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Sample records for bivalvo crassostrea angulata

  1. Effect of marine contamination on the genetic population structure of the bivalve Crassostrea angulata; Efecto de la contaminacion marina sobre la estructura genetica poblacional del bivalvo Crassostrea angulata

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    Cross, Ismael; Rebordinos, Laureana [Laboratorio de Genetica, Facultad de Ciencias del Mar, Universidad de Cadiz, Cadiz (Spain)

    2003-06-15

    Seven enzyme loci were analyzed in three natural populations of Crassostrea angulata located on the southern Atlantic coast of the Iberian Peninsula. Two of the populations showed distinct levels of contamination by heavy metals, whereas the third was not contaminated and served as control. These seven loci were shown to be very variable in terms of the number of alleles, polymorphism and average heterozygosity. The Lap and Mdh1 loci presented null alleles. A significant positive correlation was found between the number of alleles and the concentration of iron that was fitted to a model of linear regression. However, this correlation was negative for the heterozygosity, and significant for cadmium and zinc. The Em, Lap, Mdh1 y Xdh loci showed a deficit of heterozygotes in all the populations. The values of heterozygotic deficit (D) were statistically significant between the contaminated populations and the control for Mdh1 and very close to a significant level for Em. In Pgm, a heterozygotic excess appeared in the control population and deficit, which was correlated to the increased levels of metal concentration, occurred in the other two populations. The differences between the D values of the three populations were also significant in this locus. Positive, negative and significant relationships were obtained between the concentration of metals and some alleles of the Em, Lap and Pgm loci. Also, the homozygotic genotypes of the alleles with positive correlation values were selected in the contaminated areas, while the heterozygotes were more favoured in the control population, showing an adaptive behavior and corroborating the utility of some of these loci as biomarkers in studies of population dynamics in areas subjected to environmental contamination. [Spanish] Se analizaron siete loci alozimicos en tres poblaciones naturales de Crassostrea angulata localizadas en la costa suratlantica de la Peninsula Iberica. Dos de las poblaciones mostraban distintos niveles

  2. Interspecific hybridization between Crassostrea angulata and C. ariakensis

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    Yao, Tuo; Zhang, Yuehuan; Yan, Xiwu; Wang, Zhaoping; Li, Dongchun; Su, Jiaqi; Yu, Ruihai

    2015-08-01

    Interspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish species in China. We conducted 2 × 2 reciprocal crosses to determine whether these two species can cross-fertilize and their hybrids can hatch, survive and perform heterosis. Fertilization was found symmetrical without delay. The rate of fertilization success of C. angulata ♀ × C. ariakensis ♂ was lower than that of C. ariakensis ♀ × C. angulata ♂, and the success rate of both hybridizations was lower than that of two intraspecific crosses each. During the planktonic period, survival rate of the progeny was lower in the hybrid crosses than in the intraspecific crosses. On day 360, mean shell height of the progeny of C. angulata ♀ × C. angulata ♂ was highest, which was followed by that of C. angulata ♀ × C. ariakensis ♂, C. ariakensis ♀ × C. ariakensis ♂ and C. ariakensis ♀ × C. angulata ♂ in a descending order. Morphology of adults produced by the hybrid crosses was similar to that of C. angulata. Both hybrids underwent normal gonad development and produced mature gametes in the mating season. This study provided new insights into the quantitative traits in interspecific crosses of Crassostrea species, thus being of guidance value for selective breeding of oyster.

  3. The influence of different microalgal diets on Crassostrea angulata (Lamarck, 1819 broodstock conditioning

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    Catarina Anjos

    2014-06-01

    Full Text Available The Portuguese oyster Crassostrea angulata shows great potential in oyster farming. In Europe, pure populations of this species were observed only in the southern coasts of Portugal and Spain, namely in Rio Sado, Rio Mira and Guadalquivir. The conservation of C. angulata populations is important in the context of production diversification and biodiversity preservation. In this way the zootechnological development for seed hatchery production is extremely important. Broodstock conditioning is a key step in the process of rearing bivalve in hatchery. Many factors regulate the reproductive cycle, being food the most important. However the influence of the nutritional quality of different phytoplankton on sexual maturation has been poorly explored. To evaluate the effects of different diets on C. angulata sexual maturity, broodstock were conditioned with different food regimes: Diet 1: bi-specific combination of Pavlova lutheri and Isochrysis galbana clone T-ISO (1:1; Diet 2: tri-specific combination of P. lutheri, I galbana clone T-ISO and Skeletonema constatum (1:1:1; Diet 3: bi-specific combination of S. constatum and Chaetoceros calcitrans (1:1 and Diet 4: tri-specific combination of P. lutheri, S. constatum and C. calcitrans (1:1:1. During conditioning, condition index and gonad histological analysis were performed. Results showed heterogeneity between diets. At the beginning of conditioning 60% of individuals were in resting (stage 0, 30% were males in early gametogenesis (stage I and 10% were females in mature stage (stage III. At the end of the conditioning, the most effective diet was the Diet 3 (60 % of mature oysters with a mean condition index value of 2.83±0.95. Whereas those fed with Diet 1 have an unsuccessfully gonadic development, with 80% of individuals in resting stage. Indeed, the condition index, in Diet 1 decreased during the conditioning period. The results obtained in this study reinforce the idea that the diatom microalgae

  4. Influence of eutrophication on metal bioaccumulation and oral bioavailability in oysters, Crassostrea angulata.

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    Li, Shun-Xing; Chen, Li-Hui; Zheng, Feng-Ying; Huang, Xu-Guang

    2014-07-23

    Oysters (Crassostrea angulata) are often exposed to eutrophication. However, how these exposures influence metal bioaccumulation and oral bioavailability (OBA) in oysters is unknown. After a four month field experimental cultivation, bioaccumulation factors (BAF) of metals (Fe, Cu, As, Cd, and Pb) from seawater to oysters and metal oral bioavailability in oysters by bionic gastrointestinal tract were determined. A positive effect of macronutrient (nitrate N and total P) concentration in seawater on BAF of Cd in oysters was observed, but such an effect was not significant for Fe, Cu, Pb, and As. Only OBA of As was significantly positively correlated to N and P contents. For Fe, OBA was negatively correlated with N. The regular variation of the OBA of Fe and As may be due to the effect of eutrophication on the synthesis of metal granules and heat-stable protein in oysters, respectively.

  5. Temporal variations in metallothionein concentration and subcellular distribution of metals in gills and digestive glands of the oyster Crassostrea angulata

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    Chiara Trombini

    2010-11-01

    Full Text Available The metallothionein levels and metal concentrations in whole body, digestive gland and gills of Crassostrea angulata were analyzed in field samples collected from the River Guadalquivir estuary over several years following a mining waste spill upstream. The subcellular distribution of metals was analyzed to determine the mechanisms involved in the detoxification process. The highest metallothionein levels were reported in the digestive gland shortly after the mining contamination event. In this organ, metals are stored preferentially in the non-cytosolic fraction when increased bioaccumulation takes place. In the cytosol of the gills, metals are associated with metallothionein, whereas in the digestive gland, the distribution of metals between metallothioneins and high molecular weight proteins is similar. Metallothionein variation cannot be explained by metals alone; other abiotic factors must be taken into account. In order to use metallothionein as a metal exposure biomarker in field studies, natural variability needs to be taken into account for the correct interpretation of results.

  6. DNA barcoding reveals that the common cupped oyster in Taiwan is the Portuguese oyster Crassostrea angulata (Ostreoida; Ostreidae), not C. gigas

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    Hsiao, Sheng-Tai; Chuang, Shin-Chang; Chen, Kao-Sung; Ho, Ping-Ho; Wu, Chi-Lun; Chen, Chaolun Allen

    2016-09-01

    The Pacific cupped oyster, Crassostrea gigas, is one of the major aquacultural shellfish species that has been introduced to Europe and America from its native source in the West Pacific. In Taiwan, the cultivated cupped oysters along the west coast have been identified as C. gigas for over centuries; however, several molecular phylogenetic studies have cast doubt upon the existence of this species in Taiwan and adjacent waters. Indeed, our analyses of mitochondrial cytochrome oxidase I (COI) sequences from 313 Crassostrea collected from 12 locations along Taiwanese and southern Chinese coastlines confirm that all samples were the Portuguese oyster, C. angulata, rather than C. gigas. Multiple lines of evidence, including haplotypic and nucleotide diversity of the COI gene, demographic history, and population genetics, suggest that Taiwanese C. angulata is unique, probably experienced a sudden population expansion after the Last Glacial Maxima around 20,000 years ago, and has a significantly limited genetic connectivity across the Taiwan Strait. Our study applies an extended sampling and DNA barcoding to confirm the absence of C. gigas in natural and cultivated populations in Taiwan and southern China, where we only found C. angulata. We highlight the importance of conserving the gene pool of the C. angulata population in Taiwan, particularly considering the current threats by large-scale environmental disturbances such as marine pollution, habitat destruction, and climate change.

  7. Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?

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    Macías-Mayorga, Dayanara, E-mail: dayanara.macias@uleam.edu.ec [Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain); Departamento Central De Investigación (DCI), Universidad Laica Eloy Alfaro de Manabí, Vía San Mateo, Manta (Ecuador); Laiz, Irene [Departamento de Física Aplicada, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain); Moreno-Garrido, Ignacio; Blasco, Julián [Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, S/N, 11510 Puerto Real, Cádiz (Spain)

    2015-04-15

    Highlights: • The cadmium accumulation in C. angulata tended toward a stationary state. • Metallothionein-like protein (MTLP) is clearly induced by Cd accumulation. • The MTLP detoxification mechanism is affected at high Cd concentrations. • Cadmium toxicity causes GSH levels to decrease and inhibits antioxidant enzymes. - Abstract: The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system.

  8. Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?

    International Nuclear Information System (INIS)

    Macías-Mayorga, Dayanara; Laiz, Irene; Moreno-Garrido, Ignacio; Blasco, Julián

    2015-01-01

    Highlights: • The cadmium accumulation in C. angulata tended toward a stationary state. • Metallothionein-like protein (MTLP) is clearly induced by Cd accumulation. • The MTLP detoxification mechanism is affected at high Cd concentrations. • Cadmium toxicity causes GSH levels to decrease and inhibits antioxidant enzymes. - Abstract: The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system

  9. Is oxidative stress related to cadmium accumulation in the Mollusc Crassostrea angulata?

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    Macías-Mayorga, Dayanara; Laiz, Irene; Moreno-Garrido, Ignacio; Blasco, Julián

    2015-04-01

    The kinetics of cadmium (Cd) accumulation in the gills and digestive gland of Crassotrea angulata at three concentrations of cadmium (0.088 μM, 0.44 μM and 2.22 μM) was monitored for 28 days. The relationship between accumulation and toxicity was studied using metallothionein-like protein (MTLP) concentration and reduced glutathione levels (GSH) as biochemical endpoints. The activity of enzymes which form part of the antioxidant defense system, in particular glutathione reductase (GR), total glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT), as enzymatic endpoints, was also assessed. A first order kinetic model demonstrated that the accumulation process does not take place linearly, as the Cd concentration in gills and digestive gland tended toward a stationary state. Metallothionein-like protein is clearly induced by Cd accumulation; however, at high Cd concentrations the detoxification mechanism of this protein is affected. High Cd concentrations (2.22 μM) lead to a decrease in GSH levels, and also inhibit antioxidant enzyme activities, demonstrating the adverse effect of this metal on the antioxidant balance system. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Characterization of receptor of activated C kinase 1 (RACK1) and functional analysis during larval metamorphosis of the oyster Crassostrea angulata.

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    Yang, Bingye; Pu, Fei; Qin, Ji; You, Weiwei; Ke, Caihuan

    2014-03-10

    During a large-scale screen of the larval transcriptome library of the Portuguese oyster, Crassostrea angulata, the oyster gene RACK, which encodes a receptor of activated protein kinase C protein was isolated and characterized. The cDNA is 1,148 bp long and has a predicted open reading frame encoding 317 aa. The predicted protein shows high sequence identity to many RACK proteins of different organisms including molluscs, fish, amphibians and mammals, suggesting that it is conserved during evolution. The structural analysis of the Ca-RACK1 genomic sequence implies that the Ca-RACK1 gene has seven exons and six introns, extending approximately 6.5 kb in length. It is expressed ubiquitously in many oyster tissues as detected by RT-PCR analysis. The Ca-RACK1 mRNA expression pattern was markedly increased at larval metamorphosis; and was further increased along with Ca-RACK1 protein synthesis during epinephrine-induced metamorphosis. These results indicate that the Ca-RACK1 plays an important role in tissue differentiation and/or in cell growth during larval metamorphosis in the oyster, C. angulata. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Functional analysis of a tyrosinase gene involved in early larval shell biogenesis in Crassostrea angulata and its response to ocean acidification.

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    Yang, Bingye; Pu, Fei; Li, Lingling; You, Weiwei; Ke, Caihuan; Feng, Danqing

    2017-04-01

    The formation of the primary shell is a vital process in marine bivalves. Ocean acidification largely influences shell formation. It has been reported that enzymes involved in phenol oxidation, such as tyrosinase and phenoloxidases, participate in the formation of the periostracum. In the present study, we cloned a tyrosinase gene from Crassostrea angulata named Ca-tyrA1, and its potential function in early larval shell biogenesis was investigated. The Ca-tyrA1 gene has a full-length cDNA of 2430bp in size, with an open reading frame of 1896bp in size, which encodes a 631-amino acid protein that includes a 24-amino acid putative signal peptide. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis revealed that Ca-tyrA1 transcription mainly occurs at the trochophore stage, and the Ca-tyrA1 mRNA levels in the 3000ppm treatment group were significantly upregulated in the early D-veliger larvae. WMISH and electron scanning microscopy analyses showed that the expression of Ca-tyrA1 occurs at the gastrula stage, thereby sustaining the early D-veliger larvae, and the shape of its signal is saddle-like, similar to that observed under an electron scanning microscope. Furthermore, the RNA interference has shown that the treatment group has a higher deformity rate than that of the control, thereby indicating that Ca-tyrA1 participates in the biogenesis of the primary shell. In conclusion, and our results indicate that Ca-tyrA1 plays a vital role in the formation of the larval shell and participates in the response to larval shell damages in Crassostrea angulata that were induced by ocean acidification. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Acumulación de cobre y alteraciones histopatológicas en el ostión Crassostrea angulata

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    2005-01-01

    Full Text Available Ejemplares de ostión Crassostrea angulata fueron expuestos a concentraciones subletales de cobre (200 y 600 µg L–1 Cu2+ durante un periodo de 2 a 30 días. Se cuantificó la concentración de cobre, así como las alteraciones histopatológicas inducidas en branquias, glándula digestiva y corazón. Las concentraciones más elevadas de cobre correspondieron a las branquias, con valores alrededor de 2 mg g–1 peso seco en los organismos expuestos a la concentración más alta, al final del periodo de exposición (día 30. En la glándula digestiva la concentración alcanzada fue del orden de 1 mg g–1 peso seco. La tasa de bioconcentración (BCr, definida como la diferencia entre la concentración en el tejido a una concentración de exposición a tiempo t y la concentración media del control a lo largo del experimento, dividida por el tiempo de exposición, disminuyó en ambos tejidos. Los valores variaron en el intervalo entre 392 y 57 µg g–1 d–1 en las branquias y entre 133 y 18 µg g–1 día–1 en la glándula digestiva. En branquias de ejemplares tratados con una concentración de 200 µg L–1 Cu2+ se observó una desorganización del tejido conjuntivo, alteraciones en la porción apical de las células ciliadas e hiperplasia y fusión de laminillas, pudiendo llegar incluso a la pérdida de estas laminillas a 600 µg L–1 Cu2+. En la glándula digestiva (hepatopáncreas de ejemplares sometidos a 600 µg L–1 Cu2+ se detectó un adelgazamiento del epitelio y, en algunos casos, oclusión de la luz de los túbulos digestivos y dilatación de los conductos digestivos. En el corazón de los organismos expuestos a concentraciones subletales de cobre se observó un adelgazamiento del epitelio de las aurículas y del ventrículo, un incremento de las células marrones (brown cells en las paredes de las aurículas, así como una distensión de las fibras musculares y destrucción del tejido conectivo de soporte, tanto en las aur

  13. A High-Density SNP Genetic Linkage Map and QTL Analysis of Growth-Related Traits in a Hybrid Family of Oysters (Crassostrea gigas × Crassostrea angulata Using Genotyping-by-Sequencing

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    Jinpeng Wang

    2016-05-01

    Full Text Available Oysters are among the most important species in global aquaculture. Crassostrea gigas, and its subspecies C. angulata, are the major cultured species. To determine the genetic basis of growth-related traits in oysters, we constructed a second-generation linkage map from 3367 single-nucleotide polymorphisms (SNPs based on genotyping-by-sequencing, genotyped from a C. gigas × C. angulata hybrid family. These 3367 SNPs were distributed on 1695 markers, which were assigned to 10 linkage groups. The genetic linkage map had a total length of 1084.3 cM, with an average of 0.8 cM between markers; it thus represents the densest genetic map constructed for oysters to date. Twenty-seven quantitative trait loci (QTL for five growth-related traits were detected. These QTL could explain 4.2–7.7% (mean = 5.4% of the phenotypic variation. In total, 50.8% of phenotypic variance for shell width, 7.7% for mass weight, and 34.1% for soft tissue weight were explained. The detected QTL were distributed among eight linkage groups, and more than half (16 were concentrated within narrow regions in their respective linkage groups. Thirty-eight annotated genes were identified within the QTL regions, two of which are key genes for carbohydrate metabolism. Other genes were found to participate in assembly and regulation of the actin cytoskeleton, signal transduction, and regulation of cell differentiation and development. The newly developed high-density genetic map, and the QTL and candidate genes identified provide a valuable genetic resource and a basis for marker-assisted selection for C. gigas and C. angulata.

  14. Molecular Analysis of Atypical Family 18 Chitinase from Fujian Oyster Crassostrea angulata and Its Physiological Role in the Digestive System.

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    Yang, Bingye; Zhang, Mingming; Li, Lingling; Pu, Fei; You, Weiwei; Ke, Caihuan

    2015-01-01

    Chitinolytic enzymes have an important physiological significance in immune and digestive systems in plants and animals, but chitinase has not been identified as having a role in the digestive system in molluscan. In our study, a novel chitinase homologue, named Ca-Chit, has been cloned and characterized as the oyster Crassostrea angulate. The 3998bp full-length cDNA of Ca-Chit consisted of 23bp 5-UTR, 3288 ORF and 688bp 3-UTR. The deduced amino acids sequence shares homologue with the chitinase of family 18. The molecular weight of the protein was predicted to be 119.389 kDa, with a pI of 6.74. The Ca-Chit protein was a modular enzyme composed of a glycosyl hydrolase family 18 domain, threonine-rich region profile and a putative membrane anchor domain. Gene expression profiles monitored by quantitative RT-PCR in different adult tissues showed that the mRNA of Ca-Chit expressed markedly higher visceral mass than any other tissues. The results of the whole mount in-situ hybridization displayed that Ca-Chit starts to express the visceral mass of D-veliger larvae and then the digestive gland forms a crystalline structure during larval development. Furthermore, the adult oysters challenged by starvation indicated that the Ca-Chit expression would be regulated by feed. All the observations made suggest that Ca-Chit plays an important role in the digestive system of the oyster, Crassostrea angulate.

  15. Estructura comunitaria de bivalvos y gasterópodos en raíces del mangle rojo Rhizophora mangle (Rhizophoraceae en isla Larga, bahía de Mochima, Venezuela

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    Vanessa Acosta Balbas

    2014-08-01

    Full Text Available Las raíces del mangle rojo forman un complejo ecosistema donde se reproducen, refugian y establecen de manera permanente una gran diversidad de organismos. En este estudio, se evaluó la diversidad de bivalvos y gasterópodos que habitan las raíces del mangle rojo Rhizophora mangle, en isla Larga, Bahía de Mochima, estado Sucre Venezuela. Se realizaron recolectas bimensuales desde enero 2007 hasta mayo 2008, en cuatro zonas de estudio denominadas: zona sur, norte, este y oeste. En cada zona se muestrearon cinco raíces de mangle, de donde se obtuvieron los especímenes. Se analizaron un total 180 raíces y se contabilizaron 35 especies de bivalvos y 25 de gasterópodos. Los bivalvos más abundantes fueron: Isognomon alatus, Isognomon bicolor, Ostrea equestris, Crassostrea rhizophorae y Brachidontes exustus, mientras que los gasterópodos más frecuentes: Littorina angulifera, Cymatium pileare y Diodora cayenensis. Los meses donde se observaron las mayores abundancias de especies y número de individuos fueron enero y julio 2007 y marzo 2008. El ecosistema de manglar en isla Larga, presentó un número de individuos y especies superior al reportado en otros trabajos realizados en Venezuela y otras regiones del Caribe.

  16. Nuevos bivalvos para el Perú en Bahía Independencia

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    Oswaldo Cornejo

    2013-06-01

    Full Text Available Se registran por primera vez para el Perú las siguientes especies de bivalvos Nucula (Nucula pisum Sowerby I, 1833, y Lyonsia delicata Marincovich, 1973, colectadas en Bahía Independencia, Pisco, Perú, en el 2002.

  17. Decapitation of the tortoise Chersina angulata : Is the large grey ...

    African Journals Online (AJOL)

    This paper reports a previously undescribed form of predation upon the angulate tortoise, Chersina angulata, in the West Coast National Park, South Africa. Twelve recently killed C. angulata were found, within an area of 4–5 hectares, during April 2000. The head and neck were missing from all individuals, while the rest of ...

