Meeting Abstract
Social dominance hierarchies are a common system of within-group social ranking. Animals occupying subordinate and dominant ranks differ in their access to food and mating opportunities. They thus exhibit differential behavioral and physiological phenotypes associated with stress, nutrient availability and metabolic activity. We sought to evaluate the effects of social rank in male Astatotilapia burtoni on the gut microbiome, a community of microbes intimately involved in host physiological and metabolic processes. We used non-invasive sampling techniques that are novel in this system to track individual changes in microbial communities. Strikingly, we found a lag between microbial community shifts and behavioral and physiological changes associated with rank. Given this, subordinates had higher levels of pathogenic clades and decreased overall community diversity (alpha diversity) while dominants had higher levels of protective clades and increased alpha diversity. The distributions of several differentially abundant operational taxonomic units (OTUs) were correlated with alpha diversity, suggesting that these clades might be involved in structuring the community as a whole. Taken together, our results indicate that behavioral and phenotypic states associated with social rank induce dynamic, population-level shifts in microbiome composition, an effect putatively mediated by the abundances of certain clades. This study is one of the first to evaluate and track the effects of social rank on teleost microbiomes and highlights the need to integrate microbiome-derived effects into studies of behavior.
