Malacological Collection Research Articles

Semperula wallacei (Mollusca, Veronicellidae) um hospedeiro natural recém-descoberto de Angiostrongylus cantonensis (Nematoda, Angiostrongylidae) na Bacia do Pacífico.

Semperula wallacei (Issel, 1874) is a species of terrestrial slug that occurs in southeast China and the Pacific Basin and is the only species of its genus that occurs beyond the Oriental region and to the east of Wallace's line in the Australian region, where it has probably been introduced. In this study, we report for the first time S. wallacei as an intermediate host for Angiostrongylus cantonensis (Chen, 1935) based on histological and molecular analyses of slugs from Tuamasaga, Samoa, deposited at the Medical Malacological Collection (Fiocruz-CMM). DNA was obtained from the deparafinized tissues scraped from specimen slides. Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) targeted to the internal transcribed spacer 2 (ITS2) region were carried out using the restriction enzyme Cla I. The RFLP profile observed for our larval specimen of S. wallacei was identical to the profile previously established for A. cantonensis, demonstrating that S. wallacei can be naturally infected with A. cantonensis and is likely to be an intermediate host for this parasitic nematode species in the field. The potential for geographical range expansion of S. wallacei in the Pacific Basin, its small size, and the general role of veronicellids as crop pests and hosts of nematodes, indicate the significance of S. wallacei as an invasive species in the Pacific Basin. Our work also highlights the importance of biological collections for investigating the environmental impact of invasive species on agriculture, public health, and biodiversity conservation.

Scientific and educational potential of the malacological collection of the State Museum of Natural History of the National Academy of Sciences of Ukraine

The importance of the malacological collection of the State Museum of Natural History of the National Academy of Sciences of Ukraine in Lviv for the history and further development of malacological research in Ukraine is considered. The scientific potential of stock malacological materials, accumulated in the museum since the second half of the 19th century and significantly supplemented during the last decades, was analyzed in temporal and geographical aspects, as well as taking into account the taxonomic diversity and intraspecific conchological variability of the molluscs of Ukraine, the presence of typical materials, etc. It was found that the main (scientific) part of the malacological collection well represents the present land and freshwater mollusc fauna of Ukraine and its western part. Not represented in the museum's malacological collection are still some species that are mainly locally distributed in Ukraine and often have small sizes, which further complicates their sampling. Among the more recent additions to the malacological collection, we can especially mention the samples related to the study of the land mollusc fauna of the steppe zone of Ukraine, which remained poorly studied until the end of the 20th and even the beginning of the 21st century, as well as to the shell color and banding polymorphism in the Eastern European populations of two introduced species, Cepaea nemoralis and C. hortensis. Among the auxiliary part of the malacological collection, a large block of materials that can be used for exhibition purposes is selected. They allow demonstrating a wide range of topics from the taxonomic and morphological diversity of molluscs of Ukraine and the world to conchological adaptations. It can be useful when studying corresponding sections of a school biology course, as well as for students of biological specialties, amateur naturalists, etc. Various forms of virtual exhibiting allow to shown the public also numerous materials of the main (scientific) part of the malacological collection, which became possible within the framework of the Educational online program “Molluscs”. This allows us to talk about the gradual transformation of the main part of the malacological collection from a classical scientific collection to a scientific and educational one with virtual access.

New data on the distribution of anthropochorous species of land molluscs in western regions of Ukraine and possible approaches to their classification

