The skin microbiome of cow-nose rays (Rhinoptera bonasus) in an aquarium touch-tank exhibit

Public aquarium exhibits offer numerous educational opportunities for visitors while touch tank exhibits offer guests the ability to directly interact with marine life. However, despite the popularity of these exhibits, the effect of human interactions on the host-associated microbiome or the habitat microbiome remains unclear. Microbial communities, both host-associated and habitat associated can have great implications for host health and habitat function. To better understand the link between human interactions and the microbiome of a touch tank we used high-throughput sequencing of the 16S rRNA gene to analyze the microbial community on the dorsal and ventral surfaces of cow-nose rays (Rhinoptera bonasus) as well as its environment in a frequently visited touch tank exhibit at the New England Aquarium. Our analyses revealed a distinct microbial community associated with the skin of the ray that had lower diversity than the surrounding habitat. The ray skin was dominated by three orders: Burkholderiales (~55%), Flavobacteriales (~19%) and Pseudomonadales (~12%), suggesting a potentially important role of these taxa in ray health. Further, there was no difference between dorsal and ventral surface of the ray in terms of microbial composition or diversity, and a very low presence of common human-associated microbial taxa (<1.5%). Our results suggest that human contact has a minimal effect on the skin and habitat microbiome of the cow-nose ray and that the ray skin harbors a distinct and lower diversity microbial community than its environment.