Integrative phylogenetic, phylogeographic and morphological characterisation of the Unio crassus species complex reveals cryptic diversity with important conservation implications

The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on ∼ 600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus, Unio carneus, Unio crassus, Unio damascensis, Unio ionicus, Unio sesirmensis, and Unio tumidiformis, and the reinstatement of five nominal taxa: Unio desectusstat. rev., Unio gontieriistat. rev., Unio mardinensisstat. rev., Unio nanusstat. rev., and Unio vicariusstat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described.

New records of Lasiocampidae (Lepidoptera) from Zanzibar Island with taxonomic notes and description of one new species of Odontopacha Aurivillius, 1909

Seven genera and seven species of Lasiocampidae are newly recorded from the Zanzibar Island (Unguja): Bombycopsis C. & R. Felder, 1874 with Bombycopsis nigrovittata Aurivillius, 1927; Pallastica Zolotuhin & Gurkovich, 2009 with an unidentified species; Dollmania Tams, 1930 with an unidentified species; Mallocampa Aurivillius, 1902 with Mallocampa leighi Aurivillius, 1922; Eucraera Tams, 1930 with Eucraera witti Prozorov, 2016; Philotherma Möschler, 1887 with Philotherma montibia Strand, 1912; and Odontopacha Aurivillius, 1909 with Odontopacha fenestrata Aurivillius, 1909. The species are followed with taxonomic notes updating the status and distribution of the taxa. Bombycopsis nigrovittata is shown to have the maximum p-distance of 0.3% in cytochrome c oxidase I from Bombycopsis pallida Joannou & Krüger, 2009. Two specimens of Pallastica sp. from Zanzibar are different in wing coloration but identical genetically, both are 0.8-1.2% far from sequenced specimens collected in southern Malawi and eastern Zimbabwe and altogether 3.0-3.8% far from the Zambian and Malawian populations considered to be Pallastica pallens (Bethune-Baker, 1908). The barcoding revealed two distinct lineages of Dollmania in Tanzania with a p-distance of 3.5-3.7% between them, neither can be attributed to either Dollmania marwitzi (Strand, 1913) or Dollmania reussi (Strand, 1913) until the primary types or fresh topotypes are sequenced. The species Ph. montibia is taken out from the synonymy to Philotherma rosa (Druce, 1887) and is stated to be a bona species because of the difference in wing pattern and p-distance of 5.7-5.9%. A new species of the genus Odontopacha - Odontopacha dargei sp. n. - is described from southern Kenya and northern Tanzania where it occurs sympatrically with O. fenestrata. It differs from O. fenestrata by the paler coloration with the spotted external fascia on both wings and a p-distance of 3.04-3.65%. Lectotypes for D. marwitzi and Ph. montibia are established. Mallocampa leighi is recorded from Tanzania for the first time. Females of Chrysopsyche lutulenta Tams, 1923 earlier recorded from Zanzibar Island are figured and the species is recorded from DRC for the first time.

A novel assembly pipeline and functional annotations for targeted sequencing: A case study on the globally threatened Margaritiferidae (Bivalvia: Unionida)

The proliferation of genomic sequencing approaches has significantly impacted the field of phylogenetics. Target capture approaches provide a cost-effective, fast and easily applied strategy for phylogenetic inference of non-model organisms. However, several existing target capture processing pipelines are incapable of incorporating whole genome sequencing (WGS). Here, we develop a new pipeline for capture and de novo assembly of the targeted regions using whole genome re-sequencing reads. This new pipeline captured targeted loci accurately, and given its unbiased nature, can be used with any target capture probe set. Moreover, due to its low computational demand, this new pipeline may be ideal for users with limited resources and when high-coverage sequencing outputs are required. We demonstrate the utility of our approach by incorporating WGS data into the first comprehensive phylogenomic reconstruction of the freshwater mussel family Margaritiferidae. We also provide a catalogue of well-curated functional annotations of these previously uncharacterized freshwater mussel-specific target regions, representing a complementary tool for scrutinizing phylogenetic inferences while expanding future applications of the probe set.

Long forgotten record of a freshwater leech on Madagascar indicates a host-associated dispersal event from continental Africa

Madagascar houses a peculiar and largely endemic biota, having ancient Gondwanan affinities. However, the faunal composite of many invertebrate groups on the island is poorly known. For a long time, it was believed that the freshwater leech fauna of Madagascar contains a salifid species (Salifidae) only. Here, we report on a historical record of Placobdelloides multistriatus (Johansson, 1909) (Glossiphoniidae), a widespread African species, from Andrahomana, Southern Madagascar. Franz Sikora (1863-1902), an Austrian traveler and collector, who visited Andrahomana in 1899 to excavate fossils from a cave, collected the leech sample. The two specimens were obtained from an unspecified turtle species. We assume that P. multistriatus may have arrived to Madagascar relatively recently (i.e., in the Late Pleistocene or Holocene) via a long-distance dispersal event from continental Africa with its reptilian hosts such as the Nile crocodile and marsh terrapin. Based on a review of the body of available literature, two more freshwater leech species are known to occur on Madagascar: Linta be Westergren & Siddall, 2004 (Salifidae) and Alboglossiphonia sp. (Glossiphoniidae). Our findings indicate that Madagascar houses at least three freshwater leech species and that some additional taxa may have been overlooked there due to the scarcity of sampling efforts in the island’s freshwater bodies.

Integrative taxonomy of two morphologically similar species of the subgenus Cryobius Chaudoir, 1838 (Coleoptera: Carabidae: Pterostichus Bonelli, 1810) from northern Eurasia and North America

In this study, we synonymized Pterostichus (Cryobius) kolymensis Erjiomin, 1998 with P. (C.) mandibularoides Ball, 1966 by an integrative approach. Geometric morphometric analysis revealed no obvious differences in the shape of the pronotum and median lobe of the aedeagus between P. (C.) mandibularoides and P. (C.) kolymensis. According to DNA analysis, all examined specimens belong to P. (C.) mandibularoides with 11 unique haplotypes of COI from northern Canada, USA (Alaska) and Russia (Yakutia, Chukotka and Wrangel Island) and 1 haplotype of 28S rDNA from northern Eurasia (Russia). The median-joining haplotype network and the uncorrected COI p-distance values between different geographic populations of P. (C.) mandibularoides suggest the trans-Beringian origin of the species and its subsequent dispersal across North America and northern Eurasia is the most likely scenario of the biogeographic history of the species.

