Plasticity and personality of parental care in the clown anemonefish

Characterizing individual variation in parental care is critical to understanding how selection shapes and maintains patterns of care, yet little is known about how individual parents vary in their responses to the environment. Reaction norms, functions that describe how phenotypes change across an environmental gradient, provide an elegant framework for studying individual variation in behavioural responses. We use a reaction norm approach to investigate how studying plasticity, which describes variation within an individual through time, and personality, which describes repeatable variation among individuals, together explain individual variation in the parental behaviour of the anemonefish Amphiprion percula. More specifically, we test how resource availability influences individual parental responses to the environment and discuss the consequences for our understanding of plasticity and personality in parental care. Breeding pairs of A. percula were fed either a high or a low food ration and their parental behaviours were monitored. Individuals exhibited plasticity in parental behaviour across the two resource environments. Furthermore, individuals were repeatable in their behaviour through time, as evidenced by significant among-individual variation in intercept. Finally, the slope and elevation of individual reaction norms varied, revealing a level of variation not captured at the population level and providing insight into the potential mechanisms generating individual variation.