Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
parasite survey of the eastern oyster crassostrea virginica in coastal lagoons of the southern gulf of mexico.a parasitological study of the eastern oyster crassostrea virginica from 11 coastal lagoons in the southern gulf of mexico in dry and rainy seasons between late 1999 and early 2001 revealed the presence of 36 bacterial, 2 protozoan (nematopsis prytherchi and perkinsus marinus), and 4 helminth species (urastoma cyprinae, proctoeces maculatus, a bucephalus sp., and a tylocephalum sp.). the prevalence and mean abundances for the protozoa and helminths varied widely between locations but were genera ...200718333483
quantitative assessment of viable cryptosporidium parvum load in commercial oysters (crassostrea virginica) in the chesapeake bay.the epidemiological importance of increasing reports worldwide on cryptosporidium contamination of oysters remains unknown in relation to foodborne cryptosporidiosis. thirty market-size oysters (crassostrea virginica), collected from each of 53 commercial harvesting sites in chesapeake bay, md, were quantitatively tested in groups of six for cryptosporidium sp. oocysts by immunofluorescent antibody (ifa). after ifa analysis, the samples were retrospectively retested for viable cryptosporidium pa ...200716896650
maximizing recovery and detection of cryptosporidium parvum oocysts from spiked eastern oyster (crassostrea virginica) tissue samples.numerous studies have documented the presence of cryptosporidium parvum, an anthropozoonotic enteric parasite, in molluscan shellfish harvested for commercial purposes. getting accurate estimates of cryptosporidium contamination levels in molluscan shellfish is difficult because recovery efficiencies are dependent on the isolation method used. such estimates are important for determining the human health risks posed by consumption of contaminated shellfish. in the present study, oocyst recovery ...200717827306
norovirus recognizes histo-blood group antigens on gastrointestinal cells of clams, mussels, and oysters: a possible mechanism of bioaccumulation.outbreaks of norovirus (nov) gastroenteritis are often associated with the consumption of contaminated bivalves such as oysters, clams, and mussels. crassostrea virginica oysters trap the norwalk virus through the intestinal type a-like histo-blood group antigen (hbga), a possible mechanism of bioaccumulation responsible for nov outbreaks. in this study, we tested binding and inhibition of binding in three species of oysters and one species each of clams and mussels with novs, representing four ...200717900094
generation and analysis of ests from the eastern oyster, crassostrea virginica gmelin and identification of microsatellite and snp markers.the eastern oyster, crassostrea virginica (gmelin 1791), is an economically important species cultured in many areas in north america. it is also ecologically important because of the impact of its filter feeding behaviour on water quality. populations of c. virginica have been threatened by overfishing, habitat degradation, and diseases. through genome research, strategies are being developed to reverse its population decline. however, large-scale expressed sequence tag (est) resources have bee ...200717559679
a cdna microarray for crassostrea virginica and c. gigas.the eastern oyster, crassostrea virginica, and the pacific oyster, c. gigas, are species of global economic significance as well as important components of estuarine ecosystems and models for genetic and environmental studies. to enhance the molecular tools available for oyster research, an international group of collaborators has constructed a 27,496-feature cdna microarray containing 4460 sequences derived from c. virginica, 2320 from c. gigas, and 16 non-oyster dnas serving as positive and ne ...200717668266
cdna cloning and in situ hybridization of a novel lysozyme in the pacific oyster, crassostrea gigas.a novel lysozyme cdna from the pacific oyster, crassostrea gigas, was identified. this second lysozyme from the pacific oyster was designated as cgl-2. the complete cgl-2 cdna sequence comprises of 536 bp, and 429 bp of the open reading frame encodes 147 bp of amino acid residues. estimated cgl-2 molecular characteristics (isoelectric point and numbers of peptide recognition sites) resembled those of cv-lysozyme 2, a digestive lysozyme of the eastern oyster, crassostrea virginica. moreover, cgl- ...200717584512
perkinsus marinus, a protozoan parasite of the eastern oyster, has a requirement for dietary sterols.perkinsus marinus, a protozoan parasite of the eastern oyster, crassostrea virginica, causes high mortality in its host along the atlantic and gulf coasts of north america. p. marinus meronts cultured in vitro in medium containing complete lipid supplement (cod liver oil, cholesterol and alpha tocopherol acetate in detergent) are able to synthesize a wide variety of lipids, yet cultures cannot be maintained in lipid-free medium. to determine p. marinus lipid requirements meronts were inoculated ...200717112755
an rna extraction protocol for shellfish-borne viruses.the gptt virus rna extraction method, originally developed for extraction of human norovirus and hepatitis a virus rnas from contaminated shellfish, was evaluated for extraction of rna from aichi virus strain a846/88 (aiv), coxsackievirus strains a9 (cav9) and b5 (cbv5), murine norovirus (strain mnv-1), and the norovirus surrogate, feline calicivirus (fcv) strain kcd, for the purpose of rt-pcr detection within seeded oyster (crassostrea virginica) extracts. the rt-pcr equivalent sensitivities ob ...200717184849
accumulation of organic and inorganic contaminants in shellfish collected in estuarine waters near pensacola, florida: contamination profiles and risks to human consumers.we conducted a screening level assessment of contaminants in blue crabs (callinectes sapidus) and oysters (crassostrea virginica) from bays and bayous in the pensacola, fl area. tissue samples were analyzed for 17 dioxins/furans, 12 dioxin-like pcb (dl-pcbs) congeners, mercury, and various metals. contaminant levels were compared to screening values (sv) calculated using u.s. epa recommendations for establishing consumption advisories. all sampling locations exceeded the sv (0.098pgg(-1)) for di ...200716872729
complete mitochondrial dna sequence of the eastern oyster crassostrea virginica.the complete mitochondrial genome of the eastern oyster crassostrea virginica (genbank accession number ay905542) is 17,243 bp in length and contains 2 ribosomal genes, 12 protein-coding genes, and 23 transfer rnas. the arrangement of protein-coding genes is identical to that of the congeneric pacific oyster c. gigas, but trna genes show several duplications and extensive rearrangements between the species. unique features in c. virginica include an additional trnm gene, the absence of an atpase ...200816132463
effect of high hydrostatic pressure processing on freely suspended and bivalve-associated t7 bacteriophage.the effectiveness of hydrostatic pressure processing (hpp) for inactivating viruses has been evaluated in only a limited number of studies, and most of the work has been performed with viruses freely suspended in distilled water. in this work, hpp inactivation of freely suspended and shellfish-associated bacteriophage t7 was studied. t7 was selected in hopes that it could serve as a model for animal virus behavior. clams (mercenaria mercenaria) and oysters (crassostrea virginica) were homogeneou ...200818326185
localization of the bacterial agent of juvenile oyster disease (roseovarius crassostreae) within affected eastern oysters (crassostrea virginica).the bacterium roseovarius crassostreae causes seasonal mortalities among commercially produced eastern oysters (crassostrea virginica) grown in the northeastern united states. phylogenetically, the species belongs to a major lineage of marine bacteria (the roseobacter clade), within which roseovarius crassostreae is the only known pathogen to be isolated in laboratory culture. the objective of the current study was to determine the location and nature of r. crassostreae interactions with oysters ...200817931651