Associations of mayfly larvae with Corbicula clams

Currently, the parasitic and endosymbiontic fauna of Corbicula clams remain poorly studied throughout their range. Here, using samples from the Mekong basin, we describe two Symbiocloeon species new to science: Symbiocloeon corbiculinus sp. nov. and Symbiocloeon laoensis sp. nov. Our results and a review of available published data indicate that freshwater bivalve-associated mayflies are narrow host specialists, being associated with one or a few closely related species of freshwater bivalves. The bivalve-associated mayfly larvae have several specific morphological traits compared with free-living species, which include a reduction of integument chitinization and a significant reduction of the surface structures on segments. An increase in area of the respiratory surface of larval tergalia was also recorded. The possible positive and negative effects of mayflies on the clam hosts are discussed. This study is an example of the many possible hidden associations between aquatic species that remain to be described.

A freshwater mussel species reflects a Miocene stream capture between the Mekong Basin and East Asian rivers

Freshwater mussels belonging to the genus Cristaria Schumacher, 1817 (Bivalvia: Unionidae) are widespread from Mongolia to Indochina while the range of one species, C. plicata (Leach, 1814), covers two biogeographic subregions, i.e., East Asian (Amur River to Vietnam) and Sundaland (Mekong River basin). We present here a taxonomic revision of the nominal taxon Anodonta bellua Morelet, 1866 which was described from the Mekong (Lake Tonle-Sap, Cambodia) but is currently considered a synonym of C. plicata. We obtained molecular data for newly collected Cristaria representatives from the Mekong’s tributaries in Laos, which were found as a divergent species-level phylogenetic clade within the genus that is distant from C. plicata. Nevertheless, comparative morphological and morphometric studies did not reveal any significant differences between these two congeners. Our time-calibrated biogeographic modeling reveals that the split between Cristaria bellua (Mekong) and C. clessini (East Asia) probably occurred in the mid-Miocene (15.8 Ma) and may reflect an ancient stream capture between the Mekong Basin and East Asian rivers.

Cryptic taxonomic diversity and high-latitude melanism in the glossiphoniid leech assemblage from the Eurasian Arctic

The family Glossiphoniidae is a diverse and widespread clade of freshwater leeches, playing a significant role in functioning of aquatic ecosystems. The taxonomy and biogeography of leeches from temperate, subtropical, and tropical regions attracted much attention of zoologists, while their taxonomic richness and distribution in the Arctic are poorly understood. Here, we present an overview of the Eurasian Arctic Glossiphoniidae based on the most comprehensive occurrence and DNA sequence datasets sampled to date. This fauna contains 14 species, belonging to five genera and three subfamilies. One genus and five species are new to science and described here. The world's northernmost occurrences of glossiphoniids are situated on the Taymyr Peninsula at 72° N, although further records at higher latitudes are expected. Most Arctic leeches are characterized by broad ranges crossing several climatic zones (e.g., Glossiphonia balcanica and G. nebulosa), although the distribution of two new species may be confined to the high-latitude areas. The Taymyr Peninsula with the nearby Putorana Plateau represents the most species-rich area (totally 9 species), while the European Arctic, Iceland, Kolyma Highland, and Chukotka Peninsula house depleted faunas (2-4 species per subregion). Finally, we show that the high-latitude melanism is a common phenomenon in glossiphoniid leeches.

A taxonomic reassessment of native and invasive species of Corbicula clams (Bivalvia: Cyrenidae) from the Russian Far East and Korea

Currently, the validity of many nominal bivalve species of the genus Corbicula endemic to the Russian Far East and South Korea needs a critical reassessment. In this study, we clarify the taxonomic status of Corbicula species of this area based on a combination of molecular genetic, conchological and anatomical data. According to our results, four Corbicula lineages, corresponding to the nominal species Corbicula japonica, Corbicula elatior, Corbicula leana and Corbicula fluminea, can be delineated in samples collected in the Primorye and Khabarovsk regions of Russia and South Korea. Two species endemic to the Russian Far East (i.e. Corbicula finitima and Corbicula lindholmi) are considered here as junior synonyms of the species C. japonica, which is widely distributed in estuarine habitats around the Japanese Archipelago, Sakhalin Island, southern Kurile Islands, Primorye and Khabarovsk regions, Korean Peninsula and China. Three nominal species described from the Lower Amur basin (Corbicula amurensis, Corbicula nevelskoyi and Corbicula sirotskii) appeared to be synonyms of C. elatior, whose range covers the Korean Peninsula, Primorye and Khabarovsk regions and, perhaps, China. We delineated several colour morphs of C. fluminea and C. japonica. The distinctness between these colour morphs can be attributed to both heritable and environmental factors.

Tagoropsis sabulosa zanzibarica ssp. nov. from Zanzibar Island (Lepidoptera: Saturniidae)

In this study, we describe Tagoropsis sabulosa zanzibarica Spitsyn & Bolotov ssp. nov. from Zanzibar (Unguja) Island. The new subspecies differs from the nominate one by having a yellow wing coloration and a contrast postmedial line on the forewing. The male of the new subspecies does not have marginal spots on the hindwing.

Phylogeography and ecology of bumble bees on Kolguev Island, a remote European Arctic landmass

The bumble bee fauna of the Russian Arctic is rather poorly known. Kolguev Island, a remote insular territory in the Barents Sea, is one of the deficiently studied areas. In this study, material on Kolguev's bumble bees is re-examined, phylogeographic data analysed, putative scenarios explaining the origin of the bumble bee fauna on the island discussed, and the biology and phenology of these insular populations described. Five bumble bee species, i.e., Bombusflavidus, B.lapponicus, B.jonellus, B.pyrrhopygus, and B.balteatus, were recorded on this island. All of these species are widespread throughout the Eurasian Arctic. Bumble bee populations on Kolguev Island are characterised by a low level of molecular divergence from mainland populations. Based on paleogeographic reconstructions and phylogeographic patterns, it is hypothesised that the bumble bees appeared on this island in the Early Holocene. The lack of rodents (lemmings and voles) sharply decreases the number of available nesting places for bumble bees on Kolguev Island.