  18. Heavy metals in the rock oyster Crassostrea iridescens (Filibranchia: Ostreidae from Mazatlan, Sinaloa, Mexico

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    Martín G Frías-Espericueta

    1999-12-01

    Full Text Available Two populations of Crassostrea iridescens were sampled off Mazatlan and in a zone free of anthropogenic activity. The bivalves were collected from February 1992 to February 1993. Concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn were determined by flame atomic absorption spectrophotometry. Annual mean values in the sampling zone off Mazatlan were higher in Co, Cu, Fe, Mn, Ni and Zn than in the sampling zone free of anthropogenic activity; however, differences were not statistically significant at 95% confidence level. Urban discharges in the coastal zone in front of Mazatlan city, have little or no heavy metal concentrations dissolved or particulated.Dos poblaciones de Crassostrea iridescens fueron muestreadas en la zona costera de la ciudad de Mazatlan y en una zona libre de actividad antropogénica. Los bivalvos fueron colectados de febrero de 1992 a febrero de 1993. Concentraciones de Cd, Co, Cr, Cu, Fe, Mn, Ni y Zn fueron determinados por espectrofotometría de absorción atómica. Los valores medios anuales en la estación de muestreo de la ciudad de Mazatlán fueron mayores en Co, Cu, Fe, Mn, Ni y Zn que los determinados en la zona libre de actividad antropogénica; sin embargo, las diferencias no fueron significativas al nivel de confianza del 95%. Una conclusión es que las descargas urbanas en la zona costera en frente de Mazatlán no tiene, o tiene, bajas concentraciones de metales pesados disueltos o particulados.

  19. Antibacterial activity of the fruit extract of Physalis angulata and its ...

    African Journals Online (AJOL)

    The inhibitory activity of zinc oxide-ointment formulation as well as the unformulated crude extract of fruits of Physalis angulata was investigated against clinical wound isolates of Staphylococcus aureus and Pseudomonas aeruginosa. The zinc oxide-ointment formulation and the unformulated P. angulata crude extract were ...

  20. Aislamiento e identificación de Vibrio parahaemolyticus O3: K6 en pescados y moluscos bivalvos procedentes de un mercado pesquero de Lima, Perú

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    Rocío Aliaga

    2010-07-01

    Full Text Available Objetivo: Determinar la presencia de Vibrio parahaemolyticus serotipo O3:K6 en pescados y moluscos bivalvos procedentes de un mercado pesquero de Lima. Material y Métodos: Se analizaron 254 muestras entre pescados y moluscos bivalvos siguiendo la técnica descrita por Yukiko Harakudo et al, que consta de un paso de enriquecimiento, siembra en medio cromogénico, evaluación de fermentación de glucosa y la prueba de tolerancia a sales. Las cepas identificadas como Vibrio parahaemolyticus fueron serotipificadas usando anticuerpos monoclonales y evaluadas en su potencial patogénico en medio de Wagatsuma. Resultados: Se aislaron 15 cepas de V. parahaemolyticus, 9(7,5% en pescados y 6(4,5% en moluscos bivalvos. Tres (20% presentaron fenómeno de Kanagawa positivo indicando la producción de la hemolisina termoestable directa (TDH. Una cepa TDH-positiva aislada en una muestra pescado fue serotipo O3:K6. Conclusiones: Vibrio parahaemolyticus se encuentra distribuido en los recursos hidrobiológicos estudiados con mayor frecuencia en pescados, a partir de los cuales se encontró el serovar O3:K6. Este es el primer reporte de la cepa pandémica O3:K6 de Vibrio parahaemolyticus aislada de fuente no humana en el Perú. (Rev Med Hered 2010;21:139-145.

  1. Effects of Ferulago angulata Extract on Serum Lipids and Lipid Peroxidation

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    Mahmoud Rafieian-kopaei

    2014-01-01

    Full Text Available Background. Nowadays, herbs they are considered to be the main source of effective drugs for lowering serum lipids and lipid peroxidation. The present experimental animal study aimed to assess the impact of Ferulago angulata on serum lipid profiles, and on levels of lipid peroxidation. Methods. Fifty male Wistar rats, weighing 250–300 g, were randomly divided into five equal groups (ten rats in each. The rat groups received different diets as follows: Group I: fat-rich diet; Group II: fat-rich diet plus hydroalcoholic extracts of Ferulago angulata at a dose of 400 mg/kg; Group III: fat-rich diet plus hydroalcoholic extracts of Ferulago angulata at a dose of 600 mg/kg; Group IV: fat-rich diet plus atorvastatin; Group V: common stock diet. The levels of serum glucose and lipids and the atherogenic index were measured. In addition, malondialdehyde (MDA, thiol oxidation, carbonyl concentrations, C-reactive proteins, and antioxidant capacity were evaluated in each group of rats. Results. Interestingly, by adding a hydroalcoholic extract of Ferulago angulata to the high-fat diet, the levels of total cholesterol and low-density lipoproteins (LDL in the high-fat diet rats were both significantly reduced. This result was considerably greater compared to when atorvastatin was added as an antilipid drug. The beneficial effects of the Ferulago angulata extract on lowering the level of triglycerides was observed only when a high dosage of this plant extraction was added to a high fat diet. Furthermore, the level of malondialdehyde, was significantly affected by the use of the plant extract in a high-fat diet, compared with a normal regimen or high-fat diet alone. Conclusion. Administration of a hydroalcoholic extract of Ferulago angulata can reduce serum levels of total cholesterol, triglycerides, and LDL. It can also inhibit lipid peroxidation.

  2. Chemical composition, antioxidant and antibacterial activities of essential oils from Ferulago angulata.

    Science.gov (United States)

    Ghasemi Pirbalouti, Abdollah; Izadi, Arezo; Malek Poor, Fatemeh; Hamedi, Behzad

    2016-11-01

    Ferulago angulata Boiss. (Apiaceae), a perennial aromatic herb, grows wild in Iran. The aerial parts of F. angulata are used as a flavouring in foods, especially dairy foods by indigenous people in western and southwestern Iran. This study investigates variation in chemical compositions, antioxidant and antibacterial activities of the essential oils from F. angulata collected from natural habitats in the alpine regions of southwestern Iran. The antimicrobial activity, minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) of the essential oils were evaluated against four bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus and Salmonella typhimurium). Antioxidant activity of the oils was determined by DPPH assay. The essential oils were analyzed by GC-FID and GC/MS, which 49 volatile components were identified. There were significant differences between the various populations for oil yield and some main compounds. The major constituents of the essential oils from F. angulata were α-pinene, and cis-β-ocimene. The MICs of the essential oils were within concentration ranges from 62 to 250 μg/mL and the respective MBCs were 125 to > 500 μg/mL. Generally, the oils from F. angulata indicated weak to moderate inhibitory activities against bacteria, especially against Listeria monocytogenes. The highest antioxidant activity was obtained from the oil of the Kallar population (IC 50 value   =   488 μg/mL) and BHT as positive control (IC 50  value =   321 μg/mL). The essential oil of F. angulata could be serving as a potential source of α-pinene and cis-β-ocimene for use in the food, cosmetic and pharmaceutical industries.

  3. Novel Microsatellite Markers for Brazilian Mangrove Oysters ( Crassostrea gasar and their Cross-Amplification in Crassostrea rhizophorae

    Directory of Open Access Journals (Sweden)

    Renata do Socorro Corrêa Baldez

    2016-08-01

    Full Text Available ABSTRACT A microsatellite CT/GT enriched genomic library was developed for Crassostrea gasar and twelve new polymorphic loci were isolated and characterized. The markers were successfully amplified from 25 individuals of Crassostrea gasar and 11 cross-amplified individuals of Crassostrea rhizophorae. There was no evidence of linkage between loci in either species.

  4. Stabilization of soybean oil during accelerated storage by essential oil of ferulago angulata boiss.

    Science.gov (United States)

    Sadeghi, Ehsan; Mahtabani, Aidin; Etminan, Alireza; Karami, Farahnaz

    2016-02-01

    This study has been considered effect of Ferulago angulata essential oil on stabilizing soybean oil during accelerated storage. The essential oil was extracted by Clevenger-type apparatus. For analysis of the essential oil, GC/MS was used. Main components of the essential oil were monoterpene and sesquiterpene hydrocarbons. The essential oil of F. angulata at four concentrations, i.e. 125 (SBO-125), 250 (SBO-250), 500 (SBO-500) and SBO-Mixture (60 ppm TBHQ +60 ppm essential oil) were added to preheated refined soybean oil. TBHQ was used at 120 ppm as standard besides the control. Antioxidant activity index (AAI), free fatty acid (FFA) content, peroxide value (PV) and p-anisidine value (p-AnV) were served for appreciation of efficacy of F. angulata in stabilization of soybean oil. Results from different tests showed that SBO-mixture had highest effect and followed by SBO-TBHQ, SBO-250, SBO-125, SBO-500 and Ctrl. These results reveal F. angulata is a strong antioxidant and can be used instead of synthetic antioxidant.

  5. Growth performance and haematological and immunological indices of rainbow trout (Oncorhynchus mykiss fingerlings supplemented with dietary Ferulago angulata (Schlecht Boiss

    Directory of Open Access Journals (Sweden)

    Somayeh Bohlouli

    2016-01-01

    Full Text Available In this study, the effects of Ferulago angulata extract on the growth, haematological, and immunological indices of rainbow trout (Oncorhynchus mykiss fingerlings were evaluated. Basal diet was supplemented with 0 (control, 0.5, 1, and 2 g·kg-1 F. angulata and was randomly allocated to experimental fish of an initial average weight of 7.45 ± 0.02 g. After 8 weeks of experiment, the fish supplemented with F. angulata extract showed increased but non-significant (P > 0.05 growth performance. No significant differences were found between trial control groups in haematological indices such as red blood cell count, haematocrit, and haemoglobin, but there was a significant increase in white blood cells, lymphocytes, neutrophils and monocytes in the F. angulata extract groups (P < 0.05. Also, there were significant differences between the fish supplemented with dietary F. angulata extract and the control group regarding immunological indices, including immunoglobulin M, lysozyme, and classical and alternative complement pathway (P < 0.05. These findings suggest that the administration of F. angulata extract has a positive effect on the immunological indices and the immune system activity in rainbow trout fingerling.

  6. Comparison of the effects of three different Baccaurea angulata whole fruit juice doses on plasma, aorta and liver MDA levels, antioxidant enzymes and total antioxidant capacity.

    Science.gov (United States)

    Ibrahim, Muhammad; Mikail, Maryam Abimbola; Ahmed, Idris Adewale; Hazali, Norazlanshah; Abdul Rasad, Mohammad Syaiful Bahari; Abdul Ghani, Radiah; Hashim, Ridzwan; Arief, Solachuddin Jahuari; Md Isa, Muhammad Lokman; Draman, Samsul

    2017-05-17

    Baccaurea angulata (common names: belimbing dayak or belimbing hutan) is a Malaysian underutilized fruit. The preliminary work on B. angulata fruit juice showed that it possesses antioxidant properties. Therefore, further work is needed to confirm the efficacy and proper dosage of B. angulata as a potential natural antioxidant. The present study was thus carried out to compare the effects of three different B. angulata whole fruit (WF) juice doses administered at nutritional doses of 0.50, 1.00 and 1.50 ml/kg/day on plasma, aorta and liver malondialdehyde (MDA) levels, antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase) as well as total antioxidant capacity in rabbits fed high-cholesterol diet. Thirty-five male rabbits of New Zealand strain were randomly assigned to seven groups. For 12 weeks, group CH was fed 1% cholesterol diet only; group C1 was fed 1% cholesterol diet and 0.50 ml/kg/day B. angulata WF juice; group C2 was fed 1% cholesterol diet and 1.00 ml/kg/day B. angulata WF juice; group C3 was fed 1% cholesterol diet and 1.50 ml/kg/day B. angulata WF juice; group N was fed standard pellet only; group N1 was fed standard pellet and 0.50 ml/kg/day B. angulata WF juice; and group N2 was fed standard pellet and 1.00 ml/kg/day B. angulata WF juice. The three doses reduced the formation of MDA and enhanced the expression of endogenous antioxidant enzymes. The highest dose used (1.50 ml/kg/day) was, however, seen as the most potent. Higher doses of B. angulata juice exerted better antioxidant activity.

  7. First isolation of Nocardia crassostreae from Pacific oysters (Crassostrea gigas) in Europe

    NARCIS (Netherlands)

    Engelsma, M.Y.; Roozenburg, I.; Joly, J.P.

    2008-01-01

    In summer 2006 an extensive mortality of Pacific oysters Crassostrea gigas occurred in Lake Grevelingen, the Netherlands. A sample of Pacific oysters was investigated for the presence of shellfish pathogens as potential causes of the mortality. Yellow-green lesions were observed in several oysters

  8. Prevalencia del protozoario Perkinsus sp. en un cultivo de ostión japonés Crassostrea gigas en Sinaloa, México

    Directory of Open Access Journals (Sweden)

    Lizeth Carolina Villanueva-Fonseca

    2013-11-01

    Full Text Available Crassostrea gigas es un molusco bivalvo de gran importancia comercial. En el noroeste de México su producción es afectada por mortalidades cuyo origen infeccioso no ha sido determinado claramente. En este trabajo se determinó la prevalencia e intensidad de la infección por Perkinsus sp. en un cultivo de C. gigas en el ciclo 2011-2012. El cultivo se hizo en un sistema de línea suspendida con densidades de 28 y 42 ostiones/canasta y se determinó un tamaño de muestra de 30 ostiones por mes. La detección de Perkinsus sp. se hizo de acuerdo a los protocolos de la Organización Mundial de Sanidad Animal (OIE para Medio Fluido de Tioglicolato y PCR. Con ambos métodos se determinó la prevalencia de Perkinsus sp., que varió entre 3,3 y 40%. La intensidad de la infección estuvo en niveles 1 y 2, de acuerdo a la escala de Mackin. La mortalidad acumulativa en las densidades de 28 y 42 ostiones por canasta fue del 4 y 6%, respectivamente. Las mayores mortalidades del ostión y las mayores prevalencias de Perkinsus sp. ocurrieron en septiembre (2,7 y 16,6% y octubre (1,5 y 23,3%, respectivamente, cuando la temperatura fue alta. En conclusión, Perkinsus sp. fue detectado en un cultivo de C. gigas en el estero La Pitahaya con prevalencia moderada, baja intensidad de infección y mayor presencia en los meses más calurosos del ciclo de cultivo.

  9. REVISIÓN DE LOS BIOCOREMAS MARINOS GLOBALES DEL JURÁSICO SEGÚN LA DISTRIBUCIÓN DE LOS MOLUSCOS BIVALVOS

    Directory of Open Access Journals (Sweden)

    Damborenea, Susana E.

    2017-11-01

    Full Text Available Numerosos trabajos regionales o locales han propuesto el reconocimiento de unidades biogeográficas de distintos rangos (biocoremas basadas sobre la distribución de los moluscos bivalvos para el Jurásico, pero no existía una síntesis a nivel mundial. Este trabajo es una revisión de las más significativas de esas propuestas, en un intento de lograr una síntesis de los patrones biogeográficos globales desde el Jurásico Temprano al Tardío, mientras se producían cambios sustanciales en la paleogeografía de la Tierra y los patrones de circulación oceánica como resultado de la disgregación de Pangea. Se hace también un breve análisis de la evolución en el tiempo y el espacio de cada una de las principales unidades reconocidas y de sus relaciones. Estos biocoremas pueden agruparse en tres unidades de primer orden que han tenido continuidad en el tiempo: Boreal, Tethys y Austral. Las unidades revisadas aquí han sido reconocidas y caracterizadas de forma muy heterogénea por los distintos autores, pero los criterios básicos más utilizados incluyen desde el grado de endemismo y la diversidad relativa, hasta las afinidades paleobiogeográficas de los taxones a nivel genérico. Los patrones de distribución de los bivalvos jurásicos no solamente son claves para entender cuestiones puramente biogeográficas, sino que han sido utilizados como argumento y evidencia en discusiones de índole paleogeográfica (como el establecimiento de corredores oceánicos, o patrones de circulación marina superficial, e incluso son pruebas de peso para la discusión de tópicos paleotectónicos, como la localización de terrenos desplazados y la deriva continental.

  10. Length-weight relationship of Giant Oyster, Crassostrea gyphoides (Schlotheim)

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Parulekar, A.H.

    Relationship between shell length and total weight, shell weight and meat weight of giant oyster, Crassostrea gryphoides revealed that the growth of these parameters is very fast and significant. It indicates the suitability of the species concerned...

  11. Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae

    Directory of Open Access Journals (Sweden)

    Angel Isidro Campa-Córdova

    2011-03-01

    Full Text Available El ostión de placer u ostra del Cortés (Crassostrea corteziensis se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61 aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58 y de C. corteziensis (Burkholderia cepacia, cepa Y021. Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb, una mezcla de bacilos (Lb en proporción 1:1 y un grupo control. La concentración de 1x10(4UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.Effect of probiotic bacteria on survival and growth of Cortez oyster larvae, Crassostrea corteziensis (Bivalvia: Ostreidae. Disease control

  12. Hydroponic cultivation of Physalis angulata L.: growth and production under nitrogen doses

    Directory of Open Access Journals (Sweden)

    Romeu da Silva Leite

    2017-06-01

    Full Text Available The Physalis angulata L. species has attracted interest due to the production of compounds with pharmacological activity and its potential for fruiticulture. Given that it is a fast-growing and highly productive species, determining the most adequate nitrogen (N doses could contribute to higher crop yields. This study aimed at assessing the influence of N concentrations, in a hydroponic system, on the growth and production of P. angulata, as well as determining the critical N level in leaves. The experiment was conducted in individual pots with nutrient solutions, applying a completely randomized design and twelve replications, using five N doses (0 mg L-1, 56 mg L-1, 112 mg L-1, 168 mg L-1 and 224 mg L-1. Growth and production indices, amount of total N on leaves and stems and critical N levels were assessed. The increase of N doses in the nutrient solution influenced plant growth and fruit production, as well as the accumulation of total N in the leaves and stems. Based on the maximum economic yield, a dose of 162 mg L-1 of N is recommended for hydroponics, which provided a fruit yield of 7.27 g m-2 and critical total N level in leaves of 51.98 g kg-1.

  13. Seasonal changes in stress biomarkers of an exotic coastal species - Chaetopleura angulata (Polyplacophora) - Implications for biomonitoring.

    Science.gov (United States)

    Madeira, Diana; Vinagre, Catarina; Mendonça, Vanessa; Diniz, Mário Sousa

    2017-07-15

    Knowledge on baseline values of stress biomarkers in natural conditions is urgent due to the need of reference values for monitoring purposes. Here we assessed the cellular stress response of the chiton Chaetopleura angulata in situ. Biomarkers commonly used in environmental monitoring (heat shock protein 70kDa, total ubiquitin, catalase, glutathione-S-transferase, superoxide-dismutase, lipid peroxidation) were analyzed in the digestive system, gills and muscle of C. angulata, under spring and summer conditions in order to assess seasonal tissue-specific responses. Season had an effect on all targeted organs, especially affecting the digestive system which displayed clear seasonal clusters. The respective Integrated Biomarker Response (IBR) showed a 7.2-fold seasonal difference. Muscle and gills showed similar IBRs between seasons making them appropriate organs to monitor chemical pollution as they were less responsive to seasonal variation. The most stable biomarkers in these organs were ubiquitin and superoxide-dismutase thus being reliable for monitoring purposes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Bio-accumulation of copper, zinc, iron and manganese in oyster Saccostrea cucullata, Snail Cerithium rubus and Clam Tellina angulata from the Bombay coast

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Nair, V.R; Moraes, C.

    accumulation was high in S. cucullata, manganese in C. rubus and iron in T. angulata. Similarly, copper and zinc in S. cucullata and copper in C. rubus were found occasionally higher than accepted health standards...

  15. Effects of seco-steroids purified from Physalis angulata L., Solanaceae, on the viability of Leishmania sp Efeitos de seco-esteróides purificados de Physalis angulata L., Solanaceae na viabilidade de Leishmania sp

    Directory of Open Access Journals (Sweden)

    Elisalva T. Guimarães

    2010-12-01

    Full Text Available Physalis angulata L., Solanaceae, is an annual herb commonly used in popular medicine in many tropical and subtropical countries. P. angulata extracts contain a variety of substances, but little is known about their pharmacological activities. In this work we investigated the in vitro antileishmanial activity of seco-steroids (physalins purified from P. angulata. Addition of physalins B, F, and G caused a concentration-dependent inhibition in the growth of L. amazonensis promastigotes, being the IC50 values were 6.8, 1.4, and 9.2 μM, respectively. Physalin D was less active and had an IC50 value of 30.5 μM. Physalins were also active in cultures of other Leishmania species (L. major, L. braziliensis, and L. chagasi. Our results demonstrate the potent antileishmanial activity of physalins in cultures of Leishmania species of the New and Old Worlds and suggest the therapeutic potential of these seco-steroids in leishmaniasis.Physalis angulata L., Solanaceae, é uma erva anual utilizada na medicina popular em muitos países tropicais e subtropicais. Apesar dos extratos da P. angulata apresentarem uma grande variedade de substâncias, pouco é conhecido sobre a sua atividade farmacológica. Neste trabalho foi investigado a atividade antileishmania in vitro de seco-esteroides (fisalinas purificados da P. angulata. O tratamento com as fisalinas B, F e G causou uma inibição concentração-dependente do crescimento de promastigotas de Leishmania amazonensis em cultura axênica, com valores de IC50 de 6,8, 1,4, e 9,2 μM respectivamente. A fisalina D foi menos ativa, com valores de IC50 de 30,5 μM. Foi também observada uma atividade leishmanicida em culturas de outras espécies de Leishmania (L. major, L. braziliensis e L. chagasi. Nossos resultados demonstram que as fisalinas inibem o crescimento dos promastigotas com o tratamento de espécies de Leishmania do Velho e do Novo Mundos e sugerem o potencial terapêutico destas moléculas na

  16. Sensitivity of oysters (Crassostrea Brasiliana) to radiation

    International Nuclear Information System (INIS)

    Mattiolo Marchese, S.R.; Mastro, N.L. del

    1997-01-01

    Various foods including oysters, crabs and shrimps have been shown to be possible transmitters of Vibrio ssp. Irradiation of sea-foods is being considered an alternative to intervention measures in Public Health against food borne diseases. The aim of this work was to establish, the radiation resistance of the oysters Crassostrea brasiliana. The oysters were irradiated with Co-60 radiation with doses of 0, 1.5, 3 and 6 kGy. Survival curves as a function of time showed that 100% of the oysters irradiated with doses of 3 kGy survived at least 6 days. 100% those irradiated with 6 kGy survived 3 days. The obtained results are auspicious considering that a dose of 2 kGy is already effective in the diminishing of the microbial load on oysters. (author)

  17. Proteomic approach for identifying gonad differential proteins in the oyster (Crassostrea angulata) following food-chain contamination with HgCl2.

