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.

On the verge of extinction - revision of a highly endangered Swiss alpine snail with description of a new genus, Raeticella gen. nov. (Gastropoda, Eupulmonata, Hygromiidae).

The phylogenetic status of the alpine land snail Fruticicolabiconica has remained questionable since it was described by Eder in 1917. Considered a microendemic species from mountain tops in Central Switzerland, the shell is specially adapted for life under stones. Herein, we show via molecular and anatomical investigations that F.biconica neither belongs to the land snail genus Trochulus, nor to any other genus within Trochulini, but rather warrants placement within the newly established genus Raeticella Kneubühler, Baggenstos & Neubert, 2022. Phylogenetic analyses reveal that R.biconica is clearly separated from Trochulus. These findings are supported by morphological investigations of the shell and genitalia.

Revision of the " Chloritisdelibrata (Benson, 1836)" group (Gastropoda, Stylommatophora, Camaenidae).

Chloritisdelibrata (Benson, 1836), known from northeastern India, was believed to have three varietal forms, sometimes mentioned as subspecies: C.delibratavar.khasiensis (Nevill, 1877) and C.delibratavar.fasciata (Godwin-Austen, 1875) from the Khasi Hills, India, and C.delibratavar.procumbens (Gould, 1844) from Dawei in Myanmar. The reproductive anatomy of the latter form is known and does not match with those of any continental camaenid genera, but does with that of the newly examined Chloritisplatytropis Möllendorff, 1894 from Thailand. The latter species is conchologically similar to Bouchetcamaenahuberi Thach, 2018 (synonym of Helixfouresi Morlet, 1886), which is the type species of the genus Bouchetcamaena Thach, 2018. Thus, Bouchetcamaena can provisionally host the entire Chloritisdelibrata -group with the exception of var. fasciata, which is transferred to Burmochloritis Godwin-Austen, 1920 due to the multiple reddish bands on its shell. The examination of shells deposited in the Natural History Museum, London revealed that seven morphologically distinguishable forms are present, which are accepted here as representing distinct species. Four new species are described from India: Bouchetcamaenafoveata Páll-Gergely sp. nov., B.fusca Páll-Gergely sp. nov., B.raripila Páll-Gergely sp. nov., and B.subdelibrata Páll-Gergely sp. nov.

Revision of the family Milacidae from Switzerland (Mollusca, Eupulmonata, Parmacelloidea).

In this work, the presence of species of the slug family Milacidae in Switzerland was investigated by using the barcoding marker cytochrome c oxidase subunit I (COI) as well as traits of the body and the genital organs. Currently, three species of Tandonia living in Switzerland in established populations could be reported, i.e., T.rustica, T.budapestensis, and T.nigra. The three records of Milaxgagates were re-investigated, but only for one of these records could the identification be reconfirmed. This species has currently no established and thriving population in Switzerland. For all species recorded, detailed descriptions of body morphology, genital anatomy, and distribution data are provided based on the investigated Swiss animals. An unknown pale colour morph of a Tandonia sp. from Canton Ticino could be identified as T.nigra, and the barcodes of T.nigra specimens were submitted to GenBank for the first time. The identity of the Italian and Austrian populations of T.nigra from the Bergamasque Alps and north Tirol is evaluated. Observations on details of the morphology of the genital organs in T.rustica vs. T.kusceri are discussed.

Adapting mark-recapture methods to estimating accepted species-level diversity: a case study with terrestrial Gastropoda.