A new species Unionicola (Dimockatax stat. rev.) haungthayawensis sp. nov. (Trombidiformes: Unionicolidae) from the freshwater mussel Lamellidens generosus (Gould, 1847) in Myanmar

Unionicola (Dimockatax stat. rev.) haungthayawensis sp. nov. is described from the freshwater mussel Lamellidens generosus (Gould, 1847) (Bivalvia: Unionidae). The mites were collected from two sites in Myanmar. The mites were examined morphologically under the light microscope and their mitochondrial COI gene sequences have been obtained. Unionicola (Dimockatax stat. rev.) haungthayawensis sp. nov. is distinguished from another Asian member of the subgenus, U. (D.) tumidoides Vidrine, 1986, by the size of idiosoma (for males), and by the length of leg segments (for males and females) and chaetotaxy of the legs. Phylogenetic analysis reveals that these mites are phylogenetically close to two North American species belonging this subgenus, i.e. U. (Dimockatax stat. rev.) tumida (Wolcott, 1898) and U. (Dimockatax stat. rev.) ernstingi Edwards et al., 2009 (uncorrected COI p-distance = 13.6% and 17.3%, respectively). In this paper, we also restore Dimockatax Vidrine, 1992 stat. rev. as a valid subgenus, because it was supported by a broad-scale phylogenetic research.

A new freshwater leech genus from Southeast Asia (Hirudinea: Glossiphoniidae)

Based on a global two-locus phylogeny of the glossiphoniid leeches (COI and 18S rRNA gene fragments), we show that the genus Placobdelloides Sawyer, 1986 (Hirudinea: Glossiphoniidae) is a paraphyletic assemblage. Based on this evidence, we introduce a new genus, Orientobdelloides gen. nov., for a small group of freshwater turtle-associated leeches from Southeast Asia, formerly placed within Placobdelloides. The new combinations are proposed as follows: Orientobdelloides siamensis (Oka, 1917) gen. & comb. nov.; O. sirikanchanae (Trivalairat, Chiangkul & Purivirojkul, 2019) comb. nov.; O. tridens (Chiangkul, Trivalairat, Kunya & Purivirojkul, 2021) comb. nov.

First record of metacercariae trematodes Opisthioglyphe ranae (Digenea: Telorchiidae) and Echinostoma bolschewense (Digenea: Echinostomatidae) in Dreissena polymorpha (Bivalvia: Dreissenidae) from the Don and Volga river basins, Russia

It is well known that an invasive bivalve mollusk species Dreissena polymorpha plays a significant role as a host to parasites. Currently, the interaction between digenean trematodes and their bivalve hosts remains relatively poorly understood. In this study we investigate infection of D. polymorpha by trematodes using molecular genetics, histological, and light microscopy methods. We obtained sequences of one mitochondrial (molecular cytochrome c oxidase subunit 1 (COI)) and two nuclear (ITS2, rDNA 28S) gene markers. To the best of our knowledge, this is the first time that infection of metacercariae of Opisthioglyphe ranae and Echinostoma bolschewense in D. polymorpha has been detected. Our sequence was 100% identical to the 28S rDNA of the species O. ranae recorded in Penza Oblast (Russia) in pond frog. At the same time, some sequences of the 28S rDNA of O. ranae detected in Penza Oblast (Russia) and Ivano-Frankovsk Region (Ukraine) were different from our sequence by 0.2%. Our sequence was 100% identical to the 28S rDNA of the species E. bolschewense sequenced in Slovakia. In addition, we received sequences of COI for both trematode species and ITS2 of E. bolschewense for the first time.

Helobdella stagnalis (Hirudinea: Glossiphoniidae), the first facultative mussel-associated leech in Europe

The ecological group of mussel-associated freshwater leeches (Hirudinea) contains facultative and obligate inhabitants of the mantle cavity of freshwater mussels (Unionida) from Asia, Africa, North America, and South America. Here, we report on the record of a mussel-associated leech in Europe and present a list of its freshwater bivalve hosts. The widespread leech species Helobdella stagnalis (Glossiphoniidae) was recovered as a facultative inhabitant of the mantle cavity of the native Anodonta anatina, Unio pictorum, and U. tumidus, and the non-native Sinanodonta woodiana (Unionidae). Globally, the freshwater mussel-associated leech assemblage contains 17 species, including four Helobdella representatives: H. lineata and H. modesta in North America, H. adiastola in South America, and H. stagnalis in Europe.

[Capabilities of using a multifunctional led device in the study of objects of forensic examination]

The purpose of the work is to determine the capabilities of the modern multifunctional device «Photobox 3138» with LED illuminators with a high color rendering index for photofixation, colorimetric, spectrozonal and multispectral analyzes of forensic objects. The competencies of the «Photobox 3138» device were experimentally revealed in terms of visualization and photofixation of both traces of biological origin (blood, sweat fat, saliva, etc.) and traces of traditional examinations, including shot products, oil products. The design of the device with a working field of 300×300 mm provides for the optimal arrangement of LED illuminators, including white light with a high color rendering index; spectrum-zonal illuminator with 4 types of LEDs with narrow non-intersecting spectral lines (458.1; 523.1; 594.1 and 630.6 nm) in the visible range of the spectrum; UV- (370 nm) and IR- (850 nm) illuminators. The fundamental possibility of using the resulting digital images of forensic objects for subsequent mathematical processing is experimentally shown. Images taken in different spectral ranges help to detect traces and damage. It was found that «Photobox 3138» allows you to solve a variety of diagnostic tasks related to the search, visualization, fixation and analysis of trace information.

Oriental freshwater mussels arose in East Gondwana and arrived to Asia on the Indian Plate and Burma Terrane

Freshwater mussels cannot spread through oceanic barriers and represent a suitable model to test the continental drift patterns. Here, we reconstruct the diversification of Oriental freshwater mussels (Unionidae) and revise their taxonomy. We show that the Indian Subcontinent harbors a rather taxonomically poor fauna, containing 25 freshwater mussel species from one subfamily (Parreysiinae). This subfamily most likely originated in East Gondwana in the Jurassic and its representatives arrived to Asia on two Gondwanan fragments (Indian Plate and Burma Terrane). We propose that the Burma Terrane was connected with the Indian Plate through the Greater India up to the terminal Cretaceous. Later on, during the entire Paleogene epoch, these blocks have served as isolated evolutionary hotspots for freshwater mussels. The Burma Terrane collided with mainland Asia in the Late Eocene, leading to the origin of the Mekong’s Indochinellini radiation. Our findings indicate that the Burma Terrane had played a major role as a Gondwanan “biotic ferry” alongside with the Indian Plate.

