First insights into the microbiome of a carnivorous sponge

Using 454 pyrosequencing, we characterized for the first time the associated microbial community of the deep‐sea carnivorous D emosponge A sbestopluma hypogea ( C ladorhizidae ). Targeting the 16 S r RNA gene V 3 and V 6 hypervariable regions, we compared the diversity and composition of associated microbes of two individual sponges of A . hypogea freshly collected in the cave with surrounding seawater and with one sponge sample maintained 1 year in an aquarium after collection. With more than 22 961 high quality sequences from sponge samples, representing c . 800 operational taxonomic units per sponge sample at 97% sequence similarities, the phylogenetic affiliation of A . hypogea ‐associated microbes was assigned to 20 bacterial and two archaeal phyla, distributed into 45 classes and 95 orders. Several differences between the sponge and seawater microbes were observed, highlighting a specific and stable  A . hypogea microbial community dominated by P roteobacteria and B acteroidetes and T haumarchaeota phyla. A high relative abundance of ammonia‐oxidizing archaea and a dominance of sulfate oxidizing/reducing bacteria were observed. Our findings shed lights on the potential roles of associated microbial community in the lifestyle of A . hypogea .