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The study of the Neolithic period in the Lake Eyasi Basin was dominated by attempts to formulate the area’s chronology, mobility, settlement patterns, subsistence, and cultural capabilities of Neolithic people as attested by domesticated animals, pottery, and lithic artefacts. Occasionally, studies on molluscs were mentioned, but rarely described in detail. Neolithic sites across the Lake Eyasi Basin have yielded remains of both terrestrial (gastropods) and freshwater mollusc shells (mussels). The abundance of mollusc shell remains in the archaeological records of the Lake Eyasi Basin have played a great role in chronological settings, mobility and community integrations, studies of settlement patterns, and other analyses. Mollusc remains have often been widely interpreted as a food supplement to other reliable food resources such as meat, vegetables and fish. Archaeological excavations and detailed analysis of the shells from Mumba rock shelter, Jangwani 3 and Laghangasimjega 2 have shown that molluscs played different roles. They were effectively used in tool manufacturing, as practical implements for handling objects, as scraping tools, as harpoons for fishing weapons, and sometimes for symbolism and in rituals. Terrestrial and freshwater molluscs coexisted in the Lake Eyasi Basin and were utilised equally by the Neolithic people during the Mid-Holocene period. Keywords: Mollusc shells; Neolithic; Lake Eyasi Basin; Northern Tanzania

The distribution of the subtropical Asian clam (Corbicula fluminea (O.F. Müller, 1774)), one of the world’s most invasive freshwater molluscs, is reportedly constrained by a lower thermal tolerance limit of 2 °C. Although its occurrence in north temperate regions is typically restricted to artificially heated waterbodies, the species has been found to overwinter in unheated lakes and rivers. In laboratory experiments, we compared the cold tolerance of populations from several geographically distinct sites spanning 35°N to 46°N in eastern North America. Each population contained individuals that fully recovered from 2 months of continuous exposure to near-freezing (1 °C) conditions, contrary to published accounts of C. fluminea’s thermal ecology. Survivorship increased with body size and was enhanced by prior acclimation to a low temperature (10 °C) compared with a higher one (18 °C). When acclimated to 10 °C, clams from northern populations exhibited greater survivorship (55.0% ± 16.1%) than those from southern populations (26.7% ± 19.2%). However, one southern population demonstrated survivorship as great as that of the most tolerant northern population, suggesting that its clams could overwinter in unheated northern waterbodies. Differences among populations indicate either that contemporary evolution has occurred or that developmental plasticity shapes future acclimation responses.

Biological invasions are common among freshwater molluscs, with the North American planorbid gastropod Gyraulus parvus being reported from Europe (Germany) by the 1970s. It has since spread across Central and Western Europe, mostly living in artificial and highly modified habitats. However, considerable conchological and anatomical similarity exists between it and the native European G. laevis. Using four other European and one North American Gyraulus species as outgroups, separate phylogenetic analyses using mitochondrial and nuclear DNA sequences show that G. parvus and G. laevis are in fact part of the same species-level clade, with the former having nomenclatural priority. However, the structure within the mitochondrial tree suggests a North American origin of the invasive populations. It also makes it possible to track down the distribution of both races. Although native and non-native races in Europe tend to possess some differences in conchology and ecology, the degree of overlap makes it impossible to accurately distinguish between them without the DNA barcode data. Our results change the outlook on the conservation of the rare native race. While interspecific competition among snail species is rare, invasion on an intraspecific level may represent a serious threat for native populations.

We present a checklist of 86 valid freshwater mollusc species of Serbia (65 gastropods and 21 bivalves) belonging to 19 families (15 gastropods and four bivalves). The list is based on our latest research and includes data from published sources and personal communications. The most diverse family among gastropods is Planorbidae (16 species), while Sphaeriidae are most diverse within the bivalves (10 species). Ten species are local endemics (all of them gastropods), while eight are introduced species (three gastropods and five bivalves). The Danube River and its smaller tributaries harbour the most diverse gastropod community, with a total of 61 species (41 gastropods and 20 bivalves). The snail Theodoxus transversalis (Pfeiffer, 1828) and the bivalve Unio crassus Philipson, 1788 are listed as EN (endangered) on the global (IUCN) level, while the snail Plagigeyeria gladilini Kuščer, 1937 and the bivalves Pseudanodonta complanata (Rossmässler, 1835) and Sphaerium rivicola (Lamarck, 1818) are considered as VU (vulnerable) species. Of those IUCN taxa, only U. crassus is listed as protected on the national level (along with 12 mostly local endemic gastropod species). In comparison with the previous checklist of gastropods by Karaman & Karaman (2007), a total of seven species are added here: Belgrandiella serbica Glöer 2008, Bythinella istoka Glöer & Pešić 2014, B. nonveilleri Glöer 2008, B. pesterica Glöer 2008, Acroloxus lacustris (Linnaeus, 1758), Melanoides tuberculata (O.F. Müller, 1774) and Armiger crista (Linnaeus, 1758). In view of global and regional trends in taxonomy, ecology and invasive biology, an even richer diversity of the Serbian freshwater malocofauna can be expected.

