Acclimation temperature effects on locomotor traits in adult aquatic anurans (X. tropicalis and X. laevis) from different latitudes: possible implications for climate change.

Climate change is in part responsible for the 70% decline in amphibian species numbers worldwide. Although temperature is expected to impact whole-organism performance in ectotherms, reversible thermal acclimation has been suggested as a mechanism that may buffer responses to abrupt temperature changes. Here, we test for an effect of acclimation on locomotor performance traits (jump force and stamina) in adults of two predominantly aquatic and closely related frog species from different climatic regions, Xenopus tropicalis (tropical) and Xenopus laevis (temperate). We find significant effects of acclimation temperature on exertion capacity and for jump force in X. tropicalis but no effect of acclimation temperature on burst performance in X. laevis. Our results suggest that the two locomotor performance traits measured are differentially impacted by acclimation temperature in X. tropicalis. Our results further support the hypothesis that lower-latitude ectotherms might have greater acclimation capacity than high-latitude ones. Finally, our results highlight the importance of investigating multiple performance traits when evaluating how animals may cope with changes in temperature. Further work is required to evaluate the potential for acclimation in mitigating the negative impacts of climate change on amphibian populations.