    Science.gov (United States)

    Zhang, Qing-Hong; Huang, Lin; Zhang, Yong; Ke, Cai-Huan; Huang, He-Qing

    2013-12-06

    Hg discharged into the environmental waters can generally be bioaccumulated, transformed and transmited by living organisms, thus resulting in the formation of Hg-toxicity food chains. The pathway and toxicology of food chain contaminated with environmental Hg are rarely revealed by proteomics. Here, we showed that differential proteomics had the potential to understand reproduction toxicity mechanism in marine molluscs through the Hg-contaminated food chain. Hg bioaccumulation was found in every link of the HgCl2-Chlorella vulgaris-oyster-mice food chain. Morphological observations identified the lesions in both the oyster gonad and the mice ovary. Differential proteomics was used to study the mechanisms of Hg toxicity in the oyster gonad and to find some biomarkers of Hg contamination in food chain. Using 2-DE and MALDI-TOF/TOF MS, we identified 13 differential protein spots, of which six were up-regulated, six were down-regulated, while one was undecided. A portion of these differential proteins was further confirmed using real-time PCR and western blotting methods. Their major functions involved binding, protein translocation, catalysis, regulation of energy metabolism, reproductive functioning and structural molecular activity. Among these proteins, 14-3-3 protein, GTP binding protein, arginine kinase (AK) and 71kDa heat shock connate protein (HSCP 71) are considered to be suitable biomarkers of environmental Hg contamination. Furthermore, we established the gene correspondence, responding to Hg reproductive toxicity, between mouse and oyster, and then used real-time PCR to analyze mRNA differential expression of the corresponding genes in mice. The results indicated that the mechanism of Hg reproductive toxicity in mouse was similar to that in oyster. We suggest that the proteomics would be further developed in application research of food safety including toxicological mechanism. It is well known that mercury (Hg) is one of the best toxic metal elements in nature. The research reports as previously described indicated that multiple mercury compounds can directly contaminate the aquatic animals by flowing of water body and through the diffusion of air. The pollution sources of the mercury compounds in marine water were mainly found from the pathways such as steam power plant and mineral exploitation which are located on the inshore. Of note, after being released into environmental waters, mercury compounds undergo the processes of bioaccumulation, transformation and transmission in living organisms, thus resulting in the multiple forms of Hg found in Hg-toxicity food chains, and among them, methyl mercury (MeHg) showing the high toxic characteristics is the main form of Hg. The abundant reports indicated that the metal salts were easily found within the various organs of the animals, but it is difficult to judge the level of its perniciousness according to its content only in vivo. Here, the algae to have been contaminated by the mercury compounds have the ability for contaminating both the fish and shellfish as food pathway quickly. If these fish and shellfish edible as food will be taken by human, they will further affect the human health badly. However, studies about their perniciousness are rarely reported, especially in using proteomics. The oysters as normal food are largely consumed in Southern China, especially in Xiamen City. Similarly, a pathway question that the contaminated oysters can effect on the human health such as cancer is unclear or poorly understood. Here, we showed that an analytical technology such as differential proteomics has potential to understand toxicity mechanism induced by Hg-contamination through the food pathway. It is for reason that the oyster proteomics including relative analytical methods have been used to reveal the contaminant level and to determine its perniciousness using toxic algae as food. Here, we also indicated that the research here shows great significance for both analysis of food safety and toxicology of the metal compounds. In addition, a few biomarkers have shown their strong potential for monitoring the level of Hg pollution in sea in the manuscript and gene correspondence between mouse and oyster, the two contiguous links of the Hg-contaminated food chain, was further investigated to better illustrate our finding in the analysis of food chain proteomics. Moreover, similar research work is rarely reported compared to the current proteomic development, showing that a lot of novel results by proteomic methods in the manuscript have strong potential for developing the new area of food chain proteomics. © 2013 Elsevier B.V. All rights reserved.

  18. Morfologia de sementes e desenvolvimento pós-seminal de Physalis angulata L Seed morphology and post-seminal development of Physalis angulata L

    Directory of Open Access Journals (Sweden)

    Cíntia Luiza Mascarenhas de Souza

    2010-12-01

    Full Text Available Physalis angulata é conhecida como camapu, mullaca ou juá-de-capote e pertence à família Solanaceae. Esta espécie possui importância medicinal, pela presença dos vitaesteróides conhecidos como fisalinas e, atualmente, na alimentação. Essa espécie se propaga facilmente por sementes, motivo pelo qual ela é tida como infestante de outras culturas. Nesse sentido, a identificação da espécie ainda nos estágios iniciais de crescimento confunde com as demais infestantes, tornando difícil a sua caracterização taxonômica. Assim, o objetivo deste trabalho foi caracterizar morfologicamente as sementes e o desenvolvimento pós-seminal de Physalis angulata. Os ensaios foram desenvolvidos no Laboratório de Germinação da Unidade Experimental Horto Florestal, Feira de Santana - BA. Para tanto foram realizadas análises morfométricas das sementes (4 repetições de 25 e analisadas suas características externas e internas com auxilio de microscópico estereoscópico. Para a descrição das plântulas da espécie foram utilizadas placas de petri contendo duas folhas de papel filtro (4 repetições de 20 sementes e umedecidos com água destilada. As sementes foram colocadas em câmara de germinação à 35ºC (fotoperíodo de 12 horas até a emissão dos cotilédones. A metodologia para descrição do desenvolvimento pós-seminal foi realizada em condições de casa de vegetação e consistiu em avaliações realizadas cinco dias após a semeadura (emissão dos cotilédones e no intervalo de até 15 dias (emissão de eófilos e metáfilos no qual foram utilizados 2 repetições de 20 vasos. As sementes apresentaram em média 1,55 mm de comprimento, 1,26 mm de largura e 0,43 mm de espessura. O período de análise foi suficiente para caracterizar as sementes e plântulas da espécie, permitindo a adoção de critérios de anormalidade.Physalis angulata is also known as camapu, mullaca or juá-de-capote it belongs to the Solanaceae family

  19. Markers associated with disease resistance in Eastern oysters, Crassostrea virginica

    Science.gov (United States)

    Eastern oyster, Crassostrea viginica, is an economically important aquaculture species in the USA, but production has been impacted by diseases such as dermo and MSX. Efforts have been put into the development of disease-resistant oyster lines using selective breeding techniques. However, these met...

  20. Length-Weight relationships of mangrove oyster, Crassostrea gasar ...

    African Journals Online (AJOL)

    The length-weight relationships (LWRs) of mangrove oyster, Crassostrea gasar, cultured under continuous and periodic submergence in tidal ponds, for a period of seven months, February to August 2010 were determined. A total of 375 individuals each of pond A (continuous submergence) and B (periodic submergence) ...

  1. Changes in the composition and diversity of the bacterial microbiota associated with oysters (Crassostrea corteziensis, Crassostrea gigas and Crassostrea sikamea) during commercial production.

    Science.gov (United States)

    Trabal Fernández, Natalia; Mazón-Suástegui, José M; Vázquez-Juárez, Ricardo; Ascencio-Valle, Felipe; Romero, Jaime

    2014-04-01

    The resident microbiota of three oyster species (Crassostrea corteziensis, Crassostrea gigas and Crassostrea sikamea) was characterised using a high-throughput sequencing approach (pyrosequencing) that was based on the V3-V5 regions of the 16S rRNA gene. We analysed the changes in the bacterial community beginning with the postlarvae produced in a hatchery, which were later planted at two grow-out cultivation sites until they reached the adult stage. DNA samples from the oysters were amplified, and 31 008 sequences belonging to 13 phyla (including Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes) and 243 genera were generated. Considering all life stages, Proteobacteria was the most abundant phylum, but it showed variations at the genus level between the postlarvae and the adult oysters. Bacteroidetes was the second most common phylum, but it was found in higher abundance in the postlarvae than in adults. The relative abundance showed that the microbiota that was associated with the postlarvae and adults differed substantially, and higher diversity and richness were evident in the postlarvae in comparison with adults of the same species. The site of rearing influenced the bacterial community composition of C. corteziensis and C. sikamea adults. The bacterial groups that were found in these oysters were complex and metabolically versatile, making it difficult to understand the host-bacteria symbiotic relationships; therefore, the physiological and ecological significances of the resident microbiota remain uncertain. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  2. Confirmación molecular de tres especies de bivalvos xilótrofos (Familia Teredinidae en las bahías de Cartagena y Barbacoas, mar Caribe, Colombia

    Directory of Open Access Journals (Sweden)

    Michael Ahrens

    2013-12-01

    Full Text Available A pesar de la existencia de un extenso hábitat de manglares en Colombia, solo unos pocos estudios han descrito la diversidad de bivalvos teredinidos xilótrofos (conocidos como “broma” en el país. El presente estudio investigó la presencia de bivalvos teredinidos en las bahías de Cartagena y Barbacoas. En un estudio de campo llevado a cabo en marzo de 2013, diez individuos de dos géneros de Teredinidae, correspondientes morfológicamente a Neoteredo reynei y Bankia spp., fueron encontrados en las raíces sumergidas de mangle rojo (Rhizophora mangle. Identificaciones morfológicas iniciales se complementaron con identificación molecular. Para esto, dos fragmentos de genes fueron secuenciados: 588 pares de bases (pb del gen mitocondrial citocromo oxidasa subunidad 1 (CO1 y 305 pb del gen nuclear de la subunidad ribosómica pequeña (18S. Búsquedas de alineación básica (BLAST y árboles filogenéticos utilizando secuencias de CO1 y 18S de otras especies de Teredinidae públicamente disponibles y no publicadas confirmaron la identidad de Neoteredo reynei en la bahía de Barbacoas. En contraste, las secuencias obtenidas para Bankia, indicaron la presencia de dos especies distintas en la bahía de Cartagena. La confirmación de al menos tres especies de Teredinidae en las bahías de Cartagena y Barbacoas sugiere la presencia de especies adicionales y justifica un mayor esfuerzo de muestreo para este grupo de descomponedores de madera tan importante ecológica y económicamente.

  3. Sensory and Chemical Characteristics of Eastern Oysters(Crassostrea virginica)

    OpenAIRE

    Chen, Luman

    2011-01-01

    Eastern Oysters, or Crassostrea virginica, are an important dietary component in the Chesapeake region and have supported a major fishery in the Chesapeake for more than 100 years. Virginia oysters do not always receive attention in up-scale markets. It is possible that the lack of information on sensory characteristics of Chesapeake oysters may contribute to this problem. In order to differentiate Chesapeake oysters from other oysters, a descriptive sensory test (n=8) was conducted and chemi...

  4. Exploring Proteomic Variation in Pacific Oysters (Crassostrea gigas)

    OpenAIRE

    Venkataraman, Yaamini

    2017-01-01

    150 sibling Pacific oysters (Crassostrea gigas) were outplanted at five different sites around Puget Sound. Oysters were placed in exclusion cages either inside or outside of eelgrass beds. After a month of environmental exposure, gill tissue samples were collected for proteomic analyses. Initial DIA mass spectrometry methods on a subset of oysters (one per site and eelgrass condition, 10 total) provide data for upwards of 6,000 proteins. A subset of stress-related proteins reveal site-specif...

  5. Baccaurea angulata fruit juice reduces atherosclerotic lesions in diet-induced Hypercholesterolemic rabbits.

    Science.gov (United States)

    Ibrahim, Muhammad; Ahmed, Idris Adewale; Mikail, Maryam Abimbola; Ishola, Afeez Adekunle; Draman, Samsul; Isa, Muhammad Lokman Md; Yusof, Afzan Mat

    2017-07-07

    Atherosclerosis is the most common disease of large and medium-sized arteries linked to oxidative stress, dyslipidemia as well as chronic inflammation. The aim of this study was to evaluate the potential health benefits of Baccaurea angulata (BA) fruit juice on the aorta of diet-induced hypercholesterolemic rabbits, to detect an accumulation of fatty streak and evaluate the percentage of atherosclerotic lesion accrued. Thirty-five healthy male adults New Zealand White rabbits were assigned to seven different groups. Four groups were fed 1% cholesterol diet and 0, 0.5, 1.0, and 1.5 mL of BA fruit juice per kg of rabbit daily (atherogenic groups), while the other three groups were fed commercial rabbit pellet and 0, 0.5, and 1.0 mL of juice per kg of rabbit daily (normocholesterolemic groups) for 90 days. The thoracic and abdominal aorta between the heart origin and bifurcation into iliac arteries of all the rabbits were carefully removed and analyzed accordingly. The supplementation of the high-cholesterol diet of hypercholesterolemic rabbits with only 0.5 mL BA/kg rabbit per day significantly (p < 0.001) improved aortic lipid profile, attenuated aortic fatty streak development and reduced intima thickening. Higher BA doses used (1.0 and 1.5 mL/kg rabbit per day) also significantly (p < 0.001) decreased further the development of aortic fatty streaks, reduced the thickening of the tunica intima layer and preserved endothelial healing following arterial injury. Therefore, BA fruit is a potential novel functional food with effective anti-inflammatory, anti-atherogenic and hypocholesterolemic activities.

  6. Baccaurea angulata fruit juice ameliorates altered hematological and biochemical biomarkers in diet-induced hypercholesterolemic rabbits.

    Science.gov (United States)

    Ahmed, Idris Adewale; Mikail, Maryam Abimbola; Ibrahim, Muhammad

    2017-06-01

    Hypercholesterolemia is an important risk factor linked to the alteration of blood hematology and clinical chemistry associated with the development and progression of atherosclerosis. Previous studies have demonstrated the safety and potential health benefits of Baccaurea angulata (BA) fruit. We hypothesized that the oral administration of BA fruit juice could ameliorate the alteration in the hematological and biochemical biomarkers of diet-induced hypercholesterolemic rabbits. The aim of this study was to investigate the effects of different doses of BA juice on the hematological and biochemical biomarkers in normo- and hypercholesterolemic rabbits. Thirty-five healthy adult New Zealand White rabbits were assigned to seven different groups for 90days of diet intervention. Four atherogenic groups were fed a 1% cholesterol diet and 0, 0.5, 1.0, and 1.5mL of BA juice per kg of rabbit daily. The other three normal groups were fed a commercial rabbit pellet diet and 0, 0.5, and 1.0mL of BA juice per kg of rabbit daily. Baseline and final blood samples after 90days of repeated administration BA juice were analyzed for hematological parameters while serum, aortic and hepatic lysates were analyzed for lipid profiles and other biochemical biomarkers. The alteration of the hemopoietic system, physiological changes in serum and tissues lipid profiles and other biochemicals resulting from the consumption of a high-cholesterol diet were significantly (Pjuice. Improvements of the biomarkers in rabbits were dose-dependent, markedly enhanced at the highest dose of juice (1.5mL/kg/day). The results suggest potential health benefits of the antioxidant-rich BA fruit juice against hypercholesterolemia-associated hematological and biochemical alterations in the rabbit. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Physalis angulata induces death of promastigotes and amastigotes of Leishmania (Leishmania) amazonensis via the generation of reactive oxygen species.

    Science.gov (United States)

    Da Silva, B J M; Da Silva, R R P; Rodrigues, A P D; Farias, L H S; Do Nascimento, J L M; Silva, E O

    2016-03-01

    Leishmaniasis are a neglected group of emerging diseases that have been found in 98 countries and are caused by protozoa of the genus Leishmania. The therapy for leishmaniasis causes several side effects and leads to drug-resistant strains. Natural products from plants have exhibited activities against Leishmania in various experimental models. Physalis angulata is a widely used plant in popular medicine, and in the literature it has well-documented leishmanicidal activity. However, its mechanism of action is still unknown. Thus, this study aims to evaluate the mechanism driving the leishmanicidal activity of an aqueous extract of P. angulata root (AEPa). AEPa was effective against both promastigotes and intracellular amastigote forms of Leishmania amazonensis. This effect was mediated by an increase of reactive oxygen species (ROS), but not of nitric oxide (NO). The increased production of ROS induces cell death by phenotypes seems by apoptosis cell death in Leishmania, but not autophagy or necrosis. In addition, morphological analysis of macrophages showed that AEPa induced a high number of cytoplasmic projections, increased the volume of cytoplasm and number of vacuoles, caused cytoskeleton alterations and resulted in high spreading ability. AEPa also promoted superoxide anion (O2(-)) production in both uninfected macrophages and those infected with Leishmania. Therefore, these results revealed that AEPa causes cell death by phenotypes seems by apoptosis cell death in L. amazonensis and modulates macrophage activation through morphofunctional alterations and O2(-) generation to induce Leishmania death. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Biosynthesis of spherical and highly stable gold nanoparticles using Ferulago Angulata aqueous extract: dual role of extract

    Science.gov (United States)

    Alizadeh, A.; Parsafar, S.; Khodaei, M. M.

    2017-03-01

    A biocompatible method for synthesizing of highly disperses gold nanoparticles using Ferulago Angulata leaf extract has been developed. It has been shown that leaf extract acts as reducing and coating agent. Various spectroscopic and electron microscopic techniques were employed for the structural characterization of the prepared nanoparticles. The biosynthesized particles were identified as elemental gold with spherical morphology, narrow size distribution (ranged 9.2-17.5 nm) with high stability. Also, the effect of initial ratio of precursors, temperature and time of reaction on the size and morphology of the nanoparticles was studied in more detail. It was observed that varying these parameters provides an accessible remote control on the size and morphology of nanoparticles. The uniqueness of this procedure lies in its cleanliness using no extra surfactant, reducing agent or any capping agent.

  9. The invasive Pacific oyster, Crassostrea gigas, in Scandinavia coastal waters

    DEFF Research Database (Denmark)

    Dolmer, Per; Holm, Mark Wejlemann; Strand, Åsa

    visualized the need for a continued collaboration between scientists in the Scandinavian countries, as the bio-invasion is a cross-border issue and management actions then have to be synchronized, and based on a “state of the art” knowledge of the Scandinavian bio-invasion of the species. The risk assessment......A massive invasion of the Pacific oyster, Crassostrea gigas , has occurred in Scandinavia during the last decade. The introduction and dispersal was described through collaboration between scientists from Sweden, Denmark and Norway. This work has been followed up by national activities that clearly...

  10. IN VITRO KILLING OF PERKINSUS MARINUS BY HEMOCYTES OF OYSTERS CRASSOSTREA VIRGINICA

    Science.gov (United States)

    A colorimetric microbicidal assay was adapted, optimized and applied in experiments to characterize the in vitro capacity of eastern oyster (Crassostrea virginica) hemocytes to kill cultured isolates of Perkinsus marinus, a protozoan parasite causing a highly destructive disease...

  11. PARASITIC AND SYMBIONIC FAUNA IN OYSTERS (CRASSOSTREA VIRGINICA) COLLECTED FROM THE CALOOSAHATCHEE RIVER AND ESTUARY, FLORIDA

    Science.gov (United States)

    Studies of oysters, Crassostrea virginica, collected from ten sites in the Caloosahatchee River and Estuary, Florida, revealed a varied parasite and symbiotic fauna that have never been reported from this area. Organisms observed included ovacystis virus infecting gametes...

  12. SEASONAL VARIATION IN LYSOSOMAL DESTABILIZATION IN OYSTERS, CRASSOSTREA VIRGINICA. (R826201)

    Science.gov (United States)

    Lysosomal destabilization assays have been used as valuable biomarkers of pollutant exposures in a variety of bivalve and fish species. The responses of oysters, Crassostrea virginica, deployed at and native to various reference and degraded sites were evaluated for lys...

  13. DIFFERENTIAL EFFECTS OF OYSTER (CRASSOSTREA VIRGINICA) DEFENSES ON CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHEMOLYTICUS

    Science.gov (United States)

    Three clinical (2030, 2062, and 2107) and three environmental (1094, 1163, and ATCC 17802) isolates of Vibrio parahaemolyticus were exposed to hemocytes and plasma collected from oysters (Crassostrea virginica) to determine their susceptibility to putative oyster defenses. Clinic...

  14. Molecular identification, phylogeny and geographic distribution of Brazilian mangrove oysters (Crassostrea

    Directory of Open Access Journals (Sweden)

    Aline Grasielle Costa de Melo

    2010-01-01

    Full Text Available Oysters (Ostreidae manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI, revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state to Santos (São Paulo state, and C. rhizophorae from Fortim (Ceará state to Florianópolis (Santa Catarina state, although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state. An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship.

  15. Molecular identification, phylogeny and geographic distribution of Brazilian mangrove oysters (Crassostrea)

    Science.gov (United States)

    2010-01-01

    Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state) to Santos (São Paulo state), and C. rhizophorae from Fortim (Ceará state) to Florianópolis (Santa Catarina state), although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state). An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship. PMID:21637433

  16. Efeitos do caranguejo Pinnotheres ostreum em ostras Crassostrea rhizophorae

    Directory of Open Access Journals (Sweden)

    Iracema Andrade Nascimento

    1980-12-01

    Full Text Available Some biological parameters of the oyster (Crassostrea rhizopharae, during the spawning and post-spawning periods, were analised in relation to the infestation by the pea crab (Pinnotheres ostreum The biological parameters considered were: size, total weight, wet and dry meat weight, and condition index. Utilizing the χ2 test these parameters and infestation by the pea crab were shown to to be associated. The incidence of pea crabs was higher during the spawning period than in the post-spawning period, reaching a maximum (20.3% infestation in oysters with a size of 6 to 7 cm. The values of the condition index and percent of meat (wet and dry weight for these oysters were significantly (P < 0.05 lower than for uninfested oysters. From these results there seems to be no doubt that the pea crab (V. ostreum injures the mangrove oysters which supports the conclusion that these crabs are true parasites for C. rhizophorae.

