Polychaetes assemblages from the south Brazilian shelf

CAPITOLI, R.; BREMEC, C.S.; ELIAS, R.; GIBERTO, D.A.

Madrid, España

Congreso; VII International Polychaete Conference; 2004

Polychaetes assemblages were studied from the inner continental shelf off Rio Grande do Sul (Brazil), between 16 and 100 m depth. Seventy five species were identified from 44 benthic samples were collected during 1992 (DIADEMA and SARALBA cruises). Owenia fusiformis characterized sandy shallower substrates between 15-20 m depth, area with lower species richness. The sandy bottoms between 20 and 35 m depth showed an assemblage mainly composed by Phyllochaetopterus socials, Lumbrineris tetraura and Thelepus sp. A more diverse  assemblage characterized by Piromis capitata, Terebellides lanai, Chone insularis, Pista cristata, Pherusa Americana and Euclymeninae 1 was found in muddy sand bottoms between 35-50 m depth. In deeper sandy mud areas (50-100 m) the polychaete assemblage was characterized by Asychis amoena, Lumbriclymene noemia, Panthalis oerstedi, Kinbergonuphis dorsalis and Neoamphitrite sp. Excepting the shallower bottoms, Diopatra viridis was widely distributed. The trophic structure of the four assemblages is analyzed in relation with depth and type of bottom.