| fine structure of perkinsus atlanticus n. sp. (apicomplexa, perkinsea) parasite of the clam ruditapes decussatus from portugal. | a new apicomplexan species, perkinsus atlanticus, is described from gill filaments of the clam ruditapes decussatus (bivalvia) from portugal, where it causes great mortality. the zoospores differ from those of other species of perkinsus in size and shape, dimensions, insertion of the 2 flagella, and in the identity of the host. on the other hand, the life cycle stages showed some ultrastructural differences compared with perkinsus marinus, the only species previously studied in detail. when the ... | 1989 | 2760774 |
| evidence for interspecies transmission of oyster herpesvirus in marine bivalves. | since 1991, numerous herpesvirus infections associated with high mortality have been reported around the world in various marine bivalve species. in order to determine whether these infections are due to ostreid herpesvirus-1 (oshv1), a previously characterized pathogen of the japanese oyster (crassostrea gigas), pcr analysis was carried out on 30 samples of larvae collected from four bivalve species (c. gigas, ostrea edulis, ruditapes decussatus and ruditapes philippinarum), most exhibiting mor ... | 2001 | 11257192 |
| preliminary study of the clam ruditapes decussatus exposed in situ to metal contamination and originating from the gulf of gabès, tunisia. | | 2003 | 14705657 |
| isolation of vibrio alginolyticus and vibrio splendidus from aquacultured carpet shell clam (ruditapes decussatus) larvae associated with mass mortalities. | two episodes of mortality of cultured carpet shell clams (ruditapes decussatus) associated with bacterial infections were recorded during 2001 and 2002 in a commercial hatchery located in spain. vibrio alginolyticus was isolated as the primary organism from moribund clam larvae that were obtained during the two separate events. vibrio splendidus biovar ii, in addition to v. alginolyticus, was isolated as a result of a mixed vibrio infection from moribund clam larvae obtained from the second mort ... | 2005 | 15640176 |
| immune parameters in carpet shell clams naturally infected with perkinsus atlanticus. | defence parameters of non-infected clams (ruditapes decussatus) and clams heavily infected with perkinsus atlanticus were assessed. cellular (haemocyte density and phagocytic activity) and humoral (lysozyme and anti-bacterial activities, protein concentration and agglutination titre) parameters were measured in clams collected in an area enzootic for p. atlanticus. the infection intensity of each clam was assessed, and the immune parameters measured in the most infected clams were compared with ... | 2000 | 11081437 |
| [estimation of fertility and quality of oocytes emitted by the clam ruditapes decussatus (linnaeus 1758) during experimental inductions]. | experimental inductions were carried out on some genitors of clams ruditapes decussatus to obtain sexual emissions and estimate the fecondity of this species. the genitors were collected from two sites of tunisian littoral. higher percent of oocytes was found in summer with a maximum of 52 x 10(4) oocytes in gargour (golf of gabès) against 45 x 10(4) in menzel-jemil (lagoon of bizerte). the observation under the electronic microscope of free oocytes allowed us to subdivised them in three groupes ... | 1996 | 9640501 |
| metal, mutagenicity, and biochemical studies on bivalve molluscs from spanish coasts. | three species of marine bivalve molluscs (chamelea gallina, ruditapes decussatus, and crassostrea gigas) have been studied in order to evaluate the levels of pollution on the south atlantic spanish littoral. several transition metals (cu, as, cd, sn, hg, pb) were determined as a general index of total contamination. animals from putative contaminated areas exhibited higher metal contents than those from cleaner waters. c. gigas showed 5-20-fold higher total metal content than the other two speci ... | 1992 | 1541252 |
| pathogenicity of vibrio tapetis, the etiological agent of brown ring disease in clams. | brown ring disease (brd) causes high mortalities in the introduced manila clam ruditapes philippinarum cultured in western europe. the etiological agent of brd, vibrio tapetis, adheres to and disrupts the production of the periostracal lamina, causing the anomalous deposition of periostracum around the inner shell. because the primary sign of brd is found outside the soft tissues, the processes leading to death are not as obvious as those for internal pathogens. this study was designed to evalua ... | 2002 | 12033709 |
| ultrastructural description of the spore maturation stages of the clam parasite minchinia tapetis (vilela, 1951) (haplosporida: haplosporidiidae). | the fine structure of maturing spores of a haplosporidian parasite found in the gill, mantle and foot tissues of ruditapes decussatus l. (mollusca, bivalvia), a species of commercial importance in portugal, is described. when observed free in suspension, immature spores exhibit one or two epispore cytoplasmic extensions (ece) which constitute a projection of a portion of the exosporoplasm, sometimes without ultrastructural organisation, surrounded by the plasmalemma. free spores observed by ligh ... | 2001 | 11466479 |
| virus-like particles associated with mortalities of the carpet-shell clam ruditapes decussatus. | during the late summer and early fall of 1997 and 1998 heavy mortalities were detected in the carpet-shell clam ruditapes decussatus cultured in galicia (nw spain). the prevalences and intensities of the parasites found in the histopathological studies were not high enough to explain the high mortality rates. unenveloped virus-like particles were detected by transmission electron microscopy in the cytoplasm of the connective tissue cells. they had an icosahedrical-spherical shape with a diameter ... | 2000 | 10715820 |
| variation of metal and metallothionein concentrations in a natural population of ruditapes decussatus. | the spatial and seasonal variation of total and subcellular distribution of cd, cu, and zn was followed in different tissues (gills, digestive gland, and remaining tissues) of the clam ruditapes decussatus collected along a metal contamination gradient in the ria formosa lagoon (southern portugal) and compared with metallothionein (mt) concentrations.total metal concentrations decreased according to the sequence digestive gland > gills > remaining tissues for cd, digestive gland approximately gi ... | 2003 | 12434219 |
| response of antioxidant systems to copper in the gills of the clam ruditapes decussatus. | copper (cu) is an essential element for biological systems, however, when present in excess, is toxic. metallothioneins can play an important role in cu homeostasis and detoxification. moreover, cu can catalyse the production of toxic hydroxyl radicals that cause lipid peroxidation but defence systems in the cells can limit the oxidative damage. the present study was performed to investigate the effect of three cu concentrations (0.5, 2.5 and 25 microg l(-1)) on the response of antioxidant enzym ... | 2002 | 12408595 |