  17. Parasitas em ostras de cultivo (Crassostrea rhizophorae e Crassostrea gigas da Ponta do Sambaqui, Florianópolis, SC Parasites in cultured oysters (Crassostrea rhizophorae and Crassostrea gigas from Ponta do Sambaqui, Florianópolis, SC

    Directory of Open Access Journals (Sweden)

    R.C. Sabry

    2005-09-01

    Full Text Available Estudou-se a presença de parasitas e realizaram-se exames macroscópicos e histológicos em ostras (Crassostrea rhizophorae e Crassostrea gigas cultivadas. Entre agosto de 2002 a maio de 2003, 30 indivíduos adultos de cada espécie foram coletados sazonalmente, totalizando 240 ostras. Os animais, provenientes de desova em laboratório, foram mantidos em lanternas de cultivo, em sistema suspenso tipo espinhel, com densidade de 40 ostras/andar. A cada coleta era registrada a mortalidade das ostras, a temperatura e a salinidade da água. A temperatura variou de 19 a 28,5°C e a salinidade, 31 a 35‰. A mortalidade foi de 48,3% para C. gigas e 70,8% para C. rhizophorae. A infestação pelo poliqueta Polydora websteri em C. gigas foi 100% durante todo o período e em C. rhizophorae, 100% em fevereiro e maio. O mal do pé foi observado em novembro (3,3% e maio (23,3% em C. gigas e maio (6,6% em C. rhizophorae. As maiores prevalências do protozoário Nematopsis sp. foram de 70 e 60% em C. gigas e C. rhizophorae, respectivamente. O protozoário Trichodina sp. ocorreu em 1,6% de C. rhizophorae, e larvas do cestóide Tylocephalum sp. foram observadas em 2,5% de C. gigas. Nenhum dos parasitas encontrados foi associado à mortalidade das ostras.Over a 10-month period, cultured oysters (Crassostrea rhizophorae and Crassostrea gigas from Ponta do Sambaqui, Florianopolis, Santa Catarina State were evaluated microscopically and histologically for parasite infection. Thirty mature individuals of each species were examined each season, for a total of 240 oysters. The animals, which originated from laboratory spawning, were kept in culture lanterns suspended in long-line systems at a density of 40 oysters per floor. Mortality, water temperature (19 to 28.5 ºC range and salinity (31 to 35‰ were recorded at each sampling. The total amount of dead oysters was 58 (48.3% to C. gigas and 85 (70.8% to C. rhizophorae. All C. gigas individuals were infected with

  18. Utilization of detrital complexes by the oyster, Crassostrea virginica (Gmelin)

    International Nuclear Information System (INIS)

    Crosby, M.P.

    1987-01-01

    The contribution of bacteria and nonliving particulate organic matter of detrital complexes to the nutrition of the American oyster, Crassostrea virginica, was investigated in the laboratory under normal feeding conditions. Results indicate the oysters were capable of assimilating crude fiber extracted from 14 C-Spartina alterniflora with an efficiency of approximately 3% and that enteric bacteria did not enhance this process. Less than 1% of an oyster's energetic demands could be met by direct utilization of this substrate, in the Choptank River subestuary of the Chesapeake Bay. The potential contribution of refractory organics to oysters in large salt marshes having crude fiber concentration greater than in the Choptank system, are discussed. The ability of the oyster to utilize 14 C and 15 N from cellulolytic marine bacteria, isolated from a S. alterniflora dominated salt marsh, was also studied

  19. The reproductive cycle of the oyster Crassostrea gasar

    Directory of Open Access Journals (Sweden)

    CHAM Gomes

    Full Text Available The purpose of this study was to analyze the reproductive cycle of the oyster Crassostrea gasar (= C. brasiliana in the field and the laboratory. The reproductive cycle of the animals was evaluated in the field at Sambaqui Beach, Florianópolis, SC (27° 29′18″ S and 48° 32′12″ W from May 2008 through November 2009. In July, the animals were in the resting stage. The early growth stage began in August and was followed by the late growth stage in October. In November and December, the oysters began to enter the mature stage. Females in spawning condition were predominant during these months. The stages of the reproductive cycle were positively associated with temperature (r=0.77, P<0.01 and negatively associated with salinity (r=−0.56, P=0.042. These findings demonstrated that increased temperature and reduced salinity influence the reproductive development of Crassostrea gasar. The condition index (CI of the animals was also associated with the seawater temperature. The highest values of the condition index were observed during the months when the temperature of the seawater was gradually increasing. A laboratory experiment was performed to test the effect of salinity on the reproductive cycle of the oysters. The experiment was conducted in standardized tanks. The animals were conditioned using two salinities (24‰ and 34‰. The salinity regime influenced the development of the gonadal tissue of the oysters. A salinity of 24‰ produced greater reproductive development.

  20. Molecular evidence of the protozoan parasite Marteilia refringens in Crassostrea gigas and Crassostrea corteziensis from the Gulf of California

    Directory of Open Access Journals (Sweden)

    José Manuel Grijalva-Chon

    2015-09-01

    Full Text Available The search for exotic pathogens related to the outbreaks and in surveillance samplings of the Mexican oyster farms, is a recent activity achieved by academic institutions and state committees for Aquatic Animal Health, with remarkable results. In samples of Crassostrea gigas collected through December 2009, January 2010 and November 2010, and of C. corteziensis in September 2011, the protozoan Marteilia refringens was detected for the first time in the Gulf of California. The carrier oysters were from cultures without abnormal mortality rates, whereby, the use of histology, in situ hybridization and transmission electron microscopy studies are necessary to determine if M. refringens has become established in the Gulf of California oyster cultures. Detection of M. refringens is of great concern to the global oyster farming industry.

  1. JST Thesaurus Headwords and Synonyms: Crassostrea virginica [MeCab user dictionary for science technology term[Archive

    Lifescience Database Archive (English)

    Full Text Available MeCab user dictionary for science technology term Crassostrea virginica 名詞 一般 * * *... * アメリカガキ アメリカガキ アメリカガキ Thesaurus2015 200906044164726189 C LS05 UNKNOWN_2 Crassostrea virginica

  2. JST Thesaurus Headwords and Synonyms: Crassostrea gigas [MeCab user dictionary for science technology term[Archive

    Lifescience Database Archive (English)

    Full Text Available MeCab user dictionary for science technology term Crassostrea gigas 名詞 一般 * * * * マ...ガキ マガキ マガキ Thesaurus2015 200906057106354047 C LS05 UNKNOWN_2 Crassostrea gigas

  3. Comparative transcriptome analysis of two oysters, Crassostrea gigas and Crassostrea hongkongensis provides insights into adaptation to hypo-osmotic conditions.

    Directory of Open Access Journals (Sweden)

    Xuelin Zhao

    Full Text Available Environmental salinity creates a key barrier to limit the distribution of most aquatic organisms. Adaptation to osmotic fluctuation is believed to be a factor facilitating species diversification. Adaptive evolution often involves beneficial mutations at more than one locus. Bivalves hold great interest, with numerous species living in waters, as osmoconformers, who maintain the osmotic pressure balance mostly by free amino acids. In this study, 107,076,589 reads from two groups of Crassostrea hongkongensis were produced and the assembled into 130,629 contigs. Transcripts putatively involved in stress-response, innate immunity and cell processes were identified according to Gene ontology and KEGG pathway analyses. Comparing with the transcriptome of C. gigas to characterize the diversity of transcripts between species with osmotic divergence, we identified 182,806 high-quality single nucleotide polymorphisms (SNPs for C. hongkongensis, and 196,779 SNPs for C. gigas. Comparison of 11,602 pairs of putative orthologs allowed for identification of 14 protein-coding genes that experienced strong positive selection (Ka/Ks>1. In addition, 45 genes that may show signs of moderate positive selection (1 ≥ Ka/Ks>0.5 were also identified. Based on Ks ratios and divergence time between the two species published previously, we estimated a neutral transcriptome-wide substitution mutation rate of 1.39 × 10(-9 per site per year. Several genes were differentially expressed across the control and treated groups of each species. This is the first time to sequence the transcriptome of C. hongkongensis and provide the most comprehensive transcriptomic resource available for it. The increasing amount of transcriptome data on Crassostrea provides an excellent resource for phylogenetic analysis. A large number of SNPs identified in this work are expected to provide valuable resources for future marker and genotyping assay development. The analysis of natural

  4. The effect of tomato juices and bean sprout extracts on vitro shoot regeneration of Physalis angulata L.

    Science.gov (United States)

    Mastuti, Retno; Munawarti, Aminatun; Rosyidah, Mufidatur

    2017-11-01

    Physalis angulata L. (Ciplukan) which belongs to Solanaceae is an important medicinal plant. In vitro culture medium contains carbon source, inorganic substance, vitamins, and plant growth regulators. However, organic growth supplements have frequently been added to improve regeneration capability of explants. This study was conducted to observe the effect of tomato juices and extract bean sprout on shoot regeneration and multiplication of in vitro nodal explants. The explants were cultured on MS basal medium + 6-benzyl amino purine (BAP) 2 mg/L + indole-3-acetic acid (IAA) 0.05 mg/L with and without organic supplements. Tomato juices (T) 5, 7.5 and 10% or bean sprout extract (B) 1.25, 2.5, and 3.75% were added as natural organic supplements. Almost all explants have produced shoots one week after culture. After six weeks of culture maximum shoot number (12.5±3.9) was produced in medium MS + T5 while maximum shoot length (10.7 ± 0.7 cm) was obtained in medium MS + T 7.5. Medium T tends to produce more shoots than the medium B and medium control. This result indicates the potential of natural organic supplements for supporting Ciplukan propagation through in vitro culture.

  5. The combination effect of auxin and cytokinin on in vitro callus formation of Physalis angulata L. - A medicinal plant

    Science.gov (United States)

    Mastuti, Retno; Munawarti, Aminatun; Firdiana, Elok Rifqi

    2017-11-01

    Physalis angulata L. (Ciplukan) is one member of Solanaceae that has a potential as herbal medicine. This plant grows wild in the crop fields, forest edges, etc. However, ciplukan is increasingly difficult to find recently. In vitro callus is an alternative source to produce secondary metabolite production as well as to regenerate plants through indirect organogenesis. This study aims to identify the response of hypocotyl explants on in vitro callus formation induced by a combination of auxin and cytokinins. Two types of cytokinins, Kinetin and BAP (0.5 ppm) were combined with three types of auxin, i.e. 2.4-D, IBA and IAA, at three concentrations 0.5, 1.0 and 1.5 ppm. In all combinations of cytokinin and auxin, 50-100% of hypocotyl explants derived from in vitro seedling were able to produce callus either in a compact or watery friable texture. In MS medium supplemented with 2.4-D, callus FW (fresh weight) began to decline in the fourth week after culture. Callus FW that increased until 5 weeks of culture was obtained in medium IAA 0.5 + Kin 0.5, IBA 1.0 + Kin 0.5 and IBA 1 + BA 0.5. Almost all calli induced on a medium + Kinetin also produced roots. While medium + BAP was able to induce shoots regeneration.

  6. Antihepatoma activity of Physalis angulata and P. peruviana extracts and their effects on apoptosis in human Hep G2 cells.

    Science.gov (United States)

    Wu, Shu-Jing; Ng, Lean-Teik; Chen, Ching-Hsein; Lin, Doung-Liang; Wang, Shyh-Shyan; Lin, Chun-Ching

    2004-03-05

    Physalis angulata and P. peruviana are herbs widely used in folk medicine. In this study, the aqueous and ethanol extracts prepared from the whole plant of these species were evaluated for their antihepatoma activity. Using XTT assay, three human hepatoma cells, namely Hep G2, Hep 3B and PLC/PRF/5 were tested. The results showed that ethanol extract of P. peruviana (EEPP) possessed the lowest IC50 value against the Hep G2 cells. Interestingly, all extracts showed no cytotoxic effect on normal mouse liver cells. Treatment with carbonyl cyanide m-chlorophenyl hydrazone, a protonophore, caused a reduction of membrane potential (Deltapsim) by mitochondrial membrane depolarization. At high concentrations, EEPP was shown to induce cell cycle arrest and apoptosis through mitochondrial dysfunction as demonstrated by the following observations: (i) EEPP induced the collapse of Deltapsim and the depletion of glutathione content in a dose dependent manner; (ii) pretreatment with the antioxidant (1.0 microg/ml vitamin E) protected cells from EEPP-induced release of ROS; and (iii) at concentrations 10 to 50 microg/ml, EEPP displayed a dose-dependent accumulation of the Sub-G1 peak (hypoploid) and caused G0/G1-phase arrest. Apoptosis was elicited when the cells were treated with 50 microg/ml EEPP as characterized by the appearance of phosphatidylserine on the outer surface of the plasma membrane. The results conclude that EEPP possesses potent antihepatoma activity and its effect on apoptosis is associated with mitochondrial dysfunction.

  7. Characteristic crystal orientation of folia in oyster shell, Crassostrea gigas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Woo [Department of Chemical and Biomolecular Engineering, Sogang University, Seoul (Korea, Republic of); Kim, Gyeung Ho [Nano-Materials Reserch Center, Korea Institute of Science and Technology, Seoul (Korea, Republic of); Choi, Cheong Song [Department of Chemical and Biomolecular Engineering, Sogang University, Seoul (Korea, Republic of)], E-mail: cschoi@sogang.ac.kr

    2008-03-10

    The thin sheets of calcite, termed folia, that make up much of the shell of an oyster are composed of foliated lath. Folia of the giant Pacific oyster (Crassostrea gigas) were examined using TEM (transmission electron microscopy) and tested using microindentation and nanoindentation techniques. Analysis of the Kikuchi patterns obtained from the folia showed that there are two types (type I and type II) of preferred orientation, with an angle of around 70{sup o} between them. Nanoindentation tests showed that the folia exhibit a hardness of about 3 GPa and elastic modulus of about 73 GPa. Microcracks were generated using a microindenter in order to study the fracture mechanisms of the folia. Following on from these investigations, fracture mechanisms are discussed in conjunction with the correlation between preferred orientation and structural characteristics during cracking of the folia. Comparing the morphology and the polymorphism with nacre (also known as mother of pearl), the advantages of the relatively fast crystal growth and less amount of organic matrix in folia may have interesting implications for the development of sophisticated synthetic materials.

  8. Detection of Toxoplasma gondii DNA in Brazilian oysters (Crassostrea rhizophorae).

    Science.gov (United States)

    Ribeiro, L A; Santos, L K N S S; Brito, P A; Maciel, B M; Da Silva, A V; Albuquerque, G R

    2015-05-04

    The aim of this study was to detect evidence of Toxoplasma gondii using polymerase chain reaction (PCR)-based techniques in oysters (Crassostrea rhizophorae) obtained from the southern coastal region of Bahia, Brazil. A total of 624 oysters were collected, and the gills and digestive glands were dissected. Each tissue sample was separated into pools containing tissues (of the same type) from three animals, leading to a total of 416 experimental samples for analysis (208 samples each from the gills and digestive glands). Molecular analysis using PCR-based detection of the T. gondii AF 146527 repetitive fragment yielded negative results for all samples. However, when nested-PCR was used for detection of the T. gondii SAG-1 gene, 17 samples were positive, with the gills being the tissue with maximal detection of the parasite. These positive results were confirmed by sample sequencing. It is therefore suggested that C. rhizophorae oysters are capable of filtering and retaining T. gondii oocysts in their tissue. This represents a risk to public health because they are traditionally ingested in natura.

  9. The effect of filler addition and oven temperature to the antioxidant quality in the drying of Physalis angulata fruit extract obtained by subcritical water extraction

    Science.gov (United States)

    Susanti, R. F.; Christianto, G.

    2016-01-01

    Physalis angulata or ceplukan is medicinal herb, which grows naturally in Indonesia. It has been used in traditional medicine to treat several diseases. It is also reported to have antimycobacterial, antileukemic, antipyretic. In this research, Pysalis angulata fruit was investigated for its antioxidant capacity. In order to avoid the toxic organic solvent commonly used in conventional extraction, subcritical water extraction method was used. During drying, filler which is inert was added to the extract. It can absorb water and change the oily and sticky form of extract to powder form. The effects of filler types, concentrations and drying temperatures were investigated to the antioxidant quality covering total phenol, flavonoid and antioxidant activity. The results showed that total phenol, flavonoid and antioxidant activity were improved by addition of filler because the drying time was shorter compared to extract without filler. Filler absorbs water and protects extract from exposure to heat during drying. The combination between high temperature and shorter drying time are beneficial to protect the antioxidant in extract. The type of fillers investigation showed that aerosil gave better performance compared to Microcrystalline Celullose (MCC).

  10. Massive settlements of the Pacific oyster, Crassostrea gigas, in Scandinavia : Original paper

    DEFF Research Database (Denmark)

    Wrange, Anna-Lisa; Valero, Johanna; Harkestad, Lisbeth S.

    2010-01-01

    The Pacific oyster (Crassostrea gigas) is an important aquaculture species world-wide. Due to its wide environmental tolerance and high growth rate, it has also become a successful invader in many areas, leading to major ecosystem changes. Low water temperatures were previously believed to restri...... settlement in 2006, and in Norway, populations are established along the southwest coast to 60°N....

  11. Massive settlements of the Pacific oyster, Crassostrea gigas, in Scandinavia : Invasion note

    DEFF Research Database (Denmark)

    Wrange, Anna-Lisa; Valero, Johanna; Harkestad, Lisbeth S.

    2010-01-01

    The Pacific oyster (Crassostrea gigas) is an important aquaculture species world-wide. Due to its wide environmental tolerance and high growth rate, it has also become a successful invader in many areas, leading to major ecosystem changes. Low water temperatures were previously believed to restri...... settlement in 2006, and in Norway, populations are established along the southwest coast to 60A degrees N....

  12. Moderate establishment success of Pacific oyster, Crassostrea gigas, on a sheltered intertidal mussel bed

    DEFF Research Database (Denmark)

    Holm, M.W.; Davids, J.K.; Dolmer, Per

    2015-01-01

    The Pacific oyster (Crassostrea gigas Thunberg 1793) is introduced into marine ecosystems worldwide. In Denmark, C. gigas was introduced into the micro tidal Limfjord, around 1972 for aquaculture. This study describes the population structure of C. gigas at Agger Tange in 2007, 2009, 2010 and 2011...

  13. Impact of an icy winter on the Pacific oyster (Crassostrea gigas Thunberg, 1793) populations in Scandinavia

    DEFF Research Database (Denmark)

    Strand, Åsa; Blanda, Elisa; Bodvin, Torjan

    2012-01-01

    The Pacific oyster (Crassostrea gigas) is an invasive species that has dispersed into Scandinavia during the last few decades. The objective of this study was to evaluate the effects of extreme winter conditions on the mortality of the Pacific oyster in Scandinavia. The study was done by compilin...

  14. Isolation of Vibrio cholerae serotype O1 from the eastern oyster, Crassostrea virginica.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E

    1981-01-01

    Two strains of Vibrio cholerae serotype O1 Inaba were isolated from eastern oysters, Crassostrea virginica, collected from estuarine waters in Florida during April 1980. The oyster meats and waters from which the oysters were collected had low fecal coliform counts, and the area had no prior evidence of sewage contamination. PMID:7235700

  15. Induction of gynogenetic haploidy in oyster Crassostrea gigas, using ultra violet irradiated sperms

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.

    Eggs of Crassostrea gigas were fertilized with sperms exposed to different doses of UV irradiations by keeping a constant rate of 121.47 ergs. mm/2 sec/1 and changing the period of exposure from 4 to 90 sec. Samples of larvae were analysed...

  16. PARASITIC AND SYMBIOTIC FAUNA INHABITING OYSTERS (CRASSOSTREA VIRGINICA) SAMPLED FROM THE CALOOSAHATCHEE ESTUARY, FL

    Science.gov (United States)

    Oysters, Crassostrea virginica, inhabiting 5 sites in the Caloosahatchee River estuary were studied over a 13 month period to determine the suitability of oyster habitat in relation to their health and condition. Histological examination of 650 oysters (10 animals per station per...

  17. Biochemical profile of oyster Crassostrea madrasensis and its nutritional attributes

    Directory of Open Access Journals (Sweden)

    K.K. Asha

    2014-01-01

    Full Text Available Oysters are highly esteemed sea food and considered a delicacy throughout the world. Yet this resource is not optimally utilised in several parts of the world. The aim of this study is to highlight its nutritional importance. Biochemical composition and nutritional attributes of oyster meat are discussed. Proximate composition, fatty acid and amino acid profiles and mineral content were determined in oysters (Crassostrea madrasensis. Moisture, protein, fat, carbohydrate and ash contents in the oyster were 82.64%, 9.41%, 3.25% 3.2% and 1.01%, respectively and it was rich in macro-minerals and trace elements especially selenium. Polyunsaturated fatty acids (PUFA were highest of the total lipids among which eicosapentaenoic acid, docosahexaenoic acid and linoleic acid were the prominent fatty acids. The n-3/n-6 index was high indicating a predominance of n-3 fatty acids in the species. Total amino acid content was 99.33 g/100 g crude protein, of which, essential amino acid lysine was the most abundant. Valine had the lowest essential amino acid score (EAAS (0.17 while threonine had the highest EAAS of 3.62. Chemical score was 17% and the lowest limiting amino acid was valine. Protein efficiency ratio, essential amino acid index and biological value of oyster were 3.92, 120.2 and 174.0, respectively which indicates that the protein is of superior quality. Data on biochemical composition, nutritional attributes and quality indices of C. madrasensis protein may prove important for future policies regarding exploitation of this species and for inducing favourable changes in consumer preferences.