We introduce a new method of estimating accepted species diversity by adapting mark-recapture methods to comparisons of taxonomic databases. A taxonomic database should become more complete over time, so the error bar on an estimate of its completeness and the known diversity of the taxon it treats will decrease. Independent databases can be correlated, so we use the time course of estimates comparing them to understand the effect of correlation. If a later estimate is significantly larger than an earlier one, the databases are positively correlated, if it is significantly smaller, they are negatively correlated, and if the estimate remains roughly constant, then the correlations have averaged out. We tested this method by estimating how complete MolluscaBase is for accepted names of terrestrial gastropods. Using random samples of names from an independent database, we determined whether each name led to a name accepted in MolluscaBase. A sample tested in August 2020 found that 16.7% of tested names were missing; one in July 2021 found 5.3% missing. MolluscaBase grew by almost 3,000 accepted species during this period, reaching 27,050 species. The estimates ranged from 28,409 ± 365 in 2021 to 29,063 ± 771 in 2020. All estimates had overlapping 95% confidence intervals, indicating that correlations between the databases did not cause significant problems. Uncertainty beyond sampling error added 475 ± 430 species, so our estimate for accepted terrestrial gastropods species at the end of 2021 is 28,895 ± 630 species. This estimate is more than 4,000 species higher than previous ones. The estimate does not account for ongoing flux of species into and out of synonymy, new discoveries, or changing taxonomic methods and concepts. The species naming curve for terrestrial gastropods is still far from reaching an asymptote, and combined with the additional uncertainties, this means that predicting how many more species might ultimately be recognized is presently not feasible. Our methods can be applied to estimate the total number of names of Recent mollusks (as opposed to names currently accepted), the known diversity of fossil mollusks, and known diversity in other phyla.

Reappraisal of the "Molecular phylogeny of Western Palaearctic Helicidae s.l. (Gastropoda: Stylommatophora)": when poor science meets GenBank.

A paper on the 'Molecular phylogeny of Western Palaearctic Helicidae s.l.', published by Steinke et al. (2004) in this journal, is critically analysed. Several obvious errors are corrected and methodological weaknesses are revealed. BLAST searches on the sequences published in that paper and now in GenBank, showed high percentages of similarity of the alleged species with taxa that are considered only distantly related in the literature. Inspection of the so-called voucher specimens showed that some shells were misidentified, whereas others contained dirt or were bleached, indicating that these had been collected empty. Obviously the sequences published for those species could not have originated from those specimens, which cannot be considered vouchers therefore, even if they are from the same locality. In other instances, spurious sequences were published for correctly identified voucher specimens. For several species for which we collected specimens ourselves, the COI or the 16S sequence, or both, clearly differed from the results published by Steinke et al. The consequences of our results for the molecular data on helicid gastropods and their classification are listed.

New genetic data reveals a new species of Zospeum in Bosnia (Gastropoda, Ellobioidea, Carychiinae).

Recent integrative investigations of the terrestrial ellobiid genus, Zospeum, have revealed significant findings concerning its Alpine-Dinaric evolution and taxonomy. Due to the expected discrepancy between the useful, but limited, 1970s' classification system based on shell data and the results of recent genetic analyses in the latest investigation, a revision of the entire radiation was undertaken, and a new classification system was devised by the present authors in an earlier paper. Concurrent to this work, molecular sequences from two Austrian caves were published independently of our revision by another research group. By incorporating these genetic data within our phylogenetic framework here, we show that the Austrian individuals are genetically most similar to Zospeumamoenum and consequently, classify them within that species. We additionally reveal two new genetic lineages from the largely under-sampled southern extension of Zospeum's known distributional range. The first lineage, deriving from the region of Dubrovnik, Croatia, is a potential candidate for genetically clarifying Zospeumtroglobalcanicum. The second lineage derives from the municipality of Tomislavgrad, Bosnia-Herzegovina and is herein, described a new species: Zospeumsimplex Inäbnit, Jochum & Neubert, sp. nov.

A new Diancta species of the family Diplommatinidae (Cyclophoroidea) from Vanua Levu Island, Fiji.

A new species of Diancta of the staircase snail family Diplommatinidae is described from Mt. Savusavu, Vanua Levu Island, Fiji. Due to its left coiling shell and a constriction before the last whorl, it is placed in the genus Diancta. Micro-CT imaging reveals two apertural teeth and an inner lamella that is situated at the zone of constriction. The shell abruptly changes coiling direction by 45 degrees before the last whorl. Up to now, this coiling modus had not yet been documented for any species of Diplommatinidae from the Fiji Islands.