Molluscs are among the most diverse and widespread animal groups in freshwater habitats. Unfortunately, like most freshwater taxa, they are decreasing dramatically and are now among the most threatened animals on Earth, with many species already extinct or on the brink of extinction. Here, we review our current knowledge on the biodiversity and conservation of freshwater molluscs using the concept of knowledge shortfalls. We focus on seven previously proposed key shortfalls to review and analyse existing knowledge gaps relating to (1) taxonomy, the Linnean Shortfall; (2) distribution, the Wallacean Shortfall; (3) abundance and population dynamics, the Prestonian Shortfall: (4) evolution, the Darwinian Shortfall; (5) abiotic tolerances, the Hutchinsonian Shortfall; (6) traits, the Raunkiaeran Shortfall; and (7) biotic interactions, the Eltonian Shortfall. In addition, we address a new shortfall, which relates to the application and effectiveness of conservation measures, including assessments, methods, funding, and policies, the Ostromian Shortfall. Based on our review, we provide recommendations and suggest pathways to overcome these existing shortfalls. This work also introduces the articles in this special issue of Hydrobiologia, which represent key contributions to the First International Freshwater Mollusk Conservation Society Meeting held in Verbania, Italy, in 2018.

The paper presents results on the analysis of the taxonomic structure of the trematode fauna of the Ukrainian Polissia. It was found that the trematode fauna of freshwater molluscs in the Ukrainian Polissia is represented by 62 species. We supplemented the species composition of larvae of trematodes in the region with 23 species, 13 of which were first recorded in Ukraine. The results showed that the number of trematode species the definitive hosts of which are fishes have decreased. According to the obtained data, the most abundant trematode species of freshwater molluscs in the Ukrainian Polissia are those of the families Echinostomatidae, Plagiorchiidae, Diplostomidae, and Notocotylidae. The combined analysis of literature and original data revealed that in the basis of the regional trematode fauna of molluscs are species of the families Echinostomatidae (13 species) and Plagiorchiidae (10 species), which make up almost one-third of the total number of trematode larvae detected. A quite large portion of larvae belong to species of the families Notocotylidae (8 species), Strigeidae (7 species), Diplostomidae (5 species), and Haematolechidae (5 species). Most families (Diplodiscidae, Opisthorchiidae, Leucochloridiomorphidae, Prostogonimidae, Cathaemasiidae, Cyclocoelidae, Prohemistomatidae, and others) are represented only by 1–2 species. In freshwater molluscs of the studied region, we have found only 38 % of trematode species recorded in definitive hosts. Species found in vertebrate animals of the region potentially can also occur in intermediate hosts, but most of these species parasitize in birds that could be infected in other areas. When comparing the taxonomic structure of the trematode fauna of the Polissia with other well-studied regions of Ukraine (Northern Pryazovia and Crimea), some specifics were noted between them. In particular, it was found that the most abundant trematode species in the region as well as in the whole of Ukraine are those of the families Echinostomatidae, Plagiorchiidae, Diplostomidae, Notocotylidae, and Strigeidae. The obtained data allow considering that the trematode fauna of freshwater gastropods of the Ukrainian Polissia is an integral part of the Central European fauna of trematodes.

Based on the literary and personal data, as well as collections of the State Museum of Natural History of the NAS of Ukraine and the Zoological Museum of the Ivan Franko National University of Lviv, the taxonomic composition and peculiarities of the spatial distribution of gastropods and bivalve molluscs in Western Ukraine have been analyzed. Species lists have been drawn up for the Volhynian (Western) Polissia, Volhynian Upland, Male Polissia, Roztochya and Opillya, Western Podillia, Central (Northern) Podillia, Prut-Dnister interfluve, Ciscarpathian, Transcarpathian lowland and mountainous part of the Ukrainian Carpathians. It is established that in the west of Ukraine, 74 autochthonous and 6 adventitious freshwater molluscs with generally recognized species status, belonging to 35 genera and 15 families, can be considered as reliably registered. Adventitious to Western Ukraine are Potamopyrgus antipodarum, Physella acuta, Menetus dilatatus, Dreissena polymorpha, D. bugensis, Sinanodonta woodiana. Additional confirmation requires the presence of Lithoglyphus pyramidatus, Omphiscola glabra, Physella heterostropha, Planorbis carinatus, Pisidium conventus, P. tenuilineatum. Not taking into account the Central Podillia, poorly researched by malacologists, a distinctly pronounced decrease in the species richness of freshwater molluscs is observed only in the mountainous part of the Ukrainian Carpathians (38 species, 17 genera, 8 families), with the presence of some specific components of freshwater molluscs complexes (small gastropods of the genera Bythinella і Paladilhiopsis). The richest taxonomic composition of freshwater molluscs was noted for Volhynian Polissia: 67 species, 29 genera, 15 families. It has been found that most freshwater molluscs are evenly distributed throughout the plain and foothill territories of Western Ukraine. Only few species can be considered as specific components of freshwater malacocomplexes for one of the physical-geographical areas or river basins. A number of species that are not present in the malacological collection of SMNH NASU, as well as the territories poorly represented in it, have been identified. The results obtained will be taken into account when further collecting the museum collection.

Shell strength of the modern freshwater molluscs Heleobia parchappii, Biomphalaria peregrina, Uncancylus concentricus, Musculium argentinum, Physa acuta, Succinea meridionalis and Pomacea canalicul...

