Data from: Competitive growth in a social fish

Many animal societies have dominance hierarchies in which social rank is correlated with size. In such societies, the growth and size of individuals can be a strategic response to their social environment: in fishes, individuals may decrease their growth rate to remain small and retain a subordinate position; in mammals, individuals may increase their growth rate to become large and attain a dominant position — a strategy called competitive growth. Here, we investigate whether the clown anemonefish Amphiprion percula exhibits competitive growth also. We show that juvenile clownfish paired with a size-matched reproductive rival increase their growth rate and size relative to solitary controls. Remarkably, paired individuals achieved this despite being provided with the same amount of food as solitary controls. Our results demonstrate that clownfish are able to increase their growth rate in response to social competition. This study adds to the growing body of evidence that the growth of social vertebrates can be a fine-tuned plastic response to their social environment.Reed_BioLet_Data_20181210Data on growth of clown anemonefish Amphiprion percula collected in the lab at Boston University in 2016 and 2017. Two years of data, reflecting two slightly different experiments, on two separate pages. 'Final length' is the length of the fish at the end of the experiment (mm); 'Individual' is the type of individual at the end of the experiment (P1 = pair-rank-1; P2 = pair-rank-2; S = solitary); 'Treatment' is the experimental treatment (P = paired; S = solitary); 'Replicate' is the replicate ID: in both years the fish were housed in size-matched replicates at the start of the experiment