Expansion and systematics redefinition of the most threatened freshwater mussel family, the Margaritiferidae.

Two Unionida (freshwater mussel) families are present in the Northern Hemisphere; the Margaritiferidae, representing the most threatened of unionid families, and the Unionidae, which include several genera of unresolved taxonomic placement. The recent reassignment of the poorly studied Lamprotula rochechouartii from the Unionidae to the Margaritiferidae motivated a new search for other potential species of margaritiferids from members of Gibbosula and Lamprotula. Based on molecular and morphological analyses conducted on newly collected specimens from Vietnam, we here assign Gibbosula crassa to the Margaritiferidae. Additionally, we reanalyzed all diagnostic characteristics of the Margaritiferidae and examined museum specimens of Lamprotula and Gibbosula. As a result, two additional species are also moved to the Margaritiferidae, i.e. Gibbosula confragosa and Gibbosula polysticta. We performed a robust five marker phylogeny with all available margaritiferid species and discuss the taxonomy within the family. The present phylogeny reveals the division of Margaritiferidae into four ancient clades with distinct morphological, biogeographical and ecological characteristics that justify the division of the Margaritiferidae into two subfamilies (Gibbosulinae and Margaritiferinae) and four genera (Gibbosula, Cumberlandia, Margaritifera, and Pseudunio). The systematics of the Margaritiferidae family is re-defined as well as their distribution, potential origin and main biogeographic patterns

Bioerosion of siliceous rocks driven by rock-boring freshwater insects

Macrobioerosion of mineral substrates in fresh water is a little-known geological process. Two examples of rock-boring bivalve molluscs were recently described from freshwater environments. To the best of our knowledge, rock-boring freshwater insects were previously unknown. Here, we report on the discovery of insect larvae boring into submerged siltstone (aleurolite) rocks in tropical Asia. These larvae belong to a new mayfly species and perform their borings using enlarged mandibles. Their traces represent a horizontally oriented, tunnel-like macroboring with two apertures. To date, only three rock-boring animals are known to occur in fresh water globally: a mayfly, a piddock, and a shipworm. All the three species originated within primarily wood-boring clades, indicating a simplified evolutionary shift from wood to hardground substrate based on a set of morphological and anatomical preadaptations evolved in wood borers (e.g., massive larval mandibular tusks in mayflies and specific body, shell, and muscle structure in bivalves)

Barbronia gwalagwalensis Westergren & Siddall 2004

Barbronia gwalagwalensis Westergren & Siddall, 2004 Figures 3-6 Type. Holotype, AMNH Annelida 5261, fixed in 10% buffered formalin and stored in 70% ethanol (American Museum of Natural History, New York, USA). Type locality. “ Maia’s Dam, Gwalagwala, a tented-camp near Hoedspruit, South Africa ” (Westergren & Siddall 2004). Material examined. MYANMAR: Salween River drainage, Lake Inle basin, Kyee Phyu Lake, 20.8142°N, 96.9690°E, 23.ii.2018, 2 specimens, fixed in 96% ethanol [voucher RMBH Hir_58_3; one specimen sequenced: COI acc. no. MN 295405]. The sample is deposited in the RMBH — Russian Museum of Biodiversity Hotspots, N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia. Morphology of Myanmar’s sample. Small leeches, 10–15 mm long (ethanol-preserved specimens). Body subcylindrical, vermiform, tapering anteriorly and posteriorly. Dorsum light brown. Three pairs of eyespots: first dorsal, on II; second and third pairs dorsolateral on IV, and separated from anterior pair by four complete annuli. Caudal sucker directed ventrally. Clitellum indistinct (juveniles), with male and female gonopores separated by seven and one-half annuli, and with two accessory copulatory pores ventrally: one anterior of the male gonopore at X/XI, and second posterior of the female gonopore at XIII/XIV. Three pairs of pharyngeal stylets. These features correspond well to the protologue of the species, although the type series comprised full-grown adults up to 25 mm long with pronounced clitellum and distinct accessory copulatory pores (Westergren & Siddall 2004). Habitat. The specimens were collected on a submerged bamboo stick and an empty shell of the freshwater mussel species Lamellidens ferrugineus (Annandale) found near the shore of a shallow eutrophic lake with silty bottom and rich aquatic plant assemblages. They co-occurred with the freshwater glossiphonid species Alboglossiphonia sp. (Hirudinida: Glossiphoniidae) [voucher no. RMBH 58_2; COI acc. no. MN 295404] and the triclad species Dugesia sp. (Tricladida: Dugesiidae) [voucher no. RMBH 58_1]. The Dugesia species was very abundant. Distribution. This species appears to be widespread throughout the Paleotropical Region as it was found in South Africa, Southeast Asia (Myanmar), and East Asia (Korea). The occurrence from the Durance River (Rhône Basin) in southeastern France (Corse et al. 2017) most likely reflects a recent human-mediated or native dispersal event towards southern Europe. Comments. The nominal taxon Trocheta quadrioculata Oka, 1922 was described from the Inle Lake in Myanmar (Oka 1922). The type locality of this species is close to our finding of B. gwalagwalensis (ca. 25-30 km SSW). Currently, Inle Lake’s taxon is placed within Salifidae as Odontobdella quadrioculata (see Nesemann & Sharma 2012). Based on the protologue (Oka 1922), it does not have accessory copulatory pores and, hence, cannot be linked to the genus Barbronia (see Westergren & Siddall 2004). The fauna of the family Salifidae in Myanmar seems to be largely underestimated, and comprises only two species, i.e. B. gwalagwalensis and O. quadrioculata.Published as part of Klass, Anna L., Kondakov, Alexander V., Vikhrev, Ilya V., Bespalaya, Yulia V., Lunn, Zau, Chan, Nyein, Gofarov, Mikhail Y. & Bolotov, Ivan N., 2021, Is the South African leech Barbronia gwalagwalensis Westergren & Siddall, 2004 (Hirudinida: Erpobdelliformes: Salifidae) a Paleotropical species?, pp. 585-595 in Zootaxa 4974 (3) on pages 589-591, DOI: 10.11646/zootaxa.4974.3.7, http://zenodo.org/record/477812