The purpose of the research to study the mixed course of sheep infection, caused by pathogens of fasciolosis and paraphistomatosis, in the conditions of Samarkand and Tashkent regions. Materials and methods. The research material was fallen and forcibly killed sheep from two regions of Uzbekistan, simultaneously infected by Fasciola gigantica and Paramphistomum spp. (Gastrothylax crumenifer, Calicophoron calicophorum). The animals' liver was subjected to complete helminthological dissection, followed by the presence of young immature in the parenchyma, and in the bile ducts – sexually mature fasciola. To detect pathogens of paramphistomatosis, we examined the scar and mesh, and, if necessary, the mucous membranes of the abomasum and the initial part of the small intestine. To kill the collected F. gigantica and complete bleeding with a Paramphistomum spp., they were kept in water for one and three to four days, respectively. After they took their natural form, their type, age and number were determined, and then fixed in Barbagallo fluid. If necessary, coprological studies of sheep and malacological studies of biotopes of freshwater mollusks, intermediate hosts of the studied trematodes, were carried out. Results and discussion. In recent years, cases of a mixed course in sheep fasciolosis (F. gigantica) and paramphistomatosis in farms of Uzbekistan have become more frequent. When opening the liver of the fallen sheep, up to 278 specimens were found immature F. gigantica and up to 3994 sp. G. crumenifer. In some farms, the death of individual owners' sheep from calicophorosis caused by C. calicophorum was observed with an intensity of infection of 592 sp. of C. calicophorum.

Acknowledgements The authors acknowledge the two anonymous reviewers for their useful comments that improved the manuscript. Financial support for the excavations in Neumark‐Nord 2 was provided by the Lausitzer Mitteldeutsche Braunkohlengesellschaft mbH, the Landesamt fur Denkmalpflege und Archaologie Sachsen‐Anhalt (Harald Meller, Susanne Friederich), the Romisch‐Germanisches Zentralmuseum Mainz, the Leids Universiteits Fonds ‘Campagne voor Leiden’ program and the Netherlands Organization for Scientific Research (N.W.O.).

Since the end of the 19th century, the circumpolar fauna of freshwater Mollusca has not been reviewed despite the substantial increase of knowledge on this subject. A review of the freshwater mollusks of the Arctic based on an analysis of published data, own results and examination of museum collections is presented. 104 species of Mollusca have been registered, which constitutes less than 2% of the global diversity. The actual diversity of the Circumpolar freshwater molluscs may lie between 100 and 120 species. No endemic taxa are found in the Arctic. The most species-rich Arctic subregion is Siberia, whereas the North America maintains the poorest fauna. The aquatic malacofauna of Beringia is similar to that of North America, and Beringia as a biogeographic region constitutes a part of the Nearctic. The ways of formation of the Circumpolar malacofauna are discussed, with evaluation of dispersal, adaptation, and environmental filtering as the faunogenesis factors. The number of non-alien species in the Circumpolar freshwater malacofauna remains very low, and only one reliable occurrence of an alien species is known. Among the Arctic molluscs only three have a conservation status other than ‘least concern’ or ‘data deficient’, whereas most resident species are widespread and abundant.

The first in-depth revision of a lacustrine freshwater mollusc fauna of the Serbian Lake System (SLS) is carried out. We describe and discuss well-preserved faunas from two localities in central and southern Serbia (Mađere and Medoševac), along with the reinvestigation of type material of several species described in the late nineteenth and early twentieth centuries. Our revision yields 14 species of gastropods, with the families Hydrobiidae (six species) and Planorbidae (four species) being most abundant, along with one species each of Neritidae, Melanopsidae, Bithyniidae and Bulinidae, as well as two dreissenid bivalve species. Three of the hydrobiid gastropods are new to science, Prososthenia milosevici sp. nov., Prososthenia? naissensis sp. nov., and Prososthenia rundici sp. nov., and so is the bivalve Trigonipraxis madjerensis sp. nov. The present study results in 12 lectotype designations, 10 new generic combinations, and 10 new junior synonyms. About four-fifths (81.3%) of the species are endemic to the SLS, which is slightly higher than the overall SLS endemism (71.4%). The composition at the genus and family level overlaps strongly with the slightly older faunas of the Dinaride Lake System in Croatia and Bosnia and Herzegovina, as well as that of the late Miocene Lake Pannon. Its stratigraphically intermediate position and geographical proximity suggest that the SLS was a stepping stone for many of the mollusc lineages, some of which are found only in those systems.

From 2014 to 2019 at more than 100 localities freshwater molluscs were collected along the basin of Moulouya River and Oriental Region of Morocco. These samples revealed two new hydrobiid species which are described here. One new species of Islamia and one species of a new genus. Photos of the holotypes are presented in addition to the penis morphology of the new genus and a map of the sampling area with the type localities.

Based on the literary and personal data, as well as collections of the State Museum of Natural History of the National Academy of Sciences of Ukraine in Lviv City, the peculiarities of the recent spatial distribution of the freshwater molluscs – in the landscape zones and main river basins of Ukraine – have been analyzed. In both cases, relatively weak spatial differentiation of freshwater malakofauna was detected.

