Taking turns: some aspects of behavioural lateralization in schooling fish

Abstract

Lateralization of cognitive functions seems to be exceptionally widespread in nature and have been demonstrated to occur in multiple taxa. Previous studies using fish as models have suggested that social behaviours such as schooling may covary with behavioural lateralization at the population-level. Here, we assess the strength, degree and repeatability of behavioural lateralization in schooling fish. Two of the species studied (Aulorhynchus flavidus and Gasterosteus aculeatus) were found to express population-level symmetry in the direction of lateralization whereas one species (Ammodytes hexapterus) showed no indication of population-level lateralization. We also provide evidence that behavioral lateralization is repeatable over time. From our cross-species comparisons we conclude that population-level lateralization is not necessarily related to a gregarious life-style. Further studies should test repeatability over longer periods of time and the role of lateralization in schooling behavior.