On the basis of own data, materials transferred to the laboratory of malacology or the malacological collection of the State Museum of Natural History of the National Academy of Sciences of Ukraine in Lviv, as well as a critical analysis of observations in two citizen science databases (iNaturalist, UkrBIN), new records of some anthropochorous land mollusc species in Western Ukraine, and in particular, in Lviv and its immediate surroundings, are described. In tabular form, the temporal and spatial presence in the western part of Ukraine of 23 species that could appear here only due to anthropochory is analyzed. Maps of the findings of Cepaea nemoralis, Deroceras caucasicum, Oxychilus draparnaudi, and O. translucidus in and near Lviv are given. Known reliable localities of C. nemoralis in Volyn, Ivano-Frankivsk, Lviv, Rivne, Ternopil, and Khmelnytskyi regions are listed. Similar information is presented for the related species Cepaea hortensis from all administrative regions of Western Ukraine, except for Lviv region, where this species is widespread in settlements. According to the time of penetration into Western Ukraine, among the anthropochorous species of land molluscs, relatively recent invaders prevail, which were first reliably discovered not earlier than in the 1990s. At the turn of the 20th and 21st centuries, optimal conditions for the introduction and subsequent acclimatization in urbanized biotopes of many adventitious species of land molluscs, in particular thermophilic species of Mediterranean or Crimean origin, emerged in Western Ukraine. In addition to global warming, this was facilitated by the intensification of trade and transport links with other regions of Ukraine and other European countries, as well as the activities of garden centres. Besides the time of entry into the analyzed area, anthropochorous species of land molluscs can be classified according to the ways of this penetration (from other regions of Ukraine or from other European countries located to the west of it), the nature of their present distribution in Western Ukraine, as well as the ability or inability to enter natural biotopes outside settlements.

Species catalogue of Drymaeus (Mesembrinus) Alberts, 1850 (Gastropoda: Bulimulidae) from Brazil and new data on morphology and distribution of Drymaeus (Mesembrinus) interpunctus (Martens, 1887).

Herein, we attempted to obtain detailed data on the distribution of the species of Drymaeus (Mesembrinus) in Brazil, using biodiversity databases, malacological collections and literature as sources of occurrence records. We provided a catalogue of species, along with distribution maps. We also estimated the suitable distribution of Drymaeus (Mesembrinus) interpunctus using the maximum entropy approach. A detailed description of the anatomy of the soft parts of this species was provided, with new data on the pallial system. For each species we provided information on the compiled data associated with museum collections and the literature. Distribution maps including geographic boundaries, Brazilian biomes and altitude were made with QGIS software 3.16.10 Hannover. For niche modelling, nineteen bioclimatic variables and a topographic variable were used as predictors. The models were performed with MaxEnt version 3.3.3k. Most of the species are represented by scarce material in malacological collections; for some species, these records correspond to type material, indicating that they have not been recollected. Most of the species were represented by shells making anatomical comparison and DNA analysis difficult, limiting our ability to provide new criteria for species delimitation. Our results allowed us to expand the known distribution area for three species, Drymaeus dutaillyi, D. gereti and D. oreades, with new occurrence records in Brazil. The MaxEnt model showed a thin area of high suitability to D. (M.) interpunctus in the Southeastern Brazil, corresponding to the Atlantic Forest. Minimum temperature of the coldest month and mean temperature of coldest quarter were the variables that most influenced the development of the model. Drymaeus interpunctus was described based on specimens collected in Brazil without mention to the exact localities. Herein the new records from databases allowed to expand the known geographic distribution for this species and to infer its potential distribution. Although the type locality of D. interpunctus is in Brazil, the anatomy of the soft parts of specimens from this country was not previously described. The anatomy of the reproductive system of the specimens analyzed herein mostly corresponds to a previous description for specimens from Paraguay, except for the absence of penial sheath and the relative length of the bursa copulatrix duct. The results of niche modeling showed a thin area of high suitability for D. interpunctus and a vast area of moderate suitability, indicating that this species present a niche breadth that favors its occurrence in a range of different biomes, including less suitable areas. The small number of records obtained for most of the species and their restricted ranges associated with habitat destruction may indicate that they are of conservation concern.

The Amphibulimidae pulmonate forest snails deposited in the Malacological Collection of the “Museo de Biología de la Universidad Central de Venezuela – UCV”

Introduction: Since 2014,  the “AM  Project” (Brazil) has  been conducting taxonomic, bioecological and  conservationist research on molluscs present  in  the Caribbean continental territory of Venezuela, with special  emphasis  on  its  land (terrestrial and  arboreal)  forest  species (Agudo-Padrón  2021, Agudo-Padrón & Vera-Caripe 2022). Up to date, these aspects of the natural history of this geographic region have/ had been poorly studied. Objective: Substantial update of this knowledge through the unprecedented curatorial review of the collection of molluscs deposited in the malacological collection of the “Museo de Biología de la Universidad Central de Venezuela – UCV”, based in city of Caracas. Methodology: Between October 2022 and February 2023, a taxonomic review and examination of material from forest snails of the family Amphibulimidae deposited in the mollusc internal collection of the Museum was performed. Results and conclusions: Determination of fourteen (14) species, collected/ found in 16 geopolitical entities of the country, which were taxonomically grouped into one (1) family and two (2) genera.

