A fast fish swimming protocol that provides similar insights as critical sustained swimming speed

Abstract

AbstractPerformance measures are an important tool to assess the impact of environmental change on animals. In fish, performance is often measured as critical sustained swimming speed (Ucrit), which reflects individual physiological capacities. A drawback of Ucritis that trials are relatively long (∼30-75 min). Ucritis therefore not suitable for repeated measurements because of the potential for training effects, long recovery periods, and low throughput. Here we test a shorter (∼4-5 min) protocol, “Ucritfast” (UCfast) in zebrafish (Danio rerio). We show that UCfastand Ucrithave similar, significant repeatabilities within individuals. Unlike Ucrit, repeated UCfasttrials do not elicit a training effect. Both UCfastand Ucritprovide the same insights into thermal acclimation, and both provide similar estimates of individual acclimation capacity in doubly acclimated fish. We propose that UCfastis a valid substitute for Ucritparticularly when higher throughput and repeated measures are necessary.