Abstract

PALMA, Sergio; APABLAZA, Pedro  and  SOTO, Daniela. Diversity and aggregation areas of planktonic cnidarians of the southern channels of Chile (Boca del Guafo to Pulluche Channel). Investig. mar. [online]. 2007, vol.35, n.2, pp. 71-82. ISSN 0717-7178.  doi: 10.4067/S0717-71782007000200008.

We identified 36 species of cnidarians (27 hydromedusae, 9 siphonophores) collected from the Moraleda, King, Darwin, and Pulluche channels, located in southern Chile. The hydromedusae Gossea brachymera, Hybocodon unicus, and Sarsia coccometra, and the siphonophores Rosacea cymbiformis and R. plicata were recorded for the first time in the southern channels. Diversity values were higher for Hydromedusae (2.66 bits) than for Siphonophorae (1.15 bits). The largest aggregates were found in the Moraleda and Pulluche channels, with densities that exceeded 7,000 ind-1000 m^-3. The vertical distribution of the dominant species showed Solmundella bitentaculata to be located near the surface (0-20 m), whereas Sphaeronectes gracilis, Muggiaea atlántica, Clytia simplex, and Proboscidactyla ornata were found in subsurface waters (20-50 m) and Amphogona apicata in deeper waters (50-100 m). According to the Pearson analysis, salinity correlated positively with S. gracilis and S. bitentaculata and negatively with P. ornata. C. simplex was indirectly associated with temperature and the dissolved oxygen concentration

Keywords : cnidarians; gelatinous zooplankton; distribution; diversity; southern channels.