Understanding Swimming Performance Variation in Ohio Minnows (Cyprinidae)

Abstract

Understanding variability in swimming performance of freshwater fishes has implications for improving descriptions of ecological niches, establishing evolutionary relationships, and providing management and conservation recommendations. Swimming performance is associated with anatomical, physiological, and environmental variation, although the vast majority of swimming performance research to date has focused on larger game species to the exclusion of smaller non-game taxa, which represent the largest portion of North American freshwater fish diversity. Thus, the objective of this study was to assess a previously unstudied area regarding how swimming covaries with body size, sex, watershed, and habitat types of these smaller non-game taxa. A Blazka style swimming performance chamber following a stepwise critical swimming performance (Ucrit) protocol was used to quantify individual variation in four species of common Ohio Minnows (Cyprinidae: Bluntnose Minnow, Spotfin Shiner, Sand Shiner, and Redfin Shiner). Using a series of general linear models at both a global (taxa combined) and local (taxa specific) scale trends were identified across all individuals (N=150 total individuals). First, species differed in swimming performance, even after controlling for cofactors such as body size. Second, slopes depicting relationships between swimming performance and body size were not consistent among taxa and moreover, sex did not appear to play a role in swimming ability. Lastly, species specific models indicated inconsistent differences among taxa related to watershed and habitat variation. Overall, these results provide an important contribution to furthering our understanding of small bodied non-game fishes