Aliens and Returnees: Review of Neobiotic Species of Freshwater Mollusks in Siberia from the Kazakhstan Steppe to the Arctic Tundra

This article reviews all available information on the species composition, current distribution, and origins of the neobiotic (non-indigenous and restoring the lost range) freshwater mollusks in Siberia. An extensive literary search has been carried out, and virtually all existing publications of recent decades on the findings of freshwater mollusk species new to Siberia were taken into account. We examined extensive malacological collections of some of Russia’s and Kazakhstan’s scientific organizations. The core of the examined material is our own observations and collections made in various parts of Siberia and adjacent areas. An annotated checklist of neobiotic species of mollusks reliably recorded in Siberia is presented, and probable mechanisms and “corridors” of infiltration of these species into the region are discussed. Most of the discovered snail species belong to a group popular among aquarists, and their source of introduction is obvious. Another large portion of species infiltrate into the region with the development of fish farming. A classification of species of neobiotic freshwater mollusks of Siberia was proposed and a forecast was made for changes in the Siberian freshwater malacofauna for the coming decades. In our opinion, at present it is possible to accept the newest stage in the genesis of the freshwater malacofauna of Siberia, occurring in conditions specific to the Anthropocene.

I.T. Bakumenko's malaсological collection passed to the State Museum of Natural History of NAS of Ukraine

In August 2021, the State Museum of Natural History in Lviv received the conchological collection of the geologist and amateur collector I.T. Bakumenko. This made it possible to considerably supplement the sample of exotic mollusc species, mainly marine ones, intended for exposition use. During the processing of the collection, the existing identifications were checked, and most of the unlabeled specimens were also identified. Unfortunately, the vast majority of materials did not contain data on place and time of collecting, so they could not be transferred to the main fund of the museum. Most of the collection was represented by the shells of exotic marine molluscs, the list of which is given in the article. Excluding materials identified only to genus or subgenus level, the collection transferred to the museum contained 6 species of exotic land molluscs and 145 species of exotic marine ones. Most of them have previously not been presented in the malacological collection of the museum. Without taking into account taxa whose correct identification requires additional verification, three species of land exotic molluscs, one family (Pinnidae) and 86 species of marine exotic ones appeared for the first time in the malacological collection. Some shells of exotic molluscs of the families Arcidae, Ampullariidae, Cardiidae, Mactridae, Muricidae, Naticidae, Orthalicidae, Ostreidae, Patellidae, Pectenidae, Ranellidae, Tellinidae, Trochidae, Veneridae require further identification. Some of the most attractive examples of the collection transferred to the museum were demonstrated in a thematic electronic photo album “Treasures of distant seas” (2021). In the future, the digitization of other exotic species that entered the malacological collection of the museum for the first time is planned. The produced photos will be used in one of the thematic sections of the museum project Educational Internet program "Molluscs".

Land molluscs of Sucre State, Continental Northeast of Venezuela, Southeast Caribbean. II: Three (3) new species additions to the regional inventory

Introduction: Since of the year 2014, the “AM Project” (Brazil) has been carrying out taxonomic, bioecological and conservationist research on "non-marine molluscs" present in the environment of the Caribbean continental territory of the Sucre State and adjacent areas, Northeast region of Venezuela , with special emphasis on its terrestrial and arboreal forest species (Agudo-Padrón 2021), a geographic region historically little studied in this aspect of its natural history, involving today a general preliminary total of 67 verified forms/ species (44 land/ terrestrial and 23 limnic/ freshwater), included in 49 genera and 28 families. Objective: Substantial update of this knowledge, with the incorporation of new species to the regional inventory. Methodology: Updated review of cryptic regional malacological bibliography and taxonomic examination & determination of specimens (vouchers) deposited in malacological collection of scientific museum. Results and conclusions: Incorporation of three (3) land/ terrestrial gastropod (forest snail) species into the previously established regional inventory, taxonomically grouped all into 1 genera and 1 family, bringing to 47 its your number of regionally land known forms.