New collection work in Mount Flora, Hope Bay, Antarctic Peninsula, has confirmed the presence of bivalve moulds in the Jurassic Mount Flora Formation. In contrast to a twenty-first century article claiming to report the first discovery of fossil freshwater molluscs in Antarctica, evidence of these molluscs was first reported for Antarctica more than 110 years ago by J. Gunnar Andersson. The bivalve was formally described and named some 50 years later, by Camacho, as Antediplodon esperanzaensis. The species was subsequently transferred to the genus Diplodon for unknown reasons. Here, we illustrate specimens from the same locality for the first time with photographs, considering them Unionida incertae saedis, in view of the absence of diagnostic characters. In fact, two morphotypes are present, one elongated, very similar to the nominal species A. esperanzaensis, and another one subelliptical in shape. Fil: Martínez, Sergio. Universidad de la República; Uruguay Fil: Scasso, Roberto Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina Fil: Elgorriaga, Andres. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Capelli, Ignacio Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina Fil: del Valle, Rodolfo. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina Fil: Puerta, Pablo. Museo Paleontológico Egidio Feruglio; Argentina Fil: Lirio, Juan Manuel. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina Fil: Rodriguez Amenabar, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina

Background Sound knowledge of the abundance and distribution of intermediate host snails is key to understanding schistosomiasis transmission and to inform effective interventions in endemic areas. Methods A longitudinal field survey of freshwater snails of biomedical importance was undertaken in the Niger River Valley (NRV) between July 2011 and January 2016, targeting Bulinus spp. and Biomphalaria pfeifferi (intermediate hosts of Schistosoma spp.), and Radix natalensis (intermediate host of Fasciola spp.). Monthly snail collections were carried out in 92 sites, near 20 localities endemic for S. haematobium. All bulinids and Bi. pfeifferi were inspected for infection with Schistosoma spp., and R. natalensis for infection with Fasciola spp. Results Bulinus truncatus was the most abundant species found, followed by Bulinus forskalii, R. natalensis and Bi. pfeifferi. High abundance was associated with irrigation canals for all species with highest numbers of Bulinus spp. and R. natalensis. Seasonality in abundance was statistically significant in all species, with greater numbers associated with dry season months in the first half of the year. Both B. truncatus and R. natalensis showed a negative association with some wet season months, particularly August. Prevalences of Schistosoma spp. within snails across the entire study were as follows: Bi. pfeifferi: 3.45% (79/2290); B. truncatus: 0.8% (342/42,500); and B. forskalii: 0.2% (24/11,989). No R. natalensis (n = 2530) were infected. Seasonality of infection was evident for B. truncatus, with highest proportions shedding in the middle of the dry season and lowest in the rainy season, and month being a significant predictor of infection. Bulinus spp. and Bi. pfeifferi showed a significant correlation of snail abundance with the number of snails shedding. In B. truncatus, both prevalence of Schistosoma spp. infection, and abundance of shedding snails were significantly higher in pond habitats than in irrigation canals. Conclusions Evidence of seasonality in both overall snail abundance and infection with Schistosoma spp. in B. truncatus, the main intermediate host in the region, has significant implications for monitoring and interrupting transmission of Schistosoma spp. in the NRV. Monthly longitudinal surveys, representing intensive sampling effort have provided the resolution needed to ascertain both temporal and spatial trends in this study. These data can inform planning of interventions and treatment within the region.

The effect of water temperature on early-life development, growth and survival of the freshwater mussel, Hyriopsis bialata, was studied under controlled conditions. Gravid female mussels carrying gastrula embryos or early glochidia larvae were reared at 4 temperatures (25, 28, 31 and 34 °C) until they released mature glochidia; glochidia were then allowed to develop into juveniles. The highest survival rate of glochidia released from mussels carrying gastrula embryos was at 25 °C (91.4%), while survival for glochidia released from mussels carrying early glochidia larvae ranged from 83.2–91.3%. Average larval development time for gravid females carrying gastrula embryos or early glochidia larvae was between 5.0 and 9.2 days and 2.6–3.6 days, respectively. The survival of glochidia cultured to early juveniles in artificial medium was high in gravid mussels with gastrula embryos originally reared at 25 °C (93.9%) or 28 °C (93.6%), but was markedly decreased when originally reared at 31 °C (49.6%), while survival rates of those in gravid mussels with early glochidia larvae originally reared at 25, 28 or 31 °C were 92.3, 90.2 and 87.7%, respectively. The average transformation period from glochidia to early juvenile was 8–11 days, regardless of the temperature. Juveniles were reared for 1 month, and survival and length were measured. For glochidia released from gravid females with gastrula embryos, survival (85.7%) and length (0.49 ± 0.05 mm) were highest when originally reared at 25 °C, and both measures were significantly decreased at 28 and 31 °C. For glochidia released from gravid females carrying early glochidia larvae, survival (82.2%) and length (0.45 ± 0.06 mm) were highest when originally reared at 28 °C and lower when reared at 25 or 31 °C. Our results indicate that the optimal water temperature for culturing gravid female mussels carrying gastrula embryos or early glochidia larvae was 25 and 28 °C, respectively. These temperatures allowed high juvenile survival and growth.