New insights in Trichochloritis Pilsbry, 1891 and its relatives (Gastropoda, Pulmonata, Camaenidae).

The genus Bellatrachia Schileyko, 2018 was described based on a specimen identified as Helix (Chloritis) pseudomiara Bavay & Dautzenberg, 1909. We concluded that the examined specimen is not that species, but Helixcondoriana Crosse & Fischer, 1863. Therefore, (1) the type species of Bellatrachia must be replaced with Helixcondoriana; (2) the species Helix (Chloritis) pseudomiara must be re-allocated to the genus Trichochloritis; (3) the erroneous treatment of the genus Trichochloritis by Schileyko (2007) needs to be corrected through the description of a new genus, Dentichloritis gen. nov. based on Helixbrevidens Sowerby I, 1841. In addition, Chloritismicrotricha Möllendorff, 1898 is treated as a synonym of Helixcondoriana, and further information on the genitalia of Chloritis (?) bifoveata (Benson, 1856) is presented.

Anatomical and phylogenetic investigation of the genera Alabastrina Kobelt, 1904, Siretia Pallary, 1926, and Otala Schumacher, 1817 (Stylommatophora, Helicidae).

This study presents new insights in the anatomy of genital organs of some large helicid gastropods from northern Africa. The genetic analysis with the markers COI, 16S, H3, and 5.8 S rRNA+ITS2 reveales a high support for Alabastrina and Otala as separate evolutionary lineages within the Otalini. The position of Siretia as another separate lineage within the Otalini is discussed. "Tingitanaminetteidecussata" clusters within the O.xanthodon clade and confirms that the genus Tingitana can be synonymised with Otala. The genus Alabastrina differs from all other known genera by possession of a penial appendix. This character state is also found in topotypic A.tistutensis. Examination of the twin penial papilla system in Otala recovers a reduction of the proximal penial papilla in O.punctata. The position of Helixmurcica as a separate subspecies of O.lactea is not supported, and it is here considered to be a synonym of the latter species.

Revisited - the species of Tweeting vineyard snails, genus Cantareus Risso, 1826 (Stylommatophora, Helicidae, Helicinae, Otalini).

The generic allocation of Helix subaperta is clarified by using genetic data and morphological traits of the genital organs; its position within the hitherto monotypic genus Cantareus is corroborated. Further analysis of several specimens of Cantareus apertus from Algeria and Italy revealed that this taxon is composed of two species, C. apertus from Italy, and C. koraegaelius from Algeria. The morphological traits of the genital organs of all three species are discussed, and the definition of the genus Cantareus is amended. All three species confined to Cantareus are re-described, and the syntype specimen of H. aperta is illustrated.

ResuméeLa répartition générique de Helix subaperta est clarifiée en utilisant des données génétiques et des traits morphologiques des organes génitaux sa position au sein du genre Cantareus jusque-là monotypique est renforcée. Une analyse plus approfondie de plusieurs spécimens de Cantareus apertus d'Algérie et d'Italie arévélé que ce taxon est composé de deux espèces C. apertus d'Italie et C. koraegaelius d'Algérie. Les traits morphologiques des organes génitaux des trois espèces sont étudiés et la définition du genre Cantareus est modifiée. Les trois espèces confinées à Cantareus sont à nouveau décrites et le spécimen de syntype de H. aperta est illustré.

New records of the endemic Sicilian land snail species Marmorana (Murella) muralis (O. F. Müller, 1774) from the north of Tunisia (Pulmonata, Gastropoda).

