(A) Apparatus used to restrain movement in zebrafish larvae by reducing the volume of water available to the larvae to swim using a mesh barrier. Movement restraint reduced swimming on 6 to 8 dpf both between groups (B; control: n4,6,8 dpf = 12, 14, 11; restraint, n4,6,8 dpf = 13, 18, 18; Data are represented as mean ± SEM) and within individual larvae (C; control n = 6; restraint n = 13). Movement restraint also reduced the proportion of fast swims (>10 mm/s) exhibited by larvae by 6–8 dpf (D; n = 18). (E) Representative traces from 1 hr time-bins for recorded larvae from 4 to 8 dpf. Colour coding represents movement speed. *p<0.05.