Host-microbiome associations in livebearing fishes adapted to toxic environments rich in hydrogen sulfide

We used 16S rRNA amplicon sequencing to investigate commonalities and differences in the gut microbiomes of livebearing fish (Poecilia mexicana species complex, Poeciliidae) that have repeatedly colonized streams rich in hydrogen sulfide. We characterized host-associated microbiomes of 8 populations of the P. mexicana species complex as well as water and sediment microbiomes from their environments to understand how patterns of microbial diversity vary among populations and river drainages, and we identified microbes shared among the extremophile lineages that can be investigated further for potentially adaptive symbioses.