Myotis petax is a common and widespread Asian bat species, whose intraspecific sequence variability remains poorly understood. In this work we analyzed the variability of the mitochondrial control region and craniometric measurements for an extensive sample set originating from the entire species range. This made it possible to identify the main genetic lineages and to compare their distribution with the morphological groups. From our investigations, we found that the prevalent genetic lineages, namely, "Siberia," "Amur," and "Okhotsk," appear to be connected to large river systems. The cohabitation of various genetic lineages occurs only in territories where different river basins are connected, such as the Primorsky Territory, Khabarovsk Territory, Transbaikalia Territory, and Mongolia. Moreover, we discovered that the five morphological groups (Siberia, Okhotsk, Amur, Kunashir, and Korea) are partially correlated with previously identified genetic lineages and subspecies. However, M. p. petax and M. p. loukashkini were the only two out of the five subspecies that could be well-defined using specific mtDNA sequences and morphological descriptions. Nonetheless, the subspecies M. p. ussuriensis does not have a distinct genetic lineage to allow for their classification. Notably, a specific mix of morphological group and a genetic lineage characterize the "Amurian morphological form," which may support its validity as a subspecies rank. That notwithstanding, more information is needed to fully unravel the intraspecific structure of M. petax in the southern Far East and potential contact zones of diverse forms.

Morphological and genetic diversity of species of the cestode genus Neoskrjabinolepis, which parasitise Sorex shrews and are widespread in the Palaearctic, was studied. A set of morphological characteristics is presented. Because the type material of Neoskrjabinolepis schaldybini has been lost, a neotype from the type host Sorex araneus and from a region close to the type locality (Altai Republic, Russia) was designated. Host specificity and the geographical distribution of Neoskrjabinolepis species were analysed. Of the 17 species of Neoskrjabinolepis, four species parasitise hosts in the European part of the Palaearctic, 16 in the Asian part and two in the Nearctic. Neoskrjabinolepis cestodes in 16 species of Sorex have been recorded to date. High endemism (40%) and euryxeny of Neoskrjabinolepis were observed. Phylogenetic analysis based on partial sequences of the 28S rRNA gene and of the mitochondrial nad1 gene revealed significant genetic diversity of Neoskrjabinolepis species. The level of interspecific divergence was established at 0.2-1.7% for the 28S rRNA gene and 4.4-19.4% for the nad1 gene. The molecular data showed some genetic lineages that may represent separate species. Complicated genetic structure of N. schaldybini and N. merkushevae, primarily in the Caucasus, was demonstrated, suggesting that these species are composite taxa.

Matykil Island is the largest in the Yamskiye Islands archipelago located in the northern part of the Sea of Okhotsk. Northern red-backed voles inhabiting Matykil island differ sharply from other populations of the species in a number of morphological, genetic, and ecological traits. Based on a comparative analysis of external and craniometric characters, Northern red-backed voles from the Matykil island were identified as a separate subspecies, Clethrionomys rutilus matykilensis subsp. n.

The northeastern limits of the Kamchatka shrew distribution were found to extend much further and include the northeastern territories of the Koryak upland. The new capture points indicate a shift in the range of the species to the east by 500 km from the previously known ones. A distance of only 130 km separates the nearest catching sites of the Kamchatka and Portenko's shrews.

A comparative analysis of taxonomic diversity on shrew cestodes among four islands in the Sea of Japan and the Sea of Okhotsk (Sakhalin, Kunashir, Hokkaido, and Moneron) was performed. Cestode species shared among the islands were identified and their host specificity was investigated. On Sakhalin Island, 33 species of the families Hymenolepididae, Dilepididae and Mesocestoididae were recorded in four shrew species (Sorex caecutiens, S. gracillimus, S. minutissimus and S. unguiculatus). In S. caecutiens, S. gracillimus, and S. unguiculatus on Kunashir Island, 22 species of the same families were found and, on Hokkaido Island, 23 species of the families Hymenolepididae and Dilepididae were recorded. On Moneron Island, three species of cestodes were registered in S. tundrensis. The Sakhalin-Hokkaido-Kunashir complex of shrew cestodes includes eastern-Palearctic, trans-Palearctic and endemic species. High endemism (~22%) of shrew tapeworms in the Sakhalin-Kunashir-Hokkaido Islands was noted as compared to continental territories. The different numbers of cestode species in S. unguiculatus (31), S. caecutiens (29), S. gracillimus (19) and S. minutissimus (1) were found. It was concluded that the cestodes species diversity of shrews of Sakhalin-Kunashir-Hokkaido depended primarily on the history of island formation, their modern physical and geographical features, the abundance of definitive and intermediate cestodes hosts and, to a lesser extent, on the size and remoteness of the islands from the mainland and the diversity of host species.

