Macroalgas bent？nicas associadas a bancos de Hypnea musciformis (Wulfen) J.V. Lamour. (Rhodophyta - Gigartinales) em duas praias do litoral baiano

this study characterized the structure and dynamics of macroalgae communities associated with benthic populations of h. musciformis occurring in reef formations on the beaches of stella maris (salvador) and itacimirim (cama？ari), bahia. the samples were collected between august 2007 and june 2008. the reef formations were divided into compartments based on hydrodynamics. three transects where made for each compartment, and each of these had five quadrants of 20 x 20cm. data about the richness, biomass, percentage of importance (pi%), diversity (h') and evenness (j') was collected. the study recorded 60 species, 30 rhodophyta, 20 chlorophyta and 10 ochrophyta, which had an average biomass of 136 g.m-2 (dry weight) and average rates of h' and j' of 2.7 and 0.97, respectively. there was a predominance of red algae, both in values of richness and in biomass. the contribution of the morpho-functional group of the cortical algae was greater. among the flora recorded, gelidiella acerosa, sargassum cymosum and palisada perforata had higher biomasses. the reef compartment with the highest species richness and biomass was the frontal region. the communities of the beaches studied were considered distinct because of the physiognomy of the reef formations.