New Genus and Two New Species of Notocotylidae Lühe, 1909 (Digenea), from Russia: Morphomolecular Data

The study of the trematodes of the family Notocotylidae Lühe, 1909, is continued using an integrated approach based on new data. A new genus, Pseudonotocotylus n. gen., has been identified, and two species new to science, Notocotylus multipapillus n. sp. and Pseudonotocotylus martynenkoi n. sp., have been discovered. The life cycle and morphology of developmental stages of the new species are described, and the molecular data for nuclear (28S) and mitochondrial markers (cox1 and nad1) are presented. Sequences of cox1 and nad1 mtDNA genes were obtained for five previously studied notocotylid species for the first time. Phylogenetic relationships within Notocotylidae were inferred from the analysis of these markers, and the results obtained reveal some subtle differences in some of the notocotylid species despite their morphological similarities. Based on the differences in gene sequences among the species, two additional criteria are proposed to divide the genus Notocotylus into Notocotylus and Pseudonotocotylus n. gen. The criteria are based on, first, having the Pulmonata or Prosobranchia group of snails as the first intermediate host and, second, molecular properties, as shown by substitutions specific to genus at various nucleotide locations in alignments for 28S and cox1.