| molecular karyotype analysis of perkinsus atlanticus (phylum perkinsozoa) by pulsed field gel electrophoresis. | perkinsus atlanticus is a pathogenic protist that infects the clam ruditapes decussatus. although it was recently proposed that the genus perkinsus belongs to a new phylum, perkinsozoa, in the infra-kingdom alveolata, there remain different opinions about whether this genus should form a phylum on its own and consequently divergent views about its taxonomic characterization. in this work, we have identified nine chromosomes by pulsed field gel electrophoresis (pfge) combined with densitometry an ... | 2007 | 17822886 |
| influence of beta-glucans on the immune responses of carpet shell clam (ruditapes decussatus) and mediterranean mussel (mytilus galloprovincialis). | the effects of beta-glucans on several immune functions of carpet shell clam (ruditapes decussatus) and mediterranean mussel (mytilus galloprovincialis) hemocytes were determined. nitric oxide (no) production increased significantly in beta-glucan treated mussels and clams. in mussels, beta-glucans increased by themselves the release of free oxygen radicals and also were able to enhance the phorbol 12-myristate 13-acetate (pma) mediated effect on this hemocyte activity. however, high doses of be ... | 2008 | 18329901 |
| the use of acetylcholinesterase activity in ruditapes decussatus and mytilus galloprovincialis in the biomonitoring of bizerta lagoon. | the variations of acetylcholinesterase activity, considered to be a biochemical biomarker of organophosphorus and carbamate compounds, was followed in mediterranean clams (ruditapes decussatus) and mussels (mytilus galloprovincialis) as a function of season and sampling sites in the lagoon of bizerta (tunisia). results show that acetylcholinesterase activity in clams collected from station a was the lowest and was so throughout the year. this low activity may be due to the input of non-treated w ... | 2001 | 11574292 |
| characterization and infectivity of four bacterial strains isolated from brown ring disease-affected clams | four bacterial strains isolated from carpet-shell clams (ruditapes decussatus) and manila clams (r. philippinarum) exhibiting brown ring disease (brd) symptoms in galicia (northwest of spain) were characterized using biochemical and serological techniques. moreover their pathogenicity for clams and resistance against clam hemolymph were determined. all of the vibrio isolates exhibited biochemical characteristics typical of the genus. strains gr1703rp and gr6301rp, isolated from r. philippinarum ... | 1998 | 9446735 |
| does cadmium pollution affect reproduction in the clam ruditapes decussatus? a one-year case study. | the effect of cadmium (cd) on the reproduction of ruditapes decussatus was monitored over a period of 12 months, from june 2001 to june 2002. two sites "bordj d'ungha" and "el hofra" differing by their degree of cadmium contamination were chosen in the gulf of gabès area (tunisia). annual mean concentrations of cd in the whole soft tissues of clams from the site el hofra were more than 4 times higher than those from the site bordj d'ungha (reference site). the gametogenic cycle of the clam r. de ... | 2006 | 16580885 |
| monitoring pollution in tunisian coasts: application of a classification scale based on biochemical markers. | over the past decade, molecular, biochemical and cellular markers have been extensively used in pollution monitoring of aquatic environments. biochemical markers have been selected among early molecular events occurring in the toxicological mechanisms of main contaminants. this paper assesses the marine environment quality along the tunisian coasts using a statistical approach. clams (ruditapes decussatus) were collected during the four seasons of 2003 on seven different sites from the tunisian ... | 2005 | 16076726 |
| variation of metallothioneins in gills of the clam ruditapes decussatus from the gulf of gabès (tunisia). | cadmium (cd) and metallothionein (mt) concentrations were determined in the subcellular fractions of the gills of the clam ruditapes decussatus. clams were collected monthly during the period of sexual development (from june to august 2001) from two different sites situated in the gulf of gabès (tunisia). these sites differ by their degree of metal contamination. differences in condition index (ci) were observed in june and august between clams from both sites. in clams from both sites, cadmium ... | 2004 | 15683825 |
| molecular detection of a haplosporidian parasite in carpet shell clam ruditapes decussatus from spain. | a protozoan parasite identified by histology as a haplosporidian was detected in carpet shell clam ruditapes decussatus from spain during routine samplings. analysis based on the sequence of the small subunit ribosomal rna gene revealed that this organism was related to the haplosporidian group, mainly to urosporidium. a specific probe was used for in situ hybridization studies to show the specificity of the amplified sequence. | 2004 | 15584415 |
| antioxidant enzyme activities, metallothioneins and lipid peroxidation as biomarkers in ruditapes decussatus? | antioxidant enzymes (superoxide dismutase (sod), catalase (cat), glutathione peroxidases (gpx)) were studied in the gills and digestive gland of clams ruditapes decussatus from different sites of the ria formosa (south coast of portugal) in order to validate these enzymes as biomarkers of metal exposure. two other potential biomarkers, lipid peroxidation expressed as malondialdehyde (mda), and metallothionein (mt) levels were also measured. this study demonstrates that mitochondrial and cytosoli ... | 2003 | 14649424 |
| nitric oxide production by carpet shell clam (ruditapes decussatus) hemocytes. | we have demonstrated that carpet shell clam (ruditapes decussatus) hemocytes produce nitric oxide (no) in response to zymosan or bacterial lipopolysaccharide (lps). this no production was partially inhibited by the no synthase inhibitor, n-omega-nitro-l-arginine (l-name). the capability of clam hemocytes to produce no in response to the bacterial pathogen vibrio tapetis was also studied. incubation with bacteria induced a significant no production by clam hemocytes, even though exogenous no only ... | 2003 | 12590971 |
| comparison of ribotyping, randomly amplified polymorphic dna, and pulsed-field gel electrophoresis for molecular typing of vibrio tapetis. | brown ring disease, caused by vibrio tapetis, is an important pathological problem in different species of cultured clams. in order to evaluate the genetic diversity of the pathogen, twenty-seven isolates of v tapetis with different origin were screened by ribotyping (rt), pulsed-field gel electrophoresis (pfge) and randomly amplified polymorphic dna pcr (rapd). restriction with pvuii, sali, and smai gave 2 rt patterns, differentiating in all cases the strain 0202rd isolated from carpet-shell cl ... | 2002 | 12583715 |
