Species Of Freshwater Molluscs Research Articles

Měkkýši Hostýnských vrchů [Molluscs of the Hostýnské vrchy Hills

This study deals with the molluscan fauna of the Hostýnské vrchy Hills (Central Moravia, Czech Republic). The main goal was to make a systematic inventory of the molluscan fauna in this area. Snails were collected in September 2010 by hand picking and litter sampling at selected sites. Final database was pooled with earlier published and unpublished data. In total, 85 terrestrial and 20 freshwater mollusc species were recorded at 56 study sites across the area during 2000–2010. Terrestrial snails Monachoides incarnatus, Punctum pygmaeum, Vitrina pellucida, and freshwater molluscs Pisidium casertanum, and Radix labiata were the most frequently recorded species. The land snails Daudebardia brevipes, Eucobresia nivalis, Vitrea transsylvanica, and Chondrula tridens are notable species from the local viewpoint. The clausilid Vestia ranojevici moravica, an endemic subspecies that colonized some regions of Moravia during the Holocene climatic optimum, is an iconic mollusc species in the area, deserving high conservation priority.

韓国産淡水貝類 2 種に就いて

韓国産淡水貝類 2 種に就いて

Vodní měkkýši Vysočiny [Freshwater molluscs of Vysočina Region (Czech Republic)

This paper summarizes data about the distribution of freshwater molluscs in the Vysočina Region (6,800 km²). The region is one of the 14 regions of the Czech Republic, situated in its central part. The major part of this region consists of Českomoravská vrchovina (Bohemian-Moravian Highlands) with average elevation about 500 m a. s. l. Data about freshwater molluscs have been obtained by author’s field research since 1993 and from many published and unpublished papers, private collections, and collections in museums dating from 1850. Altogether, data about the occurrence of 49 species of freshwater molluscs (27 gastropods, 22 bivalves) were obtained. This number constitutes 62% of all aquatic mollusc species found in the Czech Republic. Data about the occurrence of individual species were used for the construction of distributional maps of records for three time periods (1851–1950, 1951–2000, 2001–2016). The major part of the data has originated for the last period. This clearly demonstrates a significant increase in the research intensity after 2000. The most common species, i.e. recorded at least in 40 mapping cells out of 72 covering the area to the Vysočina Region, were Galba truncatula, Radix auricularia, R. labiata, Lymnaea stagnalis, Gyraulus albus, Ancylus fluviatilis, Anodonta anatina, Pisidium casertanum, and P. subtruncatum. In contrast, Viviparus viviparus, Potamopyrgus antipodarum, Stagnicola corvus, Radix ampla, R. balthica, Planorbis planorbis, Gyraulus acronicus, Ferrissia fragilis, Unio tumidus, Pseudanodonta complanata, Sinanodonta woodiana, Pisidium amnicum, P. tenuilineatum, and Dreissena polymorpha have been found in less than five mapping cells and belong to rare species of this region. Except 29 common and widespread species, four species (Bythinella austriaca, Physa fontinalis, Pisidium milium, and P. supinum) belonging in the Red List of the Molluscs of the Czech Republic were recorded. Other six species are classified as Vulnerable (Radix ampla, Gyraulus acronicus, Segmentina nitida, Unio tumidus, Anodonta cygnea, and Pisidium hibernicum), three as Endangered (Unio crassus, Pseudanodonta complanata, and Pisidium amnicum), and two as Critically Endangered (Margaritifera margaritifera and Pisidium tenuilineatum).

Aquarium molluscs as a case study in risk assessment of incidental freshwater fauna

Because biological invasions may cause loss of biodiversity, accurate predictions are necessary for implementing effective restrictions aimed at specific high-risk taxa. The majority of freshwater macroinvertebrate invaders are molluscs and crustaceans. The pet trade has been considered one of the main pathways for new introductions of such species. Risk assessment is usually focused on traded ornamental species whereas, despite their potential importance, incidental “hitchhiking” molluscs are usually given only minimal consideration. We surveyed the Czech Republic, which is one of the leading markets for aquarium species in the European Union (EU), and found 41 freshwater mollusc species (25 ornamental gastropods, 6 ornamental clams, and 10 “hitchhiking” gastropods) representing 13 families. We extrapolated data from the Czech Republic and, using Climatch v. 1.0, matched the climate in each species’ native range to the entire territory of the EU. We also assessed the risk associated with each species by FI-ISK. “Hitchhiking” gastropods were found to be significantly more hazardous and with higher potential to become established within the EU than were ornamental gastropods and bivalves. Many “hitchhikers” may be easily overlooked due to their small size and cryptic coloration or shape. Thus, they easily can be accidentally imported in association with aquarium plants. Therefore, we recommend here to disinfect imported ornamental plants to eradicate these unwanted faunal assemblages.

