Search results for "Unionidae."
showing 10 items of 13 documents
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…
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…
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…
Does the freshwater mussel Anodonta anatina remove the fish pathogen Flavobacterium columnare from water?
2021
AbstractGlobal decline of freshwater mussels (Unionoida) is threatening biodiversity and the essential ecosystem services that mussels provide. As filter-feeding organisms, freshwater mussels remove phytoplankton and suspended particles from the water. By filtering bacteria, freshwater mussels also decrease pathogen loads in the water. The objective of this study was to evaluate whether the common freshwater bivalve Anodonta anatina (duck mussel) could remove the bacterial fish pathogen Flavobacterium columnare from the water. Mussels reduced bacteria in both of the two experiments performed, so that the bacterial concentration at the end of the 96-h monitoring in mussel treatments was only…
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…
Connection between temperature, larval production, virulence and geographical distribution of Rhipidocotyle parasites infecting the duck mussel, Anod…
2015
In this thesis, two bucephalid trematode parasites Rhipidocotyle campanula and R. fennica, which use the same first (Anodonta anatina) and second intermediate (Rutilus rutilus) host were studied. The aim was to investigate the effect of temperature on one of the key processes in the transmission of these parasites: 1) the emergence of cercarial larvae from A. anatina over short (1 h) and 2) long (throughout the annual cercarial shedding period, from May to October) time periods as well, as on 3) mussel survival and 4) the seasonal timing of cercarial release. In addition, the aim was to study how the cercarial shedding traits are linked to the 5) geographical occurrence and abundance of the…
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…
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…
The effect of temperature on cercariae production of two Rhipidocotyle trematodes parasitizing freshwater mussel, Anodonta anatina.
2013
Two bucephalid trematodes, Rhipidocotyle campanula and R. fennica are known to infect the duck mussel, Anodonta anatina. The infection will lead to decrease growth, reproduction and survival of A. anatina. Given the important role of temperature on cercariae production, a vital component of the parasite’s transmission and life cycle success, the effect of temperature on cercariae production of two Rhipidocotyle sp. in their molluscan host, Anodonta anatina, was investigated. Mussels were collected from the Rivers, Haajaistenjoki and Kuusaankoski, marked and allocated to three temperature treatments—high, intermediate and low. Between May 31-October 28, 2011, clams were individually monitore…