Figure 2

Swimming speed and pulsation frequency of R. pulmo (blue) and R. nomadica (red) under varying water velocity conditions. (A,C) Swimming speed and pulsation frequency (respectively) of R. pulmo in six water velocity conditions. (B,D) Swimming speed and pulsation frequency (respectively) of R. nomadica in six water velocity conditions. (A–D) Error bars display ± one standard deviation.