| sustainable exploitation and management of autogenic ecosystem engineers: application to oysters in chesapeake bay. | autogenic ecosystem engineers are critically important parts of many marine and estuarine systems because of their substantial effect on ecosystem services. oysters are of particular importance because of their capacity to modify coastal and estuarine habitats and the highly degraded status of their habitats worldwide. however, models to predict dynamics of ecosystem engineers have not previously included the effects of exploitation. we developed a linked population and habitat model for autogen ... | 2013 | 23865228 |
| role and value of nitrogen regulation provided by oysters (crassostrea virginica) in the mission-aransas estuary, texas, usa. | suspension-feeding activities of oysters impart a potentially significant benefit to estuarine ecosystems via reduction of water column nutrients, plankton and seston biomass, and primary productivity which can have a significant impact on human well-being. this study considered nitrogen regulation by eastern oysters crassostrea virginica in the mission-aransas estuary, texas, usa, as a function of denitrification, burial, and physical transport from the system via harvest. oyster reefs were est ... | 2013 | 23762341 |
| tissue specific responses of oysters, crassostrea virginica, to silver nanoparticles. | silver nanoparticle (agnp) toxicity in eastern oysters, crassostrea virginica, was investigated in both gill and hepatopancreas tissues, and compared to dissolved ag exposures. oysters were exposed to varying concentrations of agnps prepared with citrate coatings and dissolved ag (agno₃) for 48 h and the effects on a suite of biomarkers of cellular stress were evaluated. two biomarkers of cellular damage were evaluated-lysosomal destabilization rates of hepatopancreas cells as indicators of lyso ... | 2013 | 23728357 |
| interactive effects of elevated temperature and co2 levels on energy metabolism and biomineralization of marine bivalves crassostrea virginica and mercenaria mercenaria. | the continuing increase of carbon dioxide (co2) levels in the atmosphere leads to increases in global temperatures and partial pressure of co2 (pco2) in surface waters, causing ocean acidification. these changes are especially pronounced in shallow coastal and estuarine waters and are expected to significantly affect marine calcifiers including bivalves that are ecosystem engineers in estuarine and coastal communities. to elucidate potential effects of higher temperatures and pco2 on physiology ... | 2013 | 23707887 |
| acanthoparyphium sp. and other metazoan symbionts of the american oyster, crassostrea virginica, from south texas. | in this study, we investigated oysters, crassostrea virginica , from laguna madre in south texas, where a 45-yr old study recorded metacercarial infections of the echinostomatid trematode, acanthoparyphium spinulosum , an asian relative of which, acanthoparyphium tyosenense, has been associated with human infections via the ingestion of raw mollusks. in an effort to examine the base-line infection parameters of acanthoparyphium sp. in oysters, we examined the effect of distance from the shorelin ... | 2013 | 23641833 |
| intraspecific variation influences natural settlement of eastern oysters. | as populations decline, their intraspecific diversity also diminishes. population decline may be exacerbated if a decrease in intraspecific diversity also reduces important ecological functions that maintain population numbers. oyster reefs are severely overharvested, declining by ~85 % worldwide. we tested how increasing within-species diversity of eastern oysters (crassostrea virginica) using transplants would affect recruitment of oyster larvae, a key function necessary to maintain future pop ... | 2013 | 23543216 |
| bioaccumulation and depuration of brevetoxins in the eastern oyster (crassostrea virginica) and the northern quahog (= hard clam, mercenaria mercenaria). | the eastern oyster (crassostrea virginica) and northern quahog (= hard clam, mercenaria mercenaria) are two species of economic and ecological significance in east coast waters of the united states and the gulf of mexico. commercial industries for these species, especially within the state of florida, are significant. the current study was undertaken to build upon the already established body of knowledge surrounding effects of the toxic dinoflagellate karenia brevis on shellfish, to provide an ... | 2013 | 23419594 |
| interactive effects of elevated temperature and co(2) levels on metabolism and oxidative stress in two common marine bivalves (crassostrea virginica and mercenaria mercenaria). | marine bivalves such as the hard shell clams mercenaria mercenaria and eastern oysters crassostrea virginica are affected by multiple stressors, including fluctuations in temperature and co2 levels in estuaries, and these stresses are expected to be exacerbated by ongoing global climate change. hypercapnia (elevated co2 levels) and temperature stress can affect survival, growth and development of marine bivalves, but the cellular mechanisms of these effects are not yet fully understood. in this ... | 2013 | 23319162 |
| active downward propulsion by oyster larvae in turbulence. | oyster larvae (crassostrea virginica) could enhance their settlement success by moving toward the seafloor in the strong turbulence associated with coastal habitats. we characterized the behavior of individual oyster larvae in grid-generated turbulence by measuring larval velocities and flow velocities simultaneously using infrared particle image velocimetry. we estimated larval behavioral velocities and propulsive forces as functions of the kinetic energy dissipation rate ε, strain rate γ, vort ... | 2013 | 23264488 |