CREATION AND MAINTENANCE PROCESSES OF MALACOLOGICAL COLLECTIONS OF CEPHALOPOD BEAKS

The cephalopods have in their mouth a pair of chitinous beaks used to cut their prey. The identification of these beaks is diagnostic for species and considered a difficult task, although very useful in the identification of species and their ecological inferences. This work aimed to create and maintain a didactic collection of cephalopod beaks. The curation process involved since the preparation of the preserving liquid and bottles to the choice and identification of the specimens. It was chosen to keep the collection stored in a humid way, in 80% vol. alcohol and 5% glycerin. A total of 562 beaks, from 50 taxa from different sources along the Brazilian coast, were identified from stomach contents of predators, scientific collections and commercial fishing. Although the available bibliography on curating biological collections, the lack of specific material on malacological collections, especially on cephalopod beaks, makes the curation process more difficult, hence the importance of organizing scientific and educational collections for these purposes.Keywords:Â Cephalopoda; beaks; curation; species identification.

Revisiting the Annandale malacological collection from Inle Lake, Myanmar kept in the Kyoto University Museum

ABSTRACT Inle Lake in central Myanmar is one of the hotspots of freshwater biodiversity in Southeast Asia. A small malacological collection from the lake made by Thomas Nelson Annandale and discovered at the Kyoto University Museum, Japan was examined here. In the collection comprised of thirty specimens, nine species in seven families were identified. The collection also included four species and one subspecies which were newly described by Annandale. Two subspecies, Hydrobioides nassa lacustris Annandale, 1918 and H. n. rivulicola Annandale, 1918, were identified in a single lot. The correspondence of the shell morphology of Lamellidens ferrugineus (Annandale, 1918) between the present study and the original description indicates that the specimen is a paratype of the species. The rediscovered collection provides us with insights into the species definition of Annandale and the molluscan diversity of the lake prior to recent environmental changes.

Philophthalmus gralli in domestic waterfowl: An environmental study in an urban area from Brazil.

Philophthalmosis is a zoonotic ocular disease that affects mainly domestic and wild avian species in different parts of the world. However, aspects related to its epizoology in domestic animals are not completely known. In the present study, 47 Muscovy duck (Cairina moschata), 8 mallards (Anas platyrhynchos platyrhynchos) and 6 African geese (Anser cygnoides), free-living in an urban lake in Belo Horizonte, Minas Gerais, Brazil, were evaluated for eye fluke infection. The animals were manually contained, and the conjunctival sac and nictitating membrane were evaluated by direct ophthalmic examination (DOE), in which the fluke burden was estimated by a semiquantitative scale. Moreover, the conjunctival sac lavage (CSL) technique was applied for the search of parasite eggs. When possible, the detected trematodes were carefully removed for fixed for taxonomic identification. In order to characterize the parasite-host-environmental system, malacological collections were performed at the locality, and the collected intermediate host mollusks (Melanoides tuberculata) were evaluated for infection with larval philophthalmids. In addition, wild vertebrates found dead in the locality, including one common gallinule (Gallinula galeata) and two capybaras (Hydrochoerus hydrochaeris), were necropsied for the search of eye flukes. Samples from the developmental stages obtained from the hosts were subjected to morphological and molecular studies (amplification and sequencing of a partial region of the Nad-1 gene). In the DOE, the presence of eye flukes was verified in 67% (4/6), 31% (15/47) and 25% (2/8) in geese, Muscovy ducks and mallards, respectively. In most cases, the birds showed mild parasitism (1-5 trematodes), with no apparent eye damage, characterizing a subclinical infection. In only one goose, which had a high fluke burden (20 trematodes), it was possible to obtain eggs by CSL. Regarding the malacological survey, 73/4545 (1.6%) specimens of M. tuberculata evaluated were found infected with megalurous cercariae, compatible with representatives of the family Philophthalmidae. Additionally, 147 flukes were recovered from a specimen of G. galeata found dead at the lake. The morphological and molecular study of parasites obtained from different hosts evaluated in this study enabled the identification of Philophthalmus gralli, a species native from Asia and introduced in the Americas. Factors such as the wide distribution of the intermediate host and the participation of domestic and wild reservoirs in the parasite transmission chain may favor the occurrence of parasite spillover from wild to domestic birds. Furthermore, the occurrence of the life cycle of P. gralli in an urban waterbody serves as an alert to the possibility of human cases of this zoonotic eye parasite.