Vodní měkkýši rybníka Baroch a jejich změny po revitalizaci [Aquatic molluscs of the Baroch Pond and their changes after a restoration

This paper presents the results of a malacological survey of the Baroch Nature Reserve in Eastern Bohemia (Czech Republic) near the town of Pardubice in 2016. Altogether 16 species of freshwater molluscs (14 gastropods, 2 bivalves) were found at 12 sampling sites in 2016, while 11 species were recorded during previous research, which were all recorded also in 2016. This shows that the 2000 restoration had a positive effect on species richness and successional changes after this management did not cause disappearance of any species.

Změny malakocenóz vybraných labských ramen u Pardubic [Changes of mollusc assemblages of the selected oxbows near the town of Pardubice

This paper presents the results of a malacological survey of the selected oxbows of the Elbe River in Eastern Bohemia (Czech Republic) near the town of Pardubice in 2016. The changes in molluscan assemblages observed based on the comparison with the previous research, conducted more than 10 years ago, are described. Altogether 23 species of freshwater molluscs (20 gastropods, 3 bivalves) were found at 7 sites in five protected areas. Investigated sites were divided into three groups according to the changes of mollusc assemblages: (1) without any significant changes; (2) changes promoted by succession; (3) changes hard to explain. High fish stock, shading and succession are considered to be the main factors driving the variation of the studied mollusc assemblages.

The first freshwater molluscs from Wrangel Island, Arctic Russia

The first finding of a freshwater snail, Sibirenauta sibiricus (Westerlund, 1877), in one of the lakes on Wrangel Island (north-eastern Russia) is reported. No freshwater mollusc species have hitherto been known from this island. Specimens from the island are morphologically compared with the type series of the species. How aquatic molluscs may have migrated to the Arctic island is briefly discussed. Keywords: Arctic; freshwater snails; Physidae (Published: 19 August 2015) To access the supplementary material for this article, please see supplementary files in the column to the right (under Article Tools). Citation: Polar Research 2015, 34 , 23889, http://dx.doi.org/10.3402/polar.v34.23889

Vodní měkkýši nově vzniklého jezera Most v severních Čechách [Freshwater molluscs of the Most, a newly created lake in Northern Bohemia (Czech Republic)

This paper summarizes the knowledge of freshwater mollusc fauna of the Most Lake. It was created in 2008–2013 by flooding of the majority of the former coal quarry of Ležáky (Northern Bohemia). This water reservoir originated in the area of 311 ha and with the maximum depth of 75 m it is the largest water body of the area. The research was conducted in summer 2013, when the water level was about 0.5 m bellow the final expected level. In total, only six species of freshwater molluscs (five gastropods, one bivalve) were found at 11 sites. Two autochtonous molluscs (Radix auricularia and Gyraulus crista) and four allochtonous species (Physella acuta, Gyraulus parvus, Menetus dilatatus and Dreissena polymorpha) were found. The occurrence of all species except D. polymorpha was scattered, while the latter occurred in numerous populations sometimes with more than 80 specimens per 10 cm². Most of the molluscs were found on stones of the lake banks or at areas of shallow water. The results obtained during this research have recorded mollusc assemblages at the first successional stages of this artificial lake, thus enabling future comparison.

New Data Concerning the Freshwater Molluscs from the Romanian Sector of Timiş River (Banat, Romania)

In the Romanian sector of the Timis River, 31 species of freshwater molluscs have been found up to the present. Among them are 17 gastropod and 14 bivalve species (including all seven species of Unionidae that live in Romania, these found in the lower sector of the river – something that is extremely rare in our waters). The present synthesis used the results of a screening type field investigation carried out in 2011, as well as all the available data from the literature and our previous studies. All these data prove the ongoing degradation of the river’s ecological state and its sheltered communities. This paper presents the annotated systematic and chorological checklist of the mollusc species from this area, some of its ecological characteristics and the main environmental issues related to human impact. Changes in species distribution and the structure of communities as an answer to increased human pressure during the last decades are also thus demonstrated. New data about some alien invasive species are given, including the first encounter with Corbicula fluminea, a species formerly known only in Romanian inland waters from the Danube, in the Timis River lower sector.