| analysis of stomach and gut microbiomes of the eastern oyster (crassostrea virginica) from coastal louisiana, usa. | we used high throughput pyrosequencing to characterize stomach and gut content microbiomes of crassostrea virginica, the easter oyster, obtained from two sites, one in barataria bay (hackberry bay) and the other in terrebonne bay (lake caillou), louisiana, usa. stomach microbiomes in oysters from hackberry bay were overwhelmingly dominated by mollicutes most closely related to mycoplasma; a more rich community dominated by planctomyctes occurred in lake caillou oyster stomachs. gut communities f ... | 2012 | 23251548 |
| assimilation of oil-derived elements by oysters due to the deepwater horizon oil spill. | during and after the deepwater horizon oil spill (dwhos), oysters (crassostrea virginica) were exposed to oil and susceptible to incidental consumption of surface and subsurface oil materials. we determined the contribution of oil materials from the dwhos to diet of oysters by comparing carbon (c) and nitrogen (n) stable isotope ratios in oyster shell to ratios in suspended particulate matter (spm) and in fresh and weathered oil. average δ(13)c and δ(15)n values in oyster shell (-21 ± 1‰ and 9-1 ... | 2012 | 23131011 |
| environmental factors responsible for the incidence of antibiotic resistance genes in pristine crassostrea virginica reefs. | the occurrence of tetracycline resistance (trg) and integrase (int) genes were monitored in crassostrea virginica oyster reefs of three pristine creeks (sinerr, georgia, usa). their profiles revealed 85% similarity with the trg/int profiles observed in the adjacent to the sinerr and contaminated altamaha river estuary (barkovskii et al., 2010). the trg/int spectra and incidence frequencies corresponded to the source of oceanic input and to run-offs from creeks' watersheds. the highest incidence ... | 2012 | 23122628 |
| integrating paleobiology, archeology, and history to inform biological conservation. | the search for novel approaches to establishing ecological baselines (reference conditions) is constrained by the fact that most ecological studies span the past few decades, at most, and investigate ecosystems that have been substantially altered by human activities for decades, centuries, or more. paleobiology, archeology, and history provide historical ecological context for biological conservation, remediation, and restoration. we argue that linking historical ecology explicitly with conserv ... | 2013 | 22979917 |
| predator cue and prey density interactively influence indirect effects on basal resources in intertidal oyster reefs. | predators can influence prey abundance and traits by direct consumption, as well as by non-consumptive effects of visual, olfactory, or tactile cues. the strength of these non-consumptive effects (nces) can be influenced by a variety of factors, including predator foraging mode, temporal variation in predator cues, and the density of competing prey. testing the relative importance of these factors for determining nces is critical to our understanding of predator-prey interactions in a variety of ... | 2012 | 22970316 |
| environmental proteomics of the mussel mytilus: implications for tolerance to stress and change in limits of biogeographic ranges in response to climate change. | climate change will affect temperature extremes and averages, and hyposaline conditions in coastal areas due to extreme precipitation events and oceanic ph. how climate change will push species close to, or beyond, their physiological tolerance limits as well as change the limits of their biogeographic ranges can probably be investigated best in species that have already responded to climate change and whose distribution ranges are currently in flux. blue mussels provide such a study system, wit ... | 2012 | 22966064 |
| pilot study on effects of nanoparticle exposure on crassostrea virginica hemocyte phagocytosis. | little is known about engineered nanoparticles (nps) exposures on oysters. as sessile filter feeders, oysters are likely to be exposed to nps suspended in the water column with unknown effects of np exposure on oyster functioning. our study indicates that waterborne nps alter oyster hemocyte phagocytosis dynamics, an indication of sub-lethal effects of np exposures. silver nps, titanium dioxide (tio(2)) nps, and silver nitrate exposures reduced phagocytosis compared to the control. increasing ti ... | 2012 | 22835473 |
| effects of temperature and cadmium exposure on the mitochondria of oysters (crassostrea virginica) exposed to hypoxia and subsequent reoxygenation. | intertidal bivalves are commonly exposed to multiple stressors including periodic hypoxia, temperature fluctuations and pollution, which can strongly affect energy metabolism. we used top-down control and elasticity analyses to determine the interactive effects of intermittent hypoxia, cadmium (cd) exposure and acute temperature stress on mitochondria of the eastern oyster crassostrea virginica. oysters were acclimated at 20°c for 30 days in the absence or presence of 50 μg l(-1) cd and then sub ... | 2012 | 22660786 |
| identification of a novel metal binding protein, segon, in plasma of the eastern oyster, crassostrea virginica. | the second most abundant protein of eastern oyster plasma was purified, characterized and named segon. the 39 kda protein as determined by sds-page under reducing conditions made up about 17% of plasma proteins and was found in extrapallial fluid. race reactions with primers designed from an est sequence identified by blast search in genbank using the n-terminal amino acid sequence obtained by edman degradation of the purified protein, predicted a 997 bp complete cdna that encoded 277 amino acid ... | 2012 | 22580268 |