population structures of two genotypes of vibrio vulnificus in oysters (crassostrea virginica) and seawater.vibrio vulnificus biotype 1 strains can be classified into two genotypes based on the pcr analysis of variations in the virulence-correlated gene (vcg). genotype has been correlated with human infection for 90% of isolates from human cases having the vcgc sequence type and 87% of environmental strains having the vcge variant. in this study we examined the dynamics of v. vulnificus populations and the distribution of the two genotypes recovered from oysters and surrounding estuarine wasters. anal ...200817993556
elemental status in sediment and american oyster collected from savannah marsh/estuarine ecosystem: a preliminary assessment.sediment and american oyster (crassostrea virginica) collected from nine selected marsh/estuarine ecosystems in savannah, georgia were analyzed for elements such as al, as, b, cd, cr, cu, fe, hg, mn, mo, ni, pb, si, and zn. sediments were extracted by ammonium acetate (nh(4)oac), mehlich-3 (m-3), and water procedures, whereas an acid digestion procedure was adopted for oyster tissue. concentrations of elements were higher in m-3 extractions followed by nh(4)oac and water extraction procedures. c ...200817876649
effects of p-aminosalicylic acid on the neurotoxicity of manganese and levels of dopamine and serotonin in the nervous system and innervated organs of crassostrea virginica.manganese is a neurotoxin causing manganism in individuals chronically exposed to elevated levels in their environment. toxic manganese exposure causes mental and emotional disturbances, and a movement disorder similar to idiopathic parkinsons disease. manganese interferes with dopamine neurons involved in control of body movements. recently, p-aminosalicylic acid (pas) is being used to alleviate symptoms of manganism, but its mechanism of action is unknown. the eastern oyster, crassostrea virgi ...200821841974
numerical quantification of perkinsus marinus in the american oyster crassostrea virginica (gmelin, 1791) (mollusca: bivalvia) by modern stereology.species of perkinsus are responsible for high mortalities of bivalve molluscs world-wide. techniques to accurately estimate parasites in tissues are required to improve understanding of perkinsosis. this study quantifies the number and tissue distribution of perkinsus marinus in crassostrea virginica by modern stereology and immunohistochemistry. mean total number of trophozoites were (mean +/- se) 11.80 +/- 3.91 million and 11.55 +/- 3.88 million for the optical disector and optical fractionato ...200818372631
simulated predator extinctions: predator identity affects survival and recruitment of oysters.the rate of species loss is increasing at a global scale, and human-induced extinctions are biased toward predator species. we examined the effects of predator extinctions on a foundation species, the eastern oyster (crassostrea virginica). we performed a factorial experiment manipulating the presence and abundance of three of the most common predatory crabs, the blue crab (callinectes sapidus), stone crab (menippe mercenaria), and mud crab (panopeus herbstii) in estuaries in the eastern united ...200818409432
perkinsus marinus in pleasure oyster crassostrea corteziensis from nayarit, pacific coast of méxico.culture of the pleasure oyster crassostrea corteziensis is emerging as an alternative to the pacific oyster (crassostrea gigas) for oyster producers, who face severe mortalities since 1997 in northwest méxico. for determining the health status of this species, we conducted a histopathological analysis of cultured populations from two estuaries in the pacific coast of méxico. macroscopical analysis revealed animals with transparent and retracted mantle. histopathological analysis of these specime ...200818423484
survival of eastern oysters crassostrea virginica from three lines following experimental challenge with bacterial pathogens.shellfish production is often affected by bacterial pathogens that cause high losses in hatcheries and nurseries. we evaluated the relative survival of larvae and juveniles of 3 crassostrea virginica oyster lines: (1) ghp, a rhode island line; (2) nehy, a line resistant to dermo and multinucleated sphere x diseases; and (3) flowers, a line resistant to roseovarius oyster disease, experimental challenge with vibrio spp. isolates re22 and re101, causative agents of bacillary necrosis in pacific oy ...200818500026
conditions for high pressure inactivation of vibrio parahaemolyticus in oysters.the objective of this study was to identify the high pressure processing conditions (pressure level, time, and temperature) needed to achieve a 5-log reduction of vibrio parahaemolyticus in live oysters (crassostrea virginica). ten strains of v. parahaemolyticus were separately tested for their resistances to high pressure. the two most pressure-resistant strains were then used as a cocktail to represent baro-tolerant environmental strains. to evaluate the effect of temperature on pressure inact ...200818547664
assessment of the northern distribution range of selected perkinsus species in eastern oysters (crassostrea virginica) and hard clams (mercenaria mercenaria) with the use of pcr-based detection assays.perkinsus species are protistan parasites of molluscs. in chesapeake bay, perkinsus marinus, perkinsus chesapeaki, and perkinsus andrewsi are sympatric, infecting oysters and clams. although p. marinus is a pathogen for crassostrea virginica, it remains unknown whether p. andrewsi and p. chesapeaki are equally pathogenic. perkinsus species have been reported in c. virginica as far north as maine, sometimes associated with high prevalence, but low mortality. thus, we hypothesized that, in additio ...200818564742
monitoring of brevetoxins in the karenia brevis bloom-exposed eastern oyster (crassostrea virginica).brevetoxin uptake and elimination were examined in eastern oyster (crassostrea virginica) exposed to recurring blooms of the marine alga karenia brevis in sarasota bay, fl, over a three-year period. brevetoxins were monitored by in vitro assays (elisa, cytotoxicity assay, and receptor binding assay) and lc-ms, with in vivo toxicity of shellfish extracts assessed by the traditional mouse bioassay. measurements by all methods reflected well the progression and magnitude of the blooms. highest leve ...200818582486
factors associated with the prevalence of perkinsus marinus in crassostrea virginica from the southern gulf of mexico.the protozoan perkinsus marinus is considered the most important pathogen of the eastern oyster crassostrea virginica, causing high mortality in natural and farmed oysters on the atlantic coast of the us. in mexico, no serious p. marinus epizootic has been reported. this study describes the current state of p. marinus prevalence in terminos lagoon (mexico) associated with environmental factors including salinity, temperature, ammonium, nitrate, nitrite, silica, and phosphorus. in addition, the a ...200818590000
effects of hypercapnic hypoxia on inactivation and elimination of vibrio campbellii in the eastern oyster, crassostrea virginica.the eastern oyster, crassostrea virginica, inhabits shallow coastal waters that frequently experience periods of low dissolved oxygen (hypoxia) and elevated co(2) (hypercapnia) levels. bacteria are extremely abundant in these environments and accumulate in large numbers in filter-feeding oysters, which can act as passive carriers of human pathogens. although hypercapnic hypoxia (hh) can affect certain specific immune mechanisms, its direct effect on the inactivation, degradation and elimination ...200818676695