New Data Concerning the Freshwater Molluscs from the Romanian Sector of Timiş River (Banat, Romania)

ABSTRACT In the Romanian sector of the Timiş River, 31 species of freshwater molluscs have been found up to the present. Among them are 17 gastropod and 14 bivalve species (including all seven species of Unionidae that live in Romania, these found in the lower sector of the river - something that is extremely rare in our waters). The present synthesis used the results of a screening type field investigation carried out in 2011, as well as all the available data from the literature and our previous studies. All these data prove the ongoing degradation of the river’s ecological state and its sheltered communities. This paper presents the annotated systematic and chorological checklist of the mollusc species from this area, some of its ecological characteristics and the main environmental issues related to human impact. Changes in species distribution and the structure of communities as an answer to increased human pressure during the last decades are also thus demonstrated. New data about some alien invasive species are given, including the first encounter with Corbicula fluminea, a species formerly known only in Romanian inland waters from the Danube, in the Timiş River lower sector.

Freshwater molluscs of the Dyje (Thaya) River and its tributaries - the role of these water bodies in expansion of alien species and as a refuge for endangered gastropods and bivalves

The malacofauna of the Dyje River, including the lower sections of its five tributaries, is still rich and diversified despite the pollution, regulation and building of several dam reservoirs. In total, 42 freshwater mollusc species (24 gastropods, 18 bivalves) were found at 75 sites. The richest malacofauna (30 species) was recorded in the lower section of the Dyje. Populations of endangered or rare molluscs Theodoxus danubialis, Viviparus acerosus, Lithoglyphus naticoides, Unio crassus, Pseudanodonta complanata, Pisidium amnicum and P. moitessierianum were found. The first three species inhabit only the area under study in the Czech Republic. Especially the occurrence of Unio crassus corresponds with river sections that were only partly affected by human activities (long distance below dam reservoirs, less polluted sections, unregulated watercourses). The occurrence of five invasive species, four originating from other continents (Potamopyrgus antipodarum, Physella acuta, Ferrissia fragilis, Sinanodonta woodiana) and one (Dreissena polymorpha) originally Ponto-Caspian, was confirmed for the Dyje River and its tributaries. The Dyje River formed the main invasion route from the Danube River into Moravia (eastern part of the Czech Republic).

Contribution to the knowledge on distribution of freshwater mollusc species of İzmir (Turkey)

Izmir’in Tatlisu mollusca turlerini belirlemek amaciyla Mayis 1994-Mayis 1996 tarihleri arasinda 22 istasyondan mevsimsel olarak ornekleme yapilmistir. Kalitatif calismanin sonucunda toplam 15 takson tespit edilmis olup, bunlardan 12’si Gastropoda’ya 3’u Bivalvia’ya aittir. Istasyonlardaki mollusca turleri arasinda en yaygin olanlari Melanopsis praemorsa (9 istasyon) ve Physella acuta (7 istasyon), en az olanlari ise Unio crassus (1 istasyon) ve Theodoxus anatolicus (1 istasyon)’tur

A note on Molluscan diversity and density of some fish ponds of Lalapatti Village Development Committee (VDC), Saptari district, Nepal

Molluscan diversity of six fish ponds and a river of Lalapatti VDC, Saptari district was studied. In total, ten species of freshwater molluscs belonging to seven families and eight genera were recorded. Among them nine species were found in ponds and five species were recorded in the river samples. Maximum average density was recorded of Bellamya bengalensis (30.38/m2) and minimum for Corbicula alata (0.084/m2) DOI: http://dx.doi.org/10.3126/njbs.v1i0.7463 Nepalese Journal of Biosciences 1: 8-10 (2011)

Environmental controls on the δ18O composition of freshwater calcite and aragonite in a temperate, lowland river system: significance for palaeoclimatic studies