Invasions of non-native species are major threats for freshwater ecosystems. One of the most invasive freshwater mussels in Europe is the Asian Sinanodonta woodiana (Chinese pond mussel). It occurs in the same waterbodies as the endangered native species Anodonta cygnea and Anodonta anatina with unknown consequences for them. Thus, the analysis about the host–parasite relationship between the larvae of S. woodiana and host fish species in Europe is important to assess impacts on the native mussels regarding their competition for hosts. In this study, host suitability of ten different fish species (native and non-native to Europe) for the glochidia of S. woodiana was analyzed by simultaneous infestation of the fish. All fish species were identified as suitable hosts but differed significantly in initial infestation rate as well as duration and rate of juvenile mussel excystment. Surprisingly, the glochidia developed successfully on Rhodeus amarus (bitterling), which cannot use S. woodiana for its own reproduction, and which is an unsuitable host for native anodontines. Compared to both native Anodonta, S. woodiana glochidia developed more successfully resulting in a higher number of excysted juvenile mussels at similar larval exposure. Metamorphosis was also faster on all tested fish species. These factors, together with the faster growth and higher number of offspring in S. woodiana likely contribute to a competitive advantage over native anodontines. The great likelihood of spreading this mussel on a large number of different possible host fish species deserves attention in fisheries management and stocking programs.

Pipelines, mechanisms and hydraulic structures laid on the bottom of freshwater bodies are exposed to massive exposure of fouling organisms - mollusks Dreissena polymorpha . Such fouling hinders the equipment operation and increases the corrosion of materials, besides, utilization of mollusks ( Dreissena polymorpha ) requires financial expenditure. Therefore, to solve the problem, dreissena was suggested to be used as a raw material for producing enzymatic hydrolyzate. The data of the mass-size and chemical composition of the raw materials (dreissena flesh) are presented. During the analysis of the model of a 2-factor experiment (the amount of enzyme preparation and the duration of fermentolysis were taken as factors) there was defined the optimal amount of enzyme (bacterial protease - protozyme). The comparative analysis of a control sample (without adding the enzyme) and enzymatic hydrolyzates of dreissena was carried out. There was stated the increase in protein content (3.7-17.8%), in dry matter (7.0-22.7%), amine nitrogen (446.2-158.6 mg/100 g). The periods of the most intensive increase in the degree of hydrolysis (during the first 2 hours of enzymatic hydrolysis by 2.8% and further 3-4 hours by 1.2%), as well as periods of values stabilization (during 2-3 hours and after 4 hours of enzymatic hydrolysis an increase by 0.6% on average). The change in the optical density of hydrolyzate solutions and their TCA-filtrates has been studied, which helped to compare the degree of protein destruction. There has been presented the technological chart of producing enzymatic hydrolyzates from dreissena with following conditions for fermentolysis: temperature 50 ºС, water ratio 1:1, quantity of enzyme protozyme 0.1% to the mass of blanched dreissena with valves, duration 3-4 hours.

Mapa del riesgo de contraer schistosomiasis urogenital provocada por Bulinus truncatus (Audouin, 1827) (Mollusca Gastropoda, Bulinidae) en España y Portugal Se da a conocer el mapa de la distribución geográfica de Bulinus truncatus en España y Portugal en el que se recopilan las localidades históricas y actuales, que coincide con el mapa del riesgo de contraer schistosomiasis urogenital provocada por este caracol de agua dulce. Se revisan las muestras de esta especie depositadas en el Museu de Ciències Naturals de Barcelona y en el Museo de Ciencias Naturales de Madrid, así como datos propios, incluidas algunas aportaciones inéditas. Este mapa permitirá conocer el área óptima de esta especie y determinar las zonas de mayor riesgo de contraer schistosomiasis urogenital en los dos países. Se pone de manifiesto que el cambio global y el cambio climático pueden favorecer la presencia tanto del vector (B. truncatus) como del parásito (Schistosoma haematobium) en España y Portugal., We present a geographical distribution map of Bulinus truncatus based on historical and current localities in Spain and Portugal, that corresponds to the risk map of urogenital schistosomiasis for this freshwater snail. We reviewed samples of the species deposited at the Museu de Ciències Naturals of Barcelona and the Museo Nacional de Ciencias Naturales of Madrid, together with our own data, including some unpublished contributions. This map will help determine the optimal area for this species and identify areas of greatest risk for urogenital schistosomiasis in the two countries. We emphasize that global change and climate change may favour the presence of both the vector (B. truncatus) and the parasite (Schistosoma haematobium) in Spain and Portugal., Mapa del riesgo de contraer schistosomiasis urogenital provocada por Bulinus truncatus (Audouin, 1827) (Mollusca Gastropoda, Bulinidae) en España y PortugalSe da a conocer el mapa de la distribución geográfica de Bulinus truncatus en España y Portugal en el que se recopilan las localidades históricas y actuales, que coincide con el mapa del riesgo de contraer schistosomiasis urogenital provocada por este caracol de agua dulce. Se revisan las muestras de esta especie depositadas en el Museu de Ciències Naturals de Barcelona y en el Museo de Ciencias Naturales de Madrid, así como datos propios, incluidas algunas aportaciones inéditas. Este mapa permitirá conocer el área óptima de esta especie y determinar las zonas de mayor riesgo de contraer schistosomiasis urogenital en los dos países. Se pone de manifiesto que el cambio global y el cambio climático pueden favorecer la presencia tanto del vector (B. truncatus) como del parásito (Schistosoma haematobium) en España y Portugal.

