Abstract

We studied the association of polychaetes with the cirriped, Austromegabalanus psittacus on the Peninsula of Gualpén (VIII Region, Chile). Here we report and discuss the importance of this association for assemblages of subtidal polychaetes, we also investigated about the importance of cirriped body size on the abundance and biodiversity of polychaetes. All of the cirripeds examined contained polychaetes. We obtained 793 individuals belonging to 19 species of 12 families. The majority of the polychaetes were found in the calcareous part of the cirripeds. The most abundant and prevalent were: Sylidae (Typosyllis sp., Autolytus sp.), Nereididae (Nereis callaona), Spinonidae (Polydora sp.), Chyrospetalidae (Paleanotus chrysolepis) and Cirratulidae (Dodecaceria opulens). We observed that the biodiversity of polychaetes and the abundances of Typosyllis sp. significantly increased with the size of the cirriped host. The relationship between the size of A. psittacus and the richness of polychaete species is explained by the potential equation (Y=cX2), which empirically describes the known ratio species-area in the equilibrium model of MacArthur & Wilson (1963), where the cirripeds behave like islands for the associated polychaetes. We discuss the importance of the recorded polychaetes in relation to similar associations on other coasts of the world.