Temporal dynamic of biofilms enhances the settlement of the central-1 Mediterranean reef2 builder Dendropoma cristatum (Biondi, 1859)

Research on marine invertebrate settlement provides baseline knowledge for restoration technique implementation, especially for biogenic engineers with limited dispersion ability. Previously, we determined that the maturity of a biofilm strongly enhances the settlement of the vermetid reef-builder Dendropoma cristatum . In order to elucidate which biofilm features support a higher settlement of this species, we analyse the structure and composition of a marine biofilm over time, through microscopic observations, eukaryotic and prokaryotic fingerprinting analyses and 16S rDNA Illumina sequencing. The vermetid settlement temporal increase matched with the higher biofilm extent on the substratum and the eukaryotic abundance and diversity reduction. The prokaryotic specific composition increases the similarity with the reef-associated biofilm over time. Vermetids may gather these differences and selectively settle on those biofilms having an advantageous structure and composition. These outcomes may support the production of ideal substrates for vermetid colonisation and their further translocation to repopulate degraded reefs.