Search results for "Unionida"
showing 10 items of 16 documents
Freshwater mussels (Anodonta anatina) reduce transmission of a common fish trematode (eye fluke, Diplostomum pseudospathaceum)
2017
SUMMARYRecent results suggest that bivalves can play an important role in restraining the spread of various aquatic infections. However, the ability of mussels to remove free-living stages of macroparasites and reduce their transmission is still understudied, especially for freshwater ecosystems. We investigated the influence of the common freshwater mussel (Anodonta anatina) on the transmission of a trematode (eye fluke, Diplostomum pseudospathaceum), which frequently infects fish in farms and natural habitats. In our experiments, mussels caused a significant decrease (P < 0·001) in the abundance of trematode free-living stages, from 6520 to 1770 cercariae L−1 on average (about 4-fold i…
Research priorities for freshwater mussel conservation assessment
2018
Freshwater mussels are declining globally, and effective conservation requires prioritizing research and actions to identify and mitigate threats impacting mussel species. Conservation priorities vary widely, ranging from preventing imminent extinction to maintaining abundant populations. Here, we develop a portfolio of priority research topics for freshwater mussel conservation assessment. To address these topics, we group research priorities into two categories: intrinsic or extrinsic factors. Intrinsic factors are indicators of organismal or population status, while extrinsic factors encompass environmental variables and threats. An understanding of intrinsic factors is useful in monitor…
Conservation status of freshwater mussels in Europe: state of the art and future challenges
2016
Freshwater mussels of the Order Unionida provide important ecosystem functions and services, yet many of their populations are in decline. We comprehensively review the status of the 16 currently recognized species in Europe, collating for the first time their life-history traits, distribution, conservation status, habitat preferences, and main threats in order to suggest future management actions. In northern, central, and eastern Europe, a relatively homogeneous species composition is found in most basins. In southern Europe, despite the lower species richness, spatially restricted species make these basins a high conservation priority. Information on freshwater mussels in Europe is uneve…
Burrowing behaviour affects Paraergasilus rylovi abundance in Anodonta piscinalis.
2006
Burrowing depth may affect predation rate, feeding ability and reproduction in bivalve clams. We studied the effect of burrowing depth on the abundance of the ergasilid Paraergasilus rylovi in the freshwater bivalve clam Anodonta piscinalis. We transplanted uninfected clams to a lake where they were allowed to choose their preferred burrowing depth, and were exposed naturally to copepodids of the parasite. There was a significant positive correlation between proportionate burrowing depth (PBD) and the abundance of P. rylovi at the end of the 17-day experiment, the deeper-burrowed clams harbouring more P. rylovi. Original PBD (0%, 50%, 100%) did not influence the final PBD or parasite abunda…
Glochidial infection by the endangered Margaritifera margaritifera (Mollusca) increased survival of salmonid host (Pisces) during experimental Flavob…
2021
AbstractCo-infections are common in host-parasite interactions, but studies about their impact on the virulence of parasites/diseases are still scarce. The present study compared mortality induced by a fatal bacterial pathogen, Flavobacterium columnare between brown trout infected with glochidia from the endangered freshwater pearl mussel, Margaritifera margaritifera, and uninfected control fish during the parasitic period and after the parasitic period (i.e. glochidia detached) in a laboratory experiment. We hypothesised that glochidial infection would increase host susceptibility to and/or pathogenicity of the bacterial infection. We found that the highly virulent strain of F. columnare c…
Deep conservation of bivalve nacre proteins highlighted by shell matrix proteomics of the Unionoida Elliptio complanata and Villosa lienosa.
2016
The formation of the molluscan shell nacre is regulated to a large extent by a matrix of extracellular macromolecules that are secreted by the shell-forming tissue, the mantle. This so-called ‘calcifying matrix’ is a complex mixture of proteins, glycoproteins and polysaccharides that is assembled and occluded within the mineral phase during the calcification process. Better molecular-level characterization of the substances that regulate nacre formation is still required. Notable advances in expressed tag sequencing of freshwater mussels, such as Elliptio complanata and Villosa lienosa , provide a pre-requisite to further characterize bivalve nacre proteins by a proteomic approach. In this…
Effect of Short-Term Temperature Change on Cercarial Release by Rhipidocotyle fennica (Trematoda, Bucephalidae) from the Freshwater Bivalve Host, Ano…
2015
Cercarial release from the first intermediate host is an important stage in the transmission of trematode parasites. Besides long-term (seasonal) temperature fluctuations, short-term temperature changes can also influence cercarial emergence. We tested the response of the bucephalid trematode, Rhipidocotyle fennica (R. fennica), acclimatized to 17 °C, to an abrupt temperature change. As the natural cercarial shedding by this parasite takes place annually during the warmest season, we expected a positive effect of temperature increase. Monitoring during one hour after the transfer from 17 °C to 20 °C revealed a significant increase in R. fennica cercarial release compared to the preceding on…
Bio-vaterite formation by glycoproteins from freshwater pearls
2010
Abstract A 48 kDa acidic and putative calcium-binding glycoprotein was isolated from pearls of the freshwater mussel Hyriopsis cumingii . This protein was compared with a related 46 kDa polypeptide, obtained from the nacreous shell of the same species. Separation by two-dimensional gel electrophoresis revealed that the difference in molecular weight is due to the higher extent of glycosylation of the 48 kDa protein existing in pearls. Evidence is presented that the sugar moieties of the protein contribute to crystal growth, starting with the nucleation step. In in vitro precipitation experiments, the 48 kDa glycoprotein of pearls directed the formation of round-shaped vaterite crystals whil…
Crayfish predation on mussels : an experimental approach
2013
Tässä työssä tutkittiin kokeellisesti rapujen simpukoihin kohdistuvaa predaatiota. Käytetyt rapulajit olivat jokirapu Astacus astacus ja amerikkalainen tulokaslaji täplärapu Pascifastacus leniusculus. Jokirapupredaatiota tutkittiin pikkujärvisimpukalla Anodonta anatina ja täplärapupredaatiota pikkujärvisimpukalla sekä jokihelmisimpukalla Margaritifera margaritifera Kokeissa ravut laitettiin yksittäin 15 litran läpivirtausaltaisiin simpukan/simpukoiden kanssa. Täplärapu osoittautui tehokkaammaksi predaattoriksi onnistuen aukaisemaan seitsemän 42:sta Anodontasta. Jokirapu ei saanut avattua yhtään 37:stä Anodontasta. Aukaisemisen ja pehmytosien syömisen lisäksi rapujen havaittiin nakertavan si…
Diversity and taxonomy of the genus Unio Philipsson in Italy, with the designation of a neotype for Unio elongatulus C. Pfeiffer (Mollusca, Bivalvia,…
2019
Novel Unio spp. populations from Slovenia, the Italian peninsula, Sardinia and Sicily were genetically analysed in order to define the distribution and diversity of the genus Unio in Italy and neighbouring areas. The presence of two primarily allopatric autochtonous species, Unio elongatulus Pfeiffer, and Unio mancus Lamarck, is confirmed for the Italian peninsula, Corsica, Sardinia, and Sicily. Autochthonous populations of Unio elongatulus are present in the peri-Adriatic drainages of the Italian and Balkan peninsulas, south as far as the Ofanto River (Apulia, Italy) and Lake Skadar (Albania), while its presence in the Tyrrhenian rivers of Tuscany is likely due to anthropogenic introductio…