Overview of the comb jellies (Ctenophora) from the South-western Atlantic and Sub Antarctic region (32–60°S; 34–70°W)

Abstract

Ctenophora are important components of marine ecosystems. However, the South-western Atlantic and Sub Antarctic region are still one of the least studied region in the world. We report the species composition and spatial distribution of Ctenophora and reviewed the studies performed in this region. New data obtained between 1910 and 2019, encompassing an area of c. 7 million km2 (32–60°S, 34–70°W) were presented and published information was added. We confirm the occurrence of nine taxa, seven of which have been previously reported in the region. Mnemiopsis leidyi and Pleurobrachia pileus were the most frequent and numerous species. Beroe ovata was frequently observed but reaching high numbers only occasionally. Beroe cucumis was always observed in low numbers. Callianira antarctica, Lampea pancerina and Mertensia ovum have been reported few times as single individuals. Eurhamphaea and Beroe sp. were found for the first time in the study region. This overview represents the state of the art in ctenophore research for the studied region, providing new knowledge on species composition and patterns of spatial distribution in the area.