Meeting Abstract

P2.145  Tuesday, Jan. 5  Variation in critical thermal maxima of eastern narrowmouth toads, <1>Gastrophryne carolinensis1>;, over a latitudinal gradient CUPP, JR., P/V; Eastern Kentucky University paul.cupp@eku.edu

Critical thermal maxima (CTM) were determined for adult eastern narrowmouth toads, <1>Gastrophryne carolinensis1>, in four populations located along a latitudinal gradient from southern Kentucky to mid-Florida. At 30 C acclimation, eastern narrowmouth toads in more southerly populations usually had higher CTM’s than those in more northerly populations. Among populations, toads in the mid-Florida population had a significantly higher CTM than those in southern Georgia, which in turn had a higher CTM than toads in a NW South Carolina population. However, eastern narrowmouth toads in a southern KY population had a similar CTM as those in the Florida population and a higher CTM than the other two populations. At 20 C acclimation, populations did not show a significant difference, but the KY population had the highest CTM. The high CTM of the KY population may be influenced by variables other than latitude, such as the type of microhabitat where the frogs occur. Here the puddles were more open and exposed to sunlight, and thus were likely exposed to higher developmental temperatures for eggs and tadpoles. These factors may have contributed to the higher CTM observed in these populations.