Social aggregation and lateralised response to social stimuli in tadpoles (Bufo bufo): Influence of developmental stage

In previous studies several species of tadpoles showed a preference for using the left hemifield when approaching a conspecific and during fixation of their own mirror images. These lateral biases typically emerge 5 minutes after the placement of the animals in the test apparatus possibly due to variation in tadpoles' social propensity during the test. The aim of this study is to check whether lateralised response to social stimuli in tadpoles varies during their development. I compared tadpoles of three age classes from a few days after emergence from eggs to close to metamorphosis. In accordance with previous studies I found that tadpoles displayed a preference for the left hemifield when approaching a conspecific and that the bias emerged 5 minutes after placement in the test apparatus. No marked change with development was observed, yet the degree of laterality tended to decrease with age and tadpoles of intermediate age showed left-hemifield dominance during the test significantly earlier than the other two groups.