Fig. 8. Isometric twitch kinetics of internal red muscle from anterior (ANT) and posterior (POST) locations at 25°C. ‘Stimulus to peak force’ is the time from the stimulus until the peak of the twitch. ‘Peak force to 50 % relaxation’ is the time from the peak of the twitch until developed force declined to 50 % maximal. ‘Duration at half-amplitude’ is the period over which force remained 50 % maximal or greater. An asterisk indicates a significant difference (P<0.05) between locations. Values are means + S.E.M., N=4–6. The inset shows isometric twitches of internal red muscle from anterior (ANT, black) and posterior (POST, red) locations at 25°C. Fine broken lines are twitches from individual preparations; heavy solid lines are composite twitches made by scaling recordings from individual preparations and then averaging the data sets.