| immunomodulation in eastern oysters, crassostrea virginica, exposed to a pah-contaminated, microphytobenthic diatom. | the trophic transfer of sediment-associated pollutants is a growing concern in shellfish harvesting areas. previous studies have examined the role of phytoplankton in the transport of organic contaminants to bivalve species, but little information on microphytobenthic communities and their role as contaminant vectors exists. polycyclic aromatic hydrocarbons (pahs) are organic compounds formed during natural and industrial processes; they are termed "persistent organic pollutants" because they ar ... | 2012 | 22504373 |
| expression of candidate genes related to metabolism, immunity and cellular stress during massive mortality in the american oyster crassostrea virginica larvae in relation to biochemical and physiological parameters. | quantification of mrna of genes related to metabolism, immunity and cellular stress was examined in relation to a massive mortality event during the culture of american oyster larvae, crassostrea virginica which was probably, in regard to previous microbiological analysis, induced by vibrio infection. to document molecular changes associated with the mortality event, mrna levels were compared to biochemical and physiological data, previously described in a companion paper. among the 18 genes stu ... | 2012 | 22417898 |
| identifying and reducing aflp genotyping error: an example of tradeoffs when comparing population structure in broadcast spawning versus brooding oysters. | phylogeographic inferences about gene flow are strengthened through comparison of co-distributed taxa, but also depend on adequate genomic sampling. amplified fragment length polymorphisms (aflps) provide a rapid and inexpensive source of multilocus allele frequency data for making genomically robust inferences. every aflp study initially generates markers with a range of locus-specific genotyping error rates and applies criteria to select a subset for analysis. however, there has been very litt ... | 2012 | 22274647 |
| interactive effects of salinity and elevated co2 levels on juvenile eastern oysters, crassostrea virginica. | rising levels of atmospheric co(2) lead to acidification of the ocean and alter seawater carbonate chemistry, which can negatively impact calcifying organisms, including mollusks. in estuaries, exposure to elevated co(2) levels often co-occurs with other stressors, such as reduced salinity, which enhances the acidification trend, affects ion and acid-base regulation of estuarine calcifiers and modifies their response to ocean acidification. we studied the interactive effects of salinity and part ... | 2012 | 22162851 |
| biosorption of thorium on the external shell surface of bivalve mollusks: the role of shell surface microtopography. | external shell surface (ess) of bivalve mollusks is known to adsorb various metals dissolved in ambient water in high concentration. it is hypothesized here that the surface microtopography of the thin organic coating layer, periostracum, or calcareous shell (if periostracum was destroyed) plays a major role in the adsorption of actinides on ess. thorium (natural alpha-emitter) was used in short-term biosorption experiment with shell fragments of five bivalve mollusks. after a 72 h exposure to t ... | 2012 | 22154000 |
| the effect of structural complexity, prey density, and "predator-free space" on prey survivorship at created oyster reef mesocosms. | interactions between predators and their prey are influenced by the habitat they occupy. using created oyster (crassostrea virginica) reef mesocosms, we conducted a series of laboratory experiments that created structure and manipulated complexity as well as prey density and "predator-free space" to examine the relationship between structural complexity and prey survivorship. specifically, volume and spatial arrangement of oysters as well as prey density were manipulated, and the survivorship of ... | 2011 | 22145037 |
| effects of elevated temperature and carbon dioxide on the growth and survival of larvae and juveniles of three species of northwest atlantic bivalves. | rising co(2) concentrations and water temperatures this century are likely to have transformative effects on many coastal marine organisms. here, we compared the responses of two life history stages (larval, juvenile) of three species of calcifying bivalves (mercenaria mercenaria, crassostrea virginica, and argopecten irradians) to temperatures (24 and 28°c) and co(2) concentrations (∼250, 390, and 750 ppm) representative of past, present, and future summer conditions in temperate estuaries. res ... | 2011 | 22066018 |
| complete mitochondrial dna sequence of the european flat oyster ostrea edulis confirms ostreidae classification. | because of its typical architecture, inheritance and small size, mitochondrial (mt) dna is widely used for phylogenetic studies. gene order is generally conserved in most taxa although some groups show considerable variation. this is particularly true in the phylum mollusca, especially in the bivalvia. during the last few years, there have been significant increases in the number of complete mitochondrial sequences available. for bivalves, 35 complete mitochondrial genomes are now available in g ... | 2011 | 21989403 |