Computer Vision in Analyzing the Propagation of a Gas-Gunpowder Jet

A method of mathematically processing the digital images of targets is developed. The theoretical and mathematical justification and the experimental validation of the possibility of estimating the amount of gunshot residue (GSR) and determining the GSR distribution over the target on the basis of its digital image is provided. The analysis of the optical density in selected concentric rings in the images reveals the radial dependence of soot distribution in the cross section of a gas-gunpowder jet. The analysis of the optical density in selected sectors of the circle reveals the angular dependence of the soot distribution in the gas-gunpowder jet cross section. It is shown that the integral optical density averaged over a selected area in the target image characterizes the mass of GSP deposited on it. It is possible to quantify the differences in the radial and angular distributions of the thickness of the GSR layer on various targets obtained both with the help of weapons of different types at the same distances and with the help of weapons of the same type at different distances, by calculating the distribution of optical density on their digital images.

Trapped on the Roof of the World: Taxonomic diversity and evolutionary patterns of Tibetan Plateau endemic freshwater snails (Gastropoda: Lymnaeidae: Tibetoradix)

The high-elevation Tibetan Plateau (western China) is inhabited by a unique though not particularly species-rich community of organisms. We explored the species content and evolutionary history of the Tibetan Plateau endemic freshwater snail genus Tibetoradix. Phylogenetic relationships within the genus were reconstructed based on available sequence data. We used a single-rate Poisson Tree Processes approach for species delimitation and compared putative species-level clades with already described taxa. We found that the genus consists of at least six species, of which we described four as new to science. Shell and soft body morphology was examined and the radula in Tibetoradix was described for the first time. Based on our findings, the diversification of the genus did not result in a prominent morphological differentiation and a number of species can be regarded as morphologically cryptic. Single species found in different drainage areas indicate relatively good passive dispersal abilities of the snails. The allopatric distribution of the species could result from competitive exclusion between them. The absence of Tibetoradix spp. outside the Tibetan Plateau could be explained by a scenario of an "evolutionary trap", where adaptations to high elevation conditions prevented the taxa from a successful colonization of lower elevations. This article is protected by copyright. All rights reserved.

A new freshwater leech species from Asian Swamp Eel stocks in China

Discoveries of new Hemiclepsis species (Hirudinea: Glossiphoniidae) in East and Southeast Asia were expected. A peculiar freshwater leech was found on the body surface of Asian Swamp Eel Monopterus albus (Synbranchiformes: Synbranchidae) in Jingzhou, Hubei Province, China. Here, we describe this leech species as Hemiclepsis yangtzenensis sp. nov. It could be distinguished from other congeners based on a combination of morphological features such as very small size, translucent body with dense green reticulate markings throughout dorsum, very large posterior sucker with a characteristic reticulate pattern, and two pairs of well-developed drop-like eyespots. It also represents a phylogenetic lineage that is distant from other members of the genus based on the COI and 18S rRNA sequences. This leech species seems to be a specialized fish parasite that could negatively affect farming and wild stocks of Asian Swamp Eel in China.

Diversity, biogeography, evolutionary relationships, and conservation of Eastern Mediterranean freshwater mussels (Bivalvia: Unionidae)

Located at the junction between Europe, Africa, and Asia, with distinct evolutionary origins and varied ecological and geographical settings, together with a marked history of changes in orogeny and configuration of the main river basins, turned the Eastern Mediterranean into a region of high diversity and endemism of freshwater taxa. Freshwater mussels (Bivalvia, Unionidae) from the Western Palearctic have been widely studied in their European range, but little attention has been dedicated to these taxa in the Eastern Mediterranean region and their diversity and phylogeography are still poorly understood. The present study aims to resolve the diversity, biogeography, and evolutionary relationships of the Eastern Mediterranean freshwater mussels. To that end, we performed multiple field surveys, phylogenetic analyses, and a thorough taxonomic revaluation. We reassessed the systematics of all Unionidae species in the region, including newly collected specimens across Turkey, Israel, and Iran, combining COI + 16S + 28S and COI phylogenies with molecular species delineation methods. Phylogeographical patterns were characterized based on published molecular data, newly sequenced specimens, and species distribution data, as well as ancestral range estimations. We reveal that Unionidae species richness in the Eastern Mediterranean is over 70% higher than previously assumed, counting 19 species within two subfamilies, the Unioninae (14) and Gonideinae (5). We propose two new species, Anodonta seddonisp. nov. and Leguminaia anatolicasp. nov. Six additional taxa, Unio delicatusstat. rev., Unio eucirrusstat. rev., Unio huetistat. rev., Unio sesirmensisstat. rev., Unio terminalisstat. rev. removed from the synonymy of Unio tigridis, as well as Unio damascensisstat. rev. removed from the synonymy of Unio crassus, are re-described. The nominal taxa Unio rothi var. komarowi O. Boettger, 1880 and Unio armeniacus Kobelt, 1911 are proposed as new synonyms of Unio bruguierianus, and Anodonta cyrea Drouët, 1881 and Anodonta cilicica Kobelt & Rolle, 1895 as new synonyms of Anodonta anatina. Also, the presence of Unio tumidus in the Maritza River is confirmed. The phylogeographic patterns described here are interpreted concerning major past geological events. Conservation needs and implications are presented, together with populations and species conservation priorities.

The correct name for the South Western European species recently separated from Parnassius mnemosyne (Linnaeus, 1758) (Lepidoptera: Papilionidae)

The name nebrodensis Turati is shown to be unavailable and the first available name for the species is chosen by invoking the First Reviser Principle under the ICZN Code as Parnassius turatii Fruhstorfer, 1908. Rothschild was determined to be the first author to confer availability on the name nebrodensis by application of the Code.

Male of Spilarctia mikeli Bolotov, Kondakov amp; Spitsyn, 2018, an endemic species from Flores Island, Lesser Sunda Archipelago (Lepidoptera: Erebidae: Arctiinae)

The Lepidoptera fauna of the island of Flores (Lesser Sunda Archipelago, Indonesia) shares a large proportion of endemic species, which may reach 80100% in several groups (Zolotuhin Witt 2005; Nässig et al. 2009; Zolotuhin 2009; Nässig Bouyer 2010; Yakovlev 2015; Spitsyn Potapov 2020; Spitsyn Bolotov 2020). A plethora of new species was described from this island during the last 15 years, e.g. the tiger moth Spilarctia mikeli Bolotov, Kondakov Spitsyn, 2018 (Zolotuhin Witt 2005; Yakovlev 2006; Spitsyn Bolotov 2020a, b, c). This species was described based on a single female specimen collected in West Flores (Bolotov et al. 2018). In the present paper, we describe the male of Spilarctia mikeli for the first time, and illustrate variability of marking patterns of both the male and the female of this species.

