Characterization of Social Sleep Behavior in Astyanax Mexicanus

Sleep is a near universal behavior throughout the animal kingdom. In mammals, sleep is impacted by many different environmental traits including food availability, light-dark cycles, and social expeeence. Although, sleep behavior has been studied with individual fish, the effects of social interactions on sleep has not been studied in any fish species. Astyanax mexicanus offers a model to study sleep because it has multiple morphs derived from a common ancestor. We investigated sleep in Pachón cavefish and surface fish by comparing sleep in individual fish to those in social groups. We discovered that when Pachón cavefish are placed in a social group do not display differences in sleep relative to Pachón fish in isolation. In contrast, surface fish behaved significantly differently in social groups compared to non-social surface fish groups. This study is the first to demonstrate that sociality effects sleep and fish, and suggests this social regulation of sleep was lost in cavefish evolution.