Article Benthic organisms associated with prop roots of Rhizophora mangle: composition and zonation

Mangroves are coastal ecosystems that exist in the transition zone between terrestrial and marine environments, typical of tropical regions, and they occur in areas with frequent tidal submersion. These ecosystems shelter the species Rhizophora mangle L. (Rhizophoraceae), a mangrove tree that has rhizophores, stem projections that serve as a substrate for a variety of encrusting, sedentary animals and macroalgal species. This study was carried out in an estuarine mangrove on the Acaraú River, located in northeastern Brazil, with the aim of determining the benthic community stablished over R. mangle rhizophores. Accordingly, five trees of this species were chosen, and subsequently, three rhizophores were selected from each tree, totaling fifteen sampled rhizophores, from which all associated macrobenthos were removed. All collected organisms were identified and rhizophores were evaluated for species richness, composition, density, diversity, frequency, equitability and dominance. In addition, vertical zonation of the organisms in rhizophores was determined. The benthic community was characterized by the predominant presence of the phylum Mollusca (Bivalvia and Gastropoda) and the phylum Annelida (Polychaeta). We showed the existence of a vertical zonation of the organisms in the substrate. Understanding the community structure in the rhizophores can facilitate more detailed and experimental studies to comprehend the distribution and even the biological interactions in these environments.