effectiveness of icing as a postharvest treatment for control of vibrio vulnificus and vibrio parahaemolyticus in the eastern oyster (crassostrea virginica).the focus of this research was to investigate the efficacy of icing as a postharvest treatment for reduction of the levels of vibrio vulnificus and vibrio parahaemolyticus in commercial quantities of shellstock oysters. the experiments were conducted in june and august of 2006 and consisted of the following treatments: (i) on-board icing immediately after harvest; (ii) dockside icing approximately 1 to 2 h prior to shipment; and (iii) no icing (control). changes in the levels of pathogenic vibri ...200818680950
effects of salinity, heavy metals and pesticides on health and physiology of oysters in the caloosahatchee estuary, florida.the caloosahatchee estuary has been exhibiting signs of impaired ecological health due to the extensive hydrological alteration, agricultural land use, and increasing watershed development. this project investigated the responses of the american oyster, crassostrea virginica at five locations in the caloosahatchee river in relation to salinity changes, levels of heavy metals, pesticides, and pcbs in the water as well as in the oyster tissue. individual heavy metal and organochlorine pesticide co ...200818686029
seasonal tracking of histo-blood group antigen expression and norovirus binding in oyster gastrointestinal cells.noroviruses (nors) are the most common cause of viral gastroenteritis outbreaks. outbreaks are often associated with the consumption of contaminated oysters and generally occur between the months of november and march, when oysters produce the highest levels of glycogen. oyster glycogen has been proposed as playing a role in nor accumulation. recent research indicates that histo-blood group antigens (hbgas) function as viral receptors on human gastrointestinal cells. in this study, oyster glycog ...200818724767
shellfish tissues evaluated for perkinsus spp. using the ray's fluid thioglycollate medium culture assay can be used for downstream molecular assays.ray's fluid thioglycollate medium (rftm) culture assay is the standard, recommended method for surveillance of perkinsus spp. infections in marine molluscs. in this assay, shellfish tissues are incubated in rftm, stained with lugol's iodine solution to render perkinsus spp. cells blue-black, and evaluated microscopically to rate infection intensities. a limitation of this assay, however, is the lack of pathogen species specificity. generally, identification of perkinsus spp. requires dna sequenc ...200818814549
bioaccumulation, retention, and depuration of enteric viruses by crassostrea virginica and crassostrea ariakensis oysters.crassostrea ariakensis oysters are under review for introduction into the chesapeake bay. however, the human health implications of the introduction have not been fully addressed. this study evaluated rates of bioaccumulation, retention, and depuration of viruses by crassostrea virginica and c. ariakensis when the two oyster species were maintained in separate tanks containing synthetic seawater of various salinities (8, 12, or 20 ppt). oyster bioaccumulation tanks were seeded with 10(3) pfu/ml ...200818820067
complete mitochondrial dna sequence of oyster crassostrea hongkongensis-a case of "tandem duplication-random loss" for genome rearrangement in crassostrea?mitochondrial dna sequences are extensively used as genetic markers not only for studies of population or ecological genetics, but also for phylogenetic and evolutionary analyses. complete mt-sequences can reveal information about gene order and its variation, as well as gene and genome evolution when sequences from multiple phyla are compared. mitochondrial gene order is highly variable among mollusks, with bivalves exhibiting the most variability. of the 41 complete mt genomes sequenced so far ...200818847502
molecular epizootiology of perkinsus marinus and p. chesapeaki infections among wild oysters and clams in chesapeake bay, usa.perkinsus marinus and p. chesapeaki host ranges among wild chesapeake bay, usa, region bivalves were examined by surveying crassostrea virginica oysters and members of several sympatric clam species from 11 locations. perkinsus genus- and species-specific pcr assays were performed on dna samples from 731 molluscs, and species-specific in situ hybridization assays were performed on a selected subset of histological samples whose pcr results indicated dual or atypical perkinsus sp. infections. pcr ...200819244976
genetic analysis of selected strains of eastern oyster (crassostrea virginica gmelin) using aflp and microsatellite markers.amplified fragment length polymorphisms (aflps) and microsatellite markers were used to examine genetic variation and divergence in 4 selected strains (dbh, neh, fmf, and cts) and 1 wild population (dbw) of the eastern oyster crassostrea virginica gmelin. eighty-six aflp markers (from 3 primer pairs) and 5 microsatellite loci were used for the analysis of 30 oysters from each of the 5 populations. microsatellite loci were considerably more variable than aflps. the observed heterozygosity ranged ...200815747088
effects of acclimation temperature and cadmium exposure on mitochondrial aconitase and lon protease from a model marine ectotherm, crassostrea virginica.temperature and heavy metals such as cadmium (cd) are important stressors which can strongly affect physiology of marine ectotherms in polluted estuaries. mitochondria are among the key intracellular targets for these stressors, but the mechanisms of cd-induced mitochondrial damage are not fully understood. in this study we determined the effects of acclimation temperature (12, 20 and 28 degrees c) and cd exposure (0 or 50 microg l(-1) cd) in vivo on activity and mrna expression of a key mitocho ...200817869588
residue-response relationship between pah body burdens and lysosomal membrane destabilization in eastern oysters (crassostrea virginica) and toxicokinetics of pahs.this study was undertaken to establish residue-response relationship between lysosomal destabilization and body residues of multiple pahs in eastern oysters (crassostrea virginica) exposed to a mixture of pahs for 25 days in laboratory aquariums. the contaminated oysters were then placed in clean aquariums for 20 days to allow them to depurate and recover. the lysosomal destabilization was linearly correlated with the pah body burdens. regression analysis showed that critical body residue (cbr), ...200818780214
unintended facilitation between marine consumers generates enhanced mortality for their shared prey.we manipulated predator densities and prey vulnerability to explore how interactions between two predators affect overall mortality of their shared prey. our three-member study system included eastern oysters (crassostrea virginica) and two of its major consumers: southern oyster drills (stramonita haemastoma) and stone crabs (menippe adina). field experiments demonstrated that drills and crabs foraging together generated higher than expected oyster mortality based on each species operating inde ...200819137933
bayesian spatial modeling of lavaca bay pollutants.locational risk of increased mercury and pah concentrations in lavaca bay, texas sediments and eastern oysters (crassostrea virginica) harvested from lavaca bay, texas were analysed. chemical analysis results were evaluated utilizing bayesian geo-statistical methods for comparison of the model fit of a random effects model versus a convoluted model which included both random and spatial effects. for those results fit best with the convoluted model, continuous surface maps of predicted parameter ...200818662818
