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

DUTTO M. SOFÍA; SCHIARITI, AGUSTÍN; MORANDINI, ANDRÉ C.

Simposio; 5th International Jellyfish Bloom Symposium; 2016

Institut de Ciències del Mar

We present the frequency of occurrence and spatialdistribution patterns of  Scyphomedusae and Cubomedusae from the Argentinean andUruguayan continental shelf and their adjacent ocean basin. We gatheredinformation collected by 72 oceanographic and fishery surveys carried out between1981 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 dataon fish stock assessment. However, the bycatch of non-targeted species providedthe opportunity to assemble information about macromedusae over the broadest spatialscale ever studied in the region. We confirmed the occurrence of 14 scyphozoansand 1 cubozoan species previously reported for the region. Lychnorhiza lucerna and Chrysaoralactea were the most abundant species blooming every summer and reachingthe highest abundances/biomasses. Desmonemagaudichaudi, Chrysaora plocamiaand Periphylla periphylla werefrequently observed at low abundances blooming only occasionally. The species Phacellophora camtschatica, Aurelia aurita s.l., Drymonema gorgo,Atolla chuni, Stygiomedusa gigantea and Pelagiacf. noctiluca were observed indifferent occasions throughout the study period but never reaching highabundances. Spatial distribution patterns and their main oceanographic featuresof all these species are provided. Atollawyvillei, Stomolophus meleagris, Desmonema comatum and Tamoya haplonema were reported one ortwo times over the 34-years period. Although new species/reports can be foundas surveys are undertaken, these results are considered as a reliable baselinefor ecological studies aiming to understand the ecological role that thesejellyfish can play in the marine ecosystems due to the analyzed spatio-temporalscales.