From 3 dpf, larvae were reared in groups in a plastic canal with water flow producing (A) a weak current that did not displace larvae or (B) a strong current that would displace larvae on a daily schedule (C). By 9 dpf, larvae reared against a strong current exhibited significantly more PCNA +cells in the pallium (D; control n = 10, current n = 7), but not subpallium (E; control n = 11, current n = 10) compared to controls. Larvae reared against a strong current exhibited significantly less Elavl3/EdU co-labeling compared to controls (F; n = 6) and did not differ in body length from controls (G; control n = 17, current n = 14). *p<0.05. n.s. = not significant. Data are represented as mean ± SEM.