Global Ecology and Conservation 9 (2017) 82–89 Contents lists available at ScienceDirect Global Ecology and Conservation journal homepage: www.elsevier.com/locate/gecco Original Research Article The Japanese Red Data book marine mollusk Japonacteon nipponensis and a Japonacteon population from Russia belong to the same species: Molecular evidence and recommendations for conservation Alexander Martynov a,*, Kazunori Hasegawa b, Tatiana Korshunovaa,c a Zoological Museum of the Moscow State University, Bolshaya Nikitskaya Str. 6 125009 Moscow, Russia b National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan c Koltzov Institute of Developmental Biology RAS, Vavilova Str. 26, 119334 Moscow, Russia article info a b s t r a c t Article history: The marine gastropod Japonacteon nipponensis is a representative species of endangered Received 15 November 2016 tidal flat environments in northeastern Asia. It is rated near-threatened in Japanese Red Received in revised form 7 December 2016 Data Books. A population of a closely similar species had also been recognized in the Accepted 8 December 2016 Russian part of the Sea of Japan at a single locality in Sukhodol Bay and was recently dis- tinguished taxonomically as a subspecies distinct from the Japanese populations. Here we Keywords: present for the first time molecular evidence that confirms that both populations represent Endangered marine environments J. nipponensis with little genetic distance. The Russian population of this near-threatened Molecular systematics species will be included in a forthcoming edition of the Red Data Book of Russia. Mollusks Tidal flats in Japan and elsewhere in Asia have been seriously impacted in recent years Pacific by intensive coastal development. Although the sole known locality of this species in Russia Red data list species in Sukhodol Bay is still intact, there are plans to construct a large coal terminal on the bay. Tidal flats The presence not only of this particular species but also of others specifically associated with this particular kind of biotope make it desirable to protect the whole habitat of Sukhodol Bay and surrounding localities in the Russian part of the Sea of Japan. ' 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction A census of global biodiversity is among the key tasks in modern biological science (Gaston, 2000; Tittensor et al., 2010; Wiens, 2015). Two decades of the routine application of molecular tools has revealed significant inconsistencies within traditional morphology-based systematics and phylogenetics (Scheffers et al., 2016). This is a serious challenge for biological conservation because accurate taxonomy is indispensable in evaluating conservation status (Bickford et al., 2006) and many invertebrate taxa are already facing extinction. Here a relevant case is presented concerning a marine mollusk of the genus Japonacteon. It is a member of the shell-bearing gastropod family Acteonidae, which is now shown to be a sister to the large clade containing most of taxa previously assigned to the opisthobranchs and pulmonates (Kano et al., 2016). Japonacteon nipponensis was first described as a fossil species from Pleistocene deposits in the Tokyo region (Yamakawa, 1911). Living specimens were then found in several localities around Japan and the Korean Peninsula (Fig. 1A), and the species has until now been regarded as endemic to that region. * Corresponding author. E-mail address: [email protected] (A. Martynov). http://dx.doi.org/10.1016/j.gecco.2016.12.002 2351-9894/' 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). A. Martynov et al. / Global Ecology and Conservation 9 (2017) 82–89 83 Fig. 1. Study area. (A) Map of the northwestern part of the Pacific Ocean including Japan and Russia. Red dots indicate literature data on the occurrence of J. nipponensis (see text for detail), and blue dots indicate the data obtained in the present study based on the collection in the National Museum of Nature and Science (for Japan) and in the Zoological Museum Moscow State University (for Russia). (B) Photo of the tidal flat in the Russian part of the Sea of Japan (Sukhodol Bay) where J. nipponensis specimens were collected. