Redescription and molecular characterisation of <i>Comephoronema werestschagini</i> Layman, 1933 (Nematoda: Cystidicolidae) from the endemic Baikal fish <i>Cottocomephorus grewingkii</i> (Dybowski, 1874) (Scorpaeniformes: Cottocomephoridae) with some comments on cystidicolid phylogeny
The nematode Comephoronema werestschagini (Chromadorea: Cystidocolidae) is redescribed from the Baikal yellowfin Cottocomephorus grewingkii (Dybowski, 1874). Important morphological features, such as the presence of four submedian cephalic papillae, four well developed bilobed sublabia, two large lateral pseudolabia, pairs of rounded deirids, as well as the position of phasmids are reported for the first time in this species. The SSU rDNA-based phylogeny of the cystidicolids is defined according to the sequences obtained for C. werestschagini , C. oshmarini and Capillospirura ovotrichuria . The polyphyly of the Cystidocolidae is herein confirmed. All three studied species appear as members of Cystidicolidae s. str. clade; however, C. werestschagini and C. oshmarini are not phylogenetically related.