Genus Clytia Lamouroux, 1812

Synonymy: See Calder (1991).

Diagnosis: Medusa with normal, curved umbrella. Manubrium short, with four short perradial lips. Velum present. Normally four radial canals, but some aberrant form may have more. Marginal tentacles>16, with hollow bulbs; without many permanent, small, conical atentaculate bulbs, no excretory papillae. With many statocysts (>16), usually as many or more as tentacles, no ocelli, no cirri. Gonads on radial canals, usually short, not in contact with manubrium.

Hydroid typical for family, colonial, stolonal or erect branched, monosiphonic or polysiphonic. Hydrothecae deep, campanulate, hydrothecal rim sinuous or deeply indented true hydrothecal diaphragm, gonotheca conical.

Remarks: Very few nominal species of Clytia medusae are unambiguously identifiable. Most morphological characters used to distinguish Clytia species fall in the range of variation that can be expected in a single species and having little or no taxonomic value (Lindner & Migotto, 2002; Bouillon et al., 2006). Species identification requires usually knowledge of the entire life cycle. A recent extensive molecular phylogeny of the Campanulariidae (Cunha et al., 2017) found even more taxonomic inconsistencies, and also provides an excellent framework for barcoding studies. The 16S data set of the latter study was used in a maximum likelihood phylogeny to search for relationships of the sequences obtained in this study. The tree is not shown here due to it size and the sparse results.