LEVINE, Robert P.*; STANDEN, Em; BRAINERD, Elizabeth L.; DOMENICI, Paolo; Univ. of Massachusetts, Amherst; Univ. of British Colombia, Canada; Univ. of Massachusetts, Amherst; International Marine Center, Loc. Sa Mardini, Italy: Effect of body size on fast-start performance in the Pacific staghorn sculpin, Leptocottus armatus

The effect of body size on fast-start performance in fishes has received considerable attention the past few decades and has been the basis for interpretations of the scaling of predator-prey interactions. While many of these scaling studies have focused on maneuverability and distance-related measures of performance, other factors such as latency may also be crucial for predicting outcomes of escape responses. To examine the effects of body size on latency, turning and distance-related performance parameters, escapes from 104 Pacific staghorn sculpins, ranging in total length from 2.2 to 25.2 cm (0.11-195g), were analyzed using high-speed video. Our results show that latency, maximum velocity and acceleration increased with increasing total length while maximum turning rate decreased with increasing total length. Distance from the stimulus and initial orientation relative to the stimulus had no significant effect on latency or other measures of performance. Previous theories have suggested that acceleration should decrease with size in geometrically similar animals. Therefore, we suggest that the observed increase in acceleration with body size may be explained by allometric growth. Our results show that the scaling of escape success in fish should take into account a number of size-dependent variables, such as timing, turning and distance-related parameters.