Fig. 3

Local search is generated by increased utilization of same direction R-turn maneuvers. a Representative 10-s path trajectories of individual larva during baseline (left, yellow) and dark (right, grey) conditions. Arrows indicate path direction of the larva. Scoot (black circle) and R-turn (red circle) maneuvers are indicated along each path. Lock index (LI) for each recording noted at bottom. Scale bar 2 mm. Frequency (b, d) and LI (c, e) of maneuver pairs during full-field illumination (b, c; baseline) and during the first 10 s after loss of illumination (c, d; T₀). Baseline N = 39, T₀ N = 55. Maneuver frequency analysis excludes O-bends triggered by the sudden reduction in illumination and infrequent fast burst swims. c Baseline maneuver pair LIs are significantly increased over 0 for scoot-scoot (one-sample t-test vs. 0, t₃₉ = 8.36, P < 0.001), turn-turn (t₂₄ = 2.44, P = 0.022), and turn-scoot pairs (t₃₉ = 4.51, P < 0.001). Scoot-turn maneuver pair LI was not significantly different from 0 (t₃₈ = 1.01, P = 0.32). f Frequency of R-turn initiations (percentage of larvae that execute an R-turn per 400 ms analysis window). N = 17 groups of 10 larvae each. * P < 0.001. g LI for sequential R-turns during sustained loss of illumination. N = 51 larvae (baseline), 24 (5 s), 22 (60 s), 15 (300 s), 10 (600 s). * P < 0.05 compared to baseline time-point