Vibrio tapetis is a pathogenic bacterium causing the Brown Ring Disease (BRD) in Manilaclam Ruditapes philippinarum. This vibriosis is induced by bacterial adhesion on the periostracal lamina, yielding a decalcification of bivalve shell. We focused on one aspect of V tapetis pathogenicity never explored so far: biofilm formation. As in many bacterial species, pathogenesis is likely related to this microbial behavior that is the biofilm. In this study, V tapetis biofilm was characterized for the first time. The composition of the biofilm matrix was also examined. Different microcopy techniques were used to observe V tapetis biofilm, allowing us to highlight at the top of the biofilm the presence of spherical components. These peculiar compon...