Vol.:(0123456789) 1 3 Ichthyological Research https://doi.org/10.1007/s10228-019-00686-w FULL PAPER Phylogeography of the Chinese false gudgeon, Abbottina rivularis, in East Asia, with special reference to the origin and artifcial disturbance of Japanese populations Nian‑Hong Jang‑Liaw 1,5  · Koji Tominaga 1,6  · Chungung Zhang 2  · Yahui Zhao 2  · Jun Nakajima 3  · Norio Onikura 4  · Katsutoshi Watanabe 1 Received: 7 September 2018 / Revised: 13 February 2019 / Accepted: 18 February 2019 © The Ichthyological Society of Japan 2019 Abstract The Chinese false gudgeon, Abbottina rivularis, is a common cyprinid fsh that is widely distributed throughout continental East Asia, but exhibits a restricted, discontinuous distribution in western Japan, including Honshu and Kyushu islands. In this study, analyses of mitochondrial (cytochrome b) and nuclear (glyt, myh6, and RAG1) genes were conducted to investigate patterns and magnitudes of intraspecifc diferentiation among A. rivularis populations in Japan and adjacent continental areas. Phylogenetic analysis of the mitochondrial gene sequences resolved four major lineages—the Japan lineage (JL), a northern continental lineage (NCL), and two southern continental lineages (SCL1 and SCL2)—with uncorrected pairwise sequence distances of 9.4–15.2% (estimated divergence times, 7.9–17.1 Myr). Two lineages (JL and SCL1) occurred in both the Honshu and Kyushu districts of Japan. Compared with populations in continental areas, most Japanese populations exhib- ited less genetic diversity. The JL was divided into two well-diferentiated sub-lineages distributed on Honshu and Kyushu islands, respectively. Kyushu Island, as well as areas on Honshu where the species is known to have been introduced, also harbored the SCL1 lineage, which constituted most of the populations on Kyushu. The applied nuclear DNA data strongly suggest that hybridization between the Japan and continental lineages has occurred on Kyushu Island. The artifcial introduc- tion hypothesis, instead of a two-origin scenario, best explains the origin of the SCL1 in Japan. Keywords Abbottina rivularis · Freshwater fsh · Phylogeography · East Asia · Artifcial introduction · Mitochondrial DNA (mtDNA) · Nuclear DNA Introduction East Asia is a large region that includes several divergent geographic features. Land covers about 12,000,000 km 2 (about 9% of all land on Earth) in this region, which includes part of the Russian Far East, China, the Korean Peninsula, northern Vietnam, and surrounding islands, and several Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10228-019-00686-w) contains supplementary material, which is available to authorized users. * Nian-Hong Jang-Liaw taco.tw@gmail.com * Katsutoshi Watanabe watanak@terra.zool.kyoto-u.ac.jp 1 Department of Zoology, Division of Biological Sciences, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo, Kyoto 606-8502, Japan 2 Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichen West Road, Chaoyang District, Beijing 100101, China 3 Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu, Fukuoka 818-0135, Japan 4 Fishery Research Laboratory, Kyushu University, 2506 Tsuyazaki, Fukutsu, Fukuoka 811-3304, Japan 5 Present Address: Conservation and Research Center, Taipei Zoo, No. 30, Sec. 2, Xinguang Road, Wenshan District, Taipei 11656, Taiwan 6 Present Address: Kwansei Gakuin Senior High School, 1-155 Uegahara-ichibancho, Nishinomiya, Hyogo 662-8501, Japan