| the ability of pas, acetylsalicylic acid and calcium disodium edta to protect against the toxic effects of manganese on mitochondrial respiration in gill of crassostrea virginica. | manganese (mn) is an essential metal that at excessive levels in brain causes manganism, a condition similar to parkinson's disease. previously we showed that mn had a neurotoxic effect on the dopaminergic, but not serotonergic, innervation of the lateral ciliated cells in the gill of the eastern oyster, crassostrea virginica. while the mechanism of action of mn toxicity is not completely understood, studies suggest that mn toxicity may involve mitochondrial damage and resulting neural dysfuncti ... | 2011 | 21977482 |
| identification of dopamine d2 receptors in gill of crassostrea virginica. | the lateral epithelial cells of gill of crassostrea virginica are innervated by dopamine and serotonin nerves that regulate the beating rate of their lateral cilia. terminal release of dopamine slows down the beating rate of the cilia, while serotonin release increases the beating rate. previously, we showed that the dopaminergic, but not the serotonergic, mechanism regulating the beating rate of the lateral cilia was disrupted by manganese treatments and that this disruption was occurring posts ... | 2011 | 21850279 |
| the effects of copper and copper blocking agents on gill mitochondrial o(2) utilization of crassostrea virginica. | while essential in trace amounts, excess copper is toxic to cells and tissues. copper is a major aquatic pollutant. previously, our lab demonstrated that tissues of the bivalve mollusc crassostrea virginica readily accumulated copper and other metals from their surrounding environment. in this study we showed that o(2) consumption in isolated gill mitochondria of c. virginica was impaired by in vitro copper additions and that copper's deleterious effects on mitochondria respiration could be bloc ... | 2010 | 21841976 |
| viral basophilic inclusions in the digestive gland of razor clams ensis arcuatus (pharidae) in galicia (nw spain). | during a histological survey of razor clam ensis arcuatus (jeffreys, 1865) from galicia (nw spain), basophilic inclusion bodies were observed in epithelial cells of the digestive gland. transmission electron microscopy revealed the intranuclear position of these inclusions containing viral particles with icosahedral symmetry. size and symmetry of these unenveloped virus particles suggest similarities to the families papillomaviridae and polyomaviridae which have been described as causing a viral ... | 2011 | 21790071 |
| proteomic response to elevated pco2 level in eastern oysters, crassostrea virginica: evidence for oxidative stress. | estuaries are characterized by extreme fluctuations in co(2) levels due to bouts of co(2) production by the resident biota that exceed its capacity of co(2) consumption and/or the rates of gas exchange with the atmosphere and open ocean waters. elevated partial pressures of co(2) (p(co(2)); i.e. environmental hypercapnia) decrease the ph of estuarine waters and, ultimately, extracellular and intracellular ph levels of estuarine organisms such as mollusks that have limited capacity for ph regulat ... | 2011 | 21562170 |
| electrochemical characterization of a bioceramic material: the shell of the eastern oyster crassostrea virginica. | the shell of the eastern oyster (crassostrea virginica) is composed of multiple incongruent mineralized layers. this bioceramic composite material was investigated to determine the effects of shell thickness, orientation and layer composition on its electrochemical behavior using electrochemical impedance spectroscopy, potentiodynamic polarization and scanning electron microscopy-energy dispersive spectroscopy. sem-eds analysis of the oyster shell revealed that the multilayered biocomposite mate ... | 2011 | 21550319 |
| the transcriptomic responses of the eastern oyster, crassostrea virginica, to environmental conditions. | understanding the mechanisms by which organisms adapt to environmental conditions is a fundamental question for ecology and evolution. in this study, we evaluate changes in gene expression of a marine mollusc, the eastern oyster crassostrea virginica, associated with the physico-chemical conditions and the levels of metals and other contaminants in their environment. the results indicate that transcript signatures can effectively disentangle the complex interactive gene expression responses to t ... | 2011 | 21426432 |
| effects of age and composition of field-produced biofilms on oyster larval setting. | lack of success in restoring the native eastern oyster, crassostrea virginica, to chesapeake bay has been linked to the low occurrence of oyster larval setting in tributaries to the bay. among the many potential factors that could affect efforts to produce oysters through aquaculture or supplementation of shell beds is substratum condition. the present study examined larval setting on field-produced biofilms from little wicomico river (virginia, usa) to assess whether bacterial community structu ... | 2011 | 21360359 |
| cadmium, lead and zinc concentrations in water, sediment and oyster (crassostrea virginica) of san andres lagoon, mexico. | the spatial distribution of cadmium, lead and zinc concentrations in water, sediment and oysters from san andres lagoon was evaluated. significantly higher cadmium (0.33 mg l(-1)) and lead (0.70 mg l(-1)) concentrations in water were observed in front of the mouth of tigre river, whereas, zinc concentration (5.0 mg l(-1)) was significantly higher in the south part of the lagoon. similarly, lead and zinc values in sediment (1.01 and 9.29 μg g(-1), respectively) and oyster tissue (0.86 and 3.19 μg ... | 2011 | 21336861 |