  18. Unusual conservation of mitochondrial gene order in Crassostrea oysters: evidence for recent speciation in Asia

    Science.gov (United States)

    2010-01-01

    Background Oysters are morphologically plastic and hence difficult subjects for taxonomic and evolutionary studies. It is long been suspected, based on the extraordinary species diversity observed, that Asia Pacific is the epicenter of oyster speciation. To understand the species diversity and its evolutionary history, we collected five Crassostrea species from Asia and sequenced their complete mitochondrial (mt) genomes in addition to two newly released Asian oysters (C. iredalei and Saccostrea mordax) for a comprehensive analysis. Results The six Asian Crassostrea mt genomes ranged from 18,226 to 22,446 bp in size, and all coded for 39 genes (12 proteins, 2 rRNAs and 25 tRNAs) on the same strand. Their genomes contained a split of the rrnL gene and duplication of trnM, trnK and trnQ genes. They shared the same gene order that differed from an Atlantic sister species by as many as nine tRNA changes (6 transpositions and 3 duplications) and even differed significantly from S. mordax in protein-coding genes. Phylogenetic analysis indicates that the six Asian Crassostrea species emerged between 3 and 43 Myr ago, while the Atlantic species evolved 83 Myr ago. Conclusions The complete conservation of gene order in the six Asian Crassostrea species over 43 Myr is highly unusual given the remarkable rate of rearrangements in their sister species and other bivalves. It provides strong evidence for the recent speciation of the six Crassostrea species in Asia. It further indicates that changes in mt gene order may not be strictly a function of time but subject to other constraints that are presently not well understood. PMID:21189147

  19. GREATER HEMOCYTE BACTERICIDAL ACTIVITY IN OYSTERS (CRASSOSTREA VIRGINICA) FROM A RELATIVELY CONTAMINATED SITE IN PENSACOLA BAY, FLORIDA.

    Science.gov (United States)

    Bivalve mollusks such as Crassostrea virginica inhabiting polluted estuaries and coastal areas may bioaccumulate high concentrations of contaminants without apparent ill effects. However, changes in putative internal defense activities have been associated with contaminant accumu...

  20. Short-term feeding response of the mussel Mytilus chilensis exposed to diets containing the toxic dinoflagellate Alexandrium catenella Respuesta alimentaria inicial del bivalvo Mytilus chilensis expuesto a dietas conteniendo el dinoflagelado tóxico Alexandrium catenella

    Directory of Open Access Journals (Sweden)

    JORGE M NAVARRO

    2008-03-01

    Full Text Available The short-term feeding response of the bivalve Mytilus chilensis was measured using four diets containing different proportions of the toxic dinoflagellate Alexandrium catenella. The diets containing the highest concentrations of the dinoflagellate showed the greatest effect on the feeding activity in the mussel, with clearance and ingestión rates significantly reduced during the first hours of exposure. After this period, M. chilensis demonstrated a capacity to acclimate to the toxic diets, with feeding parameters reaching values similar to those of untreated control organisms. It was not clear if the negative effect on the feeding behavior was caused by the presence of the paralytic toxin, or due to the larger size of the dinoflagellate cells in comparison with cells of Isochrysis galbana used in the control diet. However, parallel studies with diets containing the nontoxic dinoflagellate Alexandrium affine of similar size and shape to that of A. catenella, suggested the cell size was the main cause for impairment of feeding behavior. The capacity for acclimation to either toxin or cell size by M. chilensis makes it a good indicator species for the early detection of harmful PSP events, since its relative insensitivity to the toxin allows it to quickly recover normal feeding behavior and permits it to accumulate PSP in its tissues in a short timeLa respuesta inicial del bivalvo Mytilus chilensis fue medida bajo cuatro dietas que contenían diferentes proporciones del dinoflagelado tóxico Alexandrium catenella. Las dietas que contenían las concentraciones más altas de este dinoflagelado mostraron el mayor efecto durante las primeras horas de exposición. Después de este periodo inicial, M. chilensis demostró la capacidad para aclimatarse a estas dietas tóxicas, con parámetros de alimentación que alcanzaron valores similares a aquellos de los organismos controles. No fue claro si el efecto negativo sobre la conducta de alimentación fue

  1. Nitrogenous compounds changes in emersed oysters: Crassostrea gigas

    Science.gov (United States)

    Rafrafi, Sarra; Uglow, Roger F.

    2009-01-01

    The effects of emersing oysters ( Crassostrea gigas) for up to 66 h at 4 °C under humid air and nitrogen atmospheres were studied. A significant, gradual body mass loss occurred under nitrogen (8.36 ± 0.85% final weight loss) but no significant loss occurred under humid air (4.92 ± 2.67% final weight loss). Emersion duration and the mantle cavity fluid (MCF) total ammonia (TA) concentration showed a positive, linear relationship ( r2 = 0.73 and 0.74 under humid air and N 2, respectively). The MCF TA and trimethylamine (TMA) contents were also positively related ( r2 = 0.64 and 0.69 under humid air and N 2, respectively). Proline was the most abundant soft tissue free amino acid (71.07 ± 11.8%) in the control group and its concentration did not change significantly under either treatment. The concentration of alanine and valine increased significantly only under humid air. Under N 2, the concentrations of valine and lysine increased significantly and aspartate decreased significantly. Succinate showed a large increase during the first 6 h of emersion under both treatments but significantly more was accumulated in the N 2-exposed group (4.2-fold increase and 8.1-fold increase for the humid air- and N 2-exposed groups, respectively). The succinate concentration difference remained higher in the N 2-treated groups but, in the final 24 h, levels decreased again (quadratic regressions of r2 = 0.97 and 0.95 under humid air and N 2, respectively). Although the trend of succinate accumulation was similar under both treatments, the groups held under nitrogen did not gape (whereas those under humid air did). It is concluded that the implications of gaping behaviour on succinate accumulation in the initial hours of emersion have considerable ecological significance for oysters which occupy habitats in which they may become emersed for some hours naturally. Gaping behaviour also has considerable commercial implications because emersion occurs frequently during the marketing

  2. The ANGULATA7 gene encodes a DnaJ-like zinc finger-domain protein involved in chloroplast function and leaf development in Arabidopsis.

    Science.gov (United States)

    Muñoz-Nortes, Tamara; Pérez-Pérez, José Manuel; Ponce, María Rosa; Candela, Héctor; Micol, José Luis

    2017-03-01

    The characterization of mutants with altered leaf shape and pigmentation has previously allowed the identification of nuclear genes that encode plastid-localized proteins that perform essential functions in leaf growth and development. A large-scale screen previously allowed us to isolate ethyl methanesulfonate-induced mutants with small rosettes and pale green leaves with prominent marginal teeth, which were assigned to a phenotypic class that we dubbed Angulata. The molecular characterization of the 12 genes assigned to this phenotypic class should help us to advance our understanding of the still poorly understood relationship between chloroplast biogenesis and leaf morphogenesis. In this article, we report the phenotypic and molecular characterization of the angulata7-1 (anu7-1) mutant of Arabidopsis thaliana, which we found to be a hypomorphic allele of the EMB2737 gene, which was previously known only for its embryonic-lethal mutations. ANU7 encodes a plant-specific protein that contains a domain similar to the central cysteine-rich domain of DnaJ proteins. The observed genetic interaction of anu7-1 with a loss-of-function allele of GENOMES UNCOUPLED1 suggests that the anu7-1 mutation triggers a retrograde signal that leads to changes in the expression of many genes that normally function in the chloroplasts. Many such genes are expressed at higher levels in anu7-1 rosettes, with a significant overrepresentation of those required for the expression of plastid genome genes. Like in other mutants with altered expression of plastid-encoded genes, we found that anu7-1 exhibits defects in the arrangement of thylakoidal membranes, which appear locally unappressed. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  3. Transcriptome of American oysters, Crassostrea virginica, in response to bacterial challenge: insights into potential mechanisms of disease resistance.

    Science.gov (United States)

    McDowell, Ian C; Nikapitiya, Chamilani; Aguiar, Derek; Lane, Christopher E; Istrail, Sorin; Gomez-Chiarri, Marta

    2014-01-01

    The American oyster Crassostrea virginica, an ecologically and economically important estuarine organism, can suffer high mortalities in areas in the Northeast United States due to Roseovarius Oyster Disease (ROD), caused by the gram-negative bacterial pathogen Roseovarius crassostreae. The goals of this research were to provide insights into: 1) the responses of American oysters to R. crassostreae, and 2) potential mechanisms of resistance or susceptibility to ROD. The responses of oysters to bacterial challenge were characterized by exposing oysters from ROD-resistant and susceptible families to R. crassostreae, followed by high-throughput sequencing of cDNA samples from various timepoints after disease challenge. Sequence data was assembled into a reference transcriptome and analyzed through differential gene expression and functional enrichment to uncover genes and processes potentially involved in responses to ROD in the American oyster. While susceptible oysters experienced constant levels of mortality when challenged with R. crassostreae, resistant oysters showed levels of mortality similar to non-challenged oysters. Oysters exposed to R. crassostreae showed differential expression of transcripts involved in immune recognition, signaling, protease inhibition, detoxification, and apoptosis. Transcripts involved in metabolism were enriched in susceptible oysters, suggesting that bacterial infection places a large metabolic demand on these oysters. Transcripts differentially expressed in resistant oysters in response to infection included the immune modulators IL-17 and arginase, as well as several genes involved in extracellular matrix remodeling. The identification of potential genes and processes responsible for defense against R. crassostreae in the American oyster provides insights into potential mechanisms of disease resistance.

  4. Crassostrea gigas OYSTERS SMOKING: THE HOT AND WITH LIQUID SMOKE DEFUMAÇÃO DE OSTRAS Crassostrea gigas: A QUENTE E COM FUMAÇA LÍQUIDA

    Directory of Open Access Journals (Sweden)

    Maria Luiza de Rodrigues de Souza

    2007-07-01

    Full Text Available The present study had as objective evaluates two techniques of traditional smoking the hot and with use of the liquid smoke, tends as control the Pacific oysters Crassostrea gigas cooked. They were appraised the sensorial characteristics and revenue of the processing. The animals were distributed in three treatments and the experimental design was completely randomized, with nine repetitions. For the sensorial analysis 30 fitting room were used, where each one was considered a block. There was not significant difference among the independent of the applied technique smoky oysters (T1 = 8.42% and T2 = 7.61%, but they differed of the control (T3 = 16.25%.In agreement with the applied methodology and with the results obtained in the sensorial analysis, the smoke oysters (independent of the applied technique are products with great acceptability and increased your sensorial characteristics. KEY-WORDS: Crassostrea gigas, oysters, hot smoking, liquid smoke. valiaram-se duas técnicas de defumação – tradicional a quente e com utilização da fumaça líquida –, tendo testemunha o cozimento de ostras do Pacífico Crassostrea gigas. Para tanto, examinaram-se as características sensoriais e rendimento do processamento. Distribuíram-se animais aleatoriamente, em três tratamentos, com delineamento experimental inteiramente casualizado e nove repetições. Para a análise sensorial, empregaram-se trinta provadores, considerando-se cada um deles um bloco. Não houve diferença significativa de rendimento entre as ostras defumadas, independentemente da técnica aplicada (T1 = 8,42% e T2 = 7,61%, mas elas diferiram da testemunha (T3 = 16,25%. De acordo com a metodologia aplicada e com os resultados obtidos nas análises sensoriais, as ostras defumadas (independentemente da técnica aplicada constituíram os produtos com maior aceitabilidade e houve incremento de suas características sensoriais. PALAVRAS-CHAVES: Crassostrea gigas, defumação a

  5. Behavior of pathogenic bacteria in the oyster, Crassostrea commercialis, during depuration, re-laying, and storage.

    OpenAIRE

    Son, N T; Fleet, G H

    1980-01-01

    Oysters (Crassostrea commercials) harvested from major cultivation areas within the state of New South Wales, Australia, were commonly contaminated with low levels of the food-poisoning organisms Bacillus cereus, Clostridium perfringens, and Vibrio parahaemolyticus. Salmonella was found in oysters on only one occasion. These bacteria were cleansed from oysters during oyster purification by re-laying in a non-polluted waterway. Oysters were laboratory contaminated to levels in excess 1,000 cel...

  6. Invasiveness of Cut-Leaf Ground-Cherry (Physalis angulata L. Populations and Impact of Soil Water and Nutrient Availability Potencial Invasor de Poblaciones de Tomatillos de Brihuega (Physalis angulata L. e Impacto del Contenido de Agua y Disponibilidad de Nutrientes del Suelo

    Directory of Open Access Journals (Sweden)

    Ilias S Travlos

    2012-09-01

    Full Text Available Biological invasions are a major threat to natural ecosystems and agroecosystems, while weed flora is noticeably changing globally. In this study we evaluated the potential of cut-leaf ground-cherry (Physalis angulata L., a species native to America, to invade the semi-arid regions of Greece. Greenhouse and laboratory experiments were conducted to evaluate the effects of different environmental resources (nutrient and water availability on seedling growth, biomass production, fecundity, and seed germination of four populations of cut-leaf ground-cherry. Our results suggest that cut-leaf ground-cherry does not tolerate extreme drought during the first growth stages, while it can survive and produce adequate and rapidly germinated seed (> 85% under low soil moisture conditions. Moreover, high water and nutrient availability results in high growth and biomass production and ensures high seed production, reaching more than 4000 seeds plant-1. We suggest that soil water content and nutrient availability are the two critical factors affecting the invasive potential of cut-leaf ground-cherry in semi-arid environments. Understanding the plant's ecological features through a study conducted at an early stage rather than a late stage of invasion will help us to take appropriate control measures for this species, which should primarily target frequently fertilized fields after precipitation events.Las invasiones biológicas son una amenaza importante para los ecosistemas naturales y agroecosistemas, mientras que, globalmente, la flora de malezas parece cambiar notablemente. En este estudio se evaluó el potencial de una especie nativa de América, tomatillos de Brihuega (Physalis angulata L., para invadir las regiones semiáridas de Grecia. Se realizaron experimentos de invernadero y laboratorio para evaluar los efectos de diferentes recursos ambientales (disponibilidad de nutrientes y agua, crecimiento de las plántulas, producción de biomasa, fecundidad

  7. Dinámica poblacional y reproductiva de Turbinella angulata y Busycon perversum (Mesogasteropoda: Turbinellidae y Melongenidae en el Banco de Campeche, México Turbinella angulata and Busycon perversum (Mesogasteropoda: Turbinellidae and Melongenidae population and reproductive dynamics in the Campeche Bank, Mexico

    Directory of Open Access Journals (Sweden)

    Josefina Santos Valencia

    2013-03-01

    Full Text Available Turbinella angulata y Busycon perversum aportan la mayor captura de caracol en el Golfo de México (90%.Se realizaron muestreos mediante transectos lineales (150x1.5m de abril 2008 a marzo 2010 y en las capturas comerciales del Banco de Campeche (18°-20º N - 90°- 91º O. 2 832 individuos de T. angulata fueron medidos, las tallas variaron entre 63-282mm (LS, la proporción hembras:machos fue 0.98:1. Los valores de crecimiento fueron: L=346mm, K=0.30 y t0=-0.24. El periodo reproductivo fue de enero a mayo con reposo de junio a septiembre (80%. La talla de primera madurez (L fue de 210mm (LS en hembras y 200mm en machos. De B. perversum,1 655 ejemplares fueron analizados con tallas entre 78-292mm, presentando diferencias significativas entre longitudes de machos y hembras (p0.05. La proporción hembras:machos fue 1:0.25. Los valores de crecimiento fueron L=360 mm, K=0.35 y t=-0.19. El periodo reproductivo fue de agosto a diciembre con reposo de enero a abril. La L50 fue de 215mm (LS en hembras y 190mm en machos. Se observó un pulso de reclutamiento anual en ambas especies relacionado con el incremento en la temperatura marina. Los resultados ayudarán a definir un esquema de manejo basado en los atributos poblacionales y reproductivos de las especies.Turbinella angulata and Busycon perversum are two marine gastropods that support the 90% of conch fisheries in the Gulf of Mexico, nevertheless there is no information available to support a management strategy for both species. The aim of this work was to obtain preliminary fishery information to promote management actions for both species in the Campeche Bank. The population of conchs was sampled in 12 transects (150x1.5m by SCUBA diving from April 2008 to March 2010. All conchs were collected and siphonal length (SL was measured. These samples were complemented with data from the commercial catches, analyzing a total of 2 832 individuals of T. angulata. Siphonal length varied between 63 and 282

  8. THE EFFECT OF CIPLUKAN (Physalis angulata L. FRUIT EXTRACT ON SGPT AND SGOT LEVELS AGAINST WHITE MALE MICE (Mus musculus HYPERGLYCEMIA INDUCED BY ALLOXAN AS BIOLOGY LEARNING RESOURCES

    Directory of Open Access Journals (Sweden)

    Nur Lailatul Fitri

    2016-07-01

    Full Text Available Ciplukan (Physalis angulata L. used by the community as an antidiabetic drug. Antidiabetic effects caused ciplukan fruit of this plant contain chemicals flavonoids with the percentage of fruit extract 300 mg / ml was 84%. Flavonoids are antioxidant compounds one that works a treat or neutralize free radicals that are expected with the administration of these antioxidants can be inhibited damage to body cells and can prevent damage to the body and the onset of degenerative diseases. This type of research is True Experimental Research. The research design using The Posttest-Only Control Group Design. The research design used completely randomized design (CRD. This research data is data SGPT and SGOT levels. Analysis of data using one-way analysis of variance at significance level of 0.05 and Duncan 5%. The results showed that different doses of fruit extract ciplukan effect on SGPT and SGOT levels of mice. Duncan test showed that the treatment dose ciplukan fruit extract is the most effective dose of 2 ml / kg. The research results can be used by teachers as information of an alternative to utilize medical plants of hyperglicemia and antiocsidant on Biology subject for X Grade of Senior High School, especially on the concept Maintenance and Utilizing of Biological Diversity in Core Competence 4

  9. Molecular analysis of bacterial microbiota associated with oysters (Crassostrea gigas and Crassostrea corteziensis) in different growth phases at two cultivation sites.

    Science.gov (United States)

    Trabal, Natalia; Mazón-Suástegui, José M; Vázquez-Juárez, Ricardo; Asencio-Valle, Felipe; Morales-Bojórquez, Enrique; Romero, Jaime

    2012-08-01

    Microbiota presumably plays an essential role in inhibiting pathogen colonization and in the maintenance of health in oysters, but limited data exist concerning their different growth phases and conditions. We analyzed the bacterial microbiota composition of two commercial oysters: Crassostrea gigas and Crassostrea corteziensis. Differences in microbiota were assayed in three growth phases: post-larvae at the hatchery, juvenile, and adult at two grow-out cultivation sites. Variations in the microbiota were assessed by PCR analysis of the 16S rRNA gene in DNA extracted from depurated oysters. Restriction fragment length polymorphism (RFLP) profiles were studied using Dice's similarity coefficient (Cs) and statistical principal component analysis (PCA). The microbiota composition was determined by sequencing temperature gradient gel electrophoresis (TGGE) bands. The RFLP analysis of post-larvae revealed homology in the microbiota of both oyster species (Cs > 88 %). Dice and PCA analyses of C. corteziensis but not C. gigas showed differences in the microbiota according to the cultivation sites. The sequencing analysis revealed low bacterial diversity (primarily β-Proteobacteria, Firmicutes, and Spirochaetes), with Burkholderia cepacia being the most abundant bacteria in both oyster species. This study provides the first description of the microbiota in C. corteziensis, which was shown to be influenced by cultivation site conditions. During early growth, we observed that B. cepacia colonized and remained strongly associated with the two oysters, probably in a symbiotic host-bacteria relationship. This association was maintained in the three growth phases and was not altered by environmental conditions or the management of the oysters at the grow-out site.

  10. Growth of Crassostrea gasar cultured in marine and estuary environments in Brazilian waters

    OpenAIRE

    Lopes,Gustavo Ruschel; Gomes,Carlos Henrique Araujo de Miranda; Tureck,Cláudio Rudolfo; Melo,Claudio Manuel Rodrigues de

    2013-01-01

    The objective of this work was to evaluate the growth of the mangrove oyster Crassostrea gasar cultured in marine and estuarine environments. Oysters were cultured for 11 months in a longline system in two study sites - São Francisco do Sul and Florianópolis -, in the state of Santa Catarina, Southern Brazil. Water chlorophyll-α concentration, temperature, and salinity were measured weekly. The oysters were measured monthly (shell size and weight gain) to assess growth. At the end of the...

  11. Induction of gynogenetic haploidy in oyster Crassostrea gigas, using ultra violet irradiated sperms

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, Usha [National Inst. of Oceanography, Panaji (India)

    1993-06-01

    Eggs of Crassostrea gigas were fertilized with sperms exposed to different doses of UV irradiations by keeping a constant rate of 121.47 ergs.mm[sup -2]sec[sup -1] and changing the period of exposure from 4 to 90 sec. Samples of larvae were analysed for chromosomal ploidy, rate of fertilization, developmental and chromosomal abnormalities. The gynogenetic haploid larvae first made their appearance in the 30 and 50 sec group exposed to 3644 and 6074 ergs mm[sup -2] UV. The maximum number was found in the 90 sec group exposed to 10932 ergs mm[sup -2] UV. (author). 11 refs., 1 tab., 1 fig.

  12. Development and distribution of the non-indigenous Pacific oyster (Crassostrea gigas) in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Fey-Hofstede, F.E.; Dankers, N.M.J.A.; Steenbergen, J.; Goudswaard, P.C.

    2010-01-01

    Pacific oysters (Crassostrea gigas) were first observed in the Dutch Wadden Sea near Texel in 1983. The population increased slowly in the beginning but grew exponentially from the mid-1990s onwards, although now some stabilisation seems to be occurring. They occur on a variety of substrates such as

  13. Status of the Pacific Oyster Crassostrea gigas (Thunberg, 1793) in the western Limfjord, Denmark – Five years of population development

    DEFF Research Database (Denmark)

    Groslier, Tilde; Christensen, Helle Torp; Davids, Jens

    2014-01-01

    The Pacific oyster, Crassostrea gigas, was introduced into the Netherlands in 1964 for aquaculture purposes and has since spread extensively in Northern European waters. Eight locations in the western part of the Limfjord, Denmark, first sampled in 2006 were revisited in 2011, to determine how...

  14. PROGRESSION OF DISEASES CAUSED BY THE OYSTER PARASITES, PERKINSUS MARINUS AND HAPLOSPORIDIUM NELSONI, IN CRASSOSTREA VIRGINICA ON CONSTRUCTED INTERTIDAL REEFS

    Science.gov (United States)

    The progression of diseases caused by the oyster parasites, Perkinsus marinus and Haplosporidium nelsoni, were evaluated by periodic sampling (May 1994-Dec. 1995) of oysters, Crassostrea virginica, that set on an artificial reef located in the Piankatank River, Virginia, in Augus...

