The few records of introduced barnacles in Brazil are most commonly reported on artificial (anthropic) substrates. Here we examine the barnacle assemblage in the intertidal regions of rocky shores and natural reefs and build a data base for future monitoring and study for Brazil. We sampled 24 locations between 3 and 29°S latitude. While we found three introduced (Amphibalanus reticulatus, Megabalanus coccopoma and A. amphitrite) and three cryptogenic species (M. tintinnabulum, A. improvisus and Newmanella radiata), they were uncommon at all locations and only M. coccopoma was widespread south of 20°. Native species still predominated in all samples. Management strategies should focus on preventing future invasions on locations where species have not reached yet.
