The phylogenetic position of Maritrema afanassjewi Belopol’skaya, 1952 (Digenea, Plagiorchiida: Microphallidae), a parasite of the Ussuri brown bear, Ursus arctos lasiotus Gray, 1867 (Carnivora, Ursidae)

Adult digeneans of Maritrema afanassjewi Belopol’skaya, 1952 parasitize birds and mammals at the North Pacific coasts and was previously studied in a view of morphology. However, morphological features not supported by molecular characterization are considered an insufficient tool for the identification of evolutionary lineages of microfallid digeneans. Here we provide the first data on the phylogenetic position of this species inferred from sequences of 28S rRNA gene and ITS2 locus of the nuclear DNA as well as additional morphometric data. The trematodes were isolated from the intestine of the Ussuri brown bear, Ursus arctos lasiotus Gray, 1867on Iturup Island (the southern Kuril Islands). This is the second record of M. afanassjewi in the brown bear. Phylogeny based on the 28S rRNA gene was poorly resolved for this parasite species. The analyses based on ITS2 locus dataset showed that M. afanassjewi was a low-supported sister to Maritrema subdolum Jägerskiöld, 1909.