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) It is endemic to the marine tidal flats (Fig. 1B) and has been assigned near-threatened status in Japanese red data books (Japanese Association of Benthology, 2012; Ministry of Environment, 2014) and least concern status in the Red Data Book of Endangered Mollusks in Korea (National Institute of Biological Resources, 2012). Marine tidal flats in Japan and elsewhere in Asia have been seriously impacted by intensive construction of coastal infrastructure and other industrial development (Wada et al., 1996; Sato and Koh, 2004; Mukai, 2010). A species similar to J. nipponensis has also been reported from the Russian part of the Sea of Japan (Martynov, 1998, 2001; Martynov and Korshunova, 2011), also from a marine tidal flat (Fig. 1B). Despite considerable search efforts it has been found only in a limited area within Sukhodol Bay. It was tentatively considered to be conspecific with J. nipponensis, and is to be included in the forthcoming new edition of the Red Data Book of the Russian Federation (RDBRF, in preparation; Ministry of Natural Resources and Environment of the Russian Federation, 2016). However, there is currently a plan to construct a large coal terminal in this bay (Darkin and Kvint, 2016). Japonacteon in both Japan and Russia is thus seriously endangered by the destruction of its natural habitat. It was suggested previously that Japonacteon from the Russian part of the Sea of Japan possibly represented a different, undescribed species based on slight differences in coloration and morphology (Martynov, 2005; Chaban and Martynov, 2006). Most recently the Russian population was distinguished as a distinct subspecies from the Japanese J. nipponensis (Chernyshev and Chaban, 2016). However, molecular data (including the barcoding COI gene) have not been available for Russian specimens until the present study, and this has prevented correct assessment of the conservation status of this otherwise threatened species. In this study we obtained and investigated in detail live-collected specimens of Japonacteon both from Japan and Russia. Herein we present molecular data of two gene markers for the Russian and Japanese populations. After integrating molecular and morphological data, we conclude that specimens of Japonacteon from Japan and Russia clearly belong to the same species. Appropriate recommendations for the conservation of this species are therefore proposed. 84 A. Martynov et al. / Global Ecology and Conservation 9 (2017) 82–89 Fig. 2. Morphological comparison of Russian (A–F) and Japanese (G–M) specimens of J. nipponensis. (A) Living specimen from Sukhodol Bay (Russia), shell length—5 mm. (B) Same, in the natural habitat (sand of the tidal flat). (C) Shell of specimen from Sukhodol Bay used for molecular analysis (ZMMU-Op-573), shell length—5.3 mm. (D) Shell of a specimen from Sukhodol Bay used for molecular analysis (ZMMU-Op-575), shell length—5 mm. (E) Radula of specimen from Sukhodol Bay (ZMMU-Op-575). (F) Close up of central part of the radula of specimen ZMMU-Op-575. (G) Shell of a specimen from Ise Bay (Japan) used for molecular analysis (NSMT-Mo 78972, specimen 1), shell length—4.5 mm. (H) Shell of a specimen from Ise Bay (Japan) used for molecular analysis (NSMT-Mo 78972, specimen 2), shell length—4.9 mm. (I) Shell of a specimen from Mutsu Bay (Japan) (NSMT-Mo 56129), shell length—3.6 mm. (J) Shell of a specimen from Tsuyazaki, Fukuoka Pref., Kyushu (Japan) (NSMT-Mo 78975), shell length—9 mm. (K) Shell of a specimen from Tokyo Bay (Japan) (NSMT-Mo 78974), shell length—7.3 mm. (L) Radula of specimen from Ise Bay (Japan) (NSMT-Mo 78972, specimen 1). (M) Close up of central part of the radula of specimen NSMT-Mo 78972, specimen 1. Scale bars—100 mm (E, L) and 30 mm (F, M). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) A. Martynov et al. / Global Ecology and Conservation 9 (2017) 82–89 85 2. Materials and methods 2.1. Study area For the comparative molecular and morphological study were used specimens collected on tidal flats in Sukhodol Bay (which lies within the larger Peter the Great Bay, in the Russian part of the Sea of Japan) and near the Ise Bay, Pacific coast of Honshu (Japan) (Fig. 1). 2.2. Data collection Three live-collected specimens of J. nipponensis were obtained in Onoura Cove (near the mouth of Ise Bay, Pacific coast of Honshu, Japan; Fig. 1A) through the courtesy of Mr. Shoichi Kimura (collected by Mr. Tatsuya Sato; preserved in the National Museum of Nature and Science, Tsukuba, Japan (NSMT) with the register number NSMT-78972). Seven living specimens of J. nipponensis were collected in Sukhodol Bay (Fig. 1 B) (preserved in the Zoological Museum of Moscow State University, Russia (ZMMU) with register numbers ZMMU Op-573 – Op-577). Specimens were collected using a sieve. Living examples were photographed in situ or in the laboratory using a Nikon D90 or Nikon D810, and fixed in 80% ethanol for morphological study or in 99% ethanol for molecular analysis. In addition, dry specimens (either empty shells or air-dried live-collected specimens) from various parts of Japan were studied in the National Museum of Nature and Science, Tsukuba, Japan.