This study focused on finding of freshwater molluscs in Holocene sediments outcropping in western Eritrea. Three species of gastropods were found in calcareous sediments at the bank of a tributary river named Shatera River, within the license of Bisha Mines, they are Melanoides tuberculate (O. F. Müller, 1774), Bulinus globosus (Morelet, 1866) and Indoplanorbis exustus (Deshayes, 1833). The 14C dating on the shells of I. exustus and B. globosus was also carried out. The age dating result showed (9326-9134 cal yr BP) and (9134-8999 cal yr BP) respectively, of which are in the mid-Holocene epoch (11,000–5000 yr BP). This epoch is best known for it was a time when the northern and eastern part of Africa experienced a warm and humid climate. Among the freshwater molluscs, the existence of Melanonids tuberculate makes it more significant, for its widespread occurrence in Quaternary deposits throughout Africa and Asia in both fresh and highly evaporated lakes. This is suggestive of the considerable development of the lacustrine environment in the western part of Eritrea, which at present has disappeared.

First records of invasive bivalve freshwater mollusc species Mytilopsis leucophaeata (Conrad, 1831) and Corbicula fluminalis (O. F. Müller, 1774) in Georgia are reported. No native or alien extant dreissenid species have ever been recorded form this region so far. A finding of C. fluminalis in Georgia is also a new record for the country though this species inhabits the rivers of adjacent Azerbaijan. Apart from two mentioned bivalve molluscs three non-indigenous gastropod species are registered from Georgia: freshwater Ferrisia californica (Rowell, 1863) and Physella acuta (Draparnaud, 1805) and land snail Eobania vermiculata (O. F. Müller, 1774).

Human fascioliasis is a freshwater snail borne, zoonotic disease caused by Fasciola liver flukes which are widely spread throughout Pakistan and has recently proved to be endemic in humans of the Punjab province. To verify whether fasciolids are also affecting humans outside this province, studies were conducted in four communities comprising rural and urban areas of Mardan district, Khyber Pakhtunkha province, northern Pakistan. Activities comprised two surveys, a coprological one to look for Fasciola infection and another to get information on potential human infection sources and risk factors by means of a questionnaire. Out of 540 subjects of all ages surveyed, only 4 children (0.74%) were found positive for Fasciola eggs: two 9- and 13-year old boys and two 7- and 16-year old girls. Burden per child ranged 73–146 eggs per gram of faeces (epg), with an average of 106 ± 15.4 epg. Based on the egg size, the infection was diagnosed to be caused by F. hepatica. Serum analyses showed eosinophilia and elevated enzyme values in liver function tests. The Mardan area fits well to all transmission and epidemiological requirements of F. hepatica, namely the presence of infected livestock reservoirs throughout, the appropriate climatic factors (mainly monthly temperature variation along the year), and the existence of adequate freshwater collections. The existence of the specific lymnaeid snail vector species for F. hepatica transmission was reported in the neighbouring Swat valley time ago. Results show that human fascioliasis may be widespread in Pakistan and that both F. hepatica and F. gigantica may be involved.

Freshwater mollusc diversity has repeatedly been found to peak in lowland stagnant waters, which are highly exposed to human-made degradation and the spread of non-native species. Despite the increasing loss of these habitats, little is known about the main predictors of their mollusc diversity patterns. Therefore, we aimed to determine the environmental drivers of mollusc assemblage variation between and within sites by sampling 62 water bodies in the Dyje River floodplain (south-eastern Czechia). We measured 14 environmental variables, categorized as site-specific or plot-specific. Species richness and abundances were analysed by GLM and GEE; species compositional variance was assessed by NMDS and db-RDA ordinations. Mollusc species richness, ranging between 0 and 15 species per site, and abundance sharply decreased towards high trophy sites, with the chlorophyll-a concentration and water pH highly correlated with species counts. Species compositional variation was driven mainly by water trophy and the quality of organic detritus. Site heterogeneity turned out to significantly control local assemblages of molluscs, while the presence of individual species seemed to be filtered by site trophy and the shoreline length. Thus, to maintain high regional diversity of aquatic molluscs in lowland agricultural landscapes, the presence of low trophy sites seems to be essential.

This work evaluated the molluscicidal activity of the essential oil of the Zingiber officinale Roscoe rhizomes in with of the Biomphalaria glabrata species. The essential oil was isolated q...

