Fig. 5

Incremental (A–C) and sustained (D–F) swim trials of tagged fish. For all graphs, black line represents tag estimated mean tailbeat frequency (TBF) of 10 s subset measurements with 50% overlap between subsets. For fish A–C, red line indicates tag estimated mean TBF for each 20-min interval at a specific current speed. Grey circles with a grey line indicate mean frequency of 3 visual estimates taken from camera recordings within each of those respective intervals. Error bars represents mean ± s.e.m. For fish D–F, vertical dashed lines indicate each hour from the start and end point of the 4-h sustained swim speed tests at 60 cm sec⁻¹. Here, red line indicates tag estimated mean tail beat frequency for the complete trial, and grey circles with a grey line indicate visual point estimates of tailbeat frequency in 30-min intervals