Tube epifauna of the PolychaetePhyllochaetopterus socialisClaparède

Animals greater than 1 mm, found among tangled tubes ofPhyllochaetopterus socialis(Chaetopteridae) from Araçá Beach, São Sebastião district, Brazil, were studied for 1 year, with four samples in each of four seasons. They comprised 10 338 individuals in 1722•7 g dry weight of polychaete tubes, with Echinodermata, Polychaeta (not identified to species) and Crustacea as the dominant taxa. The Shannon-Wiener diversity index did not vary seasonally, only two species (a holothurian and a pycnogonid) showing seasonal variation.Ophiactis savignyiwas the dominant species, providing 45•5% of individuals. Three other ophiuroids, the holothurianSynaptula hidriformis, the crustaceansLeptochelia savignyi,Megalobrachium soriatumandSynalpheus fritzmuelleri, the sipunculanThemiste alutaceaand the bivalveHiatella arcticawere all abundant, but most of the 68 species recorded occurred sparsely. The assemblage associated withP. socialiswas similar to the endofauna of the spongeZygomycale parishiiand the bryozoanSchizoporella unicornis, and to the epifauna of seaweedSargassum cymosum, all of which occurred nearby