title: Taxonomy and distribution of freshwater pearl mussels (Unionoida: Margaritiferidae) of the Russian Far East.
abstract: The freshwater pearl mussel family Margaritiferidae includes 13 extant species, which are all listed by IUCN as endangered or vulnerable taxa. In this study, an extensive spatial sampling of Margaritifera spp. across the Russian Far East (Amur Basin, Kamchatka Peninsula, Kurile Archipelago and Sakhalin Island) was conducted for a revision of their taxonomy and distribution ranges. Based on their DNA sequences, shell and soft tissue morphology, three valid species were identified: Margaritifera dahurica (Middendorff, 1850), M. laevis (Haas, 1910) and M. middendorffi (Rosén, 1926). M. dahurica ranges across the Amur basin and some of the nearest river systems. M. laevis is distributed in Japan, Sakhalin Island and the Kurile Archipelago. M. middendorffi was previously considered an endemic species of the Kamchatka. However, it is widespread in the rivers of Kamchatka, Sakhalin Island, the Kurile Islands (across the Bussol Strait, which is the most significant biogeographical boundary within the archipelago), and, likely, in Japan. The Japanese species M. togakushiensis Kondo & Kobayashi, 2005 seems to be conspecific with M. middendorffi because of similar morphological patterns, small shell size (<100 mm long) and overlapped ranges, but it is in need of a separate revision. Phylogenetic analysis reveals that two NW Pacific margaritiferid species, M. laevis and M. middendorffi, formed a monophyletic 18S rDNA clade together with the North American species M. marrianae and M. falcata. The patterns that were found in these Margaritifera spp. are similar to those of freshwater fishes, indicating multiple colonizations of Eastern Asia by different mitochondrial lineages, including an ancient Beringian exchange between freshwater faunas across the Pacific.
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Ivan N
authors.initials: IN
authors.lastname: Bolotov
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Yulia V
authors.initials: YV
authors.lastname: Bespalaya
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Ilya V
authors.initials: IV
authors.lastname: Vikhrev
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Aksenova
authors.affiliation: Norwegian Institute for Agricultural and Environmental Research (Bioforsk), Svanhovd, Svanvik, Norway.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Aspholm
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Mikhail Y
authors.initials: MY
authors.lastname: Gofarov
authors.affiliation: Institute of Natural Resources, Ecology and Cryology of the Siberian Branch of the Russian Academy of Sciences, Chita, Russia.
authors.forename: Olga K
authors.initials: OK
authors.lastname: Klishko
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Yulia S
authors.initials: YS
authors.lastname: Kolosova
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Kondakov
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Artyom A
authors.initials: AA
authors.lastname: Lyubas
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Inga S
authors.initials: IS
authors.lastname: Paltser
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Ekaterina S
authors.initials: ES
authors.lastname: Konopleva
authors.affiliation: Department of Biology, Faculty of Science, Maha Sarakham University, Maha Sarakham, Thailand.
authors.forename: Sakboworn
authors.initials: S
authors.lastname: Tumpeesuwan
authors.affiliation: Institute of Ecological Problems of the North of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia.
authors.forename: Nikita I
authors.initials: NI
authors.lastname: Bolotov
authors.affiliation: I.D. Papanin Institute of the Biology of Inland Waters of the Russian Academy of Sciences, Yaroslavl oblast, Nekouzsky district, Borok, Russia.
authors.forename: Irina S
authors.initials: IS
authors.lastname: Voroshilova
mesh_terms: D060105:Animal Shells / Q000033:anatomy & histology; D000818:Animals; D001499:Bayes Theorem; D049872:Bivalvia / Q000145:classification*; D017753:Ecosystem; D005618:Fresh Water; D005843:Geography; D006239:Haplotypes; D010802:Phylogeny; D011157:Population Dynamics; D012426:Russia