the neurotoxic effects of manganese on the dopaminergic innervation of the gill of the bivalve mollusc, crassostrea virginica.we examined effects of manganese on the nervous system and innervation of lateral cilia of crassostrea virginica. while essential in trace amounts, tissue manganese accumulation is neurotoxic, inducing manganism, a parkinson's-like disease in humans. lateral cilia of the gill of c. virginica are controlled by a reciprocal serotonergic-dopaminergic innervation from their ganglia. oysters were incubated 3 days in the presence of up to 1 mm manganese, followed by superfusion of the cerebral ganglia ...200818547869
effects of cadmium exposure on expression and activity of p-glycoprotein in eastern oysters, crassostrea virginica gmelin.heavy metal pollution is a worldwide problem, and cadmium (cd) is one of the most noxious pollutants in aquatic environments. we studied p-glycoprotein (p-gp) expression and function in control and cd exposed (50microgl(-1) cd, 30-40 days) oysters crassostrea virginica as a possible mechanism of cell protection against cd. our data show that p-gp is expressed on cell membrane and in mitochondria of oyster gills and hepatopancreas. inhibitor studies with verapamil, cyclosporine a and js-2190 sugg ...200818453012
differential sensitivity to cadmium of key mitochondrial enzymes in the eastern oyster, crassostrea virginica gmelin (bivalvia: ostreidae).combined effects of cadmium (cd) and temperature on key mitochondrial enzymes [including complexes i-iv of electron transport chain and krebs cycle enzymes citrate synthase (cs), and nad- and nadp-dependent isocitrate dehydrogenases (nad-idh and nadp-idh)] were studied in a marine ectotherm, crassostrea virginica in order to better understand the mechanisms of cd-induced impairment of mitochondrial function. matrix enzymes including cs and isocitrate dehydrogenases were the most sensitive to cd ...200818434254
comparison of methods for evaluating acute and chronic toxicity in marine sediments.sublethal test methods are being used with increasing frequency to measure sediment toxicity, but little is known about the relative sensitivity of these tests compared to the more commonly used acute tests. the present study was conducted to compare the sensitivity of several acute and sublethal methods and to investigate their correlations with sediment chemistry and benthic community condition. six sublethal methods (amphipod: leptocheirus plumulosus survival, growth, and reproduction; polych ...200818333680
physiological and biochemical traits correlate with differences in growth rate and temperature adaptation among groups of the eastern oyster crassostrea virginica.we tested two hypotheses in this study: first, that intraspecific growth variations in a marine bivalve are correlated with physiological (basal metabolic rate and scope for growth) and biochemical (membrane lipids) characteristics, and, second, that this bivalve shows intraspecific variations in physiological and biochemical adaptations to temperature. to test these hypotheses, five genetically distinct groups of juvenile oysters crassostrea virginica that showed differences in their growth rat ...200818310122
oxidative stress and expression of chaperones in aging mollusks.the mechanisms of aging are not well understood in animals with continuous growth such as fish, reptiles, amphibians and numerous invertebrates, including mollusks. we studied the effects of age on oxidative stress, cellular defense mechanisms (including two major antioxidant enzymes, superoxide dismutase (sod) and catalase), and molecular chaperones in two mollusks--eastern oysters crassostrea virginica and hard clams mercenaria mercenaria. in order to detect the age-related changes in these pa ...200818296092
cadmium-dependent oxygen limitation affects temperature tolerance in eastern oysters (crassostrea virginica gmelin).marine ectotherms, including oysters are exposed to variable environmental conditions in coastal shallow waters and estuaries. in the light of global climate change, additional stressors like pollution might pose higher risk to populations. on the basis of the concept of oxygen- and capacity-limited thermal tolerance in aquatic ectotherms (40), we show that a persistent pollutant, cadmium, can have detrimental effects on oysters (crassostrea virginica). during acute warming from 20 to 28 degrees ...200818272660
effects of cadmium on cellular protein and glutathione synthesis and expression of stress proteins in eastern oysters, crassostrea virginica gmelin.cadmium (cd) is an important toxicant in estuarine and coastal environments that can strongly affect energy balance of aquatic organisms by increasing the organism's basal energy demand and reducing its aerobic capacity. mechanisms of cadmium-induced increase in basal metabolic costs are not well understood and may involve elevated detoxification costs due to the synthesis of cellular protective proteins and glutathione. we studied the short-term effects of cadmium exposure (4 h) on protein and ...200818245635
visualization of shell matrix proteins in hemocytes and tissues of the eastern oyster, crassostrea virginica.the tissues of the oyster were examined for the presence of shell matrix proteins (smps) using a combination of western, proteomic, and epi-fluorescent microscopy techniques. smp, including 48 and 55 kda phosphoproteins, was detected in the epithelial cells of mantle, gill, heart, and adductor muscle and linings of arteries and veins. the 48 kda smp circulates continuously within the hemolymph, and is present in the immune system hemocytes. it appears to be secreted from hemocytes on induction o ...200818044742
wild and aquaculture populations of the eastern oyster compared using microsatellites.five new microsatellite markers were developed for the eastern oyster (crassostrea virginica), and allelic variability was compared between a wild chesapeake bay population (james river) and a hatchery strain (deby). all loci amplified readily and demonstrated allelic variability with the number of alleles ranging from 16 to 36 in the wild population and from 11 to 19 in the deby strain. average observed and expected heterozygosities were estimated at 0.66 and 0.80 in the hatchery sample. the co ...200817071849
isolation by distance in the eastern oyster, crassostrea virginica, in chesapeake bay.intensive efforts are underway to restore depleted stocks of crassostrea virginica in chesapeake bay. however, the extent of gene flow among local populations, an important force mediating the success of these endeavors, is poorly understood. spatial and temporal population structures were examined in c. virginica from chesapeake bay using eight microsatellite loci. deficits in heterozygosity relative to hardy-weinberg expectations were seen at all loci and were best explained by null alleles. p ...200816489144
differences in heat shock protein 70 expression during larval and early spat development in the eastern oyster, crassostrea virginica (gmelin, 1791).for a variety of species, changes in the expression of heat shock proteins (hsp) have been linked to key developmental changes, i.e., gametogenesis, embryogenesis, and metamorphosis. many marine invertebrates are known to have a biphasic life cycle where pelagic larvae go through settlement and metamorphosis as they transition to the benthic life stage. a series of experiments were run to examine the expression of heat shock protein 70 (hsp 70) during larval and early spat (initial benthic phase ...200919130302
effects of elevated temperature and cadmium exposure on stress protein response in eastern oysters crassostrea virginica (gmelin).stress proteins such as heat shock proteins (hsps) and metallothioneins (mts) play a key role in cellular protection against environmental stress. marine ectotherms such as eastern oysters crassostrea virginica are commonly exposed to multiple stressors including temperature and pollution by metals such as cadmium (cd) in estuaries and coastal zones; however, the combined effects of these stressors on their cellular protection mechanisms are poorly understood. we acclimated c. virginica from pop ...200919124164
