Temporal variation of the gammaridean fauna (Crustacea, Amphipoda) associated with the sponge Mycale angulosa (Porifera, Demospongiae) in southeastern Brazil

Abstract

- Marine sponges are advantageous microhabitats because of their complex architecture. The system of internal canals provides circulation of water and deposition of particulate organic matter, ensuring availability of food and shelter. Diminutive amphipods have little difficulty penetrating the spaces of sponges and remain in their aquiferous systems as one of the most abundant taxa in this association. This study evaluated the temporal variation of the gammaridean amphipod species associated with the sponge Mycale angulosa. Sponge samples were collected every three months over one year at Pontal da Cruz Beach, São Sebastião Channel, southeastern Brazil. The amphipod assembly varied over time, while the amphipod density and sponge biomass remained approximately constant. Six species contributed to the temporal variation infaunal composition, highlighting the importance of the natural history of each species. Key words: Macrofauna, Gammaridea, Ecological assembly, Biological substrate, São Sebastião Channel.