Fig. 2. Red muscle creatine phosphate (A) and ATP (B) concentrations in control fish (open circles) and in fish swum at 30 % U_crit (filled circles) and 60 % U_crit (open triangles) for up to 240 min and at 90 % U_crit (filled squares) for up to 45 min. The vertical dashed line represents the start of exercise. Overlapping data points are offset for clarity. Values are means ± S.E.M., N=8 for each point. Note the break in the horizontal axis. ^*Values significantly different (P<0.05) from control fish; different letters indicate values that are significantly different (P<0.05) within a time period.