Distributional patterns of Vetigastropoda (Mollusca) all over the world: a track analysis

AbstractThe distributional patterns of the species of the mollusc subclass Vetigastropoda were analysed using the panbiogeographical method of track analysis. We analysed distributional data of 434 species and 72 genera of the world obtained from specialized literature and records in 12 malacological collections. We constructed the individual tracks for the species analysed and superimposed them, applying a parsimony analysis of endemicity with progressive character elimination. We identified 26 generalized tracks, extending in the Pacific Ocean (14), Indian Ocean (six), Atlantic Ocean (four), Mediterranean Sea (one) and Atlantic–Pacific Oceans (one). The generalized tracks show the complex relationships of the mollusc biota, representing geographical and phylogenetic boundaries of taxa with diverse geographical affinities. Five panbiogeographical nodes were identified by the intersection of two or more generalized tracks. Our analysis offers an approximation for understanding the distributional patterns of vetigastropod species worldwide from the perspective of evolutionary or historical biogeography. The results obtained for the Vetigastropoda coincide completely or in part with those previously presented for other taxa. The generalized tracks support hypotheses of primary biogeographical homology that might be corroborated by evidence from other different, phylogenetically unrelated taxa.

History of the penetration of anthropochorous mollusc species to western Ukraine

Analysis of literary sources and materials of the malacological collection of the State Museum of Natural History of the National Academy of Sciences of Ukraine in Lviv revealed that at the end of the 19th century in western Ukraine could be present only some anthropochorous species of slugs, especially Limax maximus. Instead, mentions of a number of species not belonging to the indigenous malacofauna of Ukraine and its western region, made from the second half of the 19th to the middle of the 20th century, could most likely be based on the erroneous identification of other, native species. The process of intensive penetration into western Ukraine of alien species of land molluscs began, apparently, not earlier than the middle – second half of the 20th century and significantly accelerated at the turn of the 20th and 21st centuries. The latter could be due to both climate change, which facilitated adaptation to local climatic conditions for more thermophilic species, and the active import of seedlings of ornamental plants from other European countries. In particular, a dangerous pest from the complex Arion lusitanicus s.l. could enter the territory of Ukraine in this way. No less indicative are the relatively young colonies of Cepaea nemoralis, which are increasingly found in western Ukraine. Since the end of the 20th century, species of Caucasian origin and those that were previously observed only for the southern part of the country are increasingly registered in western Ukraine. Compared to the great taxonomic diversity of land anthropochorous molluscs and the widespread distribution of some of them, a relatively small number of freshwater species (up to 8), alien to this area, are still known in western Ukraine. For most of them, only a few finds are still known, made in the early 21st century. The exception is only one species (Physella acuta), which began to be mentioned for various areas in western Ukraine in the second half of the 20th century. Among the alien freshwater molluscs are a group of small species imported to Europe from other continents: New Zealand Potamopyrgus antipodarum, North American Menetus dilatatus, Physella heterostropha and possibly also Physa skinneri and Physella acuta. Representatives of the Dreissena genus came here from the Black Sea territories in the south of Ukraine.

