Fig 4. Difference angle of the fish’s bearing relative to the sound source (located at X = 0 cm), θS, and the local particle acceleration vectors, θF, at a given location along an individual swimming trajectory.
Small arrows indicate local particle acceleration vectors (normalized for visual comparison), and the solid line indicates a sample swimming trajectory. Difference angles were calculated with reference to the origin (i.e. both difference angles in the example would have a negative value).