Morpho-Molecular Features and Phylogenetic Relationships of Metorchis butoridi Oschmarin, 1963 (Trematoda: Opisthorchiidae) from East Asia

Adult trematodes of the genus were found in the gallbladders of ducklings that had been experimentally fed freshwater fishes of the genera and that were naturally infected by metacercariae. Some of the trematodes were identified as , whose morphology of developmental stages and molecular data had previously been described in detail. The other trematodes were confirmed as species on the basis of morphological features: subterminal oral sucker, vitelline follicles with interrupted bands, and rosette-shaped testes. An analysis of phylogenetic relationships within Opisthorchiidae using nuclear and mitochondrial markers confirmed that the obtained trematodes were actually from the genus . The morphological and molecular features indicated that a number of trematodes found in East Asia and described as belong to . Also, the individuals from Europe are, in fact, representatives of another species.