| purification and partial characterization of seven glutathione s-transferase isoforms from the clam ruditapes decussatus. | this paper deals with the purification and the partial characterization of glutathione s-transferase (gst) isoforms from the clam ruditapes decussatus. for the first step of purification, two affinity columns, reduced glutathione (gsh)-agarose and s-hexyl gsh-agarose, were mounted in series. four affinity fractions were thus recovered. further purification was performed using anion exchange chromatography. seven fractions, which present a gst activity with 1-chloro-2,4-dinitrobenzene (cdnb) as s ... | 2002 | 12199715 |
| haemocyte parameters associated with resistance to brown ring disease in ruditapes spp. clams. | brown ring disease (brd) is a shell disease caused by vibrio tapetis. this pathogen disturbs the periostracal lamina causing the appearance of a brown conchiolin deposit on the inner face of the shell, within the extrapallial space. although differences in resistance to brd have been documented, their relationship to possible defense functions has never been investigated. in this study, flow cytometry was used to analyze cellular parameters in asymptomatic and experimentally infected ruditapes p ... | 2001 | 11356217 |
| variation of metallothionein and metal concentrations in the digestive gland of the clam ruditapes decussatus: sex and seasonal effects. | metallothionein (mt) and metal (cd, cu, and zn) concentrations were determined in the digestive gland of male and female ruditapes decussatus. clams were collected monthly during the period of sexual development, from june to september, at two different sites of a coastal lagoon, the ria formosa lagoon, on the south coast of portugal. the mt concentrations were determined in the heat-treated cytosolic fraction of the digestive gland of both male and female clams. total metal (cd, cu, and zn) con ... | 2001 | 11349855 |
| characterization of the ribosomal rna locus of perkinsus atlanticus and development of a polymerase chain reaction-based diagnostic assay. | the rrna locus of perkinsus atlanticus from the clam ruditapes decussatus cultivated on the atlantic coast of spain was cloned and sequenced. sequences of the internal transcribed spacer (its) from the rrna locus were compared to sequences reported earlier for a p. atlanticus isolate from portugal and to those from other perkinsus species. the its i sequence of the spanish p. atlanticus isolate was identical to the portuguese p. atlanticus sequence and had 76.6% identity to the its1 of perkinsus ... | 2000 | 11128520 |
| the potential use of metallothionein in the clam ruditapes decussatus as a biomarker of in situ metal exposure. | this work aimed to validate the relationship between metallothioneins (mts) and metals (cd, cu and zn) in field conditions. specimens of the marine bivalve ruditapes decussatus (linné, 1758) from gargour were transferred in two sites: gargour and sidi mansour, both situated along the south-eastern coast of tunisia. the bivalves were removed from pairs of cages at day 0 (date of transplantation), day 62 and day 132. metals (cd, cu and zn) and mts were determined in the subcellular fractions of th ... | 2000 | 11083029 |
| polycyclic aromatic hydrocarbons in clams ruditapes decussatus (linnaeus, 1758). | the concentration of sixteen individual polycyclic aromatic hydrocarbons (pahs) was measured in the clam ruditapes decussatus whole soft tissues from several places of the ria formosa lagoon (portugal). total pah (tpah) concentrations were higher in the summer (august) and winter (january) than in the other months and the distribution pattern of the individual pahs was generally dominated by the 4 aromatic ring pahs, followed by the 2 + 3 aromatic rings pahs. benzo[a]anthracene and acenaphthene ... | 2007 | 17285162 |
| experimental uptake and retention of pathogenic and nonpathogenic vibrio parahaemolyticus in two species of clams: ruditapes decussatus and ruditapes philippinarum. | to describe uptake and retention of pathogenic and nonpathogenic vibrio parahaemolyticus in ruditapes decussatus and ruditapes philippinarum. | 2011 | 21457416 |
| giardia and cryptosporidium in inflowing water and harvested shellfish in a lagoon in southern italy. | giardia and cryptosporidium spp. are important enteric protozoan pathogens for humans and animals, and have been found to contaminate water as well as edible shellfish all over the world. this is the first study to simultaneously investigate the presence of giardia and cryptosporidium in inflowing water and harvested shellfish in a geographically closed environment (varano lagoon, southern italy). samples of treated wastewater were collected each month - at the outlet from the treatment plant, a ... | 2009 | 18760378 |
| first record of perkinsus olseni, a protozoan parasite infecting the commercial clam ruditapes decussatus in spanish mediterranean waters. | we present the first record in spanish mediterranean waters of the protozoan parasite perkinsus olseni infecting the clam ruditapes decussatus. perkinsus infection was detected all year around albeit at a low level of infection intensity. histological analysis, induction of zoospores and in situ hybridisation assay confirmed the presence of perkinsus sp. the identity of the parasite was determined by species-specific pcr assay in dna samples obtained from infected clams. sequencing of amplified ... | 2009 | 18823999 |
| gene expression analysis of clams ruditapes philippinarum and ruditapes decussatus following bacterial infection yields molecular insights into pathogen resistance and immunity. | the carpet shell clam (ruditapes decussatus) and manila clam (ruditapes philippinarum), which are cultured bivalve species with important commercial value, are affected by diseases that result in large economic losses. because the molecular mechanism of the immune response of bivalves, especially clams, is scarce and fragmentary, we have examined all expressed sequence tags (est) resources available in public databases for these two species in order to increase our knowledge on genes related wit ... | 2011 | 21756933 |
| biomarkers in ruditapes decussatus: a potential bioindicator species. | the clam ruditapes decussatus is distributed worldwide and due to its ecological and economical interest has been proposed as a bioindicator in areas where mussels are not available. the accumulation of several anthropogenic compounds in their tissues suggests that they possess mechanisms that allow them to cope with the toxic effects of these contaminants. besides pollutant uptake, the use of biomarkers is pointed out in this paper since it is a promising approach to monitor the effect of these ... | 2004 | 15764295 |
| differentially expressed genes of the carpet shell clam ruditapes decussatus against perkinsus olseni. | suppression-subtractive hybridization (ssh) was used to identify differentially expressed ruditapes decussatus genes against the protozoan perkinsus olseni infection. a forward and a reverse subtraction were carried out to identify up- and down-regulated genes in both haemocytes and gills of clams naturally infected with p. olseni. new genes, candidates for further investigation into the functional basis of resistance to pathogens, have been detected for the first time in the clam (r. decussatus ... | 2009 | 19028428 |