The oxygen and carbon isotopic composition of surficial carbonates is a key technique for reconstructing past environments and climates. The understanding of modern isotopic systems is, however, a vital first step before applying these techniques to fossil examples. In this study the δ18O of aragonite shells from three different freshwater mollusc species and the δ18O of tufa stromatalites are analysed and compared to the modern temperature and isotopic regime of the river system in which they form (the river Gipping, Sproughton, southeast England). In all cases this range of carbonates appear to form in isotopic equilibrium with the δ18O of modern waters at water temperatures experienced during the summer months. It is, therefore, likely that in Quaternary interglacial deposits of the UK and western Europe the δ18O of fossil freshwater molluscs and tufa stromatolite carbonates will provide an indication of past summer temperature regimes and not mean annual temperatures, as has been previously suggested. The paper concludes by discussing the implications of this study for the isotopic analysis of interglacial deposits in Britain and western Europe.

Toxic Effects of Copper, Cadmium, and Methoxychlor Shown by Neutral Red Retention Assay in Two Species of Freshwater Molluscs

We used neutral red retention assay in lysosomes of digestive gland cells as an indicator for stress effects by the environmental contaminants Cu, Cd, and the pesticide methoxychlor in two freshwater molluscs, the unionid mussel, Elliptio complanata (Lightfoot) and the ramshorn snail Helisoma trivolvis (Say). Mussels and snails were exposed for 7 and 14 days to Cu and Cd each at nominal concentrations of 2.5 µg/L, 5.0 µg/L, and 10.0 µg/L, and to methoxychlor concentrations of 1.0 µg/L, 10.0µg/L, and 100.0 µg/L. Both mussels and snails exposed to Cu showed a significant increase in the percent of destabilized lysosomes compared with lab control and freshly-collected (field control) mussels at both 7 and 14 days exposure for all concentrations. Cd-exposed mussels did not show a significant difference with either of the controls at 7 days, but at 14 days exposure, Cd significantly increased the percent of destabilized lysosomes at all concentrations compared to field control mussels. Compared to laboratory controls, Cd increased lysosomal destabilization at 5.0 µg/L and 10.0 µg/L. Snails exposed to Cd for 7 days had a significantly higher percentage of lysosomal destabilization than both lab and field controls but at 14 days, significant differences were only seen at the two highest Cd concentrations. Methoxychlor-exposed mussels showed no significant lysosomal destabilization at 7 days compared to controls. But at 14 days exposure, the pesticide increased the percentage of lysosomal destabilization at 10.0µg/L compared to lab controls, and increased at both 10.0µg/L and 100.0µg/L compared to field control mussels. Methoxychlor-exposed snails had a higher percentage of lysosomal destabilization at 7 and 14 days at all concentrations compared to both controls with the exception of the 1.0 µg/L -7 day exposure group. Snails were more sensitive to Cd and to methoxychlor than were mussels possibly because they lack an operculum and are thus completely exposed to the environment. The lowest observed effect concentration (LOEC) for Cd was 2.5 µg/L (14 days) for Elliptio and 2.5 µg/L (7 and 14 days) for Helisoma. For methoxychlor, the LOEC was 10.0 µg/L (14 days) for Elliptio and 10.0 and 1.0 µg/L (7 and 14 days, respectively) for Helisoma. The LOEC for Cu was 2.5 µg/L (7 and 14 day exposure) for both Elliptio and Helisoma. These results show that lysosomal destabilization as indicated by neutral red retention is a reliable indicator of stress from heavy metals and a pesticide in freshwater molluscs, including a taxon that is endangered or threatened in North America.

Endemic Freshwater Molluscs of Cuba and Their Conservation Status

Cuba is one of the richest places in malacological fauna in the world, especially in land snails, hosting a high degree of endemism. A study on the distribution of freshwater molluscs that occur within the limits of protected areas was carried out. The objective was to determine the status of the endemic species and the potential threats of introduced snails. It was found that the inclusion of freshwater molluscs is not a criterion for proposing protected areas no matter how ecologically important they actually can be. A total of 42 species of freshwater molluscs occur in Cuba, but only 24 exist in the National System of Protected Areas. More critical is the fact that of the 10 Cuban endemics, three are not protected and the distribution data on all of them are not abundant. Introduced species such as Tarebia granifera and Melanoides tuberculata are spread throughout the country and might be a threat for endemics and other native snails. Data on the distribution of endemic molluscs is presented and the role of some introduced/invasive species is discussed.

