The critical swimming speed of Iberian barbel Barbus bocagei in relation to size and sex

The swimming capacity of Barbus bocagei was measured with the critical swimming speed (U(crit)) standard test in a modified Blazka-type swim tunnel. Sixty B. bocagei were tested and they exhibited a mean +/- s.d. U(crit) of 0.81 +/- 0.11 m s(-1) or 3.1 +/- 0.86 total lengths per second (L(T) s(-1)). Sex had no effect on U(crit) but significant differences were found between the swimming performance of fish with distinct sizes.