| characterization of a c3 and a factor b-like in the carpet-shell clam, ruditapes decussatus. | the alternative pathway is considered to be the most ancient route for activation of the complement system. herein, we report the characterization of c3 and factor b-like proteins in the clam ruditapes decussatus, termed rd-c3 and rd-bf-like. the rd-c3 is a three-chain protein, similar to other protoc3 proteins, and the rd-bf-like is composed of two complement control protein modules (ccp domains) that differ from other described bf proteins. the inoculation of clams with live bacteria did not r ... | 2009 | 19073265 |
| heavy-metal and microbial depuration of the clam ruditapes decussatus and its effect on bivalve behavior and physiology. | the bivalve ruditapes decussatus was evaluated as a possible biomonitor of heavy-metal contamination. concentrations of copper (cu), cobalt (co), iron (fe), nickel (ni), and manganese (mn) were measured in r. decussatus. water and sediment samples were collected at two stations of timsah lake in ismailia, egypt, from october to november 2002, using atomic absorption spectrophotometry (aas). results from the heavy-metal and microbial analyses indicated that site ii was less contaminated than site ... | 2004 | 15038001 |
| in situ potential use of metallothionein as a biomarker of cadmium contamination in ruditapes decussatus. | cadmium (cd) and metallothionein (mt) concentrations were analysed in the gills and digestive gland of clams ruditapes decussatus collected from two sites of the gulf of gabès (tunisia) which differ by their degree of pollution. the effect of biotic (maturity stages, protein, sex and body mass) and abiotic factors (temperature, salinity, site and season) on cd and mt concentrations showed that in the reference site "bordj d'ungha" physiological changes caused by gamete development and maturity c ... | 2009 | 19272647 |
| polycyclic aromatic hydrocarbons concentrations and biomarker responses in the clam ruditapes decussatus transplanted in the ria formosa lagoon. | clams ruditapes decussatus were transplanted in the ria formosa lagoon and the variation of pah concentrations in the whole soft tissues measured, along with a suite of biomarkers, including the following: (a) phase i and phase ii metabolism of xenobiotics enzymes: benzo[a]pyrene hydroxylase (bph) and glutathione s-transferase (gst); (b) antioxidant enzymes: superoxide dismutase, catalase and glutathione peroxidases and (c) lipid peroxidation (lpo) levels. individual pahs were differently accumu ... | 2009 | 19539372 |
| in situ endocrine disrupting effects of cadmium on the reproduction of ruditapes decussatus. | the gulf of gabès is well known for its multiple contaminations which are closely associated with the past and present industrial and anthropogenic activity. in order to evaluate in situ the cadmium bioaccumulation in the clam ruditapes decussatus sampled in this area, we measured cadmium concentrations in the whole soft tissues and in the digestive gland during one year. energy reserves (proteins, glycogen, lipids) were monitored during gametogenesis in the remainder (mantle, adductor muscle, f ... | 2007 | 17611166 |
| effect of the herbicide roundup on perkinsus olseni in vitro proliferation and in vivo survival when infecting a permissive host, the clam ruditapes decussatus. | coastal habitats are increasingly being exposed to herbicide contamination from urban and agricultural catchments. data on its toxicity on aquatic ecosystems, especially those based on sediment, are relatively scarce. this study aimed at investigating whether the susceptibility of an aquatic filter-feeding organism, the carpet-shell clam (ruditapes decussatus) to the parasite perkinsus olseni was influenced by the herbicide roundup and its active ingredient glyphosate. the effect of roundup and ... | 2008 | 18431524 |
| variation of steroid concentrations during the reproductive cycle of the clam ruditapes decussatus: a one year study in the gulf of gabès area. | progesterone, testosterone and estradiol-17beta were measured by radio-immunoassay (ria) in the gonads of the clam ruditapes decussatus. the reproductive cycle was also investigated. our study covered a period of one year, from september 2003 to august 2004. the chosen site "kerkennah", located out of industrial effluents, belongs to the gulf of gabès area (tunisia). steroids varied from 178 to 2459 pg g(-1) wet mass for progesterone, from 40 to 326 pg g(-1) wet mass for testosterone and from 10 ... | 2007 | 17336113 |
| confirmation by lc-ms/ms of azaspiracids in shellfish from the portuguese north-western coast. | the search for azaspiracids (azas) in shellfish on the portuguese coast started in 2002, but the presence of these toxins could not be demonstrated until the summer of 2006. analysis by liquid-chromatography-tandem mass spectrometry (lc-ms/ms) allowed the confirmation of aza2 as a dominant compound, followed by aza1, in blue mussel (mytilus galloprovincialis), common cockle (cerastoderma edule), clams (venerupis senegalensis, ruditapes decussatus), razor clam (solen marginatus) and oyster (crass ... | 2008 | 18471847 |
| oxidative stress in the clam ruditapes decussatus (linnaeus, 1758) in relation to polycyclic aromatic hydrocarbon body burden. | seasonal variation of antioxidant enzymes activities (superoxide dismutase, catalase, and glutathione peroxidases) and lipid peroxidation (lpo) were studied in the clam ruditapes decussatus in relation to body burdens of polycyclic aromatic hydrocarbons (pahs). clams were sampled in eight sites from the ria formosa lagoon. pah concentrations were seasonally rather than spatially dependent, being higher in summer (august). antioxidant enzymes activities and lpo levels in the clam digestive gland ... | 2007 | 17366572 |
| changes in bioturbation of iron biogeochemistry and in molecular response of the clam ruditapes decussates upon perkinsus olseni infection. | a series of artificial microcosms was used to test the effect of clam density on benthic iron biogeochemistry and, subsequently, if the response of clam ruditapes decussatus to infection with perkinsus olseni, a common opportunistic parasite known to be iron dependent, was correlated with the dynamics of iron sediment pore waters within the chambers. three series of benthic microcosms were used in the experiment, comparing similar densities of clams (none, one, two, three, or four individuals/ch ... | 2010 | 20232199 |
| differential induction of glutathione s-transferases in the clam ruditapes decussatus exposed to organic compounds. | studies of glutathione s-transferase (gst) induction were performed in the mediterranean clam ruditapes decussatus after controlled exposure to organics in holding tanks. clams were treated with phenobarbital (pb), benzo[a]pyrene (bap), and 2,2-bis-(p-chlorophenyl)-1,1-dichlorethylene (p,p'-dde). three different substrates, i.e., 1-chloro-2,4-dinitrobenzene (cdnb), ethacrynic acid (etha), and paranitrobenzene chloride (pnbc), were used to determine gst activities in order to distinguish the isoe ... | 2001 | 11349852 |
