Figure 4.

Initiation, characterization and regulation of counterflow swim sequences. (A) Average radial position ρ₁ (left) and fluid velocity v₁ (right) at the onset of the first bout of the CSS as a function of the suction flow rate, for the three sensory conditions where CSS is observed. Error bars: standard error. (B) Average inter-bout distance δ as a function of the bout radial position ρ during the CSS. The dashed line at δ = 0 indicates perfect distance holding. The bar plot shows the probability density function of ρ for all three sensory conditions. The colored transparent surfaces indicate standard errors. (C) Probability density functions of six quantities characterizing the intra- and inter-bout behavior during the CSS for the three sensory conditions. Pdf were obtained with kernel density estimation with Gaussian kernels: ${\sigma }_k^n=0.75$, ${\sigma }_k^{{\tau }_b}=1$, ${\sigma }_k^{\left|\kappa \right|}=0.01$, ${\sigma }_k^u=2$, ${\sigma }_k^{\tau }=0.075$, and ${\sigma }_k^{\delta }=0.25$. Two-sample Kolmogorov-Smirnov tests were used to determine if distributions are significantly different from each other (^*p < 10⁻³ and ^**p < 10⁻⁶).