Abstract
In short‐horn sculpin Myoxocephalus scorpius , the power requirements for fast‐start swimming and the length‐specific velocity of the curvature wave travelling down the spine ( Û ) were not influenced significantly by acclimation to summer and winter conditions at test temperatures of 5 and 15° C. However, in‐vivo and in‐vitro muscle performance exhibited acclimation responses at 15° C. Seasonal acclimation altered the escape performance curves for power and Û significantly over a wider temperature range of 0·8–20° C. Û was significantly higher at 20° C in the summer‐ than winter‐acclimation group. The acclimation of lower levels of physiological organization at 15° C may thus serve to extend the thermal limits for escape performance in summer acclimated fish.