| oxidative dna damage levels and catalase activity in the clam ruditapes decussatus as pollution biomarkers of tunisian marine environment. | levels of the oxidative dna damage 7, 8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodg) and catalase (cat) activity were measured in the digestive gland and gills of clams ruditapes decussatus, related to the presence of pollutants along tunisian marine environment. increased levels of cat were observed in tissues of clams from all the sites studied, compared to control values, and elevated 8-oxodg levels were observed at specific sites. results obtained in this work indicate that the measurement of 8 ... | 2007 | 16897518 |
| is there a plastid in perkinsus atlanticus (phylum perkinsozoa)? | perkinsus atlanticus is a pathogenic protist that infects the clam ruditapes decussatus. the recent proposal for the inclusion of the genus perkinsus in a new phylum, perkinsozoa, in the infra-kingdom alveolata, gave rise to controversies whether this genus should form a phylum on its own. molecular analysis of some conserved nuclear genes shows a closer proximity of the genus perkinsus to the dinoflagellates than to the apicomplexans. studies on extranuclear genomes, however, could also be very ... | 2007 | 17498932 |
| molecular detection of the three major pathogenic vibrio species from seafood products and sediments in tunisia using real-time pcr. | vibrio spp. have emerged as a serious threat to human health worldwide. v. parahaemolyticus , v. cholerae , and v. vulnificus pose a considerable public health risk in tunisia because they cause sporadic and epidemic foodborne infections associated with the consumption of raw or undercooked contaminated seafood. more recently, toxr-positive v. alginolyticus was also reported to be a potential source of contaminated seafood. a total of 247 samples, including 113 fishes ( labrus viridis , penaeus ... | 2016 | 28221954 |
| genotypic diversity, antimicrobial resistance and screening of vibrio cholerae molecular virulence markers in vibrio alginolyticus strains recovered from a tunisian ruditapes decussatus hatchery. | in this study, a total of 54 vibrio alginolyticus strains were analyzed. the isolates were recovered from different compartments of the ruditapes decussatus hatchery in the national institute of marine sciences and technologies, monastir, tunisia. all isolates were biochemically identified (api 20e and api zym strips), characterized by amplification of the hsp-40 gene polymerase chain reaction (pcr) and analyzed by enterobacterial repetitive intergenic consensus (eric)-based genotyping to evalua ... | 2013 | 24459831 |
| faecal coliforms in bivalve harvesting areas of the alvor lagoon (southern portugal): influence of seasonal variability and urban development. | faecal coliform (fc) levels in surface water and clams (ruditapes decussatus) and variations in environmental parameters were studied in two bivalve harvesting areas in the alvor lagoon (southern portugal). land use and cover characteristics in adjacent subwatersheds were also analysed to assess their contributions as sources of faecal contamination. high fc levels in clams from the harvesting area in the most urbanized subwatershed (impervious surface coverage approximately 10.5%) were positive ... | 2007 | 17286181 |
| microsatellite marker development in the protozoan parasite perkinsus olseni. | the analysis of an enriched partial genomic library and of public expressed sequence tag (est) resources allowed the characterization of the first microsatellite loci in the protozoan parasite perkinsus olseni. clonal cultures from laboratory isolates derived from infected clams ruditapes decussatus (from spain), r. philippinarum (from spain and japan), and austrovenus stutchburyi (from new zealand) were used for the characterization of 12 microsatellites. low variation was detected at most loci ... | 2011 | 21648245 |
| Morphological characterization and functional immune response of the carpet shell clam (Ruditapes decussatus) haemocytes after bacterial stimulation. | The morphology and functionality of Ruditapes decussatus haemocytes have been characterized by light microscopy and flow cytometry, leading to the identification of three different cellular subpopulations. Granulocytes were the largest cells, the hyalinocytes were smaller and contained fewer granules and the intermediate cells showed a size similar to hyalinocytes and a higher number of granules. The phagocytosis of different particles and the associated production of oxygen radicals were measur ... | 2012 | 22051180 |
| A multibiomarker approach in the clam Ruditapes decussatus to assess the impact of pollution in the Ria Formosa lagoon, South Coast of Portugal. | The Ria Formosa lagoon is an ecosystem whose water quality reflects the anthropogenic influence upon the surrounding areas. In this lagoon, the clam Ruditapes decussatus has a great economical importance and has been widely used as a biomonitor. A multibiomarker approach (d-aminolevulinic acid dehydratase, metallothionein, lipid peroxidation, acetylcholinesterase, alkali-labile phosphates, DNA damage) was applied to assess the environmental quality of this ecosystem and the accumulation of conta ... | 2011 | 22001190 |
| divergent evolutionary behavior of h3 histone gene and rdna clusters in venerid clams. | histone h3 gene clusters have been described as highly conserved chromosomal markers in invertebrates. surprisingly, in bivalves remarkable interspecific differences were found among the eight mussels and between the two clams in which histone h3 gene clusters have already been located. although the family veneridae comprises 10 % of the species of marine bivalves, their chromosomes are poorly studied. the clams belonging to this family present 2n = 38 chromosomes and similar karyotypes showing ... | 2015 | 26106449 |
| molecular cytogenetics in digenean parasites: linked and unlinked major and 5s rdnas, b chromosomes and karyotype diversification. | digenetic trematodes are the largest group of internal metazoan parasites, but their chromosomes are poorly studied. although chromosome numbers and/or karyotypes are known for about 300 of the 18,000 described species, molecular cytogenetic knowledge is mostly limited to the mapping of telomeric sequences and/or of major rdna clusters in 9 species. in this work we mapped major and 5s rdna clusters and telomeric sequences in chromosomes of bucephalus minimus, b. australis, prosorhynchoides carva ... | 2015 | 26680763 |
| first report of tunisian coastal water contamination by protozoan parasites using mollusk bivalves as biological indicators. | in order to establish seawater contamination by emerging protozoan parasites, we used qpcr to molecularly characterize and evaluate the parasitic burden of giardia duodenalis, cryptosporidium spp., toxoplasma gondii, and cyclospora cayetanensis in 1255 wild bivalve mollusks collected along the tunisian coasts. t. gondii, g. duodenalis and c. cayetanensis were detected in 6.9% (99% ci=1.6-12.2%) pools of ruditapes decussatus. none of the samples were found positive to cryptosporidium spp.; 6.6% p ... | 2017 | 28168979 |