Is the South African leech Barbronia gwalagwalensis Westergren amp; Siddall, 2004 (Hirudinida: Erpobdelliformes: Salifidae) a Paleotropical species?

The freshwater leech family Salifidae Johansson has a Paleotropical range, with a hotspot of species richness in the Oriental Region, and a few species endemic to Africa, Madagascar, and Reunion. Barbronia gwalagwalensis Westergren Siddall, 2004 was thought to be a characteristic example of the latter group being a lineage endemic to South Africa. However, we found that this species also occurs in Asia (Myanmar and Korea). Our time-calibrated phylogeny based on the mitochondrial cytochrome c oxidase subunit I (COI) gene reveals that the split between the African and Asian populations of this species occurred in the mid-Pleistocene, approximately 1.3 Ma ago (95% HPD 0.7-2.1 Ma). The statistical biogeographic modeling indicates that a B. gwalagwalensis population in South Africa most likely originated due a long-distance dispersal event with a subsequent vicariance (probability = 88.9%). A Late Quaternary range extension towards South Africa is known to occur in some other freshwater taxa (e.g. the freshwater mussel Unio caffer Krauss species group), which agrees with our hypothesis on the ancient origin of the South African B. gwalagwalensis population. Conversely, we can assume that the African population of this species was recently introduced from Asia. If so, the high levels of genetic divergence between African and Asian populations could be a part of a more general phylogeographic pattern historically originated within the Asian subcontinent due to the isolation by orographic or marine barriers. These two alternative hypotheses need further research efforts, i.e. sampling and sequencing of other Barbronia taxa, the ranges of which are situated between South Africa and Southeast Asia, as well as of topotypes of B. weberi (Blanchard, 1897) from Indonesia. Finally, our results highlight that the salifid genus Barbronia Johansson originated in the Oriental Region and that these leeches share both recently and historically high potential for long-distance dispersal events.

Nominal taxa of freshwater Mollusca from Southeast Asia described by Dr. Nguyen N. Thach: A brief overview with new synonyms and fixation of a publication date

In this correspondence, we present a summary of taxonomic names of freshwater Mollusca introduced by Dr. Nguyen N. Thach, an enthusiastic and productive malacologist from Vietnam. We show that this researcher described one new genus and 12 new nominal species of freshwater molluscs from Southeast Asia. Two of these nominal species, Sinanodonta hunganhi Thach, 2016 and Lanceolaria bogani Thach, 2016 (Bivalvia: Unionidae), were already considered junior synonyms of S. jourdyi (Morlet, 1886) and L. fruhstorferi (Dautzenberg, 1900), respectively (Do et al. 2018; Đặng and Hố 2019). Here, we propose one more synonym for the invasive Golden Apple Snail as follows: Pomacea canaliculata (Lamarck, 1822) [=Pomacea thachi Huber in Thach, 2020 syn. nov.] (Gastropoda: Ampullariidae). Furthermore, we establish the formal synonymy for the following taxa: Taia Annandale, 1918 [=Boganmargarya Thach, 2018 syn. nov.]; Taia shanensis (Kobelt, 1909) [=Boganmargarya huberi Thach, 2018 syn. nov.] (Gastropoda: Viviparidae); Brotia henriettae (Gray in Griffith & Pidgeon, 1833) [=Brotia frankhuberi Thach, 2020 syn. nov.; Brotia bogani Thach & Huber in Thach, 2020 syn. nov.] (Gastropoda: Pachychilidae); Pila pesmei (Morlet, 1889) [=Pila huberi Thach, 2020 syn. nov.] (Gastropoda: Ampullariidae); and Paludomus andersoniana Nevill, 1877 [=Paludomus huberi Thach, 2020 syn. nov.] (Gastropoda: Paludomidae). Additionally, four nominal species are treated here as taxa inquirenda: Melanoides thachi Huber in Thach, 2020 (Gastropoda: Thiaridae), Trochoita frankohleri Thach & Huber in Thach, 2020 (Gastropoda: Viviparidae), Paracrostoma huberi Thach, 2018 (Gastropoda: Pachychilidae), and Pseudodon artbogani Thach & Huber in Thach, 2020 (Bivalvia: Unionidae). We also show that the publication date written on the title page of the book “New Shells of South Asia. Volume 2” (Thach, 2020a) is a bit misleading and that this book appeared in the printed form on 23 June 2020. The latter date is fixed here as the date of availability of taxonomic names introduced in this work. Finally, we present an annotated checklist of freshwater Mollusca described by N. N. Thach with approximate coordinates of the type localities and reference to corresponding river drainage basins.

Parnassius nebrodensis: A threatened but neglected Apollo butterfly species from Southern Europe (Lepidoptera: Papilionidae)

Recent multi-locus phylogenetic studies repeatedly showed that what was thought to be the Clouded Apollo butterfly Parnassius mnemosyne (Linnaeus, 1758) represents a cryptic species complex. This complex contains at least three distant species-level phylogenetic lineages. Here, we compile a set of morphology- and DNA-based evidences supporting the distinctiveness of two species in this group, i.e. P. mnemosyne s. str. and P. nebrodensis Turati, 1907 stat. rev. These species can be distinguished from each other based on a combination of diagnostic characters in the male genitalia structure, wing scale patterns, and the forewing venation. The species status of P. nebrodensis is supported based on unique nucleotide substitutions in the mitochondrial (COI, ND1, and ND5) and nuclear (Wg and EF-1a) genes. P. nebrodensis is endemic to the Western Mediterranean Region. This species shares a disjunctive range through the Pyrenees, Western and Central Alps, Apennines, and the Nebrodi and Madonie mountains on Sicily. Altogether 38 nominal taxa initially described as P. mnemosyne subspecies are considered here to be junior synonyms of P. nebrodensis. At first glance, P. nebrodensis can be assessed as an endangered species due to its restricted distribution, narrow range of habitats, and ongoing population decline. Isolated populations of this species scattered through mountain ranges need special management and conservation efforts.

