Schuchert, P. (2004). Revision of the European athecate hydroids and their medusae (Hydrozoa, Cnidaria): families Oceanidae and Pachycordylidae. Revue Suisse de Zoologie. 111 2: 315-369.
38509
Schuchert, P.
2004
Revision of the European athecate hydroids and their medusae (Hydrozoa, Cnidaria): families Oceanidae and Pachycordylidae
This paper reviews the European Hydrozoa species belonging to the families Oceanidae and Pachycordylidae. Emended diagnoses for the Oceanidae, the Pachycordylidae, and for some of their genera are provided. Due to the paucity of suitable characters, the macrotaxonomy of the two families is unsettled and must be regarded as provisional. The family Oceanidae includes the genera Cordylophora, Corydendrium, Merona, Oceania, Rhizogeton, Turritopsis, Turritopsoides, and the new genus Similomerona gen. n. The family Pachycordylidae includes the genera Pachycordyle and Silhouetta. Turritopsis polycirrha and T. dohrnii are both regarded as valid species and distinct from T. nutricula of the western Atlantic. Histological sections confirmed that Turritopsis polycirrha is hermaphroditic and larviparous, while T. nutricula is dioecious and oviparous. Turritopsis rubra (Farquhar, 1895) comb. n. from New Zealand is also regarded as a valid species and removed from synonymy with T. nutricula. The known distribution of Corydendrium dispar is extended to include the Faroe Islands. A former record of C. dispar from Denmark is referred to Pachycordyle navis (Millard, 1959) comb. n. Pachycordyle fusca Muller, 1913 is regarded as a likely synonym of Pachycordyle pusilla (Motz-Kossowska, 1905) comb. n.
Descriptor: Similomerona gen. n.
Eastern Atlantic warm temperate to boreal
New Zealand
Systematics, Taxonomy
Zoogeography, Biogeography (generalities), Geographic distribution