| metabolomic investigations of american oysters using h-nmr spectroscopy. | the eastern oyster (crassostrea virginica) is a useful, robust model marine organism for tissue metabolism studies. its relatively few organs are easily delineated and there is sufficient understanding of their functions based on classical assays to support interpretation of advanced spectroscopic approaches. here we apply high-resolution proton nuclear magnetic resonance ((1)h nmr)-based metabolomic analysis to c. virginica to investigate the differences in the metabolic profile of different or ... | 2010 | 21116407 |
| molecular characterization and mrna expression of two key enzymes of hypoxia-sensing pathways in eastern oysters crassostrea virginica (gmelin): hypoxia-inducible factor α (hif-α) and hif-prolyl hydroxylase (phd). | oxygen homeostasis is crucial for development, survival and normal function of all metazoans. a family of transcription factors called hypoxia-inducible factors (hif) is critical in mediating the adaptive responses to reduced oxygen availability. the hif transcription factor consists of a constitutively expressed β subunit and an oxygen-dependent α subunit; the abundance of the latter determines the activity of hif and is regulated by a family of o(2)- and fe(2+)-dependent enzymes prolyl hydroxy ... | 2011 | 21106446 |
| 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 ... | 2010 | 20972259 |
| 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 ... | 2010 | 20948912 |
| 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 ... | 2010 | 20851440 |
| top-down control analysis of the cadmium effects on molluscan mitochondria and the mechanisms of cadmium-induced mitochondrial dysfunction. | cadmium (cd) is a toxic metal and an important environmental pollutant that can strongly affect mitochondrial function and bioenergetics in animals. we investigated the mechanisms of cd action on mitochondrial function of a marine mollusk (the eastern oyster crassostrea virginica) by performing a top-down control analysis of the three major mitochondrial subsystems (substrate oxidation, proton leak, and phosphorylation). our results showed that the substrate oxidation and proton leak subsystems ... | 2011 | 20844261 |
| 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 ... | 2010 | 20821449 |
| 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 ... | 2010 | 20674991 |
| 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 ... | 2010 | 20597280 |
| 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 ... | 2010 | 20538354 |
| 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 ... | 2010 | 20534581 |
| 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 ... | 2010 | 20381097 |
| 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 ... | 2010 | 20153533 |
| first u.s. report of shellfish harvesting closures due to confirmed okadaic acid in texas gulf coast oysters. | between march 7 and april 12, 2008, several bay systems on the east (gulf of mexico) coast of texas, usa were closed to the harvesting of oysters (crassostrea virginica) due to the presence of the dsp (diarrheic shellfish poisoning) toxin okadaic acid in excess of the 20 microg/100 g tissue fda regulatory guidance level. this was the first shellfish harvesting closure due to the confirmed presence of dsp toxins in us history. light microscopic cell counts were performed on water samples collecte ... | 2010 | 20060850 |
| seasonal variation in mitochondrial responses to cadmium and temperature in eastern oysters crassostrea virginica (gmelin) from different latitudes. | cadmium (cd) is an important environmental pollutant that can lead to impairment of cellular functions, energy misbalance and negatively impact survival in estuarine organisms including oysters. like other marine bivalves, oysters can accumulate high cd burdens in their tissues and are susceptible to the toxic effects of this metal. presently, the factors that affect sensitivity to cd toxicity and its variation in wild oyster populations are poorly understood. we analyzed geographical and season ... | 2010 | 20047766 |
| effects of potential therapeutic agents on copper accumulations in gill of crassostrea virginica. | copper is an essential trace element for organisms, but when in excess, copper's redox potential enhances oxyradical formation and increases cellular oxidative stress. copper is a major pollutant in jamaica bay and other aquatic areas. bivalves are filter feeders that accumulate heavy metals and other pollutants from their environment. previously it was determined that seed from the bivalve crassostrea virginica, transplanted from an oyster farm to jamaica bay readily accumulated copper and othe ... | 2010 | 21841975 |
| modelling interactions of acid-base balance and respiratory status in the toxicity of metal mixtures in the american oyster crassostrea virginica. | heavy metals, such as copper, zinc and cadmium, represent some of the most common and serious pollutants in coastal estuaries. in the present study, we used a combination of linear and artificial neural network (ann) modelling to detect and explore interactions among low-dose mixtures of these heavy metals and their impacts on fundamental physiological processes in tissues of the eastern oyster, crassostrea virginica. animals were exposed to cd (0.001-0.400 microm), zn (0.001-3.059 microm) or cu ... | 2010 | 19958840 |
| effects of p-aminosalicylic acid on the neurotoxicity of manganese on the dopaminergic innervation of the cilia of the lateral cells of the gill of the bivalve mollusc, crassostrea virginica. | the lateral cilia of the gill of crassostrea virginica are controlled by a dopaminergic-serotonergic innervation. dopamine is the neurotransmitter causing cilio-inhibition. high levels of manganese are neurotoxic to people, causing manganism, a parkinson-like disease. clinical interventions for manganism have not been very successful. recently, p-aminosalicylic acid (pas) was reported as an effective treatment of severe manganism in humans; however, its mechanism of action is unknown. previously ... | 2010 | 19944778 |
