ANNELIDA POLYCHAETA ASSOCIATED WITH TUNICATA
Sovierzoski, H. H. & Correia, M. D.
Laboratory of Marine Sciences and Depto. Zoologia/Federal University of Alagoas, Brazil
The complex architecture of colonial Tunicata provides many biological substrata for different taxa of marine invertebrates. The associations between Polychaeta and Tunicata on the coast of Brazil are not well known. Samples were collected in Pajuçara beach, on the coast of Maceió city, Alagoas state, in northeast Brazil. The study area was situated near Maceió Harbor. The average water temperature in this area was 28°C, and the average salinity was 32 ppt. The associated fauna was studied on the tunicates Didemnum sp. and Eudistoma sp. These taxa of tunicates were collected because they showed different colonial forms of the fouling communities. Five samples of each tunicate, each 20 cm2, were obtained. The qualitative and quantitative analyses of associated fauna of these tunicates showed that Polychaeta was the most abundant group. The polychaetes associated with Eudistoma sp. comprised 8 families: Terebellidae, Cirratulidae, Syllidae, Sabellariidae, Sabellidae, Eunicidae, Nereidae and Paraonidae. The same families except for Paraonidae and Sabellidae were also associated with Didemnum sp. Terebellidae were numerically dominant on both taxa of tunicates. The Sabellidae, Sabellariidae and Paraonidae were registered with few individuals per group. Great quantities of sediment were associated with these colonial tunicates. This environmental feature probably created special conditions for development of the polychaete fauna, which was dominated by deposit-feeding organisms.