Biodiversity and distribution patterns of planktonic cnidarians in San Matías Gulf, Patagonia, Argentina

GUERRERO, ELENA; GILI, JOSEP-MARÍA; RODRÍGUEZ, CAROLINA; ARAUJO, ENILMA; CÁNEPA, ANTONIO; CALBET, ALBERT; GENZANO, GABRIEL; MIANZAN, HERMES; GONZÁLEZ, RAÚL

MARINE ECOLOGY-PUBBLICAZIONI DELLA STAZIONE ZOOLOGICA DI NAPOLI I

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 vol. 34 p. 71 - 82

0173-9565

The special location (40 - 42 ºS in the Southwestern Atlantic ocean) and hydrodynamic regime (limited water exchange with open ocean) in San Matías Gulf (Argentina) seem leading to a particular fauna of planktonic cnidarians where their abundances are mainly shaped by the Gulf circulation patterns. Four oceanographic cruises, covering 93 stations in 3 different seasons during 2007 and 2008 were carried out in order to quantify species richness, abundance as well as to analyse its distributions. Twenty 20 species of hydromedusae and 1 siphonophore were identified, increasing the total number of hydromedusae for the area to 23, s. A similar value to the one found in the abutting Argentine continental shelf (20) but with a different assemblage composition. Generally, Hhydromedusae abundances found were low except for a bloom of the leptomedusa Obelia spp., during the cold season. The only siphonophore (Pyrostephos vanhoeffeni) found in the area has previously been thought to be endemic to Antarctic and Subantarctic waters, this being the first record for temperate waters of the Southwest Atlantic Ocean.