18S rRNA amplicon sequencing of microbial eukaryotes from the Mid-Cayman Rise acquired Jan-Feb, 2020

Single-celled microbial eukaryotes inhabit deep-sea hydrothermal vent environments and play critical ecological roles in the vent-associated microbial food web. 18S rRNA amplicon sequencing of diffuse venting fluids from two geochemically-distinct hydrothermal vent fields was applied to investigate community diversity patterns among protistan assemblages. Piccard and Von Damm vent fields are situated 20 km apart at the Mid-Cayman Rise in the Caribbean Sea. We describe species diversity patterns with respect to hydrothermal vent field and sample type, identify putative vent endemic microbial eukaryotes, and test how vent fluid geochemistry may influence microbial community diversity. Individual vent fields supported distinct and highly diverse assemblages of protists that included potentially endemic or novel vent-associated strains. This data adds to our growing knowledge of the biogeography of deep-sea microbial eukaryotes.