Meeting Abstract
Many fishes perform quick and sudden swimming maneuvers known as fast-starts in an attempt to escape when threatened. In pulse-type weakly electric fishes, including African mormyrids, these responses are accompanied by transient increases in electrical signal production known as novelty responses. While these novelty responses may heighten an individual’s perception of their surroundings, they are aerobically powered and may come at a high energetic cost when compared to fast-start performance, which relies primarily on anaerobic muscle. The juxtaposition between the two key aspects of fast-starts in these fishes, the aerobic novelty response and the anaerobic swimming performance, makes them an interesting model for studying effects of hypoxia on performance and sensory information acquisition. In this study, the mormyrid fish Gnathonemus victoriae was acclimated to either high- or low-dissolved oxygen (DO) levels for eight weeks, after which fast-starts and concurrent novelty responses were quantified under both high and low DO test conditions. Our results indicate no effect of hypoxia on fast-start performance regardless of acclimation or test condition. Novelty responses were given upon each startle, whether or not the fish also performed a fast-start, although they were significantly stronger when accompanied by a fast-start. Novelty responses were also reduced in normoxia-acclimated individuals when tested under hypoxic conditions. Overall, our results indicate an effect of hypoxia on sensing but not fast-start performance.
