(2) Comparison between the relative velocities (length . s^-1) obtained for each species of Characidium in the tests of swimming capacity. Middle point represents Median, Box value are the percentiles and the Whisker-value is minimum and maximum values. (3) Relation between standard length (cm) and velocity (m.s^-1) for Characidium fasciatum (C.fas) and Characidium cf. zebra (C.zeb) species.