Fig. 2.

Statistical properties of the fish schools as a function of swimming speeds over the whole range of cases studied (see Tables S1 and S2). (A) Variation of the $z$-position of fish ($h_z$ is the depth normalized by the fish average body height) as a function of swimming speed. Small black dots represent the instantaneous $z$ position of each fish, whereas orange squares represent average $z$ position, averaged over all groups. (B and C) Probability density of the NND for low (B) and high (C) swimming speeds. B and C, Insets show the probability density of nearest-neighbor angles $\varphi$. (D) Probability density map of NND as a function of the swimming speed. (E) Percentage of occurrences of diamond-shaped (DS) [or T-shaped (TS)] and phalanx-shaped (PS) patterns. High-speed swimmers are mainly characterized by phalanx patterns and short NND in comparison with low speed regimes.