First record of the grove snail Cepaea nemoralis (Gastropoda, Helicidae) in Ternopil region and specificity of the phenotypic composition of the found colony

The first finding of Cepaea nemoralis, an introduced species of land molluscs with polymorphic shell colouration, in the Ternopil region of Ukraine is described. Juveniles of this species were observed in Chortkiv already in 2017, but only in 2020 their exact species affiliation was identified, the presence of an established colony was confirmed and the peculiarities of its phenotypic composition were analyzed. The obtained data were compared with other colonies of the grove snail, which were found in Western Ukraine (Lviv and its environs, Bohorodchany in Ivano-Frankivsk region) in 2019-2020 and described in previous publications. Most of the conchological material collected in Chortkiv is deposited in the malacological collection of the State Museum of Natural History of the National Academy of Sciences of Ukraine in Lviv. In the Chortkiv colony of C. nemoralis, a hereditary trait was found, which occurs sporadically in the natural range of the grove snail, but has not yet been registered in Ukraine. This feature is manifested in the uneven pigmentation of dark spiral bands on the shell, the alternation of lighter and darker fragments on them, which can create the impression of spotted, interrupted bands. In the analyzed sample, such bands had 25.6% of banded shells, and they occurred twice as often in yellow (41.2%) than in pink (18.5%) shells. This agrees well with the known data on the linked inheritance of this trait and the ground colour of the shell. However, the shells with fused bands, regardless of their ground colour, almost always had normally pigmented bands, dark along their entire length. In some individuals with unevenly pigmented bands, the splitting of the fourth or fifth band into 2-3 narrow longitudinal bands was also observed. Another feature of the Chortkiv colony of C. nemoralis compared to other known Western Ukrainian colonies of this species is the very low frequencies of all lighter variants of the shell colouration (yellow and pink unbanded or with one central band) and a very high proportion of phenotypes with 3 lower bands (49.6%). The ratio of the main variants of the shell colouration of C. nemoralis in Chortkiv, which is not typical for Western Ukraine, makes the found colony a valuable object for studying potential adaptive changes in its phenotypic composition in the future.

NERITIDAE (GASTROPODA, NERITIMORPHA) FROM THE MALACOLOGICAL COLLECTION PROF. HENRY RAMOS MATTHEWS OF THE UNIVERSIDADE FEDERAL DO CEARÁ, BRAZIL

The basic information obtained from scientific collections help us to understanding of Earth’s diverse biota and its biological processes. The Malacological Collection Prof. Henry Ramos Matthews (CMPHRM) of the Universidade Federal do Ceará (UFC), Brazil, is a reference about the biodiversity, mainly marine, of northeastern Brazil. In this collection, the gastropod molluscs of the family Neritidae were among the most representative in number of lots. Since an accurate geographical distribution knowledge is one of the fundamental factors to the study of biodiversity, the present study aimed to describe the composition and spatially analyse the neritids deposited in the CMPHRM/UFC. There is a total of 314 lots of the Neritidae deposited at CMPHRM, belonging to eight species (Nerita chamaeleon, Nerita chlorostoma, Nerita fulgurans, Nerita tessellata, Neritina virginea, Neritina meleagris, Neritina zebra, and Smaragdia viridis). The Malacological Collection Prof. Henry Ramos Matthews of the Universidade Federal do Ceará has representatives of all species of Neritidae recorded in the Brazilian Province, which are important for confirming previous records or establishing new occurrence records.
 Keywords: Neritina, Nerita, Smaragdia, Brazilian Province

POR QUÉ DEBEMOS DE CONSERVAR LAS MUESTRAS BIOLÓGICAS: UN EJEMPLO DE CONFORMACIÓN DE UNA COLECCIÓN DE MOLUSCOS LÍMNICOS

Anthropic activities have produced global effects in recent decades accelerating the loss of the ecological integrity in many ecosystems, as well as the risk of extinction of many species. The need to know and preserve endangered species drives us to document the knowledge we have of our biodiversity. The Limnology Section of the Faculty of Sciences of Uruguay has been sampling invertebrates in various limnic environments since its foundation in 1984. The aim of this work was the formation of a malacological collection from these collections. 750 benthic macroinvertebrate samples were reviewed and conditioned according to pre-established protocols. Six families of Gastropoda were recognized: Tateidae, Cochliopidae, Lymnaeidae, Physidae, Ampullariidae and Planorbidae, the latter with the subfamilies Planorbinae and Ancylinae; and six families of Bivalvia: Hyriidae, Solecurtidae, Mycetopodidae, Sphaeriidae, Corbulidae and Cyrenidae. A database was developed linking the material to the limnic system of origin and the publications to which it originated. The results are a malacological collection, with ordered information from more than 30 years of research in limnology.