On the example of cestodes, it was shown that in the Pliocene, transberingian exchanges of shrews and associated parasites took place on a larger scale than in subsequent periods. This is confirmed by 10 common genera of cestodes in shrews of the Palearctic and Nearctic. In the Pleistocene, cestodes of only three genera, Lineolepis, Neoskrjabi nolepis, and Spasskylepis, entered Alaska from Asia.

AimOur aim was to assess the population structure, genetic diversity and demographic history of the wolverine (Gulo gulo) throughout its entire Eurasian range. Additionally, we aimed to contextualize and put into perspective the state of the endangered Fennoscandian population by emphasizing its connectivity to other populations.LocationThe main study area covered most of the Eurasian wolverine range, with samples from Finland, Russia, Kazakhstan and Mongolia.MethodsUsing a 495 bp fragment of the mitochondrial DNA control region and a frequently used set of 14 microsatellite markers on an extensive dataset of samples, we assessed the population structure, genetic diversity, and demographic history of wolverines with a variety of population genetic analyses.ResultsAccording to both nuclear and mitochondrial genetic markers, Eurasian wolverines exhibit substructure, with the most distinct population located in Fennoscandia. The Fennoscandian population has undergone a genetic bottleneck, likely influencing its genetic diversity, which is notably the lowest in Eurasia. Genetic diversity in the rest of Eurasia gradually rises towards the central part of the range and decreases again in the east, although not as significantly as in the west.Main ConclusionsThis study reveals the population structure of wolverines across Eurasia and provides direction for allocating conservation efforts to sustain a diverse and connected wolverine population. While most of the Eurasian populations seem to be well-connected and genetically diverse, the Fennoscandian wolverines may need better connectivity to the other Eurasian populations to ensure gene flow and long-term persistence. Our study further highlights the importance of considering the population genetic structure and diversity of the entire species range when planning management strategies.

Our aim was to assess the population structure, genetic diversity and demographic history of the wolverine ( Gulo gulo ) throughout its entire Eurasian range. Additionally, we aimed to contextualize and put into perspective the state of the endangered Fennoscandian population by emphasizing its connectivity to other populations. The main study area covered most of the Eurasian wolverine range, with samples from Finland, Russia, Kazakhstan and Mongolia. Using a 495 bp fragment of the mitochondrial DNA control region and a frequently used set of 14 microsatellite markers on an extensive dataset of samples, we assessed the population structure, genetic diversity, and demographic history of wolverines with a variety of population genetic analyses. According to both nuclear and mitochondrial genetic markers, Eurasian wolverines exhibit substructure, with the most distinct population located in Fennoscandia. The Fennoscandian population has undergone a genetic bottleneck, likely influencing its genetic diversity, which is notably the lowest in Eurasia. Genetic diversity in the rest of Eurasia gradually rises towards the central part of the range and decreases again in the east, although not as significantly as in the west. This study reveals the population structure of wolverines across Eurasia and provides direction for allocating conservation efforts to sustain a diverse and connected wolverine population. While most of the Eurasian populations seem to be well-connected and genetically diverse, the Fennoscandian wolverines may need better connectivity to the other Eurasian populations to ensure gene flow and long-term persistence. Our study further highlights the importance of considering the population genetic structure and diversity of the entire species range when planning management strategies.

The data on biology and taxonomy of the new subspecies Bracon pallicarpus dorytomovorus Samartsev & Dokuchaev ssp. nov. are given. It was shown that in the Northern Okhotsk region, the wasps of the new subspecies are solitary univoltine parasitoids of the Dorytomus cinereus Hochhuth, 1851 (Coleoptera, Curculionidae) larvae which feed on the central axis of the catkins of the willow Salix rorida Lakschevitz (Salicaceae). Having consumed the weevil larva, the parasitoid forms a cocoon inside the host's tunnel and overwinters as a pupa inside the fallen catkin. Bracon pallicarpus dorytomovorus ssp. nov. adults emerge the next year in the second half of May. The status of the specimens of the type series of B. pallicarpus pallicarpus Thomson, 1892 was specified and its differences from 30 closely related species are presented. Bracon schmiedeknechti Fahringer, 1927 was synonymised with B. pallicarpus pallicarpus (syn. nov.).

