Diversity and spatial distribution of Scyphomedusae and Cubomedusae from Argentina and Uruguay

SCHIARITI, A.; DUTTO, M. S.; MORANDINI, A. C.

Barcelona

Simposio; 5th International Jellyfish Bloom Symposium; 2016

We present the frequency of occurrence and spatial distribution patterns of Scyphomedusaeand Cubomedusae from the Argentinean and Uruguayan continental shelf and their adjacentocean basin. We gathered information collected by 72 oceanographic and fishery surveyscarried out between 1981 and 2015 encompassing an area of ca. 1 million km2 (34-56°S, 45-70°W). The main goal of those surveys was to collect data on fish stock assessment. However,the bycatch of non-targeted species provided the opportunity to assemble informationabout macromedusae over the broadest spatial scale ever studied in the region. Weconfirmed the occurrence of 14 scyphozoans and 1 cubozoan species previously reportedfor the region. Lychnorhiza lucerna and Chrysaora lactea were the most abundant speciesblooming every summer and reaching the highest abundances/biomasses. Desmonemagaudichaudi, Chrysaora plocamia and Periphylla periphylla were frequently observed at lowabundances blooming only occasionally. The species Phacellophora camtschatica, Aureliaaurita s.l., Drymonema gorgo, Atolla chuni, Stygiomedusa gigantea and Pelagia cf. noctiluca were observed in different occasions throughout the study period but never reaching high abundances. Spatial distribution patterns and their main oceanographic features of all these species are provided. Atolla wyvillei, Stomolophus meleagris, Desmonema comatum and Tamoya haplonema were reported one or two times over the 34-years period. Although new species/reports can be found as surveys are undertaken, these results are considered as a reliable baseline for ecological studies aiming to understand the ecological role that these jellyfish can play in the marine ecosystems due to the analyzed spatio-temporal scales.