Diversity and Phylogenetics of Freshwater Mussels (Unionidae) from Southern Thailand with the Description of One New Genus and Five New Species-Group Taxa

Southern Thailand represents a region of unique freshwater biodiversity with many endemic taxa, including a number of freshwater mussel species (Bivalvia: Unionidae). In this study, we recognize 13 taxa in the tribes Contradentini, Rectidentini, Pseudodontini (subfamily Gonideinae), and Indochinellini (subfamily Parreysiinae) that inhabit different localities in the Songkhla Lake, Tapi River, and Tha Taphao River basins. Based on the results of morphological and phylogenetic analyses, we discovered among these mussels six taxa new to science, including one genus, three species, and two subspecies. New taxonomic names are introduced here as follows: Songkhlanaiagen. nov.; S. tamodienicagen. & sp. nov.; Sundadontina plugpomenicasp. nov.; Monodontina vondembuschiana tapienicassp. nov.; M. vondembuschiana thasaenicassp. nov. (Pseudodontini); and Trapezoideus thachiadensissp. nov. (Contradentini). These new taxa confirm the high conservation priority of the Southern Thai freshwater mussel fauna

Fifty-percent majority-rule consensus phylogenetic tree of <i>Creatonotos</i> spp. recovered from Bayesian inference analysis of an alignment comprising 61 <i>COI</i> haplotypes of <i>Creatonotos</i> spp. and two haplotypes of the out-group taxa (<i>Arctia menetriesii</i> and <i>A</i>. <i>tundrana</i>).

<p>The island localities are in bold. Black numbers near branches are Bayesian posterior probabilities (BPP). The red number near each primary clade is the probability of each species-level MOTU based on the highest Bayesian supported solution of the PTP model.</p

DNA barcoding unravels contrasting evolutionary history of two widespread Asian tiger moth species during the Late Pleistocene - Fig 2

<p>Phylogeography of <i>Creatonotos</i> spp. (<b>A</b>) Median-joining network of <i>COI</i> sequences (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0194200#pone.0194200.s003" target="_blank">S1 Table</a> for details). Photos (male specimens): <i>C</i>. <i>gangis</i> [Indonesia, Flores Island, voucher no. Sph0595] and <i>C</i>. <i>transiens</i> [Thailand, near Tham Lod Cave, voucher no. Sph0624] by Vitaly M. Spitsyn and <i>C</i>. <i>leucanioides</i> [Tanzania] by Roy Goff (with his permission; <a href="https://www.africanmoths.com" target="_blank">www.africanmoths.com</a>). (<b>B</b>) Map of approximate collection localities of the specimens in accordance with the respective countries (color squares). Small squares indicate island sites. The map was created using ESRI ArcGIS 10 software (<a href="https://www.esri.com/arcgis" target="_blank">www.esri.com/arcgis</a>); the base of the map was created with ESRI Data and Maps. (<b>C</b>) Frequency histogram of the barcoding gap analysis.</p

DNA barcoding unravels contrasting evolutionary history of two widespread Asian tiger moth species during the Late Pleistocene

