show Abstracthide AbstractThe Mid-Cayman Rise hosts two geochemically distinct vent fields: Von Damm, situated in ultramafic rock, and Piccard, a mafic vent field that is the deepest known vent site in the world. We have analyzed and compared taxonomic and metabolic diversity as well as strain-level variation from 11 metagenomes from Von Damm and 4 metagenomes from Piccard.