Examples of normalized tail beat frequency (<i>TBF</i>, Hz) density distributions from accelerometer records of free-swimming (a) saithe (<i>n</i> = 6) and (b) sturgeon (<i>n</i> = 6) based on weighted histograms of <i>TBF</i> extracted using the zero-crossing algorithm.

<p>Examples of normalized tail beat frequency (<i>TBF</i>, Hz) density distributions from accelerometer records of free-swimming (a) saithe (<i>n</i> = 6) and (b) sturgeon (<i>n</i> = 6) based on weighted histograms of <i>TBF</i> extracted using the zero-crossing algorithm.