| the effects of silver nanoparticles on oyster embryos. | nanoparticles may be introduced into aquatic environments during production processes and also as a result of release following their use in various commercial formulations and biologic applications. filter-feeding bivalve mollusks such as oysters are valuable model species for characterizing nanoparticle bioavailability and interactions with basic cellular processes. the adults release their gametes into the environment, so their embryos and larvae are also likely targets of nanoparticles. the ... | 2010 | 19913905 |
| flow-cytometric analyses of viability biomarkers in pesticide-exposed sperm of three aquatic invertebrates. | toxicity studies on sperm often use fertilization success as the end point. this type of assay can be affected by sperm density, egg quality, and sperm-egg compatibility. testing sperm viability biomarkers with flow cytometry is a fast, high-throughput technique for seminal analysis. in this study, we detected sperm viability biomarkers with several fluorescent reporter dyes using flow cytometry in three aquatic invertebrates (crassostrea virginica, dreissena polymorpha, and lytechinus variegatu ... | 2010 | 19876686 |
| crassostrea virginica grazing on toxic and non-toxic diatoms. | despite high abundances of toxic pseudo-nitzschia spp. over louisiana oyster beds (crassostrea virginica; eastern oyster) there have been no documented cases of amnesic shellfish poisoning (asp) in the state. two possible explanations are that oysters do not readily feed on long pointed chains of pseudo-nitzschia cells or they discriminate against toxic cells while grazing. to test these hypotheses, short-term grazing experiments were conducted with several diatoms, including the domoic acid (da ... | 2013 | 19835902 |
| 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 ... | 2009 | 19806754 |
| 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 ... | 2009 | 19726715 |
| 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 ... | 2009 | 19525006 |
| 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 ... | 2009 | 19167734 |
| 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 ... | 2008 | 19137933 |
| 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 ... | 2009 | 19130302 |
| 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 ... | 2009 | 19124164 |
| 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 ... | 2009 | 19103305 |
| 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 ... | 2009 | 20403746 |
| 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), ... | 2008 | 18780214 |
| 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 ... | 2009 | 18763037 |
| 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 ... | 2008 | 18662818 |
| 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 ... | 2008 | 18547869 |
| 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 ... | 2008 | 18453012 |
| 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 ... | 2008 | 18434254 |
| 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 ... | 2008 | 18333680 |
| 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 ... | 2008 | 18310122 |
| 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 ... | 2008 | 18296092 |
| 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 ... | 2008 | 18272660 |
| 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 ... | 2008 | 18245635 |
| 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 ... | 2008 | 18044742 |
| bioaccumulation and tissue distribution of arsenic, cadmium, copper and zinc in crassostrea virginica grown at two different depths in jamaica bay, new york. | historically, jamaica bay was a site of extensive oyster beds and shellfish culture leases that supported a significant oyster fishery in the new york area. the industrial and urban expansion of the early 1900's led to over-harvesting and a deterioration in water and bay sediment quality that coincided with shellfish decline and the ultimate disappearance of oysters from the bay. over the past 50 years, efforts to arrest and reverse the pollution problems of jamaica bay have been undertaken but ... | 2007 | 21841973 |
| 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 ... | 2008 | 17869588 |
| temperature adaptation in two bivalve species from different thermal habitats: energetics and remodelling of membrane lipids. | we compared lipid dynamics and the physiological responses of blue mussels mytilus edulis, a cold-adapted species, and oysters crassostrea virginica, a warmer-water species, during simulated overwintering and passage to spring conditions. to simulate overwintering, animals were held at 0 degrees c, 4 degrees c and 9 degrees c for 3 months and then gradually brought to and maintained at 20 degrees c for 5 weeks to simulate spring-summer conditions. changes in lipid class and fatty acid compositio ... | 2007 | 17704075 |
| effect of cadmium, chromium, lead and metal mixtures on survival and growth of juveniles of the scallop argopecten ventricosus (sowerby ii, 1842). | the effects of cd, cr, pb and their mixtures on the growth and sensitivity of the scallop argopecten ventricosus were analyzed in this study. cadmium showed to be more toxic metal to juveniles (96 hour median lethal concentration (lc(50)) = 0.396 mg cd/l), followed by lead (lc(50) = 0.830 mg pb/l) and chromium (lc(50) = 3.430 mg cr/l). cadmium toxicity was 8 times higher than chromium and 2 times than lead. the most toxic combination was cd + cr + pb. (lc(50) = 0.302 mg/l). based on toxic units ... | 2007 | 17680483 |