A new fossil piddock (Bivalvia: Pholadidae) may indicate estuarine to freshwater environments near Cretaceous amber-producing forests in Myanmar

The lower Cenomanian Kachin amber from Myanmar contains a species-rich assemblage with numerous plant and animal fossils. Terrestrial and, to a lesser degree, freshwater species predominate in this assemblage, while a few taxa with marine affinities were also discovered, e.g. isopods, ammonites, and piddocks. Here, we describe the Kachin amber piddock †Palaeolignopholas kachinensis gen. & sp. nov. It appears to be an ancestral stem lineage of the recent Lignopholas piddocks, which are estuarine to freshwater bivalves, boring into wood and mudstone rocks. Frequent occurrences and high abundance of †Palaeolignopholas borings and preserved shells in the Kachin amber could indicate that the resin-producing forest was partly situated near a downstream (estuarine to freshwater) section of a river. Multiple records of freshwater invertebrates (caddisflies, mayflies, stoneflies, odonates, and chironomids) in this amber could also manifest in favor of our paleo-environmental reconstruction, although a variety of local freshwater environments is known to occur in coastal settings.

Complete mitochondrial genome of an Arctic Collared Lemming subspecies endemic to the Novaya Zemlya Archipelago, Russia

In this study, we present an announcement of Novaya Zemlya Collared Lemming Dicrostonyx torquatus ungulatus (von Baer, 1841) complete mitogenome. This rodent was described historically as an Arctic Collared Lemming subspecies endemic to Novaya Zemlya (Arctic Russia) but its taxonomic status was unclear due to the lack of available molecular data. Based on a comprehensive mitogenomic phylogeny of the Arctic Collared Lemming, we show that this insular population shares a highly divergent mtDNA sequence (total length 16,341 bp). Hence, it should be considered a valid subspecies of the Arctic Collared Lemming. Our findings support the hypothesis that the Novaya Zemlya Archipelago had served as a cryptic polar refugium for cold-tolerant terrestrial and freshwater taxa since the mid-Pleistocene or even earlier.

A new Norwegian Lemming subspecies from Novaya Zemlya, Arctic Russia. Ecol Monten 2021. [DOI: 10.37828/em.2021.40.8]

Norwegian Lemming Lemmus lemmus is a remarkable population cycling species having a number of aposematic traits in coloration and behavior. This species was thought to be the only mammal endemic to Fennoscandia. Here, we report on the discovery of a distinct lineage of this species from Novaya Zemlya. This lineage is described here as the new subspecies Lemmus lemmus chernovi ssp. nov. that morphologically differs from the nominate subspecies by having a cryptic coloration. Our time-calibrated phylogeny revealed that this insular subspecies was isolated there since the Eemian interglacial (mean age 93 Ka). Hence, bright coloration and antipredator behavior of the nominate subspecies are novel aposematic traits that evolved since its isolation in a European refugium. This new discovery indicates that Novaya Zemlya supported a cryptic polar refugium for cold-adapted terrestrial fauna during the Pleistocene. Finally, our findings highlight that allopatric ranges of the true lemmings (Lemmus) reflect stepwise range expansions in cold climatic episodes with subsequent isolation in refugia during interglacial events.

Phylogeography and distribution of the freshwater razor clams Novaculina myanmarensis and N. gangetica in Myanmar, with notes on two doubtful nominal taxa described as Novaculina members (Bivalvia: Pharidae)

The razor clam genus Novaculina Benson, 1830 (Bivalvia: Pharidae: Pharellinae) is a group of secondary freshwater bivalves. Four allopatric species in this genus are distributed throughout Asian freshwater drainages from the Ganges River in India to the Yangtze River in China. Here, we present several new occurrences of Novaculina myanmarensis and N. gangetica from Myanmar that were confirmed by means of a molecular approach. These occurrences expand our knowledge on the ranges of both species. Furthermore, we compiled an updated distribution map for all the species in this genus. Our phylogeographic research suggests that Novaculina myanmarensis colonized the Ayeyarwady Basin from rivers of the Salween Estuary (Donthami and Ataran rivers) during the Late Pleistocene. Conversely, Novaculina gangetica populations from Myanmar does not demonstrate any clear phylogeographic structure. At first glance, this pattern can also be caused by a (sub)recent (Pleistocene) immigration into coastal rivers of western Myanmar from the Ganges Basin, although this preliminary hypothesis is yet to be confirmed using DNA sequences of samples from India and Bangladesh. Finally, the taxonomic status of two doubtful nominal taxa initially described as Novaculina members is discussed, i.e. N. gangetica theobaldi Hanley & Theobald, 1874 and N. andamanensis Preston, 1908. These taxa are considered junior subjective synonyms of the estuarine bivalve species Cultellus maximus (Gmelin, 1791) (Pharidae) and Azorinus coarctatus (Gmelin, 1791) (Solecurtidae), respectively.

Molecular data on Phyllodistomum macrocotyle (Digenea: Gorgoderidae) from an intermediate host Dreissena polymorpha (Bivalvia: Dreissenidae) in the Northern Dvina River Basin, Northwest Russia

We report the first molecular identification of Phyllodistomum macrocotyle (Digenea: Gorgoderidae) from the Northern Dvina River Basin, Northwest Russia. Comparative analysis of our sequence was 100% identical to the 28S and ITS2 rDNA sequences of the species P. macrocotyle in zebra mussels discovered in Poland (Wigry Lake), Lithuania (Elektrenai Reservoir and Sirvinta River), Russia, Belarus (Lepelskoe Lake and Lukomskoe Lake), and in fish Leuciscus idus, Scardinius erythrophthalmus in Russia (Rybinsk Reservoir on the Volga River). At the same time, some sequences of the 28S rDNA of P. macrocotyle in zebra mussel detected in Lithuania, and Belarus were different from our sequence on 0.2-0.6%. The ITS2 sequences which have 100% similarity with our specimens of P. macrocotyle were discovered in sporocyst of phyllodistomes from its intermediate host D. polymorpha in Poland, Lithuania, Russia, and Belarus. Our observation in the Yuras and Isakogorka rivers represents the northernmost record of this host-specific parasite, to the best of our knowledge.

A new genus of ultra-elongate freshwater mussels from Vietnam and eastern China (Bivalvia: Unionidae)

I this paper Sinosolenaia gen. nov. a new genus of ultra-elongate freshwater mussels (Bivalvia: Unionidae) is described from Vietnam and eastern China.