| nutrients and clam contamination by escherichia coli in a meso-tidal coastal lagoon: seasonal variation in counter cycle to external sources. | the clam ruditapes decussatus was transplanted from a natural recruitment area of ria formosa to three sites, surveyed for nutrients in water and sediments. specimens were sampled monthly for determination of escherichia coli, condition index and gonadal index. higher nutrient values in low tide reflect drainage, anthropogenic sources or sediment regeneration, emphasising the importance of water mixing in the entire lagoon driven by the tide. despite the increase of effluent discharges in summer ... | 2015 | 26003385 |
| vibrio breoganii sp. nov., a non-motile, alginolytic, marine bacterium within the vibrio halioticoli clade. | seven non-motile, facultatively anaerobic, alginolytic marine bacteria were isolated from the cultured clams ruditapes philippinarum and ruditapes decussatus. phylogenetic analysis based on 16s rrna gene sequences showed that these marine bacteria were closely related to the recently described species vibrio comitans, vibrio rarus and vibrio inusitatus (>or=99.0 % sequence similarity). phylogenetic analysis based on the housekeeping genes rpoa, reca and atpa grouped the isolates together and all ... | 2009 | 19542146 |
| complement c3 gene: expression characterization and innate immune response in razor clam sinonovacula constricta. | complement component 3 (c3) is central to the complement system, playing an important role in immune defense, immune regulation and immune pathology. several c3 genes have been characterized in invertebrates but very few in shellfish. the c3 gene was identified from the razor clam sinonovacula constricta, referred to here as sc-c3. it was found to be highly homologous with the c3 gene of ruditapes decussatus. all eight model motifs of the c3 gene were found to be included in the thiolester bond ... | 2016 | 27231190 |
| perkinsus olseni and p. chesapeaki detected in a survey of perkinsosis of various clam species in galicia (nw spain) using pcr-dgge as a screening tool. | a survey on perkinsosis was performed involving 15 locations scattered along the galician coast (nw spain) and four clam species with high market value (ruditapes decussatus, ruditapes philippinarum, venerupis corrugata and polititapes rhomboides). the prevalence of perkinsus parasites was estimated by pcr using genus-specific primers. the highest percentage of pcr-positive cases for perkinsosis corresponded to clams r. decussatus and v. corrugata, while lower values were detected in r. philippi ... | 2016 | 26628210 |
| metabolites of saxitoxin analogues in bivalves contaminated by gymnodinium catenatum. | bivalve metabolites of saxitoxin analogues, not present in microalgae, were recently described as an important toxin fraction in mussels contaminated by alexandrium tamarense. these possess very low fluorescence, and require mass spectrometry detection. hilic-ms was implemented to look for these metabolites in bivalves contaminated during gymnodinium catenatum blooms at the portuguese coast. the presence of m1 was tentatively identified in several bivalves, ranging from estuarine (mytilus gallop ... | 2010 | 19622366 |
| correlation between perkinsosis and growth in clams ruditapes spp. | perkinsosis is one of the most widespread diseases affecting commercially important species of molluscs globally. we examined the impact of perkinsus spp. on shell growth at the individual scale in 2 clam species: ruditapes decussatus from mundaka estuary (spain) and r. philippinarum from arcachon bay (france). at arcachon, 2 contrasting sites in terms of environment and perkinsus olseni presence were chosen: arguin (disease-free) and ile aux oiseaux (infected site). we monitored the dynamics of ... | 2013 | 24192002 |
| comparison of diagnostic techniques to detect the clam pathogen perkinsus olseni. | perkinsosis in clams in galicia (nw spain) is caused by the protozoan parasite perkinsus olseni lester & davis, 1981. we used 5 clam species of commercial interest cultured in galicia (ruditapes decussatus, r. philippinarum, venerupis pullastra, v. rhomboides, and donax trunculus) to compare various p. olseni diagnostic techniques. results of a nested pcr assay for the diagnosis of p. olseni were compared to those obtained using 2 classical methods of diagnosis proposed by the world organisation ... | 2010 | 20662371 |
| mrna-seq and microarray development for the grooved carpet shell clam, ruditapes decussatus: a functional approach to unravel host-parasite interaction. | the grooved carpet shell clam ruditapes decussatus is the autochthonous european clam and the most appreciated from a gastronomic and economic point of view. the production is in decline due to several factors such as perkinsiosis and habitat invasion and competition by the introduced exotic species, the manila clam ruditapes philippinarum. after we sequenced r. decussatus transcriptome we have designed an oligo microarray capable of contributing to provide some clues on molecular response of th ... | 2013 | 24168212 |
| vibrio atlanticus sp. nov. and vibrio artabrorum sp. nov. isolated from clams ruditapes philippinarum and r. decussatus. | facultative anaerobic marine bacteria isolated from cultured clams ruditapes decussatus and ruditapes philippinarum were previously investigated using aflp and 16s rrna gene sequences analyses. the isolates formed two aflp clusters and belonged to the genus vibrio, more precisely to the splendidus clade. in this study, phylogenetic analyses based on sequences of the housekeeping genes rpoa, rpod, pyrh, atpa and reca supported their inclusion in that clade forming two well differentiated groups w ... | 2010 | 21075909 |
| comparison of antibacterial activity in the hemolymph of marine bivalves from galicia (nw spain). | a screening study of in vitro antibacterial activity was conducted in marine bivalves with economical importance and widespread along the coast of galicia (nw spain). hemocyte lysate supernatant (hls) and plasma of mytilus galloprovincialis, ostrea edulis, crassostrea gigas, ruditapes decussatus, ruditapes philippinarum, and cerastoderma edule were incubated with vibrio splendidus and micrococcus sp. hls and plasma for all the species demonstrated antibacterial activity, and c. edule had the hig ... | 2010 | 21134379 |
| norovirus, hepatitis a virus and enterovirus presence in shellfish from high quality harvesting areas in portugal. | this is the first report on the screening of shellfish from portugal for the presence of human enteropathogenic viruses. approximately 2000 shellfish (curbicula fluminea, ruditapes decussatus, tellina crassa, spisula solida, dosinia exoleta, ensis spp., mytilus spp., ostrea edulis and cerastoderma edule), organized in 49 batches, were collected between march 2008 and february 2009. they were tested for norovirus (nov), hepatitis a virus (hav) and enterovirus (ev) by rt-pcr followed by nucleotide ... | 2011 | 21569936 |
