Meeting Abstract
Most fishes perform stereotyped fast-start responses to escape predation when threatened, and a fish’s ability to perform these responses can directly affect survival. As a result, individuals should be able to maximize fast-start performance even under physiologically limiting conditions such as hypoxia (low dissolved oxygen (DO) concentration). Previous studies have shown the anaerobic locomotor performance of fast-starts can be largely unaffected by hypoxia, but suggest that hypoxia negatively affects the aerobic non-locomotor aspects of fast-starts (e.g., directionality) that rely on a fish’s ability to sense their environments. However, research on these effects is limited because of the difficulty of quantifying how an individual senses their environment. To address this issue, we used a weakly electric fish (Gnathonemus victoriae) as a model system because the electric signals they produce to sense their environments can be non-invasively quantified in free-swimming individuals. In this study, we acclimated G. victoriae to either high or low DO levels for 8 weeks, and subsequently quantified fast-start performance along with electric signal production under high- or low-DO test conditions. Locomotor performance of fast-starts (e.g., displacement) was largely unaffected by low-DO test conditions regardless of acclimation. However, individuals acclimated to high-DO conditions had reduced electric signal production under low-DO test conditions. Our results suggest that exposure to acute hypoxia compromises the ability of fish to sense their environment during fast-starts; however, acclimation reduced the negative effects of hypoxia on performance.