First freshwater mussel-associated piscicolid leech from East Asia

Parasites and symbionts of freshwater mussels are poorly understood, although a diverse assemblage of mussel-associated leeches (Glossiphoniidae) was recently described. Here, we report on the discovery of a fish leech (Piscicolidae) in the mantle cavity of the freshwater mussel Cristaria plicata (Unionidae) in the Russian Far East. It is the first member of this leech family being associated with freshwater molluscs. This leech does not match any known genus and species both morphologically and genetically, and is described here as Alexandrobdella makhrovigen. & sp. nov. It uses mussels as shelter (and probably as a secondary host), while the Amur catfish Silurus asotus (Siluridae) seems to be the primary host. These novel findings indicate that mussel-associated leech assemblage contains at least one piscicolid species. Our fossil-calibrated phylogeny suggests that the crown group of Piscicolidae was originated in the Early Cretaceous. This primarily marine family shares at least five independent colonization events into freshwater environments.

The global freshwater bivalve checklist’s extension: Freshwater occurrences and phylogenetic position of Galatea clams from West Africa (Venerida: Donacidae)

The bivalve genus Galatea Bruguière, 1797 (Venerida: Donacidae) was thought to contain exclusively brackish-water clams, the ranges of which are confined to estuaries and lower tidal parts of large rivers in West Africa. This genus was therefore included to the global freshwater bivalve checklists (Bogan 2013; Graf 2013) as a largely estuarine group. Conversely, a review of published data alongside our field surveys indicate that at least three populations of Galatea spp. largely occur in freshwater environment, i.e. those from the Sanaga (Cameroon), Niger (Nigeria), and Volta (Ghana) rivers. The systematic placement of these populations is unclear, as are the taxonomic status and validity of numerous nominal taxa described in this genus from a variety of localities throughout the Atlantic Coast of Africa (Angola to Senegal). We tentatively assign the populations from Niger and Volta to Galatea paradoxa (Born, 1778), while the Sanaga’s population is considered here as Galatea schwabi (Clench, 1929). However, these taxa do not share clear morphological differences and may belong to a single widespread species. In this study, we present the first DNA sequence data for a Galatea member, i.e. G. schwabi. Our COI phylogeny supports its placement within the family Donacidae suggesting sister relationships between Galatea and Donax Linnaeus, 1758. Most Galatea populations play a vital role for local riparian communities in West Africa as an intensively exploited food source. Furthermore, the clams are heavily threaten by anthropogenic impacts such as dam construction, riverbed substrate mining, and river pollution. The fishing loads and habitat degradation altogether lead to the rapid decreasing of Galatea populations in several water bodies, e.g. the Volta River in Ghana. It is impossible to develop conservation and management plans for these clams due to the lack of reliable species-level taxonomic concept of the genus. It is clear that the Galatea taxonomy and ecology need a thorough revision in the future based on DNA sequences of newly collected samples from all West African rivers, in which these remarkable clams occur.

Dragonflies from hot springs in Russia with a country-level checklist of species known to occur in geothermal environments

Geothermal springs are known to harbor unusual assemblages of dragonflies and damselflies worldwide. A review of original records and the body of available literature revealed that 27 Odonata species were recorded from hot springs in Russia so far and that the successful larval development in geothermal environments was discovered for 17 species. Among them, four species exclusively inhabit hot springs, i.e. Mnais costalis, Anotogaster sieboldii, Orthetrum melania (Kunashir Island), and O. albistylum (Eastern Siberia). In Russia, these southern species are unable to develop beyond geothermally heated water bodies due to cold climate, and they exist as local geothermal populations there. Here, we report on several novel records of Odonata species from geothermal springs in eastern Russia. Four species were recorded on the Kunashir Island (Kurile Archipelago): Mnais costalis (adults), Anotogaster sieboldii (adults and larvae), Orthetrum melania (adults), and Sympetrum pedemontanum elatum (adults and larvae). Two species were found in the Kamchatka Peninsula, i.e. Libellula quadrimaculata (freshly emerged imago and exuvia) and Aeshna juncea (larvae). To explain the origin of isolated geothermal populations of Odonata, three alternative hypotheses can be proposed as follows: (1) pre-glacial relicts; (2) mid-Holocene relicts (since the Holocene Climate Optimum); and (3) recent (late Holocene) populations founded by long-distance dispersal events. These scenarios are yet to be tested by means of a molecular approach.

New freshwater mussel taxa discoveries clarify biogeographic division of Southeast Asia

While a growing body of modern phylogenetic research reveals that the Western Indochina represents a separate biogeographic subregion having a largely endemic freshwater fauna, the boundaries of this subregion are still unclear. We use freshwater mussels (Unionidae) as a model to reconstruct spatial patterns of freshwater biogeographic divides throughout Asia. Here, we present an updated freshwater biogeographic division of mainland Southeast Asia and describe 12 species and 4 genera of freshwater mussels new to science. We show that the Isthmus of Kra represents a significant southern biogeographic barrier between freshwater mussel faunas of the Western Indochina and Sundaland subregions, while the Indian and Western Indochina subregions are separated by the Naga Hills, Chin Hills, and Rakhine Yoma mountain ranges. Our findings highlight that the freshwater bivalve fauna of Southeast Asia primarily originated within three evolutionary hotspots (Western Indochina, Sundaland, and East Asian) supplemented by ancient immigrants from the Indian Subcontinent.

Freshwater mussels (Bivalvia: Unionidae) from the rising sun (Far East Asia): phylogeny, systematics, and distribution

