Summary The gill chamber of deep‐sea hydrothermal vent shrimp R imicaris exoculata hosts a dense community of epibiotic bacteria dominated by filamentous E psilonproteobacteria and G ammaproteobacteria . Using metagenomics on shrimp from the R ainbow hydrothermal vent field, we showed that both epibiont groups have the potential to grow autotrophically and oxidize reduced sulfur compounds or hydrogen with oxygen or nitrate. Fo...