| tem immunocytochemistry of a 48 kda mw organic matrix phosphoprotein produced in the mantle epithelial cells of the eastern oyster (crassostrea virginica). | immunohistochemical tem of eastern oyster (crassostrea virginica) mantle epithelial cells using a polyclonal antibody to a gel purified 48 kda mw oyster shell phosphoprotein revealed that it is phosphorylated in the golgi, packaged into secretory vesicles and subsequently exocytosed across the apical membrane of specialized cells. these phosphoprotein producing cells are concentrated along the mantle side facing the shell, in the region of the outer mantle lobe. a layer of calcium enriched immun ... | 2007 | 17675199 |
| the nervous system control of lateral ciliary activity of the gill of the bivalve mollusc, crassostrea virginica. | lateral cilia of the gill of mytilus edulis are controlled by a reciprocal serotonergic-dopaminergic innervation from their ganglia. other bivalves have been studied to lesser degrees and lateral cilia of most respond to serotonin and dopamine when applied directly to the gill indicating a possible neuro or endocrine mechanism. lateral cilia in crassostrea virginica are affected by serotonin and dopamine, but little work has been done regarding ganglionic control of their cilia. we examined the ... | 2007 | 17616414 |
| development and characterization of est-ssr markers in the eastern oyster crassostrea virginica. | simple sequence repeat (ssr) markers were developed from expressed sequence tags (ests) in the eastern oyster (crassostrea virginica). ests of the eastern oyster were downloaded from genbank and screened for ssrs with at least eight units of dinucleotide or five units of tri-, tetra-, penta-, and hexa-nucleotide repeats. the screening of 9101 ests identified 127 (1.4%) ssr-containing sequences. primers were designed for 88 ssr-containing ests with good and sufficient flanking sequences. polymera ... | 2007 | 17558533 |
| change in lipid composition in eastern oyster (crassostrea virginica gmelin) exposed to constant or fluctuating temperature regimes. | a temperature decrease usually induces an ordering effect in membrane phospholipids that can lead to membrane dysfunction. ectotherms typically counteract this temperature effect by remodeling membrane lipids as stipulated in the homeoviscous adaptation theory (hva). previous studies mostly focused on the remodeling of membrane lipids during long-term acclimatization or acclimation at constant temperature regimes, whereas in nature, many organisms experience variations in temperature on a daily ... | 2007 | 17468027 |
| three new satellite sequences and a mobile element found inside hsp70 introns of the mediterranean mussel (mytilus galloprovincialis). | we report the characterization of 3 new repetitive sequences from the bivalve mollusc mytilus galloprovincialis, designated mg1, mg2, and mg3, with monomer lengths of 169, 260, and 70 bp, respectively. the 3 repeats together constitute approximately 7.8% of the m. galloprovincialis genome and were found, together with apai-type 2 repeats, inside the introns of 2 genes of the hsp70 family, hsc70 and hsc71. both the monomer length and the genomic content of the repeats indicate satellite sequences ... | 2006 | 17426760 |
| effects of ammonia on cellular biomarker responses in oysters (crassostrea virginica). | | 2007 | 17333422 |
| interspecific variation in patterns of adhesion of marine fouling to silicone surfaces. | the adhesion of six fouling organisms: the barnacle balanus eburneus, the gastropod mollusc crepidulafornicata, the bivalve molluscs crassostrea virginica and ostrea/dendrostrea spp., and the serpulid tubeworms hydroides dianthus and h. elegans, to 12 silicone fouling-release surfaces was examined. removal stress (adhesion strength) varied among the fouling species and among the surfaces. principal component analysis of the removal stress data revealed that the fouling species fell into two dist ... | 2006 | 17290867 |
| comparative effects of the toxic dinoflagellate karenia brevis on clearance rates in juveniles of four bivalve molluscs from florida, usa. | the effects of karenia brevis (gymnodiniales, gymnodiniaceae) on the feeding activity of juveniles of four species of bivalve mollusc were examined in the laboratory to assess the potential impacts on these important shellfish populations from florida. clearance rates were determined under short-term (one hour) static and long-term (two days) flow-through conditions using both whole and lysed cultures of k. brevis. under short-term conditions, the bay scallop, argopecten irradians, was the most ... | 2007 | 17182073 |
| acute toxicity and acetylcholinesterase inhibition in grass shrimp (palaemonetes pugio) and oysters (crassostrea virginica) exposed to the organophosphate dichlorvos: laboratory and field studies. | the use of various organophosphates to control mosquito populations is a common practice across the globe. we review the literature (lc50s) on dichlorvos, the primary breakdown product of dibrom, and use laboratory and field experiments to determine the lethal and sublethal (bioassays) effects of dichlorvos on two widely distributed and ecologically important estuarine invertebrate species, the marsh grass shrimp, palaemonetes pugio and the eastern oyster, crassostrea virginica. laboratory resul ... | 2007 | 17171303 |
| temperature-dependent effects of cadmium and purine nucleotides on mitochondrial aconitase from a marine ectotherm, crassostrea virginica: a role of temperature in oxidative stress and allosteric enzyme regulation. | temperature and heavy metals such as cadmium (cd) are important environmental stressors that can strongly affect mitochondrial function of marine poikilotherms. in this study, we investigated the combined effects of temperature (20 degrees c and 30 degrees c) and cd stress on production of reactive oxygen species (ros) and oxidative stress in a marine poikilotherm crassostrea virginica (the eastern oyster) using mitochondrial aconitase as a sensitive biomarker of oxidative damage. we also assess ... | 2007 | 17170147 |
