Fig. 2. Tailbeat differential pressure versus swimming speed and time for a typical cod (Gadus morhua) swimming in a ‘Brett-style’ respirometer at 5°C. At each swimming speed, a continuous 9 s segment of pressure data sampled at 63 Hz is shown. Note the increase in positive and negative pressure (amplitude) and in the frequency of the tailbeat pressure signal as swimming speed increases. The section of the recording labelled ‘Burst’ represents a cod repeatedly burst swimming in the swimming chamber at high speeds prior to exhaustion.
