Social hierarchies: Size and growth modification in clownfish

Conflicts of interest are part and parcel of living in a social group, although these can reduce the fitness of individual members. Here I show that clownfish (Amphiprion percula) adjust their size and growth rate according to their position in the group hierarchy, maintaining a well-defined size difference with respect to individuals above them in social rank. This strategy to prevent conflict is a surprising departure from the more usual ploy used by many animals of modifying their behaviour within the group.