subcellular fractionation of cu exposed oysters, crassostrea virginica, and cu accumulation from a biologically incorporated cu rich oyster diet in fundulus heteroclitus in fresh and sea water.in order to examine the effect of salinity on cu accumulation from a naturally incorporated diet, oysters (crassostrea virginica) were exposed in sea water for 96 days to four waterborne [cu]: 2.9+/-0.7 (control), 4.3+/-0.6, 5.4+/-0.5, and 10.7+/-1.0 microg l(-1). after 96 days, the control whole body [cu] increased from 2.1+/-0.5 to 9.1+/-1.1 microg g(-1) w.w. and the highest [cu] was 163.4+/-27.1 microg g(-1) w.w. in the oysters. despite large differences in tissue [cu], there was no effect on ...200919103305
molecular characterization and expression of a novel homolog of uncoupling protein 5 (ucp5) from the eastern oyster crassostrea virginica (bivalvia: ostreidae).uncoupling proteins (ucps) belong to the mitochondrial anion carrier gene family which has been implicated in diverse physiological functions ranging from thermoregulation to antioxidant defense. in mammals, the ucp family is well characterized and contains five members (ucp1-5). in contrast, invertebrate homologues of uncoupling proteins are much less studied both from the viewpoints of structure and function. in this study we report nucleotide and predicted protein structure of an important me ...200920403746
geostatistical analysis of dna damage in oysters, crassostrea virginica, in lavaca bay, texas.this study evaluated the health of the marine ecosystem in lavaca bay, texas using the eastern oyster (crassostrea virginica) as the sentinel species. lavaca bay has a history of having gradients of concentrations of pollutants present with some areas containing concentrations high enough to pose a threat to marine ecosystem health. the comet assay was used to evaluate for the presence of genotoxic response in oyster hematocytes. bayesian geostatistical analysis was then used to determine if the ...200918763037
proteomic clues to the identification of qx disease-resistance biomarkers in selectively bred sydney rock oysters, saccostrea glomerata.the sydney rock oyster, saccostrea glomerata, is susceptible to infection by the protozoan parasite, marteilia sydneyi, the causative agent of qx disease. m. sydneyi infection peaks during summer when qx disease can cause up to 95% mortality. the current study takes a proteomic approach using 2-dimensional electrophoresis and mass spectrometry to identify markers of qx disease resistance among sydney rock oysters. proteome maps were developed for qx disease-resistant and -susceptible oysters. si ...200919573631
fullerene exposures with oysters: embryonic, adult, and cellular responses.oysters are an ecologically important group of filter-feeders, and a valuable toxicology model for characterizing the potential impacts of nanoparticles to marine organisms. fullerene (c60) exposure studies with oysters, crassostrea virginica, were conducted with a variety of biological levels, e.g., developmental studies with embryos, whole organism exposures with adults, and isolated hepatopancreas cells. significant effects on embryonic development and lysosomal destabilization were observed ...200919806754
cadmium affects metabolic responses to prolonged anoxia and reoxygenation in eastern oysters (crassostrea virginica).benthic marine organisms such as mollusks are often exposed to periodic oxygen deficiency (due to the tidal exposure and/or seasonal expansion of the oxygen-deficient dead zones) and pollution by metals [e.g., cadmium, (cd)]. these stressors can strongly affect mollusks' survival; however, physiological mechanisms of their combined effects are not fully understood. we studied the effects of cd exposure on metabolic responses to prolonged anoxia and subsequent recovery in anoxia-tolerant intertid ...200919726715
marine aggregates facilitate ingestion of nanoparticles by suspension-feeding bivalves.as the application of nanomaterials to science and technology grows, the need to understand any ecotoxicological effects becomes increasingly important. recent studies on a few species of fishes and invertebrates have provided data which suggest that harmful effects are possible. the way in which nanoparticles are taken up by aquatic organisms, however, has been little studied. we examined uptake of nanoparticles by two species of suspension-feeding bivalves (mussels, mytilus edulis; oysters, cr ...200919525006
an evaluation of the health status of the lavaca bay, texas ecosystem using crassostrea virginica as the sentinel species.locational risks for compromised ecosystem health for the eastern oysters (crassostrea virginica) harvested from lavaca bay, texas were estimated. flow cytometric evaluation of variations in dna content and the lysosomal destabilization assay were used for evaluation of genotoxicity and stress, respectively. bayesian geo-statistical methods were utilized to estimate and evaluate spatial effects. for models with spatial risks, continuous surface maps of predicted parameter values were created to ...200919167734
matrix solid-phase dispersion extraction and gas chromatographic screening of 14 chlorinated pesticides in oysters (crassostrea virginica).a multiresidue isolation technique known as matrix solid-phase dispersion (mspd) is presented for the extraction and subsequent gas chromatographic/electron capture detection (gc/ecd) determination of 14 chlorinated pesticides (alpha-bhc, beta-bhc, lindane, heptachlor, aldrin, heptachlor epoxide, p,p'-dde, dieldrin, endrin, 4,4'-ddd, endrin aldehyde, p,p'-ddt, endosulfan sulfate, and methoxychlor) from oysters (crassostrea virginica). pureed whole oysters (0.5 g aliquots) are fortified with the ...20098448447
inactivation of vibrio parahaemolyticus in pure culture, whole live and half shell oysters (crassostrea virginica) by x-ray.to study the inactivation effect of different doses of x-ray on vibrio parahaemolyticus in pure culture, inoculated whole live and half shell oysters and to evaluate the efficacy of x-ray doses on reduction of inherent microflora on oysters.200919291215
temperature effects on the depuration of vibrio parahaemolyticus and vibrio vulnificus from the american oyster (crassostrea virginica).this study investigated temperature effects on depuration for reducing vibrio parahaemolyticus and vibrio vulnificus in american oyster (crassostrea virginica). raw oysters were inoculated with 5-strain cocktail of v. parahaemolyticus or v. vulnificus to levels of 10(4) to 10(5) mpn (most probable number)/g and depurated in artificial seawater (asw) at 22, 15, 10, and 5 degrees c. depuration of oysters at 22 degrees c had limited effects on reducing v. parahaemolyticus or v. vulnificus in the oy ...200919323759
using bivalves as particle collectors with pcr detection to investigate the environmental distribution of haplosporidium nelsoni.recently, pcr technology has been applied to search for marine microorganisms in environmental samples. such sampling, however, has drawbacks, including the need to collect and filter large volumes of water, and the presence of substances in environmental samples that may destroy dna or interfere with dna isolation and amplification. we explored the possibility of using suspension-feeding bivalves in conjunction with pcr to investigate the environmental distribution of microparasites using the o ...200919326797
a transcriptomic analysis of land-use impacts on the oyster, crassostrea virginica, in the south atlantic bight.increasing utilization and human population density in the coastal zone is widely believed to place increasing stresses on the resident biota, but confirmation of this belief is somewhat lacking. while we have solid evidence that highly disturbed estuarine systems have dramatic changes in the resident biota (black and white if you will), we lack tools that distinguish the shades of grey. in part, this lack of ability to distinguish shades of grey stems from the analytical tools that have been ap ...200919457208
