A morphological review of the jellyfish genus Nausithoe Klliker, 1853 (Nausithoideae, Coronatae, Scyphozoa, Cnidaria).

In this study we address the diversity of the scyphozoan jellyfish genus Nausithoe Klliker, 1853 (Nausithoidae, Coronatae), questioning the feasibility of using some characters of the medusa stage to identify species and filling in gaps concerning species of the genus and their distributions. Like most scyphozoans, the vast majority of the 21 Nausithoe species have a metagenetic life cycle, but similarity of most polyps within the genus highlights the need for studying morphology of the medusa stage. By analyzing morphological features on preserved and live specimens (polyps and medusae) and comparing these data with the original descriptions, we were able to validate twenty species of the group, providing new information for some of them.

New record of (Scyphozoa, Coronatae, Nausithoidae) from the Brazilian coast and a new synonymy for .

The order Coronatae (Scyphozoa) includes six families, of which Nausithoidae Haeckel, 1880 is the most diverse with 26 species. Along the Brazilian coast, three species of the genus Kölliker, 1853 have been recorded: Broch, 1914, Kölliker, 1853, and Silveira & Morandini, 1997. Living polyps ( = 9) of an unidentified nausithoid were collected in September 2002 off Arraial do Cabo (Rio de Janeiro, southeastern Brazil) at a depth of 227 m, and have been kept in culture since then.