Seasonal and vertical distribution of medusae in Aysen region, southern Chile

Abstract

Medusae collected in winter and spring 2007 were analyzed in a longitudinal transect made between the Boca de Guafo and Elefantes Fjord, southern Chile. A total of 30 species were identified, Hydromedusae (29) and Scyphozoa (1), where Bougainvillia macloviana, Hybocodon chilensis, Hydractinia tenuis, Laodicea pulcra, L. undulada, Modeeria rotunda and Chrysaora plocamia represent new records for the area. A significant increase in the jellyfish abundance was higher in spring than in winter (fourteen times higher), with 68% of common species in both seasons. The specific diversity was slightly higher in winter (3.4 bits) than spring (3.2 bits), the species richness instead was higher in spring than in winter, with a mean of 5 and 12 species, respectively. The vertical distribution showed the presence of surface (H. borealis), deep (A. apicata, C. peregrina and R. velatum) and wide bathymetric distribution (B. muscoides and B. muscus) species. Results from the area were compared with previous results (2002-2003) thus proving that most species identified are common in southern Chilean fjords and channels.