An annotated checklist of Planorbinae (Heterobranchia, Hygrophila, Planorbidae) from northwestern Argentina

The family Planorbidae comprises freshwater gastropods with planispiral, spiral and limpet-shaped shells. Subfamily Planorbinae sensu stricto, has a richness of almost 300 species, with some of the main genera being Biomphalaria Preston, 1910 and Drepanotrema Fischer & Crosse, 1880. Some Biomphalaria species are of concern to human health as they are intermediate hosts of blood flukes in Latin America. In Argentina, the family Planorbidae is represented by 15 species in four genera. In Northern Argentina (NOA region), records of the family are scarce, and most of them are a result of occasional collecting. We provide an updated checklist of Planorbinae in NOA resulting from fieldwork, material in malacological collections, and data in the literature. Nine species occur in the area: four species of Biomphalaria and five of Drepanotrema. Among Biomphalaria species, we recorded Biomphalaria straminea (Dunker, 1848), which is considered a natural host of the blood fluke Schistostoma mansoni Sambon, 1907, for first time in Salta province; the known geographic distribution of B. straminea is extended in the country.

Holotypes for three Caspian gastropods of the family Hydrobiidae tracked down: description and taxonomic interpretations.

Type series of three nominal taxa of the hydrobiid gastropods inhabiting the Caspian Sea were traced recently in the uncatalogued part of the malacological collection of the Zoological Institute of Russian Academy of Sciences, Saint-Petersburg. Images of the holotypes and some paratypes of Pyrgula isseli Logvinenko Starobogatov, 1969, P. sowinskyi Logvinenko Starobogatov, 1969 and P. derzhavini Logvinenko Starobogatov, 1969 are presented. The first two species belong to the genus Clathrocaspia (subfamily Caspiinae) and P. sowinskyi is considered a junior synonym of C. pallasii (Clessin W. Dybowski in W. Dybowski, 1887). The attribution of the third species, P. derzhavini, to Laevicaspia (Pyrgulinae) is confirmed based on the newly discovered type material. Based on the additional information we update ecological data and distribution ranges of the species, provide comments on their nomenclature, systematic position and taxonomic rank.

Systematic redescription of Solen/ (Ensisolen/) tehuelchus/ and Ensis/ macha/ (Bivalvia: Solenoidea) from Argentina, southwestern Atlantic Ocean.

In the present study, bivalves belonging to the superfamily Solenoidea that inhabit the Argentinean Sea are redescribed. The specimens studied in this work were collected by scuba diving in the Gulf of San José, Argentina. Additional specimens from different malacological collections were revised to update the geographical distribution of valid species. According to the literature, there exist two species for the "Argentinean" and "Magellan" biogeographical provinces. However, ten nominal taxa, with uncertain taxonomic status, have been mentioned for the study area. Field work, local collection survey and type material examination allow confirming two valid species: Solen (Ensisolen) tehuelchus Hanley (Solenidae) and Ensis macha (Molina) (Pharidae). A morphological comparison between S. tehuelchus and S. gaudichaudi Chenu and S. obliqua Spengler is provided as well type locality, repository and synonymy list. The type material of all related species are illustrated whenever possible. Establishing the valid names of these species is the first step towards more integrative studies including genetic and zoogeographical analyses.

Revisiting a 135-year-old Taxonomic Account of the Freshwater Snail Semisulcospira multigranosa: Designating its Lectotype and Describing a New Species of the genus (Mollusca: Gastropoda: Semisulcospiridae).

The type series of Semisulcospira multigranosa Boettger, 1886 was found in the Malacological Collection at the Senckenberg Naturmuseum for the first time ca. 135 years after its original description. The syntypes consisted of 38 specimens that can be classified into four species. The examination of adult shell morphology of these original materials revealed that the current taxonomic account of S. multigranosa should be amended. Therefore, we designate a lectotype for S. multigranosa, and thus describe S. multigranosa auct. as Semisulcospira davisi sp. nov. Semisulcospira davisi can be discriminated from the other congeners by the characteristics of adult and embryonic shells, and radulae morphology. The present study resolves one of the fundamental taxonomic problems remaining in Semisulcospira snails.