“Continentalis” and “Insularis”: Two Highly Diverged Mitochondrial Lineages of the Japanese Big-Footed Bat (Myotis macrodactylus (Temminck, 1840), Vespertilionidae, Chiroptera)

Abstract The Japanese Big-footed Bat, Myotis macrodactylus, is a protected and vulnerable Far Eastern Bat species. In Russia, the distribution range consists of two isolated parts: the south of Primorsky Krai and Kunashir Island. Three morphological subspecies were distinguish in the Japanese Big-footed Bat: the nominotypical one, distributed on the Japanese islands, M. m. continentalis, described from the southern Primorye, and M. m. insularis, presumably living on the Kunashir Island. Nevertheless, the intraspecific variability in the mainland part of the range, as well as the genetic differences between the subspecies, remains unknown. The work we carried out allowed us to identify for the first time two highly divergent mitochondrial lineages in M. macrodactylus with an average p-distance between them amounting to 3.97%, indicating a subspecific level of divergence. The Insularis lineage is distributed on the Japanese islands and Kunashir Island, this coinciding with the supposed range of the nominotypical subspecies, as well as in South Korea, including the Jeju Island. The Continentalis lineage is revealed exceptionally in the southern Primorye and in adjacent areas of northeastern China, this correlating with the supposed range of M. m. continentalis. In contrast to the mainland lineage, the island one is more strongly differentiated and contains at least four clades (I–IV) with unclear distributions. All M. macrodactylus studied from the Kunashir Island belong to Clade I, prevailing on Honshu and Hokkaido, within which they are characterized by the lowest nucleotide diversity. The Continentalis lineage is characterized by a star-like structure with the predominance of the central haplotype, while the greatest genetic diversity was identified in the Primorsky Krai, this possibly indicating a favorable position of this rare protected species’ population.