Macrozoobentos asociado a los agregados de Phyllochaetopterus socialis Claparède 1870 en el Puerto de Mar del Plata, Buenos Aires, Argentina

MARIANO ALBANO; JUAN SECO PON; SANDRA OBENAT

REVISTA DE INVESTIGACIONES MARINAS

Escuela de Ciencias del Mar, Facultad de Recursos Naturales de la Pontificia de la Pontificia Universidad Católica de Valparaíso.

Lugar: Valparaíso; Año: 2006 vol. 34 p. 197 - 203

0252-1962

Aggregates of the polychaete Phyllochaetopterus socialis were recorded for the first time in Mar del Plata Harbour in December 2003. These ones were found about 6 m depth in the limit between the north break-water rocks and soft sediments. Three randomly seasonal, either mensual or bimensual, samples were obtained by SCUBA diving. We registered 56 species belonging to 11 phyla: Porifera, Cnidaria, Nematoda, Plathyhelminta, Arthropoda, Sipuncula, Bryozoa, Annelida, Mollusca, Echinodermata and Chordata. Summer was the season with higher numbers of organisms. The more abundant taxa were crustacean (amphipods and tanaidaceans), molluscs, polychaetes and bryozoans. In summer crustaceans were dominant, while the rest of the groups (molluscs, polychaetes and others) doesn´t showed significant differencies in their densities along the sampling seasons. Bryozoans were the sessile organisms with the highest relative frequency. This study extends the distribution range for some species such as Hydroides plateni, Elysia patagonica that never have been cited in Mar del Plata harbour before. The macrofauna associated with the aggregates is more diverse than those found in the neighbourhood. These organisms, belonging to different trophic guilds, are related in a complex web within the aggregates where they found shelter, refuges, settlement sites and food resources.