Phylogeographic study on a cryptic dojo loach species (Misgurnus sp. Type I) in Japan

Abstract

Event Abstract Back to Event Phylogeographic study on a cryptic dojo loach species (Misgurnus sp. Type I) in Japan Ryuya Okada1*, Keigo Morita1, Taichiro Toyama2, Hiroshi Onozato3, Keisuke Takata4 and Tadao Kitagawa1 1 Faculty of Agriculture, Kindai University, Japan 2 Other, Japan 3 Other, Japan 4 Faculty of Science, Shinshu University, Japan Recent genetic study revealed that the Japanese population of the dojo loach (Cypriniformes: Cobitidae: Misgurnus anguillicaudatus species complex) included a cryptic species distributed in discontinuous restricted areas in certain parts of north-eastern Japan (Misgurnus sp. Type I, hereafter called as Type I loach), and a common dojo loach species widely distributed throughout the Japanese Archipelago (Misgurnus anguillicaudatus, hereafter called as Type II loach). Type I loach is considered a relic species of the ancestral dojo loach type and its phylogeographic information can provide crucial perspective on the formation of Japanese archipelago and its fauna. However, its original distribution range is ambiguous due to the recent artificially created species and existence of hybrid populations involving Type II loach. In this study, we conducted comprehensive sample collection throughout the possible species’ range. Furthermore, we performed genetic analysis using the cytochrome b (cyt b) gene sequence of mtDNA to reveal the phylogeographic pattern of Type I loach. Mitochondrial haplotypes originating from Type I loach were detected from 34 populations from an eastern part of Honshu Island and Hokkaido Island. In the phylogenetic tree, the haplotypes of the Type I loach formed two major clades, namely consisting of haplotypes from populations in eastern Honshu’s Pacific slope and those from other areas (averaged sequence divergence was about 9 %). This intimated long-term isolation of the populations between the regions. Furthermore, the eastern Pacific Honshu clade consisted of three subclades, corresponding well with their geographic proximity. Similarly, the other clade consisted of three subclades; however, two subclades were haplotype admixtures detected from geographically distant areas. Since some haplotypes were commonly detected ranging from northern Honshu to Hokkaido even across the major faunal boundary line between the Honshu and Hokkaido Island (Brakiston Line), we found that the current distribution patterns are strongly affected by artificial introductions. No significant geographical genetic structures in Hokkaido Island populations were observed, suggesting that their origin was artificial. The hybrid origin populations’ distribution pattern corresponded with the areas related to artificial introductions. Conclusively, artificial disturbances within natural distribution are likely contributors of hybrid population formation. Keywords: mitochondrial DNA, Relic, Native population, Introduced population, hybridization, Hokkaido Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019. Presentation Type: Poster Topic: TAXONOMY, PHYLOGENY AND ZOOGEOGRAPHY Citation: Okada R, Morita K, Toyama T, Onozato H, Takata K and Kitagawa T (2019). Phylogeographic study on a cryptic dojo loach species (Misgurnus sp. Type I) in Japan. Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00118 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 12 May 2019; Published Online: 14 Aug 2019. * Correspondence: Dr. Ryuya Okada, Faculty of Agriculture, Kindai University, Nara, Japan, cop1008bz@yahoo.co.jp Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Ryuya Okada Keigo Morita Taichiro Toyama Hiroshi Onozato Keisuke Takata Tadao Kitagawa Google Ryuya Okada Keigo Morita Taichiro Toyama Hiroshi Onozato Keisuke Takata Tadao Kitagawa Google Scholar Ryuya Okada Keigo Morita Taichiro Toyama Hiroshi Onozato Keisuke Takata Tadao Kitagawa PubMed Ryuya Okada Keigo Morita Taichiro Toyama Hiroshi Onozato Keisuke Takata Tadao Kitagawa Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.