Freshwater mollusc thiolase cloning, expression and structural analysis

A considerable gap remains in the knowledge of lipid metabolism and lipid biochemistry in molluscs. Many species of freshwater molluscs exist in North America. Among these are the common gastropods Helisoma trivolvis, Physa acuta, and Goniobasis virginica. Recent advances, including high‐resolution x‐ray crystal structures, in structural analysis of acetoacetyl CoA thiolase from various species has advanced the understanding of the catalytic mechanism of these important enzymes. The purpose of this research is to clone and express thiolase enzymes in various freshwater molluscs and to use other known thiolase structures to study the structure of the mollusc thiolases.

Strategies for the conservation of endangered freshwater pearl mussels (Margaritifera margaritifera L.): a synthesis of Conservation Genetics and Ecology

Freshwater pearl mussels (Margartifera margaritifera L.) are among the most critically threatened freshwater bivalves worldwide. The pearl mussel simultaneously fulfils criteria of indicator, flagship, keystone and umbrella species and can thus be considered an ideal target species for the process conservation of aquatic ecosystem functioning. The development of conservation strategies for freshwater pearl mussels and for other bivalve species faces many challenges, including the selection of priority populations for conservation and strategic decisions on habitat restoration and/or captive breeding. This article summarises the current information about the species’ systematics and phylogeny, its distribution and status as well as about its life history strategy and genetic population structure. Based on this information, integrative conservation strategies for freshwater mollusc species which combine genetic and ecological information are discussed. Holistic conservation strategies for pearl mussels require the integration of Conservation Genetics and Conservation Ecology actions at various spatial scales, from the individual and population level to global biodiversity conservation strategies. The availability of high resolution genetic markers for the species and the knowledge of the critical stages in the life cycle, particularly of the most sensitive post-parasitic phase, are important prerequisites for conservation. Effective adaptive conservation management also requires an evaluation of previous actions and management decisions. As with other freshwater bivalves, an integrative conservation approach that identifies and sustains ecological processes and evolutionary lineages is urgently needed to protect and manage freshwater pearl mussel diversity. Such research is important for the conservation of free-living populations, as well as for artificial culturing and breeding techniques, which have recently been or which are currently being established for freshwater pearl mussels in several countries.

Aragonite Prism−Nacre Interface in Freshwater Mussels Anodonta anatina (Linnaeus, 1758) and Anodonta cygnea (L. 1758)

Electron backscatter diffraction is used to characterize the transition interface between aragonite prisms and nacre in two species of freshwater molluscs, Anodonta anatina (Linnaeus, 1758) and Anodonta cygnea (L. 1758). In the duck mussel, Anodonta anatina, the shell thickness is comprised mainly of nacre with only a thin outer prismatic layer, whereas in the swan mussel, A. cygnea, the shell comprises a greater thickness of aragonite prisms relative to the nacreous layer. In A. anatina, the prism−nacre interface is flat and featureless. In A. cygnea, the nacre below the base of the prisms is characterized by distinct concave footholds. In both species, the c-axis of aragonite nanogranules comprising the prisms is parallel with the prism length. This crystallographic orientation, with the c-axis perpendicular to the shell exterior, occurs in the nacreous layer and thus is conserved throughout the shell thickness. In A. cygnea alternate prisms have a crystallographic orientation with the c-axis deviating from the prism long axis by approximately 20 deg. The initial nacreous layer adopts the crystallographic orientation of the preceding prisms and subsequent nacreous laminae are oriented in register with the bulk nacre. This is consistent with the hypothesis that nacre evolved through horizontal partitioning of prisms.

Cloning and expression of thiolase enzymes in freshwater molluscs

Many species of freshwater molluscs exist in North America. Among these are the common gastropods Helisoma trivolvis, Physa acuta, and Goniobasis virginica. Additionally, the Asian clam, Corbicula fluminea, which found its way from China to North America some 70 years ago, is a very common bivalve. A considerable gap remains in the knowledge of lipid metabolism and lipid biochemistry in molluscs. The purpose of this research is to clone and express thiolase enzymes in various freshwater molluscs.