  15. PARASITIC AND SYMBIOTIC FAUNA IN OYSTERS (CRASSOSTREA VIRGINICA) AND MUD CRABS (PANOPEUS SPP.) FROM THE CALOOSAHATCHEE ESTUARY, FLORIDA, USA.

    Science.gov (United States)

    Volety, Aswani K., S. Greg Tolley and James T. Winstead. 2002. Parasitic and Symbiotic Fauna in Oysters (Crassostrea virginica) and Mud Crabs (Panopeus spp.) from the Caloosahatchee Estuary, Florida, USA (Abstract). Presented at the 4th International Conference on Molluscan Shell...

  16. Ferulago angulata activates intrinsic pathway of apoptosis in MCF-7 cells associated with G1 cell cycle arrest via involvement of p21/p27

    Directory of Open Access Journals (Sweden)

    Karimian H

    2014-09-01

    Full Text Available Hamed Karimian,1 Soheil Zorofchian Moghadamtousi,2 Mehran Fadaeinasab,3 Shahram Golbabapour,2 Mahboubeh Razavi,1 Maryam Hajrezaie,2 Aditya Arya,1 Mahmood Ameen Abdulla,4 Syam Mohan,5 Hapipah Mohd Ali,2 Mohamad Ibrahim Noordin1 1Department of Pharmacy, Faculty of Medicine, 2Institute of Biological Sciences, Faculty of Science, 3Department of Chemistry, 4Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia, 5Medical Research Centre, Jazan University, Jazan, Saudi Arabia Abstract: Ferulago angulata is a medicinal plant that is traditionally known for its ­anti-inflammatory and antiulcer properties. The present study was aimed to evaluate its anticancer activity and the possible mechanism of action using MCF-7 as an in vitro model. F. angulata leaf extracts were prepared using solvents in the order of increasing polarity. As determined by MTT assay, F. angulata leaves hexane extract (FALHE revealed the strongest cytotoxicity against MCF-7 cells with the half maximal inhibitory concentration (IC50 value of 5.3±0.82 µg/mL. The acute toxicity study of FALHE provided evidence of the safety of the plant extract. Microscopic and flow cytometric analysis using annexin-V probe showed an induction of apoptosis in MCF-7 by FALHE. Treatment of MCF-7 cells with FALHE encouraged the intrinsic pathway of apoptosis, with cell death transducing signals that reduced the mitochondrial membrane potential with cytochrome c release from mitochondria to cytosol. The released cytochrome c triggered the activation of caspase-9. Meanwhile, the overexpression of caspase-8 suggested the involvement of an extrinsic pathway in the induced apoptosis at the late stage of treatment. Moreover, flow cytometric analysis showed that FALHE treatment significantly arrested MCF-7 cells in the G1 phase, which was associated with upregulation of p21 and p27 assessed by quantitative polymerase chain reaction. Immunofluorescence

  17. Determinación de metabolitos secundarios en Physalis angulata (L) 1758 "mullaca" y su importancia en el efecto hipoglucemiante en Rattus norvegicus "rata albina", Iquitos - Perú;

    OpenAIRE

    Donayre Ramirez, Marjorie Raquel; Carrasco Montañez, Daniel Diomedes

    2013-01-01

    El presente trabajo se desarrolló en el laboratorio de Química Analítica de la Universidad Nacional de la Amazonía Peruana (UNAP) y en el Instituto de Medicina Tradicional (IMET) de la Ciudad de !quitos - Perú. Se evaluó la actividad hipoglucemiante de los extractos, etanólico y metanólico de raíz, tallo y hoja de Physalis angulata (Linneo) "mullaca", en ratas albinas machos Rattus norvegicus cepa Holtzman, previa inducción de un estado de hiperglicemia con alloxano al 5% (125mg/kg de masa co...

  18. Detection of Perkinsus marinus in the oyster Crassostrea rhizophorae in southern Bahia by proteomic analysis

    Directory of Open Access Journals (Sweden)

    Thiago Ramos Pinto

    2017-01-01

    Full Text Available This study reports the presence of the pathogen Perkinsus marinus, notifiable to the World Organization for Animal Health (Office International des Èpizooties = OIE in the oyster Crassostrea rhizophorae in southern Bahia via proteomic analysis. We analyzed Crassostrea brasiliana from a long-line cultivation system and C. rhizophorae from an adjacent mangrove in Porto do Campo, Camamu Bay, Bahia, Brazil. The collections (n = 100 were performed in October 2012. In the laboratory, the oysters were measured and opened to remove the meat, which was steeped in dry ice. For extraction of proteins, adaptation of a protocol used for mussels was used, after which separation in the first dimension was taken by isoelectric focusing (IEF. The peptides were transferred to a Mass Spectrometer. The obtained spectra were analyzed with the ProteinLynx Global Server 4.2 software tool and also by MASCOT (Matrix Science and compared to the databases of the SWISSPROT and NCBI, respectively. The identification was evidenced by beta-tubulin, Perkinsus marinus ATCC 50983 and protein homology code in the database NCBI = gi | 294889481. This is the first record of P. marinus in Bahia and the fourth in Brazil.

  19. Polymorphic microsatellite loci for two Atlantic oyster species: Crassostrea rhizophorae and C. gasar.

    Science.gov (United States)

    Cavaleiro, Nathalia P; Solé-Cava, Antonio M; Lazoski, Cristiano; Cunha, Haydée A

    2013-12-01

    Using a CA/CAA enriched library screening procedure, we isolated and characterised a total of seventeen polymorphic microsatellite loci for two species of Crassostrea with recognised economic importance. Eleven microsatellite loci were developed for C. rhizophorae, a Western Atlantic species for which no microsatellites were previously known. Another six loci were developed for C. gasar, a species that occurs on both sides of the South Atlantic, adding to the ten loci previously described for the species. The levels of polymorphism were estimated using 24 C. rhizophorae from Southeast Brazil (São Paulo) and 23 C. gasar individuals from North Brazil (Maranhão). The number of alleles per polymorphic locus varied from 3 to 27, and the observed and expected heterozygosities ranged between 0.174 and 0.958 and between 0.237 and 0.972 in C. rhizophorae and C. gasar, respectively. No linkage disequilibrium was found between any locus pair, and four of them exhibited deviations from Hardy-Weinberg expectations. Of the 17 loci developed, 8 cross-amplified in C. gigas and 13 in C. virginica. These markers are useful for evolution and population genetics studies of Crassostrea species and may provide fundamental data for the future cultivation of native oysters in Western Atlantic.

  20. Streptomyces effect on the bacterial microbiota associated to Crassostrea sikamea oyster.

    Science.gov (United States)

    García Bernal, M; Trabal Fernández, N; Saucedo Lastra, P E; Medina Marrero, R; Mazón-Suástegui, J M

    2017-03-01

    To determine the composition and diversity of the microbiota associated to Crassostrea sikamea treated during 30 days with Streptomyces strains N7 and RL8. DNA was extracted from oysters followed by 16S rRNA gene amplification and pyrosequencing. The highest and lowest species diversity richness was observed in the initial and final control group, whereas Streptomyces-treated oysters exhibited intermediate values. Proteobacteria was the most abundant phylum (81·4-95·1%), followed by Bacteroidetes, Actinobacteria and Firmicutes. The genera Anderseniella, Oceanicola, Roseovarius, Ruegeria, Sulfitobacter, Granulosicoccus and Marinicella encompassed the core microbiota of all experimental groups. The genus Bacteriovorax was detected in all groups except in the final control and the depurated N7, whereas Vibrio remained undetected in all Streptomyces-treated groups. RL8 was the only group that harboured the genus Streptomyces in its microbiota. Principal component analysis showed that Streptomyces strains significantly changed oyster microbiota with respect to the initial and final control. Crassostrea sikamea treated with Streptomyces showed high species diversity and a microbiota composition shift, characterized by keeping the predator genus Bacteriovorax and decreasing the pathogenic Vibrio. This is the first culture-independent study showing the effect of Streptomyces over the oyster microbiota. It also sheds light about the potential use of Streptomyces to improve mollusc health and safety for consumers after the depuration process. © 2016 The Society for Applied Microbiology.

  1. DNA methylation patterns provide insight into epigenetic regulation in the Pacific oyster (Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Gavery Mackenzie R

    2010-08-01

    Full Text Available Abstract Background DNA methylation is an epigenetic mechanism with important regulatory functions in animals. While the mechanism itself is evolutionarily ancient, the distribution and function of DNA methylation is diverse both within and among phylogenetic groups. Although DNA methylation has been well studied in mammals, there are limited data on invertebrates, particularly molluscs. Here we characterize the distribution and investigate potential functions of DNA methylation in the Pacific oyster (Crassostrea gigas. Results Methylation sensitive PCR and bisulfite sequencing PCR approaches were used to identify CpG methylation in C. gigas genes and demonstrated that this species possesses intragenic methylation. In silico analysis of CpGo/e ratios in publicly available sequence data suggests that DNA methylation is a common feature of the C. gigas genome, and that specific functional categories of genes have significantly different levels of methylation. Conclusions The Pacific oyster genome displays intragenic DNA methylation and contains genes necessary for DNA methylation in animals. Results of this investigation suggest that DNA methylation has regulatory functions in Crassostrea gigas, particularly in gene families that have inducible expression, including those involved in stress and environmental responses.

  2. Radiosensitivity of Salmonella spp and Vibrio parahaemolyticus artificially incorporated by oysters (Crassostrea brasiliana).; Radiossensibilidade de Salmonella spp e Vibrio parahaemolyticus incorporadas artificialmente por ostras (Crassostrea brasiliana)

    Energy Technology Data Exchange (ETDEWEB)

    Jakabi, Miyoko

    2001-07-01

    Irradiation is considered one of the most efficient technological process to reduce the number of microorganisms in food. It can be used to improve the safety of food products as well as their shelf life. Oysters are considered one of the most important vehicle of pathogenic bacteria due to their feeding characteristic and because they are usually ingested raw. The aim of this study was to evaluate the influence of gamma radiation process on high levels of Salmonella Enteritidis, Salmonella Infantis and Vibrio parahaemolyticus incorporated by oysters (Crassostrea brasiliana) as well as on the survival of the animals and sensory attributes. The oysters were submitted to gamma radiation treatment ({sup 60}Co) with doses ranging from 0.5 kGy to 3.0 kGy. At least four trials were conducted for each serotype. The dose of 3.0 kGy was, generally, sufficient to reduce the level of Salmonella serotypes in 6 log while for V.parahaemolyticus the dose as 1.o kGy. Animals were not killed and sensory attributes were not changed by the highest irradiation dose. Therefore, 3.0 kGy is a dose that is effective on the inactivation of Salmonella spp and V.parahaemolyticus in oysters without changing their odour, flavour and appearance. (author)

  3. Study of the U and Th series in Crassostrea mangle shell

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Wellington M.; Damatto, Sandra R.; Silva, Paulo S.C., E-mail: wellington.m@usp.br, E-mail: damatto@ipen.br, E-mail: pscsilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Simone, Luiz R.L.; Amaral, Vanessa S., E-mail: lrsimone@usp.br, E-mail: vanessamolusco@gmail.com [Universidade de Sao Paulo (MZ/USP), Sao Paulo, SP (Brazil). Museu de Zoologia

    2015-07-01

    Foraminifera, corals and mollusks shells have been used as proxies for environmental, paleoenvironmental and climatic change studies in marine system by using elemental and isotopic ratios as recorder of such events. Nevertheless, there is little information available on the U and Th radionuclides decay series applied on those fields. In this sense, the objective of this paper was to evaluate the activity concentrations of the U and Th nuclide decay series in Crassostrea mangle shell samples as a function of the geographic location. Samples from Sao Paulo, Parana, Alagoas, Rio Grande do Norte and Pernambuco states were analyzed by Neutron Activation Analysis and Gross Alpha and Beta Counting. Statistical analysis applied to the obtained results allowed differencing samples coming from Sao Paulo from that coming from Parana. (author)

  4. Study of the U and Th series in Crassostrea mangle shell

    International Nuclear Information System (INIS)

    Farias, Wellington M.; Damatto, Sandra R.; Silva, Paulo S.C.; Simone, Luiz R.L.; Amaral, Vanessa S.

    2015-01-01

    Foraminifera, corals and mollusks shells have been used as proxies for environmental, paleoenvironmental and climatic change studies in marine system by using elemental and isotopic ratios as recorder of such events. Nevertheless, there is little information available on the U and Th radionuclides decay series applied on those fields. In this sense, the objective of this paper was to evaluate the activity concentrations of the U and Th nuclide decay series in Crassostrea mangle shell samples as a function of the geographic location. Samples from Sao Paulo, Parana, Alagoas, Rio Grande do Norte and Pernambuco states were analyzed by Neutron Activation Analysis and Gross Alpha and Beta Counting. Statistical analysis applied to the obtained results allowed differencing samples coming from Sao Paulo from that coming from Parana. (author)

  5. Effets des sels organiques de tributyletain sur l'huître adulte Crassostrea gigas

    OpenAIRE

    Heral, Maurice; Alzieu, Claude; Caux, O.; Razet, Daniel; Garnier, Jacqueline

    1983-01-01

    La toxicité des composés organostanniques a été mise en évidence à l'égard de l'huître Crassostrea gigas tant aux stades larvaires (His & Robert, 1980) que chez l'adulte (Alzieu & al., 1980, 1981). Parallèlement ces mêmes auteurs ont montré l'accumulation d'étain dans les huîtres contaminées expérimentalement ainsi que le rôle que peut jouer le fluorure de TBT dans la perturbation de la croissance (Héral & al. 1981) et dans la malformation de la coquille des huîtres (Alzieu & al., 1981). Dans...

  6. Rare occurrence of heart lesions in Pacific oysters Crassostrea gigas caused by an unknown bacterial infection.

    Science.gov (United States)

    Meyer, Gary R; Lowe, Geoffrey J; Bower, Susan M

    2017-09-20

    On rare occasions, small cream-coloured cysts have been observed in the heart and pericardial cavity of Pacific oysters Crassostrea gigas from British Columbia, Canada. Histopathology revealed the presence of large colonies of bacteria (up to 800 µm in diameter) causing significant host response and hypertrophy of the heart epithelium. The causative bacteria were characterized as follows: Gram-negative, coccoid to small rod-shaped, typically <1.5 µm in size, cell walls highly endowed with surface fimbriae and division via binary fission. Although these bacteria shared some morphological characteristics with the order Rickettsiales, they did not require an intracellular existence for multiplication. Unfortunately, a cultured isolate was not available, and a retrospective attempt to further characterize the bacteria using DNA sequence analysis of a fragment from the 16S rDNA region proved to be uninformative.

  7. Feeding traits of the European flat oyster, Ostrea edulis, and the invasive Pacific oyster, Crassostrea gigas

    DEFF Research Database (Denmark)

    Nielsen, Mette; Hansen, Benni Winding; Vismann, Bent

    2017-01-01

    Two oysters, the native flat oyster, Ostrea edulis, and the non-indigenous Pacific oyster, Crassostrea gigas, have partially overlapping distributions in European waters. Relatively little is known about particle selection by O. edulis, and the goal of the present study was to establish baselines...... for particle selection by both oyster species under controlled conditions in the laboratory. The study was carried out with adult oysters of similar shell size collected in the Limfjord estuary, Denmark (56°47′N, 08°51′E), in November 2011. The feeding traits of both species [clearance rate (CR), retention...... efficiency (RE) and lower threshold for clearance (LTC)] were compared using five algal species with different cell sizes (5−32 µm ESD) (Isochrysis galbana, Rhodomonas salina, Thalassiosira weissflogii, Prorocentrum micans and Akashiwo sanguinea). Oysters were acclimated to an experimental temperature of 22...

  8. Eastern oyster (Crassostrea virginica) δ15N as a bioindicator of nitrogen sources: Observations and modeling

    International Nuclear Information System (INIS)

    Fertig, B.; Carruthers, T.J.B.; Dennison, W.C.; Fertig, E.J.; Altabet, M.A.

    2010-01-01

    Stable nitrogen isotopes (δ 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 δ 15 N, manipulative fieldwork in Chesapeake Bay and corresponding modeling exercises were conducted. This study (1) determined that five individuals represented an optimal sample size; (2) verified that δ 15 N in oysters from two locations converged after shared deployment to a new location reflecting a change in nitrogen sources; (3) identified required exposure time and temporal integration (four months for muscle, two to three months for gill and mantle); and (4) demonstrated seasonal δ 15 N increases in seston (summer) and oysters (winter). As bioindicators, oysters can be deployed for spatial interpolation of nitrogen sources, even in areas lacking extant populations.

  9. A comparative proteomic study on the effects of metal pollution in oysters Crassostrea hongkongensis.

    Science.gov (United States)

    Xu, Lanlan; Ji, Chenglong; Wu, Huifeng; Tan, Qiaoguo; Wang, Wen-Xiong

    2016-11-15

    The metal pollution has posed great risk on the coastal organisms along the Jiulongjiang Estuary in South China. In this work, two-dimensional electrophoresis-based proteomics was applied to the oysters Crassostrea hongkongensis from metal pollution sites to characterize the proteomic responses to metal pollution. Metal accumulation and proteomic responses indicated that the oysters from BJ site were more severely contaminated than those from FG site. Compared with those oyster samples from the clean site (JZ), metal pollution induced cellular injuries, oxidative and immune stresses in oyster heapatopancreas from both BJ and FG sites via differential metabolic pathways. In addition, metal pollution in BJ site induced disturbance in energy and lipid metabolisms in oysters. Results indicated that cathepsin L and ferritin GF1 might be the biomarkers of As and Fe in oyster C. hongkongensis, respectively. This study demonstrates that proteomics is a useful tool for investigating biological effects induced by metal pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Viral gametocytic hypertrophy of the Pacific oyster Crassostrea gigas in Ireland.

    Science.gov (United States)

    Cheslett, Deborah; McKiernan, Frank; Hickey, Cathy; Collins, Evelyn

    2009-02-25

    Viral gametocytic hypertrophy (VGH) was detected during an investigation of mortalities in Pacific oysters Crassostrea gigas from 2 separate Irish production sites. The basophilic inclusions were observed in the gonad tissue of oysters sampled in August and October 2007. The oysters involved did not show any macroscopic disease signs. Transmission electron microscopy demonstrated the presence of viral particles in these intranuclear inclusions. The particles were small, non-enveloped, icosahedral and approximately 50 nm in diameter, and thus had characteristics similar to the Papillomaviridae and Polyomaviridae families. No host defence reaction was observed. The viral particles described here appear to be similar to those described in C. virginica from the USA and Canada and to those described in C. gigas from Korea and France.

  11. Levantamento de estoques da ostra Crassostrea sp. em bancos naturais no litoral paranaense

    Directory of Open Access Journals (Sweden)

    Euler Batista Erse

    2011-09-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2008v21n2p57 A importância econômica de diversas espécies de ostras nativas, em especial a Crassostrea sp., torna atrativa a exploração desta espécie pelas comunidades litorâneas. A explotação deste recurso natural, baseada somente no extrativismo não sustentável acaba por ameaçar os estoques naturais com a sobrepesca. Baseado neste fato, uma avaliação das condições dos estoques naturais desse animal torna-se importante para futuros projetos de conservação e manejo sustentáveis do recurso. Neste trabalho foram levantados dados referentes aos estoques da ostra Crassostrea sp. de três bancos naturais distintos, sendo estes, um na Ilha da Cotinga, na foz do Rio Maciel e outro na foz do Rio Biguaçú. Em cada banco, foram feitas três amostragens aleatórias durante a maré baixa sizígia utilizando-se de um quadrado de amostragem com dimensão de 30x30 cm. Observamos também neste trabalho que, dos locais de estoques naturais da ostra nativa Cras- sostrea sp. presentes na Baía de Paranaguá, o da Ilha da Cotinga apresenta signifi cativamente os maiores valores quanto ao tamanho se comparados com a o Rio Maciel e o Rio Biguaçú, sendo que, entre os dois últimos, o primeiro apresentou maiores valores. Porém, não houve diferenças signifi cativas nos valores biométricos encontrados entre os bancos amostrados nos respectivos bosques.

  12. Oxygen isotope fluctuations in a modern North Sea oyster (Crassostrea gigas) compared with annual variations in seawater temperature

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz; Wiechert, Uwe; Korte, Christoph

    2010-01-01

    A total of 181 oxygen isotope values from sequential samples of the left shell of a modern Pacific Oyster (Crassostrea gigas) that lived on a sub-tidal oyster bank in the List Basin (North Sea, Germany) shows periodically varying values between + 1.3‰ and -2.5‰. In order to test whether these d18O...... fluctuations reflect seawater temperature changes, the isotope values of the shell were compared to actual seawater temperature variations from the region. C. gigas serves as an excellent proxy for temperature of palaeoseawater and the results show that the examined oyster precipitated its shell in d18O...... equilibrium with the ambient seawater. A cessation of the oyster shell calcification starts at water temperatures below 6 °C, at lower temperatures than previously thought for Crassostrea. For palaeoclimate investigations the termination of shell production is important because the lowest temperatures might...

  13. Elemental composition of Chesapeake Bay oyster Crassostrea virginica in the vicinity of Calvert Cliffs Nuclear Power Plant

    International Nuclear Information System (INIS)

    Gavrilas, M.; Munno, F.J.

    1984-01-01

    The stable element composition of the American oyster Crassostrea virginica collected between June 1978 and August 1983 in the Chesapeake Bay in the vicinity of Calvert Cliffs Nuclear Power Plant was analyzed by neutron activation. The minimum, maximum and the mean values of the elemental concentrations are given. The seasonal effect and the linear correlation between elements entering the oyster composition are shown. 7 references, 1 figure, 4 tables

  14. Spatial distribution in a temperate coastal ecosystem of the wild stock of the farmed oyster Crassostrea gigas (Thunberg)

    OpenAIRE

    Cognie, B; Haure, Joel; Barille, L

    2006-01-01

    The Pacific oyster, Crassostrea gigas, well known throughout the world because of its ability to adapt to a wide range of environmental conditions, was introduced for cultivation into France on a massive scale in the 1970s. With global warming, the reproductive population, confined at the beginning to the south of the French Atlantic coast, became established at more northern latitudes (above 45 degrees 58'N), and wild C gigas began to colonize coastal areas such as our study site, Bourgneuf ...

