Lines of fish selected for opposite direction of lateralization show consistency of left-right asymmetry among different behavioural tasks

Lines of fish Girardinus falcatus preferentially turning rightward (RD) or leftward (LD) when facing a predator visible behind a barrier have been obtained by selective breeding. To check wheter laterality in this response was mantained in other behavioural tasks, five different tests were performed. They comprise measures of (1) turning direction in a T-maze, (2) proportion of clockwise and anticlockwise direction of rotation in a circular arena, (3) preferential eye use during scrutiny at their own mirror image reflection, (4) eye use in males while turning around a barrier to join a group of females and (5) while attacking a rival into the mirror. In all five tests the two selected lines showed opposite direction of lateralization. Results thus indicate that behavioural asymmetries in the detour test are predictive of laterality in other types of behavioural responses. Moreover results suggest that RD and LD fish have an identical, but specular pattern of localization of cognitive/ behavioural functions, which is suggestive of a similarly specular brain organization.