Meeting Abstract

P3-86   -   Electrocardiograms and Energetics: Using heart rate to assess energy consumption in Lepomis macrochirus Kelleher, BK*; Clark, AD; Tytell, ED; Tufts University; Tufts University; Tufts University Brendan.kelleher@tufts.edu

Swimming is a distinctive form of locomotion performed by a vast array of fish species and is central to survival and reproduction. Swimming, including specific movements such as rapid acceleration, maintained cruising, and precise maneuvering, allows fish to feed, reproduce, and evade predators. These movements are all energetically costly for the fish and thus, understanding the use of energy is central to understanding the biomechanical behavior of fish during swimming. Measurement of energy consumption in organisms is often done through measurement of oxygen levels in a closed system across the space of several hours, but this cannot measure short term changes of the scale of seconds to several minutes during dynamic movement. A different form of quantification such as heart rate measured through ECG recordings could identify changes in energy consumption over shorter time periods to analyze short term changes during dynamic swimming. We hypothesized that given the anatomical structure and physiological function of the heart in bluegill, heart rate would increase with steady swimming speed to a certain point and then plateau as fish then began to increase stroke volume or used other mechanisms to address the growing energetic needs. To test this, we developed a protocol for the insertion of ECG electrodes into the pericardial cavity of bluegill sunfish to measure heart rate in bluegill across several swimming speeds with high temporal resolution. We examine both average heart rate at different swimming speeds and during unsteady behavior, and also the variation in the heart rate during different behaviors. This technique may help us better quantify the short-term changes in energy consumption during both steady and unsteady swimming.