A re-evaluation of conflicting taxonomic structures of Eurasian<i>Triaenophorus</i>spp. (Cestoda, Bothriocephalidea: Triaenophoridae) based on partial<i>cox1</i>mtDNA and 28S rRNA gene sequences

Cestodes of the genus Triaenophorus Rudolphi, 1793 are widely distributed parasites Esocidae, Percidae, Salmonidae, Thimallidae, Cobitidae, Osmeridae, Cyprinidae, Cottiidae, Lotidae, and several others in Holarctic. The taxonomic arrangements different authors, based on morphological ecological–biogeographic characters, suggest presence two to five species this Eurasia. genetic variation Eurasian spp. was evaluated using DNA barcoding ( cox1 28S gene sequences). This confirmed validity species: T. amurensis, crassus, meridionalis, nodulosus, orientalis. We demonstrated systematic concordance between traditional meristic criteria sequence data. Phylogenetic reconstructions support monophyletic origin group with a long basal plate scolex hook orientalis). crassus is represented by haplogroups, associated Siberia northwestern Russia. Our results show differences terms haplotype diversity level, which probably related Quaternary history development their ranges, as well degree euryxeny second intermediate host.