Morphological and Molecular Identification of Tissue Nematode Philometroides strelkovi (Chromadorea: Dracunculoidea) from Three Cyprinid Species in the North of Primorsky Region

The paper presents a redescription of the parasitic nematode Philometroides strelkovi (Chromadorea: Dracunculoidea) based on the new morphometric data. New hosts from the Cyprinidae family (Rhodeus sericeus, Hemiculter leucisculus, Hemibarbus labeo) and locality—the Luchegorsk reservoir belonging to the Amur River basin (Pozharsky district of Primorsky Krai in the south of the Russian Far East) have been described. For the first time, sequences of the 18S rRNA marker gene have been obtained for P. strelkovi. On the basis of genetic data, we performed phylogenetic reconstruction and showed the clustering of P. strelkovi, separate from the sister species P. moraveci, confirmed by high statistical support at branching nodes and the size of genetic distances—0.11–0.56% between P. strelkovi and other representatives of the genus, along with intergeneric divergence of >4%. In the light of new molecular data, the question of the artificiality of the genera Philometroides and Philometra is raised.