Summary Freshwater snails serve as one of trematodes’ intermediate hosts. Previous studies on trematode larval stages in the Philippines have largely focused on species with public health importance. This study sought to investigate the prevalence of cercarial morphotypes in several freshwater snail species found in different habitat types (rice field, irrigation canals, and residential area) in selected agricultural areas in Los Baños and Bay in Laguna. Cercarial emergence was induced through exposure to artificial light. A total of 2,720 freshwater snails were collected and were represented by seven species, namely, Melanoides tuberculata Muller 1774 (n = 1229), Radix quadrasi von Moellendorf (n = 630), Tarebia granifera Lamarck, 1816 (n = 417), Pomacea canaliculata Lamarck 1819 (n = 257), Vivipara angularis philippinensis Nevill (n = 18), Stenomelania sp. (n = 104), Thiara scabra Muller 1774 (n = 65). A 2.57 % over-all prevalence was recorded; the infected snail species were M. tuberculata (2.21 %), R. quadrasi (0.21 %), T. granifera (0.11 %). Four cercarial morphotypes, namely, Parapleurolophocercous cercaria (1.80 %), Virgulate xiphidiocercaria (0.26 %), Megaluruous cercaria (0.29 %), and Echinostome cercaria (0.22 %) were recovered from the infected snail species. Prevalence of cercarial infection was significantly different (p < 0.05) among habitat types.

The syntype of Pseudamnicola brachia (Westerlund, 1886), the only known Pseudamnicola sp. from Crete, is compared with a recently collected Pseudamnicola sp. which could be identified as a species new to science. Comparisons with data in the literature show us that P. brachia (Westerlund, 1886) has nothing in common with P. brachia sensu Schutt, 1980 as well as P. brachia sensu Szarowska et al ., 2015, but both are possibly conspecific with the new species which is described here. In addition we describe two new Bythinella spp. from Crete which could be found in addition to B. cretensis Schutt, 1980, and a new Valvata ( Tropidina ) sp. from Lake Kournas.

Glycogen is a primary metabolic reserve in bivalves and can be suitable for the evaluation of bivalve condition and health status, but the use of glycogen as a diagnostic tool in aquaculture and biomonitoring is still relatively rare. A tissue biopsy combined with a simplified phenol-sulfuric acid method was used in this study to evaluate the inter- and intraindividual variation in the glycogen concentrations among several tissues (foot, mantle, gills, adductor muscle) of the unionid bivalve, the duck mussel Anodonta anatina. This short report documents that individual bivalves differ in the spatial distribution of glycogen among tissues. Sampling of different types of tissues can cause distinct results in the evaluation of energetic reserves at the individual level. At the same time, spatial variability in glycogen content has the potential to provide a more detailed evaluation of physiological conditions based on tissue-specific glycogen storage. The results obtained and the simplified methodology provide a new opportunity for researching the energetic reserves and health status of freshwater mussels in various applications.

This is the first review of life cycles of trematodes with parthenitae and larvae in freshwater gastropods from forest biocoenoses of Ukrainian Polissia. Altogether 26 trematode species from 14 families were found circulating in 13 ways in molluscs from reservoirs connected with forest ecosystems of the region. Three-host life cycle is typical of 18 trematode species, two-host life cycle has found in 7 species, and four-host cycles has found in one species. Alaria alata Goeze, 1782, has three-host (Shults, 1972) and four-host cycles. Opisthioglyphe ranae (Froehlich, 1791) can change three-host life cycle to two-host cycle replacing the second intermediate host (Niewiadomska et al., 2006) with the definitive host. Species with primary two-host life cycle belong to Notocotylidae Lühe, 1909, Paramphistomidae Fischoeder, 1901 and Fasciolidae Railliet, 1758 families. Trematodes with three-host cycle have variable second intermediate hosts, including invertebrates and aquatic or amphibious vertebrates. Definitive hosts of trematodes are always vertebrates from different taxonomic groups. The greatest diversity of life cycles is typical for trematodes of birds. Trematodes in the forest biocoenoses of Ukrainian Polissia infect birds in six ways, mammals in three, amphibians in four, and reptiles in one way. The following species have epizootic significance: Liorchis scotiae (Willmott, 1950); Parafasciolopsis fasciolaemorpha Ejsmont, 1932; Notocotylus seineti Fuhrmann, 1919; Catatropis verrucosa (Frölich, 1789) Odhner, 1905; Cotylurus cornutus (Rudolphi, 1808); Echinostoma revolutum (Fröhlich, 1802) Dietz, 1909; Echinoparyphium aconiatum Dietz, 1909; Echinoparyphium recurvatum (Linstow, 1873); Hypoderaeum conoideum (Bloch, 1782) Dietz, 1909; Paracoenogonimus ovatus Kasturada, 1914; Alaria alata Goeze, 1782.

River floodplain ecosystems host one of the highest freshwater molluscan biodiversity on Earth. However, multiple human disturbances, such as loss of hydrological connectivity and deterioration of water quality, are seriously threatening most floodplain lakes throughout the world. Given the high imperilment rate of freshwater molluscs but the scarcity of studies examining the anthropogenic effects on this fauna, we test the response of mollusc assemblages to river-lake disconnection and eutrophication in 30 lakes in the Yangtze River floodplain, China. The species richness of entire Mollusca, Gastropoda and Bivalvia and 6 dominant families were all much lower at disconnected lakes than that in connected lakes, and decreased with increasing water eutrophication. The assemblage structure differed significantly among four lake groups for datasets based on entire Mollusca, Gastropoda and Bivalvia, indicating the serious impacts of hydrological disconnection and eutrophication. Moreover, the connected lakes showed significantly lower values of average taxonomic distinctness (Δ+) but higher values of variation in taxonomic distinctness (Λ+) than disconnected lakes. Such variations were triggered by the extirpation of congeneric and endemic species (mainly from families Unionidae and Viviparidae), which giving a waring of the loss of mollusc endemism in this region. In general, the present study showed that river-lake disconnection and deterioration of water quality resulted in serious biodiversity declines of both gastropods and bivalves in the Yangtze River floodplain lakes. A systematic approach including restoration of river-lake connectivity and habitats and improvement of water quality should be implemented in the conservation planning in this large river floodplain.

