Macrofauna associated to Mycale microsigmatosa (Porifera, Demospongiae) in Rio de Janeiro State, SE brazil

The macrofauna (endo- and epi-biotic) associated to the sponge Mycale (Carmia) microsigniatosa Arndt, 1927 was studied at three sites in Rio de Janeiro State, Brazil (Arraial do Cabo, Niteroi, and Rio de Janeiro). A total of 2235 individuals (over I mm long) of 75 invertebrate species were found associated to 19 specimens of the sponge. The most abundant and diverse taxa were the crustaceans (83%, 31 spp.), polychetes (10%, 18 spp.), and molluscs (3.7%, 15 spp.). Cnidarians, platyhelminthes, ascidians, echinoderms, pycnogonids, bryozoans, and sponges were also represented. Amphipod crustaceans were the dominant group, comprising 61% of all individuals collected. Species richness and abundance of associated fauna were highly correlated with sponge volume, but diversity and evenness were not. The site of collection influenced the species composition of the fauna associated to M. microsigniatosa but did not change significantly its diversity, abundance, richness, and dominance patterns of higher taxa. Pregnant females and juvenile stages of 29% of the species associated, including crustaceans, molluscs, echinoderms, and pycnogonids were frequently found inside ill. microsigmatosa. Although many of these organisms do occur and reproduce in other habitats outside the sponge as well, M. microsigmatosa is also important for their reproduction and survivorship, thus contributing for the maintenance of biodiversity in Southwestern Atlantic sublittoral rocky shores. (C) 2003 Elsevier Ltd. All rights reserved.