Effect of cirripeds on the recruitment of the keyhole limpet Fissurella picta (Gmelin)

Abstract

Correlation and experimental protocol were used to test the hypothesis that in intertidal and subtidal substrata, the recruitment of the keyhole limpet, Fissurella picta (Gmelin), is determined by the settlement of barnacles. Measurements and experiments made in Metri Bay showed that the abundance of juveniles of F. picta smaller than 20 mm occurs mainly in zones exposed to waves, where barnacle species are dominant. In the intertidal zone, temporal variations in the recruitment of F. picta were positively associated with temporal variations in the recruitment of the barnacle Jehlius cirratus (Darwin). In the subtidal zone, the abundance of F. picta recruits was greater in substrata previously colonized by the barnacle Austromegabalanus psittacus (Molina) than in those colonized by the mussel Mytilus chilensis (Hupé), the most abundant fouling species. These data are added to previous findings that show a decrease in the recruitment of the keyhole limpet in the Mehuín Marine Reserve, where man has been excluded. This in turn has lead to an increase in the populations of a gastropod that has continually diminished the barnacle populations. The results indicate the importance of the variations in the settlement and persistence of barnacle populations in intertidal and subtidal zones for the recruitment of species of high commercial value, such as F. picta.