evidence indicating the existence of a novel family of serine protease inhibitors that may be involved in marine invertebrate immunity.a new serine protease inhibitor, designated cvsi-2, was purified and characterized from the plasma of the eastern oyster, crassostrea virginica. cvsi-2 inhibited the serine protease subtilisin a in a slow-tight binding manner, with an overall dissociation constant ki* of 0.18 nm. it also inhibited perkinsin, the major extracellular protease of the oyster protozoan parasite perkinsus marinus. sequencing of cvsi-2 cloned cdna revealed an open reading frame of 258 bp encoding a polypeptide of 85 am ...200919464375
in vitro and in vivo anti-angiogenic activities and inhibition of hormone-dependent and -independent breast cancer cells by ceramide methylaminoethylphosphonate.ceramide methylaminoethylphosphonate (cmaepn) was isolated from eastern oyster ( crassostrea virginica ) and screened against in vitro and in vivo angiogenesis and against mcf-7 and mda-mb-435s breast cancer cell lines. in vitro angiogenesis was evaluated by the vascular endothelial growth factor (vegf)-induced human umbilical vein endothelial cell (huvec) tube formation assay. mcf-7 and mda-mb-435s cell viability was evaluated by the celltiter 96 aq(ueous) one solution cell proliferation assay. ...200919476359
shellfish face uncertain future in high co2 world: influence of acidification on oyster larvae calcification and growth in estuaries.human activities have increased atmospheric concentrations of carbon dioxide by 36% during the past 200 years. one third of all anthropogenic co(2) has been absorbed by the oceans, reducing ph by about 0.1 of a unit and significantly altering their carbonate chemistry. there is widespread concern that these changes are altering marine habitats severely, but little or no attention has been given to the biota of estuarine and coastal settings, ecosystems that are less ph buffered because of natura ...200919478855
phase variation, capsular polysaccharide, pilus and flagella contribute to uptake of vibrio vulnificus by the eastern oyster (crassostrea virginica).vibrio vulnificus infections are associated with raw oyster consumption, and disease reservoirs are determined by the ability of this bacterium to infect and persist in oysters. surface structures, such as capsular polysaccharide (cps), pili and flagella, function as virulence factors in mouse infection models. furthermore, virulence is related to phase variation in colony morphology, which reflects cps expression and includes opaque (encapsulated, virulent), translucent (reduced encapsulation, ...200919689704
differential localization and bacteriostasis of vibrio campbellii among tissues of the eastern oyster, crassostrea virginica.in bivalve mollusks the roles of individual tissues in antimicrobial defense remain unclear. in this study, crassostrea virginica were injected in the adductor muscle with 10(5) live vibrio campbellii. major tissues were dissected at 10, 30, 60 or 120 min postinjection (pi); in each tissue undegraded (intact) bacteria were quantified by real-time pcr and culturable bacteria were enumerated by selective plating. at 10 min pi, accumulation of bacteria varied among tissues from approximately 2.4 x ...200919022286
reduction of vibrio vulnificus in pure culture, half shell and whole shell oysters (crassostrea virginica) by x-ray.the purpose of this investigation was to study the inactivation effect of x-ray treatments on inoculated vibrio vulnificus in pure culture, half shell and whole shell oysters to achieve a 5.0 log reduction, which is recommended by the interstate shellfish sanitation conference and the food and drug administration. a mixed culture of three v. vulnificus strains was used to prepare the pure culture and inoculated oysters. the pure culture and inoculated oysters were treated with 0.0, 0.1, 0.5, 0.7 ...200919217681
genetic relatedness among tdh+ and trh+ vibrio parahaemolyticus cultured from gulf of mexico oysters (crassostrea virginica) and surrounding water and sediment.pathogenic vibrio parahaemolyticus (vp) (tdh(+)/trh(+)) represent a small percentage of environmental vp populations, and very little is known about this subpopulation. repetitive extragenic palindromic pcr and multilocus sequence analysis revealed heterogeneity among 41 vp containing thermostable direct hemolysin (tdh) and tdh-related hemolysin (trh) that were isolated from mississippi coastal environments from october 2006 to april 2007. there was no source-specific sequestering in oysters, wa ...200918607657
lectins associated with the feeding organs of the oyster crassostrea virginica can mediate particle selection.despite advances in the study of particle selection in suspension-feeding bivalves, the mechanisms upon which bivalves rely to discriminate among particles have not been elucidated. we hypothesized that particle sorting in suspension-feeding bivalves could be based, in part, on a biochemical recognition mechanism mediated by lectins within the mucus that covers the feeding organs. using crassostrea virginica, the eastern oyster, our investigations demonstrated that lectins from oyster mucus can ...200919875818
development of an in vitro assay to examine intracellular survival of perkinsus marinus trophozoites upon phagocytosis by oyster (crassostrea virginica and crassostrea ariakensis) hemocytes.perkinsus marinus is a facultative intracellular parasite that causes "dermo" disease in the eastern oyster crassostrea virginica. although hemocytes from healthy oysters rapidly phagocytize p. marinus trophozoites, they fail to efficiently kill them. instead, trophozoites survive and proliferate, eventually overwhelming the host. because chesapeake bay oyster populations have been reduced to unprecedented levels, the introduction of the suminoe oyster, crassostrea ariakensis (synonymous c. rivu ...200920049995
effects of heavy metals on the oyster (crassostrea virginica) at mandinga lagoon, veracruz, mexico.the mandinga lagoon in the mexican state of veracruz is an important ecological zone that produces 32% of the oyster output in the state of veracruz, the main oyster producer in mexico. samples of water, sediment, and oysters were collected in 2003 and 2004 to study heavy metal pollution. metal concentrations were determined in water, soil, and oyster tissues from fresh and detoxified crassostrea virginica, and histology samples were analyzed. metal (cr, cd, and pb) concentrations in water were ...200920073327
flow cytometry studies on the populations and immune parameters of the hemocytes of the suminoe oyster, crassostrea ariakensis.the suminoe oyster crassostrea ariakensis has been attempted to be introduced in the chesapeake bay, usa, as an alternative to the eastern oyster crassostrea virginica. commercial production of suminoe oysters is currently restricted due to the incomplete understanding of their biological, physiological and immunological nature. accordingly, understanding immune system of c. ariakensis is crucial to prevent disease associated mortality and subsequent management of the suminoe oyster. we investig ...200919490941
uptake and depuration of the c- and e-genotypes of vibrio vulnificus by the eastern oyster (crassostrea virginica).the human pathogen vibrio vulnificus is a gram-negative estuarine bacterium that infect via wounds and ingestion, and is the leading cause of seafood-borne death in the united states. vibrio vulnificus is part of the naturally occurring flora of both estuaries and estuarine mollusks (especially oysters). vibrio vulnificus is divided into two genotypes, including a clinically associated c-type, and an environmentally associated e-type that is more rarely involved in septicemia. these two genotype ...201023766004