| seasonal variation of oxidative stress biomarkers in clams ruditapes decussatus sampled from tunisian coastal areas. | seven (7) sites from to the tunisian coastal area were monitored through four seasons using several oxidative stress biomarkers including lipid peroxidation. catalase (cat) specific activity was determined in clam ruditapes decussatus digestive gland. lipid peroxidation was assessed in the same tissues using malondialdehyde (mda) concentration, neutral lipid (nl) and lipofuscin accumulation. results show that catalase specific activity varies between sites and fluctuates in time. the highest cat ... | 2009 | 18594996 |
| mortality event involving larvae of the carpet shell clam ruditapes decussatus in a hatchery: isolation of the pathogen vibrio tubiashii subsp. europaeus. | diseases caused by bacteria belonging to the genus vibrio are a common, as yet unresolved, cause of mortality in shellfish hatcheries. in this study, we report the results of routine microbiological monitoring of larval cultures of the carpet shell clam ruditapes decussatus in a hatchery in galicia (nw spain). previous episodes of mortality with signs similar to those of vibriosis affecting other species in the installation indicated the possibility of bacterial infection and led to division of ... | 2017 | 28093770 |
| assessing the spatial variability, level and source of organic chemical contaminants in bivalve fishing grounds on the galician coast (nw spain). | polychlorinated biphenyls, organochlorine pesticides, organotin compounds and triazines were quantified in sediments and bivalves collected in four areas on the galician coast. one or several species were analysed at each site depending on their availability, including mussels (mytilus galloprovincialis), cockles (cerastoderma edule), clams (venerupis pullastra and ruditapes decussatus) and razor shells (ensis siliqua). the general spatial distribution of contaminants was consistent in spite of ... | 2013 | 23849952 |
| effect of acclimatization on hemocyte functional characteristics of the pacific oyster (crassostrea gigas) and carpet shell clam (ruditapes decussatus). | most experimental procedures on molluscs are done after acclimatization of wild animals to lab conditions. similarly, short-term acclimation is often unavoidable in a field survey when biological analysis cannot be done within the day of sample collection. however, acclimatization can affect the general physiological condition and particularly the immune cell responses of molluscs. our aim was to study the changes in the hemocyte characteristics of the pacific oyster crassostrea gigas and the ca ... | 2011 | 21906683 |
| increasing genomic information in bivalves through new est collections in four species: development of new genetic markers for environmental studies and genome evolution. | the generation of est information is an essential step in the genomic characterisation of species. in the context of the european network marine genomics, a common goal was to significantly increase the amount of ests in commercial marine mollusk species and more specifically in the less studied but ecologically and commercially important groups, such as mussel and clam genera. normalized cdna libraries were constructed for four different relevant bivalves species (crassostrea gigas, mytilus edu ... | 2008 | 18054177 |
| genetic responses to metal contamination in two clams: ruditapes decussatus and ruditapes philippinarum. | coastal ecosystems are subjected to a wide variety of disturbances, including those due to xenobiotics of agricultural and industrial origin. these pollutants as heavy metals can modify the genetic diversity of populations by favouring or counter-selecting certain alleles or genotypes by differential mortality. in the present study, two genetic markers (phosphoglucomutase and glucosephosphate isomerase) and a protein marker (metallothionein) were monitored in order to determine the impact of hea ... | 2015 | 12408612 |
| cytotoxicity assessment of antibiofouling compounds and by-products in marine bivalve cell cultures. | short-term primary cell cultures were derived from adult marine bivalve tissues: the heart of oyster crassostrea gigas and the gill of clam ruditapes decussatus. these cultures were used as experimental in vitro models to assess the acute cytotoxicity of an organic molluscicide, mexel-432, used in antibiofouling treatments in industrial cooling water systems. a microplate cell viability assay, based on the enzymatic reduction of tetrazolium dye (mtt) in living bivalve cells, was adapted to test ... | 2000 | 10806375 |
| new evidence for the involvement of paracartia grani (copepoda, calanoida) in the life cycle of marteilia refringens (paramyxea). | the dynamics of the protozoan parasite marteilia refringens was studied in thau lagoon, an important french shellfish site, for 1 year in three potential hosts: the mediterranean mussel mytilus galloprovincialis (mytiliidae), the grooved carpet shell ruditapes decussatus (veneriidae) and the copepod paracartia grani (acartiidae). parasite dna was detected by pcr in r. decussatus. in situ hybridisation showed necrotic cells of m. refringens in the digestive epithelia of some r. decussatus suggest ... | 2013 | 24080113 |
| morphological characterization of the hemocytes of the clam, ruditapes decussatus (mollusca: bivalvia). | hemocytes play an important role in internal defence in molluscs. the morphology of hemolymph cells was studied for the first time in ruditapes decussatus. two main types of hemocytes (hyalinocytes and granulocytes) exist in r. decussatus. three types of granulocytes were identified by light microscopy, in accordance with the presence of basophilic or acidophilic granules or a mixture of both in the cytoplasm. the existence of hyalinocytes and granulocytes was confirmed by electron microscopy. s ... | 1997 | 9028928 |
| evolutionary dynamics of rdna clusters in chromosomes of five clam species belonging to the family veneridae (mollusca, bivalvia). | the chromosomal changes accompanying bivalve evolution are an area about which few reports have been published. to improve our understanding on chromosome evolution in veneridae, ribosomal rna gene clusters were mapped by fluorescent in situ hybridization (fish) to chromosomes of five species of venerid clams (venerupis corrugata, ruditapes philippinarum, ruditapes decussatus, dosinia exoleta, and venus verrucosa). the results were anchored to the most comprehensive molecular phylogenetic tree c ... | 2014 | 24967400 |
| molecular cloning of superoxide dismutase (cu/zn-sod) from aquatic molluscs. | the potential of the first line of the active oxygen-scavenging system, partial cdna encoding cu/zn superoxide dismutase (sod) was isolated in three aquatic mollusc species: ruditapes decussatus (marine clam), dreissena polymorpha (continental water mussel) and bathymodiolus azoricus (hydrothermal vent mussel). these sod cdna fragments were amplified by pcr with degenerate oligonucleotide primers derived from the amino acid sequence conserved in the cu/zn-sod from several other organisms. a part ... | 2013 | 15178089 |
