Assessment of Sargassum spp. macrofauna at Queimada Pequena Island, Ecological Station of Tupiniquins, southern coast of São Paulo State, Brazil

Abstract

This work represents the first effort to assess the phytal macrofauna of Queimada Pequena island and was focused in mollusks, crustaceans and echinoderms associated to Sargassum spp. Sampling of the macrofauna was performed by random collections of 6 Sargassum fronds 6 m deep using SCUBA. The fronds were sealed underwater in individual 200 mm mesh bags and detached from the rocky shore. The samples were preserved in recipients in 10% formalin and carried to the laboratory to remove and identify the associated fauna. Forty one taxa were registered, with dominance of peracarid crustaceans. Mollusk composition is different from that of northern São Paulo coast. From the sixteen mollusk species recorded, only the gastropod genera Anachis and Odostomia and the bivalves Musculus and Modiolus were recorded in the Sargassum macrofauna at both coastal regions of São Paulo state, although the genus Fissurela had already been recorded at Santos region associated with the alga Amphiroa fragilissima. The occurrence of the exotic bivalve Isognomon bicolor was also confirmed. Our data suggest differences in the composition of molluskan fauna between southern and northern coasts of the state. Extensive investigations are necessary to confirm these results and to support management strategies in this conservation unit.