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.