan. 7 14:00  Copper tolerance in the southern toad, Anaxyrus terrestris: a quantitative genetic approach FLYNN, RW*; LANCE, SL; University of Georgia, Savannah River Ecology Laboratory; University of Georgia, Savannah River Ecology Laboratory wflynn@srel.uga.edu

Amphibian population declines have been extensively studied, and environmental contaminants have been implicated as co-factors in many of the declines. Copper is an environmental contaminant that is common in aquatic habitats worldwide due to anthropogenic activities. Copper is acutely toxic to virtually all aquatic plants and animals, including amphibians. In environments with elevated Cu, organisms can be differentially selected based on tolerance to Cu, as well as other fitness-related traits. Southern toads (Anaxyrus terrestris) exhibit considerable variation in their response to Cu, both among individuals and populations. We used a quantitative genetics approach (four female, four male full-sib crosses) to quantify the parental contributions to embryonic and larval responses to Cu. Embryo survival was affected by Cu concentration and parentage, with a significant Cu x sire interaction. Larval growth and development also differed among Cu levels and parents, with a significant dam x Cu interaction. Overall heritabilities were higher for developmental stage reached than growth rate. Environmental exposure to elevated Cu could have evolutionary consequences for this population of southern toads. The differential parental contributions to Cu tolerance could have further implications if tolerance constrains other fitness-related traits. Populations may adapt to tolerate Cu, but may cope poorly with other environmental stressors thought to be affecting amphibian populations, such as shortened hydroperiods and increased drought frequency.