The history of research on species of Pachycordyle and related genera is discussed. A description and differential diagnosis of a new species, Pachycordyle kubotai, is presented. Hydroid colonies, hydranths, and gonophores of this species are described in detail. Peculiarities of medusoid development and oocyte maturation are analyzed. The genus Pachycordyle is rediagnosed and an identification key to species assigned to it is provided. Clavopsella is regarded as congeneric with Pachycordyle. Thieliana is established as a new genus for species subsequently and erroneously assigned to Clavopsella. The taxonomic status of species referable to Thieliana is discussed. Justification is provided for our position that these genera belong to the family Clavidae. Characteristics of genera assigned to the family Clavidae are summarized. Data on the geographic distribution and ecology of the species of Cordylophora, Pachycordyle, and Thieliana, referred here to the subfamily Cordylophorinae, are presented.
Stepanjants, S. D., Timoshkin, O. A., Anokhin, B. A., & Napara, T. O. (2000). A new species of Pachycordyle (Hydrorozoa, Clavidae) from Lake Biwa (Japan), with remarks on this and related Clavid genera. Scientia Marina, 64(SUPPLEMENT 1), 225–236. https://doi.org/10.3989/scimar.2000.64s1225