Freshwater mussels (Bivalvia: Unionidae) is a diverse family with around 700 species being widespread in the Northern Hemisphere and Africa. These animals fulfill key ecological functions and provide important services to humans. Unfortunately, populations have declined dramatically over the last century, rendering Unionidae one of the world's most imperiled taxonomic groups. In Far East Asia (comprising Japan, Korea, and Eastern Russia), conservation actions have been hindered by a lack of basic information on the number, identity, distribution and phylogenetic relationships of species. Available knowledge is restricted to studies on national and sub-national levels. The present study aims to resolve the diversity, biogeography and evolutionary relationships of the Far East Asian Unionidae in a globally comprehensive phylogenetic and systematic context. We reassessed the systematics of all Unionidae species in the region, including newly collected specimens from across Japan, South Korea, and Russia, based on molecular (including molecular species delineation and a COI + 28S phylogeny) and comparative morphological analyses. Biogeographical patterns were then assessed based on available species distribution data from the authors and previous reference works. We revealed that Unionidae species richness in Far East Asia is 30% higher than previously assumed, counting 43 species (41 native + 2 alien) within two Unionidae subfamilies, the Unioninae (32 + 1) and Gonideinae (9 + 1). Four of these species are new to science, i.e. Beringiana gosannensissp. nov., Beringiana fukuharaisp. nov., Buldowskia kamiyaisp. nov., and Koreosolenaia sitgyensisgen. & sp. nov. We also propose a replacement name for Nodularia sinulata, i.e. Nodularia breviconchanom. nov. and describe a new tribe (Middendorffinaiini tribe nov.) within the Unioninae subfamily. Biogeographical patterns indicate that this fauna is related to that from China south to Vietnam until the Mekong River basin. The Japanese islands of Honshu, Shikoku, Kyushu, Hokkaido, and the Korean Peninsula were identified as areas of particularly high conservation value, owing to high rates of endemism, diversity and habitat loss. The genetically unique species within the genera Amuranodonta, Obovalis, Koreosolenaiagen. nov., and Middendorffinaia are of high conservation concern.

A taxonomic review of Trapezidens (Bivalvia: Unionidae: Lamellidentini), a freshwater mussel genus endemic to Myanmar, with a description of a new species

Trapezidens Bolotov, Vikhrev & Konopleva, 2017 (Bivalvia: Unionidae: Lamellidentini) is a peculiar freshwater mussel genus, the range of which is confined to the Western Indochina Subregion (Myanmar). Here we show that this genus contains five allopatric species: Trapezidens angustior (Hanley & Theobald, 1876) from the Bago, Sittaung, and Bilin rivers; T. dolichorhynchus (Tapparone-Canefri, 1889) from the Ayeyarwady River; T. exolescens (Gould, 1843) from the Dawei River; T. scutum (Sowerby, 1868) from the Tanintharyi (Great Tenasserim) River; and T. yeti sp. nov. from the Ye River. Phylogenetically, Trapezidens angustior, T. dolichorhynchus, and T. yeti sp. nov. are closely related to each other, forming a species complex, while T. exolescens and T. scutum represent the most distant lineages within the genus. An updated synonymy for each species is compiled.

Phylogeographic affinities, distribution and population status of the non-native Asian pond mussels Sinanodonta lauta and S. woodiana in Kazakhstan

Here, we present an integrative review of the non-native Sinanodonta spp. from Kazakhstan based on molecular and morphological data. Sinanodonta woodiana (Lea, 1834) inhabits the Syr Darya River, while two species, S. woodiana and S. lauta (Martens, 1877), have established viable populations in the Ili River basin, a tributary of the Balkhash Lake. The latter species was probably introduced in 1961-1971 from the Sungari River, a Chinese tributary of the Amur River. A distribution map of the two Sinanodonta species spreading in Middle Asia is provided. In Kazakhstan and Uzbekistan, these species were recorded from endorheic drainages limiting their native expansion throughout the region, although further human-mediated dispersal events are expected. There are no reliable records of these alien freshwater mussels from Kyrgyzstan, Tajikistan, and Turkmenistan. Our study highlight that Sinanodonta lauta represents one more invasive lineage of the Asian pond mussels and that this East Asian species can successfully colonize plain water bodies of inland desert areas such as Middle Asia.

A new Radix species from Qinling Mountains, China (Gastropoda: Lymnaeidae)

A new representative of the genus Radix has been recorded from eastern China, Radix dgebuadzei sp. nov. This peculiar species was recorded from the Qinling Mountains, a remote highland region sharing the high levels of faunal and floral endemism. The phylogeny indicate that the new species belongs to the Radix alticola species group, being sister to the widespread species R. plicatula (Yunnan and Gansu in China and Southeast Asia) and R. euphratica (Middle East, Central Asia, and Eastern Europe). At first glance, we could assume that Radix dgebuadzei sp. nov. represents a local lineage endemic to the Qinling Region, while this preliminary hypothesis needs to be confirmed in the future. Our novel discovery highlights that China harbors a largely endemic fauna of the Lymnaeidae and that isolated mountain ranges in East Asia could be considered evolutionary hotspots of the radicine pond snails.

A new Najadicola species (Acari: Hydrachnidia: Pionidae) from Asia

In this paper, we describe Najadicola loeiensis sp. nov. (Pionidae: Najadicolinae), a new water mite species from the Loei River, a tributary of the Mekong River in Thailand. The only other species in this small genus, N. ingens (Koenike, 1895), inhabits North America. Our novel tropical Asian species can be distinguished from N. ingens by the shape of coxal plates and body size. N. loeiensis sp. nov. is a parasite of the inner cavity of freshwater mussels (Bivalvia: Unionidae) as its Nearctic congener.

A new Contradens from Laos (Bivalvia: Unionidae: Contradentini)

Here, we describe Contradens novoselovi sp. nov. (Bivalvia: Unionidae), a new freshwater mussel species from the Mekong Basin in Laos. Phylogenetic and morphological analyses reveal that the new taxon is closely related to Contradens comptus (Deshayes & Jullien, 1874) but can be distinguished from it by a smaller size, sub-ovate shell shape, tiny wrinkles near umbo, stronger pseudocardinal and lateral teeth, and fixed nucleotide substitutions. Contradens novoselovi sp. nov. is known only from the type locality in northwestern Laos and may represent a rare endemic species with restricted range.

Freshwater mussels house a diverse mussel-associated leech assemblage

Freshwater mussels (Unionida) are one of the most imperiled animal groups worldwide, revealing the fastest rates of extinction. Habitat degradation, river pollution and climate change are the primary causes of global decline. However, biological threats for freshwater mussels are still poorly known. Here, we describe a diverse ecological group of leeches (Hirudinea: Glossiphoniidae) inhabiting the mantle cavity of freshwater mussels. So far, examples of mussel-associated leech species are recorded from East Asia, Southeast Asia, India and Nepal, Africa, and North America. This group comprises a dozen glossiphoniid species with a hidden life style inside the mantle cavity of their hosts largely overlooked by researchers. We show that the association with freshwater mussels evolved independently in three leech clades, i.e. Batracobdelloides, Hemiclepsis, and Placobdella, at least since the Miocene. Seven mussel-associated leech species and two additional free-living taxa are described here as new to science.