Trachymedusae and Narcomedusae of South-east Australian Waters

Abstract

Thirteen species of Trachymedusae and seven of Narcomedusae are recorded from south-east Australian waters, where both orders were previously unknown. Eight Trachymedusae and four Narcomedusae are new records for the entire Australian region. Additions are made to the descriptions of some species.

Eight species are epipelagic, seven bathypelagic, and five probably eurybathic in the upper 1000 m of the sea; the second and third groups contain several cosmopolitan species, but the species of the first (epipelagic) group tend to be restricted to tropical and, subtropical latitudes. One epipelagic species, Liriope tetraphylla (Chamisso & Eysenhardt), has not been found south of lat. 39º S. in south-east Australian waters and may serve as an indicator of one of the two main water masses which meet in that region.

The most abundant species of either order is Aglauru hemistoma Peron & Lesueur, which is the commonest of all hydromedusae on the continental shelf off Queensland and New South Wales. Aglaura and Liriope are also recorded from the neighbourhood of Fremantle, W.A.