New records of hydropolyps (Cnidaria, Hydrozoa) from South-western Atlantic Ocean

Resumen

Eight hydroid species found in different sectors of the Argentine continental shelf are analyzed. Descriptions, measurements and illustrations for the new subantarctic records are shown: Opercularella belgicae (Hartlaub, 1904) (Leptomedusae, Campanuliniidae), Campanularia agas (Cornelius, 1982) and Clytia hemisphaerica (Linnaeus, 1767) (Leptomedusae, Campanulariidae). Filellum antarcticum (Hartlaub, 1904) (Leptomedusae, Lafoidea), Synthecium robustum Nutting, 1904 (Leptomedusae, Syntheciidae) and Eudendrium ramosum (Linnaeus, 1758) (Anthomedusae, Eudendriidae) are first records in the Argentine biogeographical province; whereas Plumularia insignis Allman, 1883 (Leptomedusae, Plumulariidae) and Bougainvillia ramosa (Van Beneden, 1844) (Anthomedusae, Bougainvilliidae) extend their distributions towards the north of the Argentine continental shelf.