effects of cadmium exposure and intermittent anoxia on nitric oxide metabolism in eastern oysters, crassostrea virginica.nitric oxide (no) is an intracellular signaling molecule synthesized by a group of enzymes called nitric oxide synthases (nos) and involved in regulation of many cellular functions including mitochondrial metabolism and bioenergetics. in invertebrates, the involvement of no in bioenergetics and metabolic responses to environmental stress is poorly understood. we determined sensitivity of mitochondrial and cellular respiration to no and the effects of cadmium (cd) and intermittent anoxia on no me ...201020086128
microalgal cell surface carbohydrates as recognition sites for particle sorting in suspension-feeding bivalves.cell surface carbohydrates play important roles in cell recognition mechanisms. recently, we provided evidence that particle selection by suspension-feeding bivalves can be mediated by interactions between carbohydrates associated with the particle surface and lectins present in mucus covering bivalve feeding organs. in this study, we used lectins tagged with fluorescein isothiocyanate (fitc) to characterize carbohydrate moieties on the surface of microalgal species and evaluate the effect of oy ...201020203255
apoptosis as a host defense mechanism in crassostrea virginica and its modulation by perkinsus marinus.dermo disease caused by the obligatory intracellular protozoan perkinsus marinus causes extensive oyster mortalities leading to tremendous losses in the oyster industry and damage to estuarine ecosystems. to better understand the mechanisms of the parasite's evasion of the host immune defense system, we have investigated the molecular mechanisms of p.marinus-induced inhibition of apoptosis in oyster cells as a potential parasite's survival strategy. we found that p. marinus modulates apoptosis o ...201020371290
the alveolate perkinsus marinus: biological insights from est gene discovery.perkinsus marinus, a protozoan parasite of the eastern oyster crassostrea virginica, has devastated natural and farmed oyster populations along the atlantic and gulf coasts of the united states. it is classified as a member of the perkinsozoa, a recently established phylum considered close to the ancestor of ciliates, dinoflagellates, and apicomplexans, and a key taxon for understanding unique adaptations (e.g. parasitism) within the alveolata. despite intense parasite pressure, no disease-resis ...201020374649
filtration rate, assimilation and assimilation efficiency in crassostrea virginica (gmelin) fed with tetraselmis suecica under cadmium exposure.crassostrea virginica is an epibentic filter-feeding bivalve of economical importance in coastal lagoons of the gulf of mexico, locations with increasing inputs of heavy metals such as cadmium that have become environmental stressors. in this study, feeding and assimilation of the species were evaluated as physiological indicators of cadmium exposure. for this purpose, the filtration rate (fr), food assimilation (a) and assimilation efficiency (ae) of oysters from the mandinga lagoon, veracruz, ...201020390836
linking optimization and ecological models in a decision support tool for oyster restoration and management.restoration of ecologically important marine species and habitats is restricted by funding constraints and hindered by lack of information about trade-offs among restoration goals and the effectiveness of alternative restoration strategies. because ecosystems provide diverse human and ecological benefits, achieving one restoration benefit may take place at the expense of other benefits. this poses challenges when attempting to allocate limited resources to optimally achieve multiple benefits, an ...201020437969
the combined influence of sub-optimal temperature and salinity on the in vitro viability of perkinsus marinus, a protistan parasite of the eastern oyster crassostrea virginica.perkinsus marinus is a major cause of mortality in eastern oysters along the gulf of mexico and atlantic coasts. it is also well documented that temperature and salinity are the primary environmental factors affecting p. marinus viability and proliferation. however, little is known about the effects of combined sub-optimal temperatures and salinities on p. marinus viability. this in vitro study examined those effects by acclimating p. marinus at three salinities (7, 15, 25 ppt) to 10 degrees c t ...201020600094
a new lysozyme from the eastern oyster, crassostrea virginica, and a possible evolutionary pathway for i-type lysozymes in bivalves from host defense to digestion.lysozymes are enzymes that lyse bacterial cell walls, an activity widely used for host defense but also modified in some instances for digestion. the biochemical and evolutionary changes between these different functional forms has been well-studied in the c-type lysozymes of vertebrates, but less so in the i-type lysozymes prevalent in most invertebrate animals. some bivalve molluscs possess both defensive and digestive lysozymes.201020633278
microarray analysis of gene expression in eastern oyster (crassostrea virginica) reveals a novel combination of antimicrobial and oxidative stress host responses after dermo (perkinsus marinus) challenge.dermo disease, caused by perkinsus marinus, is one of the most severe diseases of eastern oysters, crassostrea virginica. it causes serious mortalities in both wild and aquacultured oysters. using existing expressed sequence tag (est) resources, we developed a 12k in situ oligonucleotide microarray and used it for the analysis of gene expression profiles of oysters during the interactions between p. marinus and its oyster host. significant gene expression regulation was found at day 30 post-chal ...201020708691
removal of escherichia coli, enterococcus fecalis, coliphage ms2, poliovirus, and hepatitis a virus from oysters (crassostrea virginica) and hard shell clams (mercinaria mercinaria) by depuration.filter-feeding bivalve mollusks (shellfish) can bioaccumulate pathogenic microorganisms in up to 1000-fold higher levels than overlying waters, and therefore disease risks are associated with consuming raw or partially cooked shellfish. many of these shellfish-borne diseases are due to enteric bacteria and viruses associated with fecal contamination. to control shellfish-borne diseases, guidelines for shellfish harvest waters and shellfish meat have been devised, which include cleansing of conta ...201020864199
upregulation in response to infection and antibacterial activity of oyster histone h4.several histones and histone-derived peptides have been shown to have antimicrobial activity and a potential role in innate immune defenses. a histone h4 sequence was identified in a subtractive suppression library containing genes upregulated in american cupped oysters, crassostrea virginica, in response to challenge with the protozoan parasite perkinsus marinus. oyster histone h4 protein levels significantly increased in hemocyte lysates and cell free hemolymph of oysters experimentally challe ...201020883794
interactive effects of cadmium and hypoxia on metabolic responses and bacterial loads of eastern oysters crassostrea virginica gmelin.pollution by toxic metals including cadmium (cd) and hypoxia are important stressors in estuaries and coastal waters which may interactively affect sessile benthic organisms, such as oysters. we studied metabolic responses to prolonged hypoxic acclimation (2 weeks at 5% o2) in control and cd-exposed (30 d at 50 μg l(-1) cd) oysters crassostrea virginica, and analyzed the effects of these stressors on abundance of vibrio spp. in oysters. hypoxia-acclimated oysters retained normal standard metabol ...201020971492