<div><p>Populations of widespread pest insects in tropical areas are characterized by a complex evolutionary history, with overlapping natural and human-mediated dispersal events, sudden expansions, and bottlenecks. Here, we provide biogeographic reconstructions for two widespread pest species in the tiger moth genus <i>Creatonotos</i> (Lepidoptera: Erebidae: Arctiinae) based on the mitochondrial <i>cytochrome c oxidase subunit I</i> (<i>COI</i>) gene. The Asian <i>Creatonotos transiens</i> reveals shallow genetic divergence between distant populations that does not support its current intraspecific systematics with several local subspecies. In contrast, the more widespread <i>Creatonotos gangis</i> comprises at least three divergent subclades corresponding to certain geographic areas, i.e. Australia, Arabia + South Asia and Southeast Asia. With respect to our approximate Bayesian computation (ABC) model, the expansion of <i>Creatonotos gangis</i> into Australia is placed in the Late Pleistocene (~65–63 ka). This dating coincide with an approximate time of the earliest human migration into the continent (~65–54 ka) and the period of intervisibility between Timor and Australia (~65–62 ka). Our findings highlight that the drying Sunda and Sahul shelf areas likely support successful migrations of Asian taxa into Australia during the Pleistocene. The phylogeographic patterns discovered in this study can be used to improve the effectiveness of integrated pest control programs that is a task of substantial practical importance to a broad range of agricultural stakeholders.</p></div

Simplified summary of expansion routes inferred across populations of <i>Creatonotos gangis</i>, and examples of male specimens and habitat of Southeast Asian population.

<p>(<b>A</b>) Map of expansion routes. Color circles indicate an approximate range of each population: Southeast Asian population (blue), Arabian–South Asian population (green), and Australian population (orange). Red arrows indicate the directions of expansion routes. The numbers near arrows show the mean age of putative expansion events (in thousands of years) obtained from the ABC model. The map was created using ESRI ArcGIS 10 software (<a href="https://www.esri.com/arcgis" target="_blank">www.esri.com/arcgis</a>); the base of the map was created with ESRI Data and Maps. (<b>B</b>) Male specimen, Maehongson, Thailand. (<b>C</b>) Male specimen, Kachin, Myanmar. (<b>D</b>) Paddy field, a typical habitat of the species, Thanh Hoa Province, Vietnam. (Photos: Vitaly M. Spitsyn).</p

Mismatch distributions of <i>Creatonotos</i> spp. samples based on the mitochondrial <i>COI</i> gene.

<p>Solid black lines indicate observed distribution, and solid red lines represent simulated distribution under a spatial expansion model. Dashed lines represent lower and upper confidence intervals (<i>p</i> = 0.01). (<b>A</b>) <i>C</i>. <i>gangis</i>, Eurasia (<i>N</i> = 40 sequences; Raggedness <i>P</i> = 0.342; Model (SSD) <i>P</i> = 0.317). (<b>B</b>) <i>C</i>. <i>gangis</i>, Arabia and South Asia (<i>N</i> = 20 sequences; Raggedness <i>P</i> = 0.264; Model (SSD) <i>P</i> = 0.273). (<b>C</b>) <i>C</i>. <i>gangis</i>, mainland Southeast Asia (<i>N</i> = 20 sequences; Raggedness <i>P</i> = 0.089; Model (SSD) <i>P</i> = 0.331). (<b>D</b>) <i>C</i>. <i>gangis</i>, Australia (<i>N</i> = 15 sequences; Raggedness <i>P</i> = 0.910; Model (SSD) <i>P</i> = 0.736). (<b>E</b>) <i>C</i>. <i>gangis</i>, the entire range (<i>N</i> = 57 sequences; Raggedness <i>P</i> = 0.715; Model (SSD) <i>P</i> = 0.557). (<b>F</b>) <i>C</i>. <i>transiens</i>, Eurasia (<i>N</i> = 39 sequences; Raggedness <i>P</i> = 0.671; Model (SSD) <i>P</i> = 0.596).</p

Host Range and Phylogenetic Position of Acipenserobdella volgensis (Zykoff, 1904) (Hirudinea: Piscicolidae) with a Global Checklist of Bivalve-Associated Fish Leeches

The fish leech Acipenserobdella volgensis (Hirudinea: Piscicolidae) is a rare and poorly known freshwater species, which is thought to be an obligate parasite of sturgeons. This leech has a disjunctive range in Europe and Eastern Siberia. Here, we estimate the phylogenetic affinities and host range of A. volgensis using a set of DNA sequences (COI and 18S rRNA gene fragments), field observation data, and a review of the body of literature. Based on a time-calibrated Bayesian phylogeny, we show that the European and Siberian lineages of A. volgensis have been separated since the latest Pliocene (mean age = 2.7 Ma). The analysis of available host records indicates that this leech is characterized by a broader host range as it was collected from fish belonging to four families (Acipenseridae, Cyprinidae, Salmonidae, and Esocidae). Conversely, only a few suitable primary hosts (six sturgeons, one cyprinid, and one salmonid fish) were confirmed by earlier research. Moreover, this leech could be considered a facultative mussel-associated species that uses bivalves (duck mussel Anodonta anatina; Unionidae) as shelter. Globally, three other piscicolid leeches have been recorded from the mantle cavity of bivalve molluscs, that is, the freshwater taxa Caspiobdella fadejewi and Alexandrobdella makhrovi, and the marine species Austrobdella coliumicus