Meeting Abstract
Sponges (Porifera) can host diverse and abundant communities of microbial symbionts that make critical contributions to host metabolism. Observations suggest that these microbiomes may be transferred by a combination of vertical and horizontal transmission, and although direct evidence of this process is rare, current research indicates that most associated microbial communities are species-specific. While species specificity is commonly shown, the evolutionary history of the host species is often not considered. In collaboration with the Earth Microbiome Project (EMP), we investigated the microbiomes associated with sponges collected over a narrow geographic range in the Bocas del Toro archipelago, Panama. We used high-throughput sequencing of the V4 region of the 16S ribosomal RNA gene to assess community structure in 90 specimens representing 20 sponge species. The number of bacterial operational taxonomic units varied significantly among host species, with a strong phylogenetic signal for microbial community diversity. Host identity and phylogeny explained 73% of the observed variance in microbial community composition, and 91% of the observed variance in microbial phylogenetic dissimilarity. These results suggest that host identity and relatedness encompass the major factors that structure sponge-associated microbial communities.