| variable protein profiles in extracellular products of the protistan parasite perkinsus olseni among regions of the spanish coast. | the variability of the protein expression profiling in the extracellular products (ecps) of in vitro cultured perkinsus olseni deriving from 4 regions of the spanish coast was evaluated. the regions involved were the rías of arousa and pontevedra (galicia, nw spain), carreras river (andalusia, sw spain) and delta de l'ebre (catalonia, ne spain). p. olseni in vitro clonal cultures were produced from parasite isolates from four clams from each region. proteins released by the in vitro cultured par ... | 2015 | 26555510 |
| perkinsosis in the clams ruditapes decussatus and r. philippinarum in the northeastern atlantic and mediterranean sea: a review. | perkinsosis is a disease of gastropod and bivalve molluscs caused by protozoan parasites of the perkinsus genus. these parasites have been responsible for mass mortalities worldwide, with a significant impact in both fisheries and aquaculture, and resulting in severe economic losses. this review focuses mainly on current knowledge of diagnostic methods and on the distribution of perkinsus spp. in the northeastern atlantic and mediterranean sea, which infect the grooved carpet shell clam ruditape ... | 2015 | 26239015 |
| update of information on perkinsosis in nw mediterranean coast: identification of perkinsus spp. (protista) in new locations and hosts. | this study addressed perkinsosis in commercially important mollusc species in the western mediterranean area. perkinsus olseni was found in santa gilla lagoon (sardinia) infecting ruditapes decussatus, cerastoderma glaucum and venerupis aurea, in balearic islands infecting venus verrucosa and in delta de l'ebre (ne spain) parasitising ruditapes philippinarum and r. decussatus. perkinsus mediterraneus was detected infecting ostrea edulis from the gulf of manfredonia (se italy) and alacant (e spai ... | 2015 | 25553580 |
| chromosomal localisation of five genes in perkinsus olseni (phylum perkinsozoa). | the molecular karyotype of perkinsus olseni, a pathogenic protist that infects the clam ruditapes decussatus, comprises nine chromosomes, ranging in size from 0.15 mb to 6.5 mb, representing a haploid genome of about 28 mb. in order to establish chromosome specific markers, pcr-amplified dna sequences belonging to five conserved genes (18s rrna, actin type i, hsp90, β-tubulin and calmodulin) were hybridised to chromosomal bands separated by pulsed-field gel electrophoresis. three of those probes ... | 2012 | 22342132 |
| vibrio bivalvicida sp. nov., a novel larval pathogen for bivalve molluscs reared in a hatchery. | three isolates were obtained from cultures of carpet shell clam (ruditapes decussatus) reared in a bivalve hatchery (galicia, nw spain) from different sources: healthy broodstock, moribund larvae and the seawater corresponding to the larval tank. all isolates were studied by a polyphasic approach, including a phylogenetic analysis based on concatenated sequences of the five housekeeping genes ftsz, gyrb, pyrh, reca and rpoa. the analysis supported their inclusion in the orientalis clade of the g ... | 2016 | 26654527 |
| uptake and retention of vibrio parahaemolyticus in a cohabitating population of ruditapes decussatus and ruditapes philippinarum under experimental conditions. | the presence of vibrio parahaemolyticus in bivalve mollusc is an important cause of foodborne illnesses, and their levels are influenced by environmental changes, such as temperature and salinity. clams are common species in estuaries and are used in environmental monitoring programmes. present study compared the uptake and retention of nonpathogenic v. parahaemolyticus by two species of clam (ruditapes decussatus and r. philippinarum), cohabitating in a closed system. results showed no signific ... | 2013 | 23397223 |
| application of neutral red retention assay to caged clams (ruditapes decussatus) and crabs (carcinus maenas) in the assessment of dredged material. | dredged material management is a key issue for the protection of aquatic environments. the in situ approach using caged bioindicator species has been chosen lately as a new methodology for the assessment of dredged material. in a tier testing approach, neutral red retention (nrr) assay has been applied as a screening tool to detect adverse changes in health status associated with contamination. nevertheless, to authors' knowledge, little is known about the application and validation of this tech ... | 2012 | 21870173 |
| vibrio barjaei sp. nov., a new species of the mediterranei clade isolated in a shellfish hatchery. | seven isolates were obtained from different culture stages of carpet shell clam (ruditapes decussatus) reared in a bivalve hatchery (galicia, nw spain). three groups were differentiated by genotyping techniques and phenotypic profiles and representative trains were selected to further taxonomic studies. these strains were studied by a polyphasic approach and in basis of the phylogenetic analysis based on concatenated sequences of the five housekeeping genes ftsz, gyrb, pyrh, reca and rpoa formed ... | 2016 | 27693041 |
| marinomonas gallaica sp. nov. and marinomonas atlantica sp. nov., isolated from reared clams (ruditapes decussatus). | three gram-negative bacterial strains (cmf 17.2t, rd 20.33 and cmf 18.22t) isolated from reared clams in galicia were subjected to a taxonomic study, based on genetic and phenotypic characterization. analysis of the 16s rrna gene allowed the identification of the strains as members of the genus marinomonas, sharing the highest similarity with marinomonas aquimarina cect 5080t (97.8 %-98.5 % 16s rrna gene sequence similarity). phylogenetic analysis of the sequences showed that the three isolates ... | 2016 | 27199280 |
| development and application of a novel histological multichrome technique for clam histopathology. | a novel and expedient histological tetrachrome technique was developed and applied to whole-body sections of the clam ruditapes decussatus (l. 1758). the technique involves fixation in carnoy's fluid followed by immediate embedding in paraffin with staining with a combination of alcian blue, periodic acid-schiff's, haematoxylin and picric acid. fixation and staining was perfect for all tissues and resolved good identification of perkinsus sp. infection and high structural detail. among the surve ... | 2012 | 22564259 |
| fine structural observations of the natural spore excystment of minchinia sp. (haplosporida). | the ultrastructure of the sequential phases of the spore excystment and the earliest plasmodial development of the haplosporidian minchinia sp., pathogenic to the portuguese clam ruditapes decussatus (mollusca, bivalvia), were observed. before spore excystment the endosporoplasm became lighter and its typical structures were rendered more visible. like the endosporoplasm, the liberated amoebula and the uninucleate plasmodia evidenced a similar morphology: spherulosome, haplosporosomes, lipid dro ... | 1989 | 23195569 |