Search results for " mussel"
showing 10 items of 58 documents
Parasite transmission in aquatic ecosystems under temperature change: effects of host activity and elimination of parasite larvae by filter‐feeders
2020
A moderate raise in temperature was suggested to enhance the impact of parasites on aquatic ecosystems. Under higher temperatures, poikilothermic animals (e.g. fish) increase their activity, which can result in a more frequent encounter with parasites. However, temperature increase may also trigger processes counteracting an increased risk of parasitic infections. Thus, the removal of free‐living stages of parasites by filter‐feeding organisms can increase with temperature and potentially mitigate disease risk in ecosystems under climate change. We aimed to study whether an increased infection transmission under higher temperatures can be compensated by the increased removal of parasitic la…
Effects of organic mercury on Mytilus galloprovincialis hemocyte function and morphology
2020
Abstract Filter-feeding organisms accumulate xenobiotics and other substances in their tissues. They can be useful as sentinel organisms in biomonitoring of the marine compartment. Bivalve cellular immunity is ensured by phagocytosis and cytotoxic reactions carried out by hemocytes in a network with humoral responses. These can be affected by chemical contaminants in water that can be immunosuppressors also at a low concentration increasing the sensibility to pathogens. This work is an attempt to individuate cellular markers for pollution detection, investigating the effect of methylmercury (CH3HgCl) at different concentrations on the activity and hemocyte morphology of the Mediterranean m…
The shell of the invasive bivalve species Dreissena polymorpha: biochemical, elemental and textural Investigations.
2016
28 pages; International audience; The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an extern…
The ‘killer shrimp’Dikerogammarus villosus(Crustacea, Amphipoda) invading Alpine lakes: overland transport by recreational boats and scuba-diving gea…
2013
The alien freshwater amphipod of Ponto-Caspian origin, Dikerogammarus villosus, also known as the killer shrimp, is recognized as being one of the worst invasive alien species in Europe, representing a major conservation problem. Recently, the species has been reported to invade lakes in the Alps in putative association with overland transport linked with recreational activities. This study provided a method to assess risk associated with this overland transport and an opportunity to set up a rationale for effective preventive conservation management. A field survey of 60 lakes encompassing all the Alpine area has revealed the presence of killer shrimp in 12 lakes. Subsequent multivariate d…
In-Gel Assay to Evaluate Antioxidant Enzyme Response to Silver Nitrate and Silver Nanoparticles in Marine Bivalve Tissues
2022
Silver is back in vogue today as this metal is used in the form of nanomaterials in numerous commercial products. We have developed in-gel electrophoretic techniques to measure the activity of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX), and used the same techniques in combination with HSP70 Western blot analysis to evaluate the effects of nanomolar amounts of silver nitrate and 5 nm alkane-coated silver nanoparticles in tissues of the marine bivalve Mytilus galloprovincialis (Lam.) exposed for 28 days in mesocosms. Our results showed a negligible effect for nanosilver exposure and dose-dependent effects for the nitrate form.
Parasites in sympatric populations of native and invasive freshwater bivalves
2021
An increasing threat to local, native freshwater mussels (Unionida)—an ecologically important but globally alarmingly declining group— is the invasion by exotic bivalves. The Enemy Release Hypothesis predicts that introduced species should benefit from enemy-mediated competition because they are less likely to be harmed by natural enemies, such as parasites, than their native competitors. We investigated within-site differences in parasitism between sympatric native (tot. five spp.) and invasive (tot. three spp.) bivalves in eight northern European waterbodies, which harboured totally 15 parasite taxa. In paired comparisons using within-site averages, the mean number of parasite species in …
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…
Induction of apoptosis in the blue mussel Mytilus galloprovincialis by tri-n-butyltin chloride
2001
Induction of apoptosis by tri-n-butyltin (TBT) in gill tissue of the mussel Mytilus galloprovincialis was investigated. The terminal dUTP nick-end labeling technique (TUNEL) was used to detect cells displaying DNA fragmentation within gill structures. Genomic DNA fragmentation was detected as characteristically ladder-like pattern of DNA fragments induced by single injection of different doses of TBT (1-5 microg/g) below the mantle, directly into the pallial fluid, after 24 h of incubation. DNA degradation of higher order DNA structure, as well as reduced G(0)/G(1) cell cycle region (the sub-G(1) region) was detectable after 1.5 h of TBT incubation. Presence of apoptotic cells in mussels' g…
Effect of pH, iron and aluminum on survival of early life history stages of the endangered freshwater pearl mussel, Margaritifera margaritifera
2011
Glochidium larvae and juveniles of the endangered freshwater pearl mussel Margaritifera margaritifera may be sensitive to low pH and metal exposure, but to our knowledge, no tolerance tests have been performed. Therefore, we exposed glochidia, fish-attached glochidia, and juveniles of the pearl mussel to low pH and increased iron (Fe) and aluminum (Al) by using realistic pH (6.0–4.5), Fe (0.5–2.0 mg L−1), and Al (0.25–1.0 mg L−1) levels periodically observed in this study site. Survival of glochidia decreased with decreasing pH, increasing Fe, and increasing Al, as well as with increasing Fe + Al concentration in a 72 h exposure. All glochidia died within 24 h in pH 4.5 and Fe 2.0 mg L−1. W…
Identification, cloning and environmental factors modulation of a αβ defensin from the lessepsian invasive mussel Brachidontes pharaonis (Bivalvia: M…
2015
International audience; Immunological effectors of invasive species playing a role in addressing new colonization are still poorly studied. In the present study the cDNA sequence of the defensin from a Lessepsian invasive species, the Red Sea mussel Brachidontes pharaonis, was cloned using RACE method. Defensins are a class of widely known antimicrobial peptides (AMPs), oligopeptides with a broad spectrum of targeted organisms ranging from viruses to parasites. Analysis of BpDef sequence (262 bp) revealed the presence of an ORF coding for 81 amino acids. The full-length amino acid sequence showed the highest similarity to antimicrobial peptides MGD1 and MGD2 sequence from Mytilus galloprovi…