Nucleotide sequence polymorphism and haplotypic diversity of the cytochrome b gene were studied in samples of the Laxmann’s Shrew subspecies-Sorex caecutiens koreni from the populations of the Kolyma River basin and Chukotka Peninsula. Fifty-six cytb haplotypes differing among themselves by 87 mutations in 84 sites were found. The cytb haplotypes of individuals of the subspecies S. c. koreni and S. c. macropygmaeus were shown to belong to the same maternal mtDNA lineage; their monophyletic origin from the same ancestral haplotype Scb1 and the presence of identical cytb haplotypes in both subspecies were revealed. The mutual isolation of the shrew populations in the upper basin of the Kolyma River and Chukotka is shown. The proportion of intrapopulation genetic variability is 95.74

A significant polymorphism of the complete amino acid sequence of the cytb polypeptide was found in A. oeconomus of Northeast Russia and Alaska. 29 cytb isoforms were found in representatives of the Central Asian phylogroup, and 15 ones – in the Bering phylogroup, differing in 30 amino acid substitutions. The amino acid substitution F333L pretends to be a genetic marker of the Bering phylogroup. The methods of Snit, Bachinsky, Grantsem and TreeSAAP analysis reliably confirm the conservative type of amino acid substitutions, which indicates the effect of stabilizing selection on the cytb enzyme in tundra voles. Convergence of the amino acid sequence of the cytb polypeptide during divergence of the cytb nucleotide sequence – isoform FEcbCA-1 encodes 21 and FEcbBr-1-26 cytb haplotypes with high values of molecular diversity indices is revealed. This indicates a significant polymorphism in the nucleotide sequences of cytb haplotypes encoding the same amino acid sequence of the polypeptide. The rapid change of generations in this species causes the emergence of many mutations. Degeneracy of the genetic code ensures that populations of different genotypes encoding the same vital phenotypes are fixed in the gene pool. Apparently, the most common isoforms of FEcbCA-1 and FEcbBr-1 in the tundra voles’ populations are functionally optimal for the species in the ecological conditions of Northeast Russia and Alaska.

A fragment of 875 bp of the 18S rRNA gene was studied in 12 samples of Mesocestoides tetrathyridia from small mammals of 7 species collected in geographically distant localities. Five haplotypes were identified, differing from each other by 27 nucleotide substitutions in 24 sites. It has been found that the 18S rRNA haplotypes belong to two genetically distinct haplogroups. Molecular diversity indices were calculated for each of them. The conducted analysis allowed to suggest the following: 1) Mesocestoides sp. haplogroups A and B belong to two different species, but do not belong to any of the confirmed species of the genus; 2) the deletion of bp 729–747 and the insertion at site 761 of guanine can be regarded as a genetic marker for the species Mesocestoides litteratus.

A fragment of 875 bp of the 18S rRNA gene was studied in 12 samples of Mesocestoides tetrathyridia from small mammals of 7 species collected in geographically distant localities. Five haplotypes were identified, differing from each other by 27 nucleotide substitutions in 24 sites. It has been found that the 18S rRNA haplotypes belong to two genetically distinct haplogroups. Molecular diversity indices were calculated for each of them. The conducted analysis allowed to suggest the following: 1) Mesocestoides sp. haplogroups A and B belong to two different species, but do not belong to any of the confirmed species of the genus; 2) the deletion of bp 729–747 and the insertion at site 761 of guanine can be regarded as a genetic marker for the species Mesocestoides litteratus.

A taxonomic review was performed on cestodes of the genus Neoskrjabinolepis Spassky, 1947 that parasitize different species of Sorex shrews in different regions of the northern Palearctic and in the Nearctic (Alaska, USA). Information on Palearctic Neoskrjabinolepis cestodes published in various articles is summarized. An overview of the geographical distribution of the Neoskrjabinolepis species is also presented. Currently, the genus includes 17 species. In the European part of the Palearctic, four species of the genus are registered; in the Asian part, 13 species; and on the American continent (Seward Peninsula, Alaska, USA), two species. Descriptions, illustrations, and differential diagnoses are given for a new species of Neoskrjabinolepis, i.e. N. paradoxa n. sp., which was found in shrews Sorex unguiculatus Dobson and S. caecutiens Laxmann on Sakhalin Island. A unique feature of the new species is irregularly alternating genital pores in the uterus series in the strobila. Amended new differential features (positioning of the uterus relative to osmoregulatory canals and alternation of genital pores) of genus diagnosis and an identification key for Neoskrjabinolepis spp. are presented.

The article presents the data on structures of the nucleotide sequence fragments of the 12S ribosomal RNA gene (12S rRNA) for 19 tetrathyridia specimens of the genus Mesocestoides Vaillant, 1863 from representatives of 10 insectivore and rodent species from different regions of RussiaТs East and Alaska (USA). For the first time, the participation of three shrew species in the life cycle of Mesocestoides has been established. Nucleotide sequence fragments of the 12S rRNA gene have been analyzed phylogenetically. The researched tetrathyridia do not assumingly belong to any of the confirmed species of the genus; however, the identity of five of the 12S rRNA sequence fragments from micromammalian tetrathyridia and two nucleotide sequences of 12S rRNA from carnivorous mammals of Mongolia, placed in GenBank, has been established.