| a new lysozyme from the eastern oyster (crassostrea virginica) indicates adaptive evolution of i-type lysozymes. | a new lysozyme (cv-lysozyme 2) with a maldi molecular mass of 12 984.6 da was purified from crystalline styles and digestive glands of eastern oysters (crassostrea virginica) and its cdna sequenced. quantitative real time rt-pcr detected cv-lysozyme 2 gene expression primarily in digestive gland tissues, and in situ hybridization located cv-lysozyme 2 gene expression in basophil cells of digestive tubules. cv-lysozyme 2 showed high amino acid sequence similarity to other bivalve mollusk lysozyme ... | 2007 | 17160350 |
| the development of an aquatic bivalve model: evaluating the toxic effects on gametogenesis following 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-tcdd) exposure in the eastern oyster (crassostrea virginica). | the objective of this study is to develop a gametogenesis protocol to serve as a model for evaluating the toxic effects of chemicals on oogenesis and spermatogenesis in the eastern oyster (crassostrea virginica). the compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-tcdd) was selected as a "proof of principle" toxicant to examine developmental toxicity in this invertebrate system. the studies were designed to: (1) test the model using 2,3,7,8-tcdd and (2) to use histopathological evaluations ... | 2007 | 17156862 |
| 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 ... | 2008 | 17071849 |
| combined effects of temperature acclimation and cadmium exposure on mitochondrial function in eastern oysters crassostrea virginica gmelin (bivalvia: ostreidae). | cadmium and temperature have strong impacts on the metabolic physiology of aquatic organisms. to analyze the combined impact of these two stressors on aerobic capacity, effects of cd exposure (50 microg/l) on mitochondrial function were studied in oysters (crassostrea virginica) acclimated to 12 and 20 degrees c in winter and to 20 and 28 degrees c in fall. cadmium exposure had different effects on mitochondrial bioenergetics of oysters depending on the acclimation temperature. in oysters acclim ... | 2006 | 16986802 |
| new resources for marine genomics: bacterial artificial chromosome libraries for the eastern and pacific oysters (crassostrea virginica and c. gigas). | large-insert genomic bacterial artificial chromosome (bac) libraries of two culturally and economically important oyster species, crassostrea virginica and c. gigas, have been developed as part of an international effort to develop tools and reagents that will advance our ability to conduct genetic and genomic research. a total of 73,728 c. gigas clones with an average insert size of 152 kb were picked and arrayed representing an 11.8-fold genome coverage. a total of 55,296 clones with an averag ... | 2006 | 16896533 |
| temperature-dependent stress response in oysters, crassostrea virginica: pollution reduces temperature tolerance in oysters. | combined effects of temperature and a toxic metal, cadmium (cd), on energy metabolism were studied in a model marine bivalve, the eastern oyster crassostrea virginica, acclimated at 20, 24 and 28 degrees c and exposed to 50microgl(-1) of cd. both increasing temperature and cd exposure led to a rise in standard metabolic rates, and combined stressors appeared to override the capability for aerobic energy production resulting in impaired stress tolerance. oysters exposed to elevated temperature bu ... | 2006 | 16887206 |
| effects of the dinoflagellate karenia brevis on larval development in three species of bivalve mollusc from florida. | the effects of karenia brevis (wilson clone) on larval survival and development of the northern quahog, mercenaria mercenaria, eastern oyster, crassostrea virginica and bay scallop, argopecten irradians, were studied in the laboratory. larvae were exposed to cultures of whole and lysed cells, with mean total brevetoxin concentrations of 53.8 and 68.9 microgl(-1), respectively. survival of early (3-day-old) larvae was generally over 85% for all shellfish species at k. brevis densities of 100 cell ... | 2006 | 16814341 |
| assessment of gamete quality for the eastern oyster (crassostrea virginica) by use of fluorescent dyes. | evaluation of sperm motility is the single most widely used parameter to determine semen quality in mammals and aquatic species. while a good indicator for fresh sperm viability, post-thaw motility is not always effective at predicting fertilizing ability. techniques using fluorescent dyes can assess functionality of mammalian sperm, but have not been widely applied in aquatic organisms. the eastern oyster crassostrea virginica is an important mollusk in the united states, and cryopreservation p ... | 2006 | 16777086 |
| temperature-dependent effects of cadmium on mitochondrial and whole-organism bioenergetics of oysters (crassostrea virginica). | intertidal mollusks are exposed to multiple stressors in estuaries, including temperature and trace metals such as cadmium, which may interactively affect their physiology. we have studied the combined effects of temperature and cadmium stress on metabolism of oysters at the whole animal and mitochondrial levels. in vivo exposure to 50 microg l(-1) cd led to a significant increase in basal metabolic rate (bmr) in 20 degrees c-acclimated but not in 28 degrees c-acclimated oysters. cadmium exposur ... | 2006 | 16690114 |