Shallow water Cirripedia of the northeastern coast of Brazil: The impact of life history and invasion on biogeography

This paper reports on shallow water barnacles listed in inventories carried out by several authors and collected from the northeastern coast of Brazil; it pays particular attention to commensal species and their hosts, as well as their dispersive ocean pathways. The 53 barnacles found were grouped together and classified as non-symbiont (28 species) and symbiont species (25); host type (sponges, corals, crustaceans, turtles and other fortuitous associations) was used to group them. Obligate symbionts included four crustacean parasites and 19 commensals, in addition to six other species reported in two or more animal groups as facultative or incidental commensals. The barnacles' geographic distribution was discussed in relation to anthropogenic pathways of dispersion and close relationships with hosts, in the case of obligate commensals. The species are predominantly cosmopolitan (39.6%), but the distribution of 35.8% is restricted to the Western Atlantic Ocean. The geographic distribution of some species was extended northward or southward, mainly for those that had been observed associated with vessel hulls. Additionally, the bathymetric limits of occurrence of some other species have been modified.