  15. Isolation of vibrio spp. In oysters (crassostrea rhizophorea) caught in the ‘de la virgen’ swamp

    OpenAIRE

    López Gutiérrez, Lercy; Autor; Manjarrez Pava, Ganiveth; Autor; Herrera Rodríguez, Lilibeth; Autor; Montes Payares, Ana Elena; Autor; Olascuaga Ruíz, Yuranis Paola; Autor; Ortega Quiroz, Rolando José; Autor

    2015-01-01

    Objective:  To establish contamination by Vibrio in oysters (Crassostrea rhizophorae) caught in De La Virgen Swamp, in order to alert entities in charge or protecting consumer health in Cartagena city. Methods: Between February and April 2006, 67 oysters from 5 strategic sites along De La Virgen Swamp, were analyzed. Insulation and identification of Vibrio was performed through a culture and biochemical tests.Results.  Predominant species were V. alginolyticus (23%),V fluvialis  (20%),V. para...

  16. Effects of storage on microbial loads of two commercially important shellfish species, Crassostrea virginica and Mercenaria campechiensis.

    OpenAIRE

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-01-01

    The effects of storage on the microbial load in two commercially important species of shellfish were examined. Oysters (Crassostrea virginica) were stored as shellstock, shucked meats, and fully processed meats at four temperatures for up to 21 days, and clams (Mercenaria campechiensis) were stored only as shellstock. The concentrations of most microbiological groups of organisms increased with the duration and temperature of storage in both shellfish species, although the increases were sign...

  17. Essais de decontamination des huitres Crassostrea gigas en bassin par renouvellement et circulation de l''eau

    OpenAIRE

    Faury, Nicole; Masson, Daniel; Ratiskol, Jacqueline

    1992-01-01

    The germs decreasing of artificially contaminated oysters Crassostrea gigas has been studied in experimental tanks similar to a shellfish depuration plant, without any chemical or physical water treatment. The oyster were treated by three different water management pattern, compared to a control tank and the germs decreasing studied by MPN method of fecal Coliforms and Streptococus. As a result: 1) it appaears somewhat difficult to conclude in this first attempt about the most efficient treat...

  18. Les phénoloxydases chez l’huître creuse Crassostrea gigas : biomarqueurs potentiels de stress environnemental

    OpenAIRE

    Luna Acosta , Andrea

    2010-01-01

    The Pacific oyster Crassostrea gigas is the leading aquaculture product at the worldwide level. However, massive summer mortalities affect dramatically cultivated and natural oyster populations, especially at young life stages. These events could be linked to an unbalance between the different actors of the triad host – pathogen agent – environment, which could favour a weakening of defence mechanisms in the host, and consequently, the emergence and/or increase of diseases. Among environmenta...

  19. Molecular taxonomy of cupped oysters (Crassostrea, Saccostrea, and Striostrea) in Thailand based on COI, 16S, and 18S rDNA polymorphism.

    Science.gov (United States)

    Klinbunga, S; Khamnamtong, B; Puanglarp, N; Jarayabhand, P; Yoosukh, W; Menasveta, P

    2005-01-01

    Genetic diversity of oysters Crassostrea belcheri (Sowerby, 1871), C. iredalei (Faustino, 1932), Saccostrea cucullata (Born, 1778), S. forskali (Gmelin, 1791), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819) (Ostreoida, Mollusca) was analyzed by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) of 16S ribosomal DNA with AcsI, AluI, DdeI, DraI, RsaI, and TaqI, 18S ribosomal DNA with HinfI, and cytochrome oxidase subunit I with AcsI, DdeI and MboI. A total of 54 composite haplotypes were observed. Species-diagnostic markers were specifically found in C. belcheri, C. iredalei, and S. cucullata, but not in S. forskali and Striostrea mytiloides, which shared common composite haplotypes. Neighbor-joining trees constructed from genetic distances between pairs of composite haplotypes and species indicated large genetic differences between Crassostrea and Saccostrea (including Striostrea mytiloides), but closer relationships were observed within each genus. Four groups of unidentified oysters (Crassostrea sp. and Saccostrea sp. groups 1, 2, and 3) were also genetically analyzed. Fixed RFLP markers were found in Crassostrea sp. and Saccostrea sp. group 2, but not in Saccostrea sp. groups 1 and 3. Phylogenetic and genetic heterogeneity analyses indicated that Crassostrea sp. and Saccostrea sp. group 2 should be considered as newly unidentified oyster species in Thailand.

  20. Proximate composition and fatty acid content of the mangrove oyster Crassostrea rhizophorae along the year seasons

    Directory of Open Access Journals (Sweden)

    Ricardo Cavalcanti Martino

    2004-11-01

    Full Text Available Mangrove oysters, Crassostrea rhizophorae were collected at the mangrove of "Barra de Guaratiba" district, Rio de Janeiro, Brazil, with the aim to determine the proximate composition and fatty acid content. Along the year seasons no statistical (P>0.05 difference was observed in the values of moisture, crude protein, crude lipid and ash. They were 82.0%; 9.7%; 1.7%; 3.2%, in average, respectively. However, glycogen was significantly (PCom o objetivo de determinar a composição centesimal e de ácidos graxos da ostra de mangue Crassostrea rhizophorae, amostras foram coletadas durante um ano no manguezal localizado na Barra de Guaratiba, na cidade do Rio de Janeiro, Brasil. Nenhuma diferença estatística (P>0,05 foi observada para os valores de umidade, proteína bruta, lipídio bruto e cinza, que foram em média: 82%; 9,7%; 1,7% e 3,2%, respectivamente. Por outro lado, os valores encontrados para o glicogênio foram significativamente diferentes (P<0,05 para as amostras de primavera (4,4% e inverno (4,2% do que para as amostras de verão (2,7% e outono (2,9%. Os ácidos graxos saturados e poliinsaturados foram respectivamente, os principais grupos de ácidos graxos das ostras, sendo que o ácido palmítico (16:0 foi o ácido graxo mais abundante em todos as amostras de ostras coletadas. O presente estudo demonstrou que esta espécie é caracterizada tanto por uma baixa concentração de lipídios (< 2,0% como também, por uma elevada concentração dos ácidos eicosapentaenóico (20:5n-3, EPA e docosahexaenóico (22:6n-3, DHA. Portanto, baseado no presente resultado é possível concluir que em termos de lipídios e de ácidos graxos a composição nutricional da C.rhizophorae é recomendável para o consumo humano.

  1. Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

    Energy Technology Data Exchange (ETDEWEB)

    Queiroga, Fernando Ramos [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Marques-Santos, Luis Fernando [Laboratório de Biologia Celular e do Desenvolvimento (LABID), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Hégaret, Hélène [Laboratoire des Sciences de l' Environnement Marin (LEMAR), UMR 6539 CNRS UBO IRD IFREMER, Institut Universitaire Européen de la Mer, Technopôle Brest-Iroise, 29280, Plouzané (France); Sassi, Roberto [Laboratório de Ambientes Recifais e Biotecnologia de Microalgas (LARBIM), Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); Farias, Natanael Dantas; Santana, Lucas Nunes [Laboratório de Imunologia e Patologia de Invertebrados (LABIPI), Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58051-900, João Pessoa, Paraíba (Brazil); and others

    2017-06-15

    Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

  2. Transcriptional changes in oysters Crassostrea brasiliana exposed to phenanthrene at different salinities

    International Nuclear Information System (INIS)

    Zacchi, Flávia Lucena; Lima, Daína; Flores-Nunes, Fabrício de; Mattos, Jacó Joaquim; Lüchmann, Karim Hahn; Araújo de Miranda Gomes, Carlos Henrique; Bícego, Márcia Caruso; Taniguchi, Satie; Sasaki, Silvio Tarou; Dias Bainy, Afonso Celso

    2017-01-01

    Highlights: • Salinity effect on Crassostrea brasiliana exposed to phenanthrene. • Higher transcription of biotransformation genes under hyposmotic condition. • Elevated transcription of oxidative stress-related genes under hyposmotic condition. • Amino acid metabolism-related genes changes according to salinity. • Phenanthrene does not affect amino acid metabolism-related genes. - Abstract: Euryhaline animals from estuaries, such as the oyster Crassostrea brasiliana, show physiological mechanisms of adaptation to tolerate salinity changes. These ecosystems receive constant input of xenobiotics from urban areas, including polycyclic aromatic hydrocarbons (PAHs), such as phenanthrene (PHE). In order to understand the influence of salinity on the molecular responses of C. brasiliana exposed to PHE, oysters were acclimatized to different salinities (35, 25 and 10) for 15 days and then exposed to 100 μg L"−"1 PHE for 24 h and 96 h. Control groups were kept at the same salinities without PHE. Oysters were sampled for chemical analysis and the gills were excised for mRNA quantification by qPCR. Transcript levels of different genes were measured, including some involved in oxidative stress pathways, phases I and II of the xenobiotic biotransformation systems, amino acid metabolism, fatty acid metabolism and aryl hydrocarbon receptor nuclear translocator putative gene. Higher transcript levels of Sulfotransferase-like gene (SULT-like) were observed in oysters exposed to PHE at salinity 10 compared to control (24 h and 96 h); cytochrome P450 isoforms (CYP2AU1, CYP2-like1) were more elevated in oysters exposed for 24 h and CYP2-like2 after 96 h of oysters exposed to PHE at salinity 10 compared to control. These results are probably associated to an enhanced Phase I biotransformation activity required for PHE detoxification under hyposmotic stress. Higher transcript levels of CAT-like, SOD-like, GSTm-like (96 h) and GSTΩ-like (24 h) in oysters kept at salinity

  3. Effects of cyanobacteria Synechocystis spp. in the host-parasite model Crassostrea gasar–Perkinsus marinus

    International Nuclear Information System (INIS)

    Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; Hégaret, Hélène; Sassi, Roberto; Farias, Natanael Dantas; Santana, Lucas Nunes

    2017-01-01

    Highlights: • Synechocystis cyanobacteria cause functional weakness of oysters haemocytes. • Synechocystis cyanobacteria cause a strengthening of Perkinsus marinus. • Synechocystis cyanobacteria may contribute to an imbalance of P. marinus–Crassostrea gasar relationship. - Abstract: Perkinsosis is a disease caused by protozoan parasites from the Perkinsus genus. In Brazil, two species, P. beihaiensis and P. marinus, are frequently found infecting native oysters (Crassostrea gasar and C. rhizophorae) from cultured and wild populations in several states of the Northeast region. The impacts of this disease in bivalves from Brazil, as well as the interactions with environmental factors, are poorly studied. In the present work, we evaluated the in vitro effects of the cyanobacteria Synechocystis spp. on trophozoites of P. marinus and haemocytes of C. gasar. Four cyanobacteria strains isolated from the Northeast Brazilian coast were used as whole cultures (WCs) and extracellular products (ECPs). Trophozoites of P. marinus were exposed for short (4 h) and long (48 h and 7 days, the latter only for ECPs) periods, while haemocytes were exposed for a short period (4 h). Cellular and immune parameters, i.e. cell viability, cell count, reactive oxygen species production (ROS) and phagocytosis of inert (latex beads) and biological particles (zymosan and trophozoites of P. marinus) were measured by flow cytometry. The viability of P. marinus trophozoites was improved in response to WCs of Synechocystis spp., which could be a beneficial effect of the cyanobacteria providing nutrients and reducing reactive oxygen species. Long-term exposure of trophozoites to ECPs of cyanobacteria did not modify in vitro cell proliferation nor viability. In contrast, C. gasar haemocytes showed a reduction in cell viability when exposed to WCs, but not to ECPs. However, ROS production was not altered. Haemocyte ability to engulf latex particles was reduced when exposed mainly to ECPs of

  4. Nervous system development in the Pacific oyster, Crassostrea gigas (Mollusca: Bivalvia).

    Science.gov (United States)

    Yurchenko, Olga V; Skiteva, Olga I; Voronezhskaya, Elena E; Dyachuk, Vyacheslav A

    2018-01-01

    Bivalves comprise a large, highly diverse taxon of invertebrate species. Developmental studies of neurogenesis among species of Bivalvia are limited. Due to a lack of neurogenesis information, it is difficult to infer a ground pattern for Bivalvia. To provide more comprehensive morphogenetic data on bivalve molluscs and relationships among molluscan clades, we investigated neurogenesis in the Pacific oyster, Crassostrea gigas , from the appearance of the first sensory cells to the formation of the larval ganglionic nervous system by co-immunocytochemistry of the neuronal markers FMRFamide or 5-HT and vesicular acetylcholine transporter (VAChT). Neurogenesis begins with the emergence of the apical serotonin-immunoreactive (5-HT-ir) sensory cells and paired sensory posttrochal dorsal and ventral FMRFamide-immunoreactive (FMRFamide-ir) cells at the early trochophore stage. Later, at the early veliger stage, the apical organ (AO) includes 5-HT-ir, FMRFamide-ir, and VAChT-ir cells. At the same stage, VAChT-ir cells appear in the posterior region of larvae and send axons towards the AO. Thus, FMRFamide-ir neurites and VAChT-ir processes form scaffolds for longitudinal neurite bundles develop into the paired ventral nerve cords (VNC). Later-appearing axons from the AO/CG neurons join the neurite bundles comprising the VNC. All larval ganglia appear along the VNC as paired or fused (epiathroid) clusters in late veliger and pediveliger larvae. We observed the transformation of the AO into the cerebral ganglia, which abundantly innervated the velum, and the transformation of ventral neurons into the pedal ganglia, innervating the foot, gills, and anterior adductor muscle. The visceral ganglia appear last in the pediveliger oyster and innervate the visceral mass and posterior adductor of premetamorphic larvae. In addition, a local FMRFamide-ir network was detected in the digestive system of pediveliger larvae. We identified VAChT-ir nervous elements in oyster larvae, which

  5. High mobility group protein DSP1 negatively regulates HSP70 transcription in Crassostrea hongkongensis

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zongyu; Xu, Delin; Cui, Miao; Zhang, Qizhong, E-mail: zhangqzdr@126.com

    2016-06-10

    HSP70 acts mostly as a molecular chaperone and plays important roles in facilitating the folding of nascent peptides as well as the refolding or degradation of the denatured proteins. Under stressed conditions, the expression level of HSP70 is upregulated significantly and rapidly, as is known to be achieved by various regulatory factors controlling the transcriptional level. In this study, a high mobility group protein DSP1 was identified by DNA-affinity purification from the nuclear extracts of Crassostrea hongkongensis using the ChHSP70 promoter as a bait. The specific interaction between the prokaryotically expressed ChDSP1 and the FITC-labeled ChHSP70 promoter was confirmed by EMSA analysis. ChDSP1 was shown to negatively regulate ChHSP70 promoter expression by Luciferase Reporter Assay in the heterologous HEK293T cells. Both ChHSP70 and ChDSP1 transcriptions were induced by either thermal or CdCl{sub 2} stress, while the accumulated expression peaks of ChDSP1 were always slightly delayed when compared with that of ChHSP70. This indicates that ChDSP1 is involved, very likely to exert its suppressive role, in the recovery of the ChHSP70 expression from the induced level to its original state. This study is the first to report negative regulator of HSP70 gene transcription, and provides novel insights into the mechanisms controlling heat shock protein expression. -- Highlights: •HMG protein ChDSP1 shows affinity to ChHSP70 promoter in Crassostrea hongkongensis. •ChDSP1 negatively regulates ChHSP70 transcription. •ChHSP70 and ChDSP1 transcriptions were coordinately induced by thermal/Cd stress. •ChDSP1 may contribute to the recovery of the induced ChHSP70 to its original state. •This is the first report regarding negative regulator of HSP70 transcription.

  6. Transcriptional changes in oysters Crassostrea brasiliana exposed to phenanthrene at different salinities

    Energy Technology Data Exchange (ETDEWEB)

    Zacchi, Flávia Lucena; Lima, Daína; Flores-Nunes, Fabrício de [Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry − LABCAI, Federal University Santa Catarina, Florianópolis (Brazil); Mattos, Jacó Joaquim [Aquaculture Pathology Research Center – NEPAQ, Federal University of Santa Catarina, Florianópolis (Brazil); Lüchmann, Karim Hahn [Laboratory of Biochemistry and Molecular Biology – LBBM, Fishery Engineering Department, Santa Catarina State University, Laguna (Brazil); Araújo de Miranda Gomes, Carlos Henrique [Laboratory of Marine Mollusks – LMM, Federal University of Santa Catarina, Florianópolis (Brazil); Bícego, Márcia Caruso; Taniguchi, Satie; Sasaki, Silvio Tarou [Laboratory of Marine Organic Chemistry – LABQOM, Oceanographic Institute, University of São Paulo, São Paulo (Brazil); Dias Bainy, Afonso Celso, E-mail: afonso.bainy@ufsc.br [Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry − LABCAI, Federal University Santa Catarina, Florianópolis (Brazil)

    2017-02-15

    Highlights: • Salinity effect on Crassostrea brasiliana exposed to phenanthrene. • Higher transcription of biotransformation genes under hyposmotic condition. • Elevated transcription of oxidative stress-related genes under hyposmotic condition. • Amino acid metabolism-related genes changes according to salinity. • Phenanthrene does not affect amino acid metabolism-related genes. - Abstract: Euryhaline animals from estuaries, such as the oyster Crassostrea brasiliana, show physiological mechanisms of adaptation to tolerate salinity changes. These ecosystems receive constant input of xenobiotics from urban areas, including polycyclic aromatic hydrocarbons (PAHs), such as phenanthrene (PHE). In order to understand the influence of salinity on the molecular responses of C. brasiliana exposed to PHE, oysters were acclimatized to different salinities (35, 25 and 10) for 15 days and then exposed to 100 μg L{sup −1} PHE for 24 h and 96 h. Control groups were kept at the same salinities without PHE. Oysters were sampled for chemical analysis and the gills were excised for mRNA quantification by qPCR. Transcript levels of different genes were measured, including some involved in oxidative stress pathways, phases I and II of the xenobiotic biotransformation systems, amino acid metabolism, fatty acid metabolism and aryl hydrocarbon receptor nuclear translocator putative gene. Higher transcript levels of Sulfotransferase-like gene (SULT-like) were observed in oysters exposed to PHE at salinity 10 compared to control (24 h and 96 h); cytochrome P450 isoforms (CYP2AU1, CYP2-like1) were more elevated in oysters exposed for 24 h and CYP2-like2 after 96 h of oysters exposed to PHE at salinity 10 compared to control. These results are probably associated to an enhanced Phase I biotransformation activity required for PHE detoxification under hyposmotic stress. Higher transcript levels of CAT-like, SOD-like, GSTm-like (96 h) and GSTΩ-like (24 h) in oysters kept at

  7. Patrones de colonización y ecología de poblaciones de dos bivalvos invasores (mejillón cebra Dreissena polymorpha Pallas, 1771 y almeja asiática Corbicula fluminea Müller, 1774 en un tramo lótico del Ebro medio (Castejón, Navarra.

    Directory of Open Access Journals (Sweden)

    MORALES, J., FLECHOSO, F., LIZANA, M., NEGRO, A.

    2013-01-01

    Full Text Available Los bivalvos dulceacuícolas son un componente importante de la ecología fluvial, fundamentalmente por el papel que desempeñan como organismos filtradores y de remoción del sedimento. Además son un grupo zoológico diverso y amenazado a escala global, en el que se incluyen algunas de las especies invasoras más dañinas. El estudio de sus poblaciones es imprescindible para conocer el estado de conservación de las comunidades bentónicas. Para esto se prospectaron 17 parcelas vadeables y 7 escolleras a lo largo de 7,38 km de meandros del río Ebro en Castejón (Navarra, tanto el cauce principal como en brazos secundarios de corriente permanente y/o temporal. El mejillón cebra Dreissena polymorpha Pallas, 1771 se encontró en 7 escolleras y 6 parcelas. El sustrato preferente fueron rocas (85%, donde la densidad resultó 0,31-5,45 mejillones/m2; el 2,6% se hallaron sobre plásticos agrícolas abandonados. En las escolleras sólo el 3,6% de los ejemplares eran juveniles y un 33% tenían una edad > 4 años. La almeja asiática Corbicula fluminea Müller, 1774 se encontró en todas las parcelas. La densidad resultó muy diferente en los tres tipos de ambientes fluviales con valores máximos de 15.100 almejas/m2, lo que constituye un nuevo máximo fluvial en Europa. Se encontraron subpoblaciones de almeja asiática con diferentes estructuras de edad según los ambientes fluviales, además de poblaciones menos numerosas en el brazo principal del río que en los otros tipos. Los resultados muestran que junto a estas especies alóctonas en expansión, con altas tasas de reclutamiento, se encuentra una estructura poblacional muy precaria para las autóctonas, de las cuales únicamente se localizaron 12 náyades vivas y ningún esférido.

  8. Parental diuron-exposure alters offspring transcriptome and fitness in Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Bachère, Evelyne; Barranger, Audrey; Bruno, Roman; Rouxel, Julien; Menard, Dominique; Piquemal, David; Akcha, Farida

    2017-08-01

    One of the primary challenges in ecotoxicology is to contribute to the assessment of the ecological status of ecosystems. In this study, we used Pacific oyster Crassostrea gigas to explore the effects of a parental exposure to diuron, a herbicide frequently detected in marine coastal environments. The present toxicogenomic study provides evidence that exposure of oyster genitors to diuron during gametogenesis results in changes in offspring, namely, transcriptomic profile alterations, increased global DNA methylation levels and reduced growth and survival within the first year of life. Importantly, we highlighted the limitations to identify particular genes or gene expression signatures that could serve as biomarkers for parental herbicide-exposure and further for multigenerational and transgenerational effects of specific chemical stressors. By analyzing samples from two independent experiments, we demonstrated that, due to complex confounding effects with both tested solvent vehicles, diuron non-specifically affected the offspring transcriptome. These original results question the potential development of predictive genomic tools for detecting specific indirect impacts of contaminants in environmental risk assessments. However, our results indicate that chronic environmental exposure to diuron over several generations may have significant long term impacts on oyster populations with adverse health outcomes. Copyright © 2017. Published by Elsevier Inc.

