Is the occurrence of caprellid amphipods associated with Sargassum (Phaeophyta) influenced by algal and hydrozoan epibiosis?

Resumo

The presence of epiphytic organisms can influence the distribution of macroinvertebrates associated with algae. This study evaluated the influence of Sargassum epibiosis by epiphytic algae and hydroids on the occurrence of caprellid amphipods. The sampling was carried out on Sargassum beds of Ubatuba beaches, northern coast of São Paulo state, in October 2006. The presence of epiphytic algae and hydroids on Sargassum fronds was evaluated using five cover categories. Epiphytic algae showed significant cover differences among beaches, while hydroids occurrence was more uniform, without significant differences on the levels of epibiosis. None of the caprellid species identified showed differences in its density among beaches. Despite the epibiosis variation, it was not a determinant factor in the distribution of caprellid species.