Meeting Abstract
Locomotion is key to survival of many fishes and depends upon their ability to use their body and fins to generate thrust. Economic swimmers should exhibit lower metabolic rates at a given swim velocity, allowing energy to be used for other tasks. However, previous studies disagree on whether fin damage impairs swimming energetics. A common metric to assess swimming performance and energetics is critical swimming speed (Ucrit) which forces fish to swim continually at increasing incremental speeds. However, the energy used at higher speeds may be confounded by the duration of the trial. The purpose of this study is to find out if fin damage impacts swimming energetics and whether differences are repeatable using modifications to the Ucrit protocol. Bluegill sunfish (Lepomis macrochirus) are common in the United States and have been used in previous studies on swimming performance. Bluegill were collected from a hatchery using a monofilament cast net, which caused fin damage (n=6 damaged fish), and an electrofisher, which did not damage fins (n=6 healthy fish). Fish were randomly exposed to 6 ecologically relevant flow speeds (5-30 cm/s) in a swim tunnel respirometer for 10 minute intervals with 5 minutes of rest between speeds. All fish were tested again at least 2 weeks later using different randomization of speed intervals. We predict that damaged fish will repeatedly display higher metabolic rates at each speed compared to healthy fish. Allowing rest periods between randomized changes in speed should reduce exhaustion as a limiting factor and increase repeatability of measurements. This study has the potential to shed light on the consequences of fin damage for locomotor performance in bluegill.