  9. Changes in the microbiological quality of mangrove oysters (Crassostrea brasiliana) during different storage conditions.

    Science.gov (United States)

    Montanhini, Maike Taís Maziero; Montanhini Neto, Roberto

    2015-01-01

    This study aimed to determine the effect of temperature and period of postharvest storage on the microbiological quality and shelf life of raw mangrove oysters, Crassostrea brasiliana. A total of 150 dozen oysters were collected directly from the points of extraction or cultivation in southern Brazil, and in the laboratory, they were stored raw at 5, 10, 15, 20, and 25°C for 1, 4, 8, 11, and 15 days. On each of these days, the oysters were subjected to microbiological analyses of aerobic mesophilic count, total coliforms, enterococci, Escherichia coli, Staphylococcus aureus, and Salmonella. None of the tested samples under any storage condition showed contamination levels above those allowed by Brazilian legislation for E. coli, S. aureus, and Salmonella, and there was no change (P > 0.05) in the counts of these microorganisms due to the temperature and/or period of oyster storage. Counts of enterococci and total coliforms showed a tendency to increase (P mangrove oysters remain in safe microbiological conditions for consumption up to 8 days after harvesting, regardless of temperature, and their shelf life may be extended to 15 days if they are stored at temperatures not exceeding 15°C.

  10. Environmental factors responsible for the incidence of antibiotic resistance genes in pristine Crassostrea virginica reefs

    International Nuclear Information System (INIS)

    Barkovskii, Andrei L.; Thomas, Michael; Hurley, Dorset; Teems, Clifford

    2012-01-01

    Highlights: ► Estuary was the major source of antibiotic resistance genes (ARG) for tidal creeks. ► Watersheds were the secondary source of ARG for tidal creeks. ► Watershed contribution corresponded to the degree of its anthropogenic disturbance. ► ARG in tidal creeks were carried by native hosts preferring low termohaline niches. ► ARG incidence was the highest in oysters implying ARG bioaccumulation/proliferation. - Abstract: 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 frequencies and concentrations were observed in oysters. TRG/INT incidences correlated positively (Spearman Rank = 0.88), and negatively correlated (−0.63 to −0.79) with creek salinity, conductivity, dissolved solids, and temperature. Coliform incidence positively correlated with temperature, and not with the TRG/INT incidence. The Altamaha River estuary was the primary TRG/INT source for the reefs with contributions from creek’s watersheds. TRG/INT were carried by non-coliforms with a preference for low-to-temperate thermohaline environments coupled with bioaccumulation by oysters.

  11. Stress tolerance of a subtropical Crassostrea virginica population to the combined effects of temperature and salinity

    Energy Technology Data Exchange (ETDEWEB)

    Heilmayer, Olaf; DiGialleonardo, Julian J.; Qian, Lianfen; Roesijadi, Guritno

    2008-08-10

    The combination of salinity and temperature has synergistic effects on virtually all aspects of the biology of estuarine organisms. Of interest were site-specific characteristics in the response of the eastern oyster, Crassostrea virginica, from the St. Lucie River Estuary to the interactive effects of temperature and salinity. This estuary, one of the largest on the central east coast of Florida, is strongly influenced by anthropogenic modifications due to management needs to control the patterns of freshwater flow in the St. Lucie River watershed. C. virginica is designated a valued ecosystem component for monitoring the health of this estuary. Our approach used a multidimensional response surface design to study the effects of temperature and salinity on sublethal measures of oyster performance: (1) body condition index as an overall indicator of bioenergetic status and (2) the RNA/DNA ratio as a biochemical indicator of cellular stress. The results showed that there was a greater ability to withstand extreme salinity conditions at lower temperatures. However, there were no site-specific attributes that differentiated the response of the St. Lucie Estuary population from populations along the distribution range. Condition index was a less variable response than the RNA/DNA ratio, and the final models for mean condition index and the RNA:DNA ratios explained 77.3% and 35.8% of the respective variances.

  12. Temperature-dependent stress response in oysters, Crassostrea virginica: Pollution reduces temperature tolerance in oysters

    International Nuclear Information System (INIS)

    Lannig, Gisela; Flores, Jason F.; Sokolova, Inna M.

    2006-01-01

    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 deg. C and exposed to 50 μg l -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 but not Cd showed no significant change in condition, survival rate and lipid peroxidation, whereas those exposed to both Cd and temperature stress suffered high mortality accompanied by low condition index and elevated lipid peroxidation. Furthermore, RNA/DNA ratios indicative of protein synthesis rate, and levels of glutathione, which is involved in metal detoxification, increased in Cd-exposed oysters at 20 deg. C but not at 28 deg. C. Implications of the synergism between elevated temperatures and cadmium stress on energy metabolism of oysters are discussed in the light of the potential effects of climate change on oyster populations in polluted areas

  13. Oyster vasa-like gene as a marker of the germline cell development in Crassostrea gigas

    International Nuclear Information System (INIS)

    Fabioux, C.; Huvet, A.; Lelong, C.; Robert, R.; Pouvreau, S.; Daniel, J.Y.; Minguant, C.; Le Pennec, M.

    2004-01-01

    The oyster vasa-like gene was previously demonstrated to be specifically expressed in germline cells of adult oysters Crassostrea gigas. In the present study, this gene was used as a molecular marker to establish the developmental pattern of germline cells during oyster ontogenesis, using whole-mount in situ hybridization and real-time PCR. The Oyvlg transcripts appeared to be localized to the vegetal pole of unfertilized oocytes and maternally transmitted to embryos. At early development, these maternal transcripts were observed to segregate into a single blastomere, from the CD macromere of 2-cell stage to the 4d mesentoblast of blastula. From late blastula stage, the mesentoblast divided into two cell clumps that migrated to both sides of the larvae body and that would correspond to primordial germ cells (PGCs). Based on these results, we postulate that the germline of C. gigas is specified at early development by maternal cytoplasmic determinants including Oyvlg mRNAs, in putative PGCs that would differentiate into germinal stem cells in juvenile oysters

  14. Predatory blue crabs induce stronger nonconsumptive effects in eastern oysters Crassostrea virginica than scavenging blue crabs

    Directory of Open Access Journals (Sweden)

    Avery E. Scherer

    2017-02-01

    Full Text Available By influencing critical prey traits such as foraging or habitat selection, predators can affect entire ecosystems, but the nature of cues that trigger prey reactions to predators are not well understood. Predators may scavenge to supplement their energetic needs and scavenging frequency may vary among individuals within a species due to preferences and prey availability. Yet prey reactions to consumers that are primarily scavengers versus those that are active foragers have not been investigated, even though variation in prey reactions to scavengers or predators might influence cascading nonconsumptive effects in food webs. Oysters Crassostrea virginica react to crab predators by growing stronger shells. We exposed oysters to exudates from crabs fed live oysters or fed aged oyster tissue to simulate scavenging, and to controls without crab cues. Oysters grew stronger shells when exposed to either crab exudate, but their shells were significantly stronger when crabs were fed live oysters. The stronger response to predators than scavengers could be due to inherent differences in diet cues representative of reduced risk in the presence of scavengers or to degradation of conspecific alarm cues in aged treatments, which may mask risk from potential predators subsisting by scavenging.

  15. Role of dissolved and particulate cadmium in the accumulation of cadmium in cultured oysters (Crassostrea gigas)

    Energy Technology Data Exchange (ETDEWEB)

    Lekhi, Priyanka [Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)], E-mail: anka.lekhi@ubc.ca; Cassis, D. [Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Pearce, C.M. [Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7 (Canada); Ebell, N. [Odyssey Shellfish Ltd., Nanoose Bay, BC V0R 9G0 (Canada); Maldonado, M.T. [Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Orians, K.J. [Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)

    2008-04-15

    Pacific oysters (Crassostrea gigas) collected on the coast of British Columbia, Canada have occasionally shown cadmium (Cd) concentrations at or above 2 {mu}g g{sup -1} (wet weight), which has resulted in the loss of some international markets. This study investigated the source and transfer of Cd to oysters by focusing on the role of dissolved and particulate Cd in seawater. Parameters monitored for 1 year at two oyster farm sites on Vancouver Island included: oyster tissue mass and shell length, Cd in oysters, dissolved Cd, particulate Cd, temperature and salinity. Results show that dissolved Cd was the main source of Cd to the oysters and that Cd was mainly concentrated in the gut tissues. A seasonal trend was observed in Cd in oysters, in which levels were lowest during periods of higher temperatures. Results also indicate that the local oceanographic inputs and sediment diagenesis directly affect dissolved Cd and thereby influence the Cd levels in oysters. Particulate matter was not found to be a source of Cd in oysters, and was actually negatively correlated. This was likely due to the uptake of dissolved Cd by phytoplankton and the effect of phytoplankton on oyster tissue mass.

  16. Epizootiology of Perkinsus sp. inCrassostrea gasar oysters in polyculture with shrimps in northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Patricia Mirella da Silva

    2016-03-01

    Full Text Available Abstract Bivalve culture is of considerable economic and social interest in northeastern (NE Brazil. The polyculture is an alternative approach to traditional monoculture for reducing the environmental impact of shrimp farming and improving oyster culture. Perkinsus marinus andPerkinsus olseni were found infecting oysters in NE Brazil and can threaten oyster production. This study evaluatedPerkinsus spp. occurrence in Crassostrea gasar during all production stages. Oyster spats were produced in a hatchery and grown in shrimp ponds in Rio Grande do Norte state.Perkinsus spp. were surveyed by Ray’s fluid thioglycollate medium and confirmed by polymerase chain reaction. Prevalence and intensity of infection were determined in oysters until they reached 7 cm. Results showed that the broodstock was already infected by Perkinsus (60%, but the derived spats were Perkinsus-free. Oyster spats acquired Perkinsus infection when transferred to ponds. The prevalence gradually increased in the seven months following placement in ponds (73%, and then decreased to 17% by the tenth month. The infections were initially mild, but intensity increased at the final growth stage. In conclusion, it is possible to produce Perkinsus-free C. gasar oyster spats from infected broodstock, and their culture in shrimp ponds is feasible.

  17. Behavior of pathogenic bacteria in the oyster, Crassostrea commercialis, during depuration, re-laying, and storage.

    Science.gov (United States)

    Son, N T; Fleet, G H

    1980-12-01

    Oysters (Crassostrea commercials) harvested from major cultivation areas within the state of New South Wales, Australia, were commonly contaminated with low levels of the food-poisoning organisms Bacillus cereus, Clostridium perfringens, and Vibrio parahaemolyticus. Salmonella was found in oysters on only one occasion. These bacteria were cleansed from oysters during oyster purification by re-laying in a non-polluted waterway. Oysters were laboratory contaminated to levels in excess 1,000 cells per g with either B. cereus, C. perfringens, V. parahaemolyticus, Salmonella typhimurium, or S. senftenberg. These species were cleansed from such oysters during purification in a laboratory depuration unit that used ultraviolet light for sterilizing the depuration water. Escherichia coli was also cleansed from oysters under the same re-laying or depuration conditions so that its measurement alone could be used to indicate the cleansing of the above pathogenic species. The levels of these bacteria were also measured during the storage of oysters under conditions that occur during marketing. While B. cereus counts remained relatively stable during storage, the Salmonella spp. gradually decreased in numbers and C. perfringens rapidly died off. V. parahaemolyticus counts increased slightly during the first 4 days of storage, after which decreases occurred.

  18. Genetic diversity and substantial population differentiation in Crassostrea hongkongensis revealed by mitochondrial DNA.

    Science.gov (United States)

    Li, Lu; Wu, Xiangyun; Yu, Ziniu

    2013-09-01

    The Hong Kong oyster, Crassostrea hongkongensis, is an important fisheries resource that is cultivated in the coastal waters of the South China Sea. Despite significant advances in understanding biological and taxonomic aspects of this species, no detailed study of its population genetic diversity in regions of extensive cultivation are available. Direct sequencing of the mtDNA cox1 gene region was used to investigate genetic variation within and between eleven C. hongkongensis populations collected from typical habitats. Sixty-two haplotypes were identified; only haplotype 2 (21.74% of total haplotypes) was shared among all the eleven populations, and most of the observed haplotypes were restricted to individual populations. Both AMOVA and FST analyses revealed significant population structure, and the isolation by distance (IBD) was confirmed. The highest local differentiation was observed between the sample pools from Guangxi versus Guangdong and Fujian, which are separated by a geographic barrier, the Leizhou Peninsula. Current knowledge from seed management suggests that seed transfer from Guangxi province has likely reduced the divergence that somewhat naturally exists between these pools. The findings from the present study could be useful for genetic management and may serve as a baseline by which to monitor future changes in genetic diversity, either due to natural or anthropogenic impacts. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Population genetics of the black scar oyster, Crassostrea iredalei: repercussion of anthropogenic interference.

    Science.gov (United States)

    Zainal Abidin, Danial Hariz; Mustaffa, Suzana; Rahim, Masazurah A; Nair, Devakie M; Naim, Darlina Md; Mohd Nor, Siti Azizah

    2016-01-01

    Mitochondrial cytochrome oxidase subunit I (COI) gene was utilized to assess the population genetics of the commercially important black scar oyster, Crassostrea iredalei among 11 populations throughout the west and east coasts Peninsular Malaysia and Sabah (Malaysian Borneo). Overall, populations of C. iredalei demonstrated low nucleotide diversity π (0.000-0.004) and low-to-high haplotype diversity h (0.000-0.795) levels. Genetic structuring was detected between the Peninsular Malaysia and Sabah populations as revealed by the FST analysis. However, the COI gene analyses showed minimal and non-significant (p > 0.05) population differentiation within the east and west coasts Peninsular Malaysia and Sabah regions. This was attributed to both high larval dispersal along the east and west coasts and human-driven spat translocation between the two coastlines due to C. iredalei cultivation practices. Phylogeographic relationships inferences were also conducted to further support these hypotheses. The neutrality and mismatch distribution analyses suggested that C. iredalei had experienced a/several bottleneck event(s), followed by population expansion. The molecular information obtained from this study could be incorporated in a pragmatic aquaculture management strategy of wild broodstock and the hatchery lines of C. iredalei in Malaysia.

  20. Trojan Horse Strategy for Non-invasive Interference of Clock Gene in the Oyster Crassostrea gigas.

    Science.gov (United States)

    Payton, Laura; Perrigault, Mickael; Bourdineaud, Jean-Paul; Marcel, Anjara; Massabuau, Jean-Charles; Tran, Damien

    2017-08-01

    RNA interference is a powerful method to inhibit specific gene expression. Recently, silencing target genes by feeding has been successfully carried out in nematodes, insects, and small aquatic organisms. A non-invasive feeding-based RNA interference is reported here for the first time in a mollusk bivalve, the pacific oyster Crassostrea gigas. In this Trojan horse strategy, the unicellular alga Heterocapsa triquetra is the food supply used as a vector to feed oysters with Escherichia coli strain HT115 engineered to express the double-stranded RNA targeting gene. To test the efficacy of the method, the Clock gene, a central gene of the circadian clock, was targeted for knockout. Results demonstrated specific and systemic efficiency of the Trojan horse strategy in reducing Clock mRNA abundance. Consequences of Clock disruption were observed in Clock-related genes (Bmal, Tim1, Per, Cry1, Cry2, Rev.-erb, and Ror) and triploid oysters were more sensitive than diploid to the interference. This non-invasive approach shows an involvement of the circadian clock in oyster bioaccumulation of toxins produced by the harmful alga Alexandrium minutum.

  1. A molecular method to detect and identify the native species of southwestern Atlantic Crassostrea (Mollusca: Ostreidae

    Directory of Open Access Journals (Sweden)

    Sandra Ludwig

    2011-08-01

    Full Text Available Among oysters, species of Crassostrea (Sacco, 1897 are the most attractive to aquaculture. In Brazil, the genus is represented by C. rhizophorae (Guilding, 1828 and C. brasiliana (Lamarck, 1819. Because the maturation and breeding technology is not well developed for these species, aquaculturists need a reliable method to decide the correct time to place spat collectors in the field, and to identify both species, which are morphologically similar. In this study a specific Multiplex PCR protocol was developed, using one pair of universal primers from 18S rDNA as a positive control and a pair of specific primers for each target species. The sensitivity and specificity of the protocol was evaluated. It detected C. rhizophorae DNA in low concentrations, and C. brasiliana DNA in even lower concentrations. Further, the Multiplex PCR proved efficient in detecting DNA in concentrations equivalent to that of a single larva of each species, either separated or combined, when mixed with total DNA extract of a plankton sample representing 1000 L of filtered water. Field tests confirmed the applicability of the protocol, which holds the promise to become an important tool for aquaculture or conservation programs, allowing for the continuous monitoring of the life cycle of C. brasiliana and C. rhizophorae, by detecting the right periods of larval release and settlement.

  2. New insights from the oyster Crassostrea rhizophorae on bivalve circulating hemocytes.

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    Mauro de Freitas Rebelo

    Full Text Available Hemocytes are the first line of defense of the immune system in invertebrates, but despite their important role and enormous potential for the study of gene-environment relationships, research has been impeded by a lack of consensus on their classification. Here we used flow cytometry combined with histological procedures, histochemical reactions and transmission electron microscopy to characterize the hemocytes from the oyster Crassostrea rhizophorae. Transmission electron microscopy revealed remarkable morphological characteristics, such as the presence of membranous cisternae in all mature cells, regardless of size and granulation. Some granular cells contained many cytoplasmic granules that communicated with each other through a network of channels, a feature never previously described for hemocytes. The positive reactions for esterase and acid phosphatase also indicated the presence of mature cells of all sizes and granule contents. Flow cytometry revealed a clear separation in complexity between agranular and granular populations, which could not be differentiated by size, with cells ranging from 2.5 to 25 µm. Based on this evidence we suggest that, at least in C. rhizophorae, the different subpopulations of hemocytes may in reality be different stages of one type of cell, which accumulates granules and loses complexity (with no reduction in size as it degranulates in the event of an environmental challenge.

  3. Perkinsus sp. infecting the oyster Crassostrea rhizophorae from estuaries of the septentrional Northeast, Brazil

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    M. P. Dantas-Neto

    Full Text Available Abstract The mangrove oyster Crassostrea rhizophorae is an estuarine resource exploited by riverside communities in Northeast Brazil. Despite its socioeconomic importance, studies on the health status of this bivalve are scanty in this region. The purpose of the present study was to investigate the presence of the protozoan Perkinsus sp. in C. rhizophorae collected in August and September 2011 in three estuaries of the septentrional Northeast, Brazil: Jaguaribe (Ceará, Camurupim (Piauí and Carnaubeiras (Maranhão (n= 150 specimens/site. The samples were submitted to Ray’s fluid thioglycollate medium (RFTM, PCR and histology assays. The RFTM assay revealed spherical, blue or bluish-black hypnospores of the genus Perkinsus in 50 specimens (Jaguaribe= 17.3%, Camurupim= 5.3%, Carnaubeiras= 10.6%. The intensity of the infection ranged from very light (1-10 cells per slide to severe (more than 40 cells in each of 10 fields of the slide for Jaguaribe; very light for Camurupim and very light to moderate (at least 40 cells observed in each of 10 fields of the slide for Carnaubeiras. When submitted to confirmatory PCR analysis, 6 cases were confirmed (Jaguaribe=3, Camurupim=1, Carnaubeiras=2. The histology confirmed 21 cases of infection in specimens from the three estuaries. Although local collectors have reported no mortality in oyster populations that might be attributed to infection by Perkinsus, health surveillance of oyster populations in the septentrional region of Northeast Brazil is advisable.

  4. Uniquely high turnover of nickel in contaminated oysters Crassostrea hongkongensis: Biokinetics and subcellular distribution.

    Science.gov (United States)

    Yin, Qijun; Wang, Wen-Xiong

    2018-01-01

    Despite the environmental concerns regarding nickel (Ni) especially in China, it has received little attention in aquatic animals due to its comparatively weak toxicity. In the present study, we explored the bioaccumulation, biokinetics, and subcellular distribution of Ni in an estuarine oyster Crassostrea hongkongensis. We demonstrated that Ni represented a new pattern of bioaccumulation in oysters characterized by rapid elimination and low dissolved uptake. The waterborne uptake rate constant and dietary assimilation efficiency were 0.036L/g/h and 28%, respectively, and dissolved uptake was the predominant exposure route. The efflux rate constant was positively related to tissue Ni concentration, with the highest efflux of 0.155d -1 . Such high elimination resulted in a high Ni turnover and steady-state condition reached rapidly, as shown with a 4-week waterborne exposure experiment at different Ni concentrations. Ni in oysters was mainly sequestered in metallothionein-like protein (MTLP), metal-rich granule, and cellular debris. MTLP was the most important binding fraction during accumulation and depuration, and played a dynamic role leading to rapid Ni elimination. Pre-exposure to Ni significantly reduced the dissolved uptake, probably accompanied by depressed filtration activity. Overall, the high turnover and regulation of Ni in oysters were achieved by enhanced efflux, suppressed uptake, and sequestration of most Ni into the detoxified pool. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Role of bacteria in bioaccumulation of mercury in the oyster Crassostrea virginica

    International Nuclear Information System (INIS)

    Sayler, G.S.; Nelson, J.D. Jr.; Colwell, R.R.

    1975-01-01

    An investigation of mercury-resistant bacteria was undertaken to determine their role in the accumulation of mercury in a simplified food chain. Oysters (Crassostrea virginica) were maintained in a closed system, sealed aquarium with stirred, aerated water containing 10 μg of 203 HgCl 2 per liter. Uptake of 203 Hg by oysters held under control conditions was compared with that of 203 Hg uptake by oysters under similar conditions except that mercury-accumulating and mercury-metabolizing species of Pseudomonsa, isolated from Chesapeake Bay, were added to the experimental oysters. After