Click on image to view larger version.

Fig. 2. Mean wave amplitudes (± S.E.M.) for seven points along the body for
four fish at three swimming speeds. The y axes show amplitude as a
percentage of the total body length (L) and in cm. Black bars, 2.0
L s-1 (absolute speed 46.5 cm s-1), gray bars,
1.0 L s-1 (absolute speed 23.3 cm s-1) and
white bars, 0.25 L s-1 (absolute speed 5.8 cm
s-1). At the lowest speed, only the posterior 44% of the body
undulates. As the swimming speed increases, a larger proportion of the body
undulates and the body wave amplitude increases non-linearly. Note that over
the speeds tested the tail-beat amplitude (determined by tracking point 7)
does not plateau.