Diversity of benthic polychaetes in the Argentinean Biogeographical province (35-38S)

BREMEC, C.S.; GIBERTO, D.A.

Madrid, España

Congreso; VII International Polychaete Conference; 2004

This study deals with the species composition and abundance of benthic polychaetes between 35° and 38°S, in marine waters adjacent to the Río de la Plata estuary and continental shelf. Benthic samples were collected during INIDEP summer cruises EH09-2001 and CC02-2002, with dredges. The hard substrates (30 m depth) are conspicuous feeding grounds for fishes: “Pez Limón bank” (PL) and “Mejillón bank” (ME). The benthic assemblage in PL was conformed by 66 invertebrate species, most abundant the mollusks Transenpitar americana, Halystilus columna, Tegula atra and Gammaridae and ME by 89 species, Mytilus e. platensis, Tripalea clavaria, Pyromaia tuberculata and Pseudechinus magellanicus. Polychaetes represented 25% of species in PL and 16% in ME, more frequent Lumbrineris latrellei and Lumbrinerides gesae and Diopatra viridis, Eunice argentinensis, Lagisca sp. and Cirratulidae, respectively. The soft bottoms, between 30 and 270 m depth, presented a total of 97 species, 28 of them polychaetes. Deeper areas are characterized by the abundance of Ninoe falklandica, Aglaophamus uruguayi, Cistenides ehlersi, Terebellidae, Ampharetidae, Maldanidae, while Diopatra viridis was more abundant in the middle shelf.