Marmorana (Murella) muralis is known as an endemic species of Sicily Island, which is introduced in many European countries. Here, M. (M.) muralis is recorded from the north of Tunisia. In order to confirm the identification of samples collected from several localities, shell morphology, details of genital organs and two mitochondrial markers (COI and 16S) were investigated. The results of the molecular study, as well as the morphological and anatomical studies confirm the identification of all Tunisian samples as M. (M.) muralis. The analysis of mitochondrial markers shows a low divergence between Sicilian and Tunisian samples suggesting a recent introduction of M. (M.) muralis to the North of Tunisia. The comparison of morphological characters of M. (M.) muralis with shell characters of Murella nicollei described by Pallary (1926) confirms that the latter should be considered as synonym of M. (M.) muralis.

Résumé Marmorana (Murella) muralis est connue comme une espèce endémique de l'île de Sicile qui est actuellement introduite dans plusieurs pays européens. Dans la présente étude, nous enregistrons, la présence de M. (M.) muralis dans différentes localités du Nord de la Tunisie. Dans le but de valider l'authenticité des spécimens collectés de différentes localités, la morphologie de la coquille, l'anatomie de l'appareil génital ainsi que deux marqueurs mitochondriaux (COI et 16S) ont été analysés. Les résultats de l'étude moléculaire ainsi que ceux de l'étude morphologique et anatomique confirment qu'il s'agit bien de l'espèce Sicilienne M. (M.) muralis. L'analyse des deux marqueurs mitochondriaux montre une faible divergence entre les populations Sicilienne et Tunisienne suggérant ainsi une récente introduction de cette espèce en Tunisie. La comparaison des critères morphologiques de l'espèce M. (M.) muralis avec les critères de la coquille de l'espèce Murella nicollei décrite par Pallary (1926) confirme que cette dernière doit être considérée comme synonyme de l'espèce M. (M.) muralis.

At home at least: the taxonomic position of some north African Xerocrassa species (Pulmonata, ).

In order to clarify the systematic position of Helix latastei Letourneux in Letourneux & Bourguignat, 1887, and Helix latasteopsis Letourneux & Bourguignat, 1887, a comprehensive approach using morphological and molecular methods is presented. The investigation of the genital organs of both species showed that they belong to the genus Xerocrassa Monterosato, 1892 with two very small dart sacs and a few tubiform glandulae mucosae. In our phylogenetic analysis using the mitochondrial markers COI, 16S and the nuclear cluster 5.8-ITS2-28S, the results of the anatomical research were confirmed. Thus, the genus Ereminella Pallary, 1919, which is based on H. latastei, becomes a junior synonym of Xerocrassa. A review of the genus-level taxa Xerobarcana Brandt, 1959, and Xeroregima Brandt, 1959, showed that these should also be considered as synonyms of Xerocrassa. A third species, Helix lacertara Bourguignat, 1863 from Algeria was found to be closely related to X. latastei based on its shell morphology. A map showing the distribution of the three species treated is supplied.

RésuméUne étude basée sur des approches morphologiques et moléculaires a été réalisée dans le but de clarifier la position systématique de deux espèces Helix latastei Letourneux 1887 et Helix latasteopsis Letourneux & Bourguignat, 1887. L'examen des organes génitaux a montré des critères typiques du genre Xerocrassa Monterosato, 1892 avec la présence de deux petits "Dart Sac" et des glandes digitiformes à mucus. Les résultats de l'analyse phylogénétique de deux gènes mitochondriaux (COI et 16S) et un gène nucléaire 5.8S-ITS2-28S ont confirmé les résultats de l'étude anatomique. Par conséquent, le genre Ereminella Pallary, 1919, qui a été basé sur Helix latastei est donc un synonyme du genre Xerocrassa. La révision de deux genres Xerobarcana Brandt, 1959 et Xeroregima Brandt, 1959, suggère que ces deux genres sont aussi des synonymes du genre Xerocrassa. L'examen de la coquille de l'espèce Algérienne Helix lacertara Bourguignat, 1863 a montré une forte ressemblance avec X. latastei, ce qui nous a permis, ainsi, de la classer dans le genre Xerocrassa. Une carte montrant la distribution des trois espèces a été fournie.

