Cestode fauna of murid and cricetid rodents in Hokkaido, Japan, with assignment of DNA barcodes

The cestode fauna of murid and cricetid rodents in Hokkaido, the northernmost island of Japan, was evaluated based on our parasite collection and a review of the literature. Adult and larval cestodes collected from Apodemus speciosus (Temminck, 1844), Myodes rufocanus (Sundevall, 1846), and Rattus norvegicus (Berkenhout, 1769) in Hokkaido were identified by both morphological and molecular diagnoses. A total of 10 species from 5 families were confirmed in our collection. Arostrilepis tenuicirrosa Makarikov, Gulyaev, and Kontrimavichus, 2011, Paranoplocephala kalelai (Tenora, Haukisalmi, and Henttonen, 1985), and Taenia crassiceps (Zeder, 1800) were recorded for the first time from Hokkaido. A comprehensive look at both the present and previous studies revealed that the cestode fauna of rodents in Japan consists of at least 30 species from 6 families. Among them, 23 species occur in Hokkaido. The species composition is strongly affected by the nearby Eurasian continent, suggesting parasite migrations with rodent hosts over land bridges between Hokkaido and Sakhalin and between Hokkaido and Honshu, the main island of Japan. A DNA barcoding system using sequences of nuclear 28S rDNA and mitochondrial cox1 allowed us to identify cestodes at species and genus levels, even in different developmental stages. The integration of morphological and molecular diagnoses is essential in cestode taxonomy to establish a common ground for biogeographical studies worldwide. The standardization of DNA barcoding is particularly of critical importance.