Cladonema Dujardin, 1843

Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, Zootaxa 2590 (1), pp. 1-91 : 55-56

Genus Cladonema Dujardin, 1843

Cladonema Dujardin, 1843: 1134 .

Type species. Cladonema radiatum Dujardin, 1843 , by monotypy.

Diagnosis. Cladonematid hydroids typically stolonal; hydranth with an oral whorl of capitate tentacles, usually with an aboral whorl of filiform sensory tentacles proximally.

Gonophores free medusae; medusa buds given off singly from hydranth distal to filiform sensory tentacles. Medusae as for family; apical chamber above manubrium absent; umbrella bell-shaped; marginal tentacles with several branches, each bearing knobs of nematocysts and organs of adhesion.

Remarks. The taxonomy and nomenclature of Cladonema Dujardin, 1843 has been reviewed in Calder (1988) and Schuchert (2006).

Hydroids of Cladonema are virtually indistinguishable morphologically from those of Staurocladia Hartlaub, 1917 (a genus regarded as identical with Eleutheria Quatrefages, 1842a by Nawrocki et al. 2010) and separation of the genera is based on characters of medusa buds and medusae ( Bouillon et al. 2006). Moreover, species of both Cladonema and Staurocladia strongly resemble certain species of corynids ( Brinckmann & Petersen 1960; Calder 1970; Bouillon 1971), often rendering identification of sterile material difficult.