Assessing Temperature Related Variation in Routine Metabolic Rate Across the Geographic Range of the Bluntnose Minnow

Predicted changes in climate will potentially affect aquatic taxa via increasing water temperatures.  Consequently, an attempt to understand the relationships between species distributions and the potential effects of climate change in aquatic environments requires an approach that integrates physiological trait data and local environmental conditions for individual species.  Routine metabolic rate (RMR) is a reasonable measure of normal daily activity cycle and may represent one of the most important traits when considering predicted changes in regional temperatures.  We predict that variation in RMR is correlated with variation in mean annual temperature among sites across the geographic range of P. notatus.  To test this prediction, individuals representing ten populations of P. notatus were collected from throughout the mid-western United States.   Routine metabolic rate data were collected using intermittent flow through respirometry from individuals from each population which were acclimated to three temperature treatments (9°C, 18°C, and 27°C).  Results indicate a correlation between RMR and latitude of the collection location and suggest the importance of understanding population-level responses to predicted changes in climate when considering potential future distributions of aquatic taxa.