Movie 1.

Horizontal tracking of coral larva trajectories in shallow cuvette. The video is split into four panels to show each of the 90 s light-on and dark phases. Playback is sped up by 10x. Tracks are coloured by larva ID and persist for each light phase showing the total trajectory. Light-on periods are characterized by faster swimming, covering greater distances in the cuvette. During dark periods, the larvae often tended to spin on the spot.