The aim of this study was to assess the taxonomic diversity and prevalence of shrew cestodes on the Kamchatka Peninsula and Paramushir Island on the basis of current understanding of cestode taxonomy. The diversity of shrew cestodes included 22 species from three families: Hymenolepididae, Dilepididae, and Mesocestoididae. In Paramushir, the diversity of shrew cestodes was substantially lower than in Kamchatka (14 and 22, respectively). In Kamchatka, three genera of cestodes (Novobrachylepis, Mathevolepis, Ditestolepis) were not found, but three species from genera Lineolepis, Staphylocystis, and Monocercus are possibly new species. The potential for endemic species and the unique characteristics of the cestode fauna on Kamchatka suggest that the peninsula may have been a refugium for shrews and their parasites in the last glacial maximum. In Kamchatka and Paramushir, two Nearctic species (Lineolepis parva and L. pribilofensis) were found, which indicates potential dispersal from North America. Most cestode species in Kamchatka were associated with the host shrew Sorex caecutiens, while in Paramushir most cestodes were associated with Sorex isodon. In Paramushir, shrews had higher prevalence of infection with cestodes than in Kamchatka. The dominant cestode taxa in shrews on Paramushir Island were species rare in Kamchatka. Conversely, the most abundant cestode species in shrews on Kamchatka were absent from the island fauna.

The nucleotide sequence polymorphism and haplotype diversity of the cytochrome b gene in samples of the tundra vole (Alexandromys oeconomus) from Northeast Asia and Alaska were studied. Sixty-three haplotypes of the cytb gene (51 variants of Central Asian and 12 of Beringian genetic lineages), differing among themselves by 94 mutations, were found. The Upper Kolyma River is inhabited by voles of the Central Asian clade. A mixed population of this species in the basin of the Omolon River (right tributary of the Kolyma River) was found. In Chukotka and Alaska, only specimens of the Beringian phylogroup were found. The genetic differences between all samples are statistically significant. Genetic data of A. oeconomus populations of the Kolyma River basin, Alaska, and Northern Okhotomorye (Northern Sea of Okhotsk area) were compared. A total of 231 substitutions at 226 sites were found in the nucleotide sequence of the mtDNA cytochrome b gene in voles from both clades. The values of molecular diversity indices testify to the stability of populations with a high value of effective abundance over a long period of time. An analysis of the population gene pool formation was performed and a reconstruction of the complex dispersal history of this species across Northeast Asia was proposed.

The Seimchan–Buyunda Depression in the basin of the upper reaches of Kolyma River is distinguished by a number of natural and climatic features: the presence of an extensive ground-filtration talik, rich vegetation of the valley forest complex, and relatively high summer temperatures. The structure of shrew community in the Seimchan–Buyunda Depression also differs significantly from that of the adjacent territories. With an obvious dominance of Sorex caecutiens , S. isodon stably occupies a subdominant position there. Within the Okhotsk–Kolyma region, such a high proportion of S. isodon in the shrew community is more typical of northern Cisokhotia. Thus, the Seimchan–Buyunda Depression is a kind of “oasis” for the species that must have entered the Upper Kolyma River from the Sea of Okhotsk coast.

Based on our own data and that borrowed from available sources, polymorphism of the cytochrome b polypeptide of the gray red-backed vole (Craseomys rufocanus Sundevall, 1846) is considered in the populations of Northeast Asia. Twenty-seven isoforms of the enzyme amino acid sequence were found. A comparative analysis of the frequencies of the cytochrome b variants was carried out in the samples of the gray red-backed vole. The localization of amino acid substitutions was determined in the model of the secondary structure of the enzyme. The method of TreeSAAP analysis, and Snit’s, Bachinsky’s, and Grantsem’s methods reliably confirm the conservative type of amino acid substitutions, which indicates the effect of stabilizing selection aimed at the preservation of two physicochemical properties in a number of polypeptide variants.

Cestodes Paranoplocephala kalelai, which parasitizes in the small intestine of Myodes voles and is distributed in northern Fennoscandia, was found in six habitats in the Asian part of Russia and eastern Kazakhstan, which indicates a wider distribution of P. kalelai on the continent. Analysis of mtDNA showed that P. kalelai is characterized by significant molecular variability in Eurasia. This study complements the data on the distribution of P. kalelai and provides the first molecular data from the territory of Russia and Kazakhstan. The sequence variability of two mitochondrial genes cox1 and nad1 of P. kalelai was studied in two species of voles: gray red-backed Myodes rufocanus and northern red-backed vole Myodes rutilus. Five haplotype groups in the cox1 and nad1 gene networks were identified, and the existence of two mtDNA lines in P. kalelai outside northern Fennoscandia was confirmed. The geographical distribution of the identified haplotypes suggests that the foothills of the Altai-Sayan mountains and southern West Siberia may serve as a refugium for P. kalelai during repeated glaciations.