OBJECTIVES: Identify freshwater mollusks and trematode larvae from drainage ditches in the Municipality of Peruibe, Sao Paulo State, Brazil, and describe the morphology of emerged larvae. MATERIALS AND METHODS: Mollusks were collected from 53 ditches. In the laboratory, the specimens were morphologically identified, and parasitological analysis was carried out to determine and describe the larvae. RESULTS: 5,969 mollusks belonging to the families Planorbidae, Lymnaeidae, Physidae, Thiaridae, and Ampullariidae were collected. The parasitological analysis of the mollusks revealed nine different larvae corresponding to the following seven types of cercariae: xiphidio cercariae, echinostome cercariae, strigea cercariae, brevifurcate pharyngeate distome cercariae, brevifurcate apharyngeate distome cercariae, pleurolophocercous cercariae, and amphistome cercariae. Biomphalaria tenagophila (d'Orbigny, 1835) was susceptible to eight of the nine cercariae found, and six specimens of mollusks were parasitized by Schistosoma mansoni Sambon, 1907. CONCLUSION: It is fundamental to establish malacological control and surveillance programs in vulnerable areas when mollusks, intermediate host of parasites of medical and veterinary importance, colonize these environments, especially when infected with S. mansoni larvae.

Molluscs are the most important resources among all the seafood items in South-East Asian countries. However, very little information available on nutritional value of molluscs in these regions. In this study, we evaluated the 7 economically important species of molluscs in terms of proximate composition, amino acids profile, fatty acids profile, cholesterol and heavy metal contents in the bivalves (mussels, oysters, clams and cockles) and univalve (snail) collected from freshwater and marine environments of Bangladesh. The results of the proximate analyses revealed that significantly higher amount of crude protein contents were present in marine water oysters, clams and cockles (59.3 ± 0.3 to 75.4 ± 0.2%) than the freshwater mussels and snail (36.9 ± 0.4 to 49.6 ± 0.6%) on dry matter basis. However, carbohydrate contents were significantly higher in freshwater mussels and snail (30.2 ± 0.9 to 57.3 ± 0.2%) compared to the marine water bivalves (8.1 ± 0.4 to 20.2 ± 0.6%). Crude lipid contents were ranged from 2.5 ± 0.2 to 11.2 ± 0.1% and ash from 11.4 ± 0.1 to 16.8 ± 0.6% among the bivalves and snail species. The amino acid contents were comparatively higher in marine water bivalves than their freshwater counterparts. Saturated fatty acid contents were found to be higher in marine water bivalves than the freshwater mollusc species. The results also show that the omega-3 (eicosapentaenoic acid, EPA and docosahexaenoic acid, DHA) fatty acids were comparatively higher in oysters, clams and cockles in marine water than those in freshwater mussels and snail. However, omega-6 fatty acids like linoleic acid (LA), α- linolenic acid (ALA) and arachidonic acid (ARA) were higher in freshwater mussels and snail than in the marine bivalves. The n-3/n-6 ratio were significantly higher in oysters and cockle species than the other groups of bivalves and snail. The index of atherogenicity and index of thrombogenicity of the mollusc species ranged from 0.74 ± 0.1 to 1.74 ± 0.2 and 0.5 ± 0.1 to 2.6 ± 0.2, respectively. The results show that marine water bivalves contained higher amount of potassium, sodium, iron, chlorine especially oyster species contained significantly higher iodine than the freshwater bivalves and snail. However, freshwater mussels and snail showed significantly higher amount of zinc contents than the marine bivalves. The heavy metal contents such as arsenic, chromium and mercury were absent or present in very tiny amounts among the mollusc species. Significantly higher amount of cholesterol was present in marine bivalves and freshwater snail species than the freshwater mussels. Overall, the results indicate that marine bivalves can be good sources of high quality protein and lipid especially EPA and DHA. On the other hand, freshwater mussels and snails also could be good sources of protein, LA and ARA but scarcity of EPA and DHA., Seafood; Nutritive value; Bivalves; Macronutrients; Micronutrients; Heavy metals

The diversity and distribution of freshwater molluscs is poorly studied in the Republic of Georgia, due to the scarcity of field studies during the last 50 years. Here, we present the results of the first concerted investigation of freshwater mollusc biodiversity in the Javakheti Highlands, in the southern, mountainous region of Georgia. In total, we were able to collect 22 species from 42 sampling localities, including different kinds of freshwater habitats. Amongst the 22 collected species, 12 were recorded for the first time from Javakheti. From the newly-recorded species,Bathyomphalus contortusis a new country record, whose identity is supported by 16S rRNA sequence data.