The Diplommatinidae of Fiji - a hotspot of Pacific land snail biodiversity (Caenogastropoda, Cyclophoroidea).

The minute (adult size 1.3-4.8 mm) land snail species of the family Diplommatinidae in the Fiji archipelago are revised based on historical material and modern (1998-99) collections targeting limestone outcrops on the largest island, Viti Levu, and several smaller islands in the Lau group. The forty-two species (including 30 new species) belong to the genera Moussonia Semper, 1865, Palaina Semper, 1865 and Diancta Martens, 1867, which are briefly characterized and keyed. The diagnostic structure of the inner lamellar system of each species is illustrated. All species except one are endemic to Fiji. In Viti Levu, the 12 localities surveyed each had 1-13 (average 5) species of Diplommatinidae; ten species were each found at a single site only. In the Lau islands, five islands were visited, with 1-4 species per island; four species are known from single islands. The number of historically known species not recollected in 1998-99 (7 species), the number of single-site occurrences (14 species), and the numerous islands - including limestone islands - that have not been surveyed at all, indicate that the 42 species of Diplommatinidae currently known from Fiji represent perhaps only half of the Fiji diplommatinid fauna. Such numbers approach the diplommatinid diversity of Palau (39 described and more than 60 undescribed species), and surpasses by far the diversity of other South Pacific archipelagos of comparable land area (New Caledonia, Vanuatu, Samoa). Nomenclatural acts: Lectotypes designated: Diplommatinafuscula, Diplommatinafusculavar.vitiana, Diplommatinagodeffroyana, Diplommatinagodeffroyanavar.latecostata, Diplommatinatuberosa, Diplommatinamartensivar.macrostoma, all Mousson, 1870. Neotypes designated: Diplommatinasubregularis, Diplommatinaascendens, Diplommatinaquadrata, all Mousson, 1870. New species: Dianctaaurea sp. n., Dianctaaurita sp. n., Dianctabasiplana sp. n., Dianctacontroversa sp. n., Dianctadensecostulata sp. n., Dianctadextra sp. n., Dianctadilatata sp. n., Dianctadistorta sp. n., Dianctapulchella sp. n., Dianctarotunda sp. n., Dianctasubquadrata sp. n., Dianctatrilamellata sp. n., Moussoniaacuta sp. n., Moussoniabarkeri sp. n., Moussoniabrodieae sp. n., Moussonialongipalatalis sp. n., Moussoniaminutissima sp. n., Moussoniaobesa sp. n., Moussoniapolita sp. n., Moussoniauncinata sp. n., Moussoniavitianoides sp. n., Palainaalberti sp. n., Palainaflammulata sp. n., Palainaglabella sp. n., Palainakitteli sp. n., Palainalabeosa sp. n., Palainaparietalis sp. n., Palainasulcata sp. n., Palainatruncata sp. n., Palainatuberosissima sp. n.

On the Monacha species of Lebanon (Gastropoda, Hygromiidae).

In this paper, all seven hitherto known species of the hygromiid genus Monacha from Lebanon are briefly characterised and illustrated, and distribution maps are supplied (Monacha (Monacha) syriaca (Ehrenberg, 1831), Monacha (Monacha) nummus (Ehrenberg, 1831), Monacha (Monacha) obstructa (L. Pfeiffer, 1842), Monacha (Monacha) crispulata (Mousson, 1861), Monacha (Monacha) solitudinis (Bourguignat, 1852), Monacha (Monacha) bari Forcart 1981, and Monacha (Monacha) cf. compingtae (Pallary, 1929)). One species, Monacha (Monacha) bari Forcart, 1981, is recorded for the country for the first time, and its relationship to Monacha (Monacha) compingtae (Pallary, 1929) is discussed. Based on recently collected specimens, the genital organs of a long time ignored species, Helix solitudinis Bourguignat, 1852 could be investigated. It is here re-described as a Monacha species endemic for Lebanon.