multiple antibacterial histone h2b proteins are expressed in tissues of american oyster.we have previously identified a histone h2b isomer (cvh2b-1) from tissue extracts of the bivalve mollusk, the american oyster (crassostrea virginica). in this paper, we isolate an additional three antibacterial proteins from acidified gill extract by preparative acid-urea-polyacrylamide gel electrophoresis and reversed-phase high performance liquid chromatography. extraction of these proteins from tissue was best accomplished by briefly boiling the tissues in a weak acetic acid solution. additio ...201021145411
american oyster, crassostrea virginica, expresses a potent antibacterial histone h2b protein.an antibacterial protein was purified from acidified gill extract of a bivalve mollusk, the american oyster (crassostrea virginica). protein isolation was best accomplished by briefly boiling the tissues in a weak acetic acid solution. adding protease inhibitors while boiling did not have a major effect on activity recovery. in contrast, use of only protease inhibitors (without boiling) resulted in virtually no recovery of this activity. the amino acid sequence of this antibacterial protein was ...201019949827
co-localized crassostrea virginica and crassostrea ariakensis oysters differ in bioaccumulation, retention and depuration of microbial indicators and human enteropathogens.to evaluate the bioaccumulation, retention and depuration rates of nine pathogens and surrogates when two oyster species were co-localized in tanks of seawater.201019735333
differential fertilization success between two populations of eastern oyster, crassostrea virginica.identification of mechanisms promoting prezygotic reproductive isolation and their prevalence are key goals in evolutionary biology because of their potential role in speciation. in marine broadcast-spawning species, molecular interactions between gamete surface proteins are more important than mating behavior for determining reproductive compatibility. evidence for differential fertilization capacity has been reported from experiments utilizing competing sperm from two males sampled within popu ...201020972259
applications of chemical shift imaging to marine sciences.the successful applications of magnetic resonance imaging (mri) in medicine are mostly due to the non-invasive and non-destructive nature of mri techniques. longitudinal studies of humans and animals are easily accomplished, taking advantage of the fact that mri does not use harmful radiation that would be needed for plain film radiographic, computerized tomography (ct) or positron emission (pet) scans. routine anatomic and functional studies using the strong signal from the most abundant magnet ...201020948912
the occurrence, spatial and temporal distribution, and environmental routes of tetracycline resistance and integrase genes in crassostrea virginica beds.rapid spread of antibiotic resistance genes has placed them under consideration as emerging environmental contaminants. the occurrence and distribution of tetracycline resistance genes (trg) and integrons (int) have been monitored for 2 years in seven oyster beds located in the altamaha river (georgia, usa) estuary. trg/int profiles varied both temporally (p<0.025) and spatially between oysters and their environment (p<0.005) suggesting shifts in sources of contamination and selection of trg/int ...201020851440
a comparison of the copper sensitivity of six invertebrate species in ambient salt water of varying dissolved organic matter concentrations.the copper sensitivity of four saltwater invertebrates (the mussel mytilus galloprovincialis, the oyster crassostrea virginica, the sand dollar dendraster excentricus, and the sea urchin strongylocentrotus purpuratus) was determined experimentally using chronic-estimator embryo-larval test procedures. the effect of sample dissolved organic matter (dom) content on cu bioavailability was determined for these species using commonly prescribed test procedures. comparisons were made among these test ...201020821449
domoic acid uptake and elimination kinetics in oysters and mussels in relation to body size and anatomical distribution of toxin.toxin accumulation by suspension-feeding qualifier depends on a balance between processes regulating toxin uptake (i.e. ingestion and absorption of toxic cells) and elimination (i.e. egestion, exchange among tissues, excretion, degradation and/or biotransformation) during exposure to toxic blooms. this laboratory study compares the size-specific uptake and elimination kinetics of domoic acid (da) from pseudo-nitzschia multiseries in two co-occurring bivalves, the oyster crassostrea virginica and ...201020674991
evaluating ecosystem response to oyster restoration and nutrient load reduction with a multispecies bioenergetics model.many of the world's coastal ecosystems are impacted by multiple stressors each of which may be subject to different management strategies that may have overlapping or even conflicting objectives. consequently, management results may be indirect and difficult to predict or observe. we developed a network simulation model intended specifically to examine ecosystem-level responses to management and applied this model to a comparison of nutrient load reduction and restoration of highly reduced stock ...201020597280
effects of cadmium on anaerobic energy metabolism and mrna expression during air exposure and recovery of an intertidal mollusk crassostrea virginica.marine organisms are exposed to periodical oxygen deficiency and pollution stress in estuarine and coastal zones which may strongly affect their performance and survival. we studied the combined effects of exposure to a common pollutant, cadmium (cd), and intermittent anoxia on anaerobic metabolism, energy status and mrna expression of 13 genes involved in and/or controlled by the hypoxia inducible factor-1 (hif-1) pathway in hepatopancreas of an intertidal bivalve, the eastern oyster crassostre ...201020538354
reconstructing early 17th century estuarine drought conditions from jamestown oysters.oysters (crassostrea virginica) were a central component of the chesapeake bay ecosystem in 1607 when european settlers established jamestown, va, the first permanent english settlement in north america. these estuarine bivalves were an important food resource during the early years of the james fort (jamestown) settlement while the colonists were struggling to survive in the face of inadequate supplies and a severe regional drought. although oyster shells were discarded as trash after the oyste ...201020534581
eastern oyster (crassostrea virginica) delta(15)n as a bioindicator of nitrogen sources: observations and modeling.stable nitrogen isotopes (delta(15)n) in bioindicators are increasingly employed to identify nitrogen sources in many ecosystems and biological characteristics of the eastern oyster (crassostrea virginica) make it an appropriate species for this purpose. to assess nitrogen isotopic fractionation associated with assimilation and baseline variations in oyster mantle, gill, and muscle tissue delta(15)n, manipulative fieldwork in chesapeake bay and corresponding modeling exercises were conducted. th ...201020381097
feeding mechanics as the basis for differential uptake of the neurotoxin domoic acid by oysters, crassostrea virginica, and mussels, mytilus edulis.the neurotoxin domoic acid (da), produced by diatoms pseudo-nitzschia spp., is transferred to humans via consumption of contaminated bivalves. this study examines feeding mechanisms, namely reduced filtration, pre-ingestive rejection and poor absorption, that might explain the comparatively low da levels commonly found in oysters during toxic pseudo-nitzschia blooms. clearance rate (cr), absorption efficiency (ae) of organic matter and selective rejection in pseudofeces of oysters (crassostrea v ...201020153533
Refresh
firstprev
1234567
nextlast
Displaying items 401 - 500 of 695