Summary Ecological studies indicate that aerobic anoxygenic phototrophic bacteria (AAP) that use bacteriochlorophyll to support phototrophic electron transport are widely distributed in the oceans. All cultivated marine AAP are alpha‐3 and alpha‐4 Proteobacteria , but metagenomic evidence indicates that uncultured AAP Gammaproteobacteria are important members of ocean surface microbial communities. Here we report the descripti...