Oceaniidae Eschscholtz, 1829

Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, Zootaxa 2590 (1), pp. 1-91 : 9

Family Oceaniidae Eschscholtz, 1829

Oceanidae Eschscholtz, 1829: 96 [emended to Oceaniidae by Kühn (1913: 233); name placed on Official List of Family- Group Names in Zoology (ICZN Opinion 2166)]

Diagnosis. Filiferan hydroids with stolonal or erect colonies, arising from a creeping hydrorhiza or stolonal mat. Hydrocaulus of erect colonies branched or unbranched, monosiphonic or polysiphonic, growth monopodial with terminal hydranths. Zooids monomorphic, or polymorphic with gastrozooids, gonozooids, and dactylozooids. Perisarc filmy to firm, investing only hydrorhiza or on both hydrorhiza and base of hydranths in stolonal colonies, covering both hydrorhiza and hydrocaulus in erect colonies, usually terminating at base of hydranth. Hydranths or gastrozooids clavate to fusiform, with filiform tentacles scattered over distal third or more of body; hypostome conical to proboscis-shaped. Nematophores present or absent.

Gonophores fixed sporosacs or free medusae, arising variously from hydrorhiza, hydrocaulus, pedicels, gonozooids, or blastostyles. Medusae, when present, bell-shaped with short manubrium; mouth surrounded by four lips, margins of lips fringed with clusters of nematocysts; radial canals four, simple; marginal tentacles solitary, numerous in adult. Ocelli present, adaxial. Gonads interradial, on manubrium.

Remarks. Genera in this family were until recently assigned to Clavidae McCrady, 1859 . However, Clava Gmelin, 1791 , type genus of the family, is now known to be more closely related to Hydractinia Van Beneden, 1844a and related genera than to others earlier included in Clavidae ( Schuchert 2001a; Miglietta et al. 2009). Schuchert (2004) resurrected the name Oceanidae Eschscholtz, 1829 (emended to Oceaniidae by Kühn 1913) to accommodate these genera. Three genera of oceaniids have been reported from Hawaii: Corydendrium Van Beneden, 1844a , Turritopsis McCrady, 1857 , and Rhizogeton L. Agassiz, 1862 . Nine genera and about 37 species are currently recognized in the group worldwide ( Schuchert 2009).