New taxa of terrestrial molluscs from Turkey (Gastropoda, Pristilomatidae, Enidae, Hygromiidae, Helicidae).

This paper reports on results of several collecting trips of the authors in Turkey. In the course of this research, a long-lasting question was addressed. It could be proven that the nominal species Bulimus frivaldskyi L. Pfeiffer, 1847 is closely related to Meijeriella canaliculata Bank, 1985, and thus this species is shifted from the genus Ena Turton, 1831, to the genus Meijeriella Bank, 1985. Meijeriella canaliculata Bank, 1985, could be recorded from Turkey for the first time. The nomenclatural situation of the species Euchondrus septemdentatus (Roth, 1839) vs. its replacement name Euchondrus borealis (Mousson, 1874) is discussed. A new arrangement of the species formely comprised in the genus Zebrina Held, 1837 is presented, and the genera Rhabdoena Kobelt & Moellendorff, 1902, and Leucomastus A. Wagner, 1927 are re-established. The following species and subspecies new to science could be described: Vitrea gosteliisp. n. (Pristilomatidae), Turanena demirsoyisp. n., Euchondrus paucidentatussp. n., Rhabdoena gosteliisp. n. (all Enidae), Metafruticicola kizildagensissp. n. (Hygromiidae), and Assyriella thospitis menkhorstissp. n. (Helicidae). For several other species, new distribution records are listed.

Sexual dimorphism in shells of Cochlostoma septemspirale (Caenogastropoda, Cyclophoroidea, Diplommatinidae, Cochlostomatinae).

Sexual dimorphisms in shell-bearing snails expressed by characteristic traits of their respective shells would offer the possibility for a lot of studies about gender distribution in populations, species, etc. In this study, the seven main shell characters of the snail Cochlostoma septemspirale were measured in both sexes: (1) height and (2) width of the shell, (3) height and (4) width of the aperture, (5) width of the last whorl, (6) rib density on the last whorl, and (7) intensity of the reddish or brown pigments forming three bands over the shell. The variation of size and shape was explored with statistical methods adapted to principal components analysis (PCA) and linear discriminant analysis (LDA). In particular, we applied some multivariate morphometric tools for the analysis of ratios that have been developed only recently, that is, the PCA ratio spectrum, allometry ratio spectrum, and LDA ratio extractor. The overall separation of the two sexes was tested with LDA cross validation.The results show that there is a sexual dimorphism in the size and shape of shells. Females are more slender than males and are characterised by larger size, a slightly reduced aperture height but larger shell height and whorl width. Therefore they have a considerable larger shell volume (about one fifth) in the part above the aperture. Furthermore, the last whorl of females is slightly less strongly pigmented and mean rib density slightly higher. All characters overlap quite considerably between sexes. However, by using cross validation based on the 5 continuous shell characters more than 90% of the shells can be correctly assigned to each sex.

Sphincterochilidae from Tunisia, with a note on the subgenus Rima Pallary, 1910 (Gastropoda, Pulmonata).

In order to establish an updated checklist of terrestrial gastropod from Tunisia, a revision of the species of Sphincterochilidae is presented, using bibliographic and museum records and the results of our own field work. As a result, only two species, Sphincterochila candidissima and Sphincterochila tunetana, are accepted to occur in Tunisia, and their type specimens are illustrated. The study of the morphological characters of the genital organs of both species clarified their subgeneric affiliation. Comparison of Sphincterochila tunetana with Sphincterochila cariosa from Lebanonshowed that the first has to be classified within the subgenus Albea, and the latter within Sphincterochila s. str.; the subgenus Rima Pallary, 1910 remains in the synonymy of Sphincterochila s. str. Bibliographic records of Sphincterochila baetica and Sphincterochila otthiana from Tunisia could not be confirmed, the latter probably lives close to the border with Algeria.