Bacterial communities associated with three Brazilian endemic reef corals (Mussismilia spp.) in a coastal reef of the Abrolhos shelf

The diversity of bacterial communities associated with three Brazilian endemic reef corals from genus Mussismilia (M. hispida, M. braziliensis, and M. harttii) at a single site was assessed using 16S rRNA clone libraries. The study site, Pedra do Leste, is a coastal reef within the largest and richest South Atlantic coralline reef complex (Abrolhos Bank) and is subject to high fishing pressure, high sedimentation loads, and other land-based stressors. The three coral species are Neogene relicts with unique biological and morphological traits that enable them to survive relatively high sedimentation levels. Our results show that sequences affiliated with γ-Proteobacteria predominated, accounting for more than 60% of the examined sequences. Indeed, the most frequent species were related to Alteromonas, Marinomonas, Neptuniibacter, and Vibrio, which are copiotrophic microorganisms common in environments highly affected by anthropogenic stress. Principal component analysis revealed that bacterial communities of M. braziliensis and M. hispida were more similar to each other than to M. harttii-associated bacteria. Such pattern is likely related to distinct morphological properties of M. harttii, such as the existence of phaceloid colonies, in which polyps are not connected by soft tissue. This is the first investigation assessing the bacterial communities of the three Brazilian endemic Mussismilia species at the same location.