Author(s)

Jun-Ichi Miyazaki^1*, Seiya Hida¹, Takurou Ozaki¹, Yuichirou Tabata¹, Misaki Iwata¹, Masashi Nakazawa¹, Youki Fukasawa², Tomonari Asaka³

¹Faculty of Education and Human Sciences, University of Yamanashi, Kofu, Japan.
²Department of Education, Graduate School of Medical and Engineering, University of Yamanashi, Kofu, Japan.
³Mikawa Freshwater Life Network, Toyokawa, Japan.

Two species Lefua echigonia and Lefua sp. 2 of the eight-barbel loach inhabit the Tokai region of Honshu, Japan. We determined sequences of the mitochondrial D-loop region to elucidate intraspecific phylogenetic relationships and variation in these two species. Lefua sp. 2 represented high intraspecific genetic similarity and complicated haplotype network, but three assemblages were recognized, including specimens mainly from Yahagi, Toyo, and Tenryu River systems, respectively, and named Groups 1 to 3. Divergence of Group 1 from the others was marginally supported, but Group 2 was paraphyletic to Group 3, suggesting the existence of two populations, i.e. Yahagi River population and Toyo-Tenryu River population. Lefua echigonia also represented high intraspecific genetic similarity, and two assemblages with slight genetic differentiation were discernible, including specimens from Shizuoka and southeastern Aichi prefectures and those from northwestern Aichi, Gifu, and Mie prefectures, respectively, and named Groups A and B. Star-like relationships of haplotypes suggested the dispersal origin located in eastern Aichi prefecture. The two species are threatened to extinction and thus we proposed evolutionary significant units for conservation.

Population, Phylogeography, Mitochondrial D-Loop Region, Conservation, River Capturing

Miyazaki, J. , Hida, S. , Ozaki, T. , Tabata, Y. , Iwata, M. , Nakazawa, M. , Fukasawa, Y. and Asaka, T. (2017) Intraspecific Relationships and Variation of Two Lefua Species (Balitoridae, Cypriniformes) in the Tokai Region, Honshu, Japan. Journal of Water Resource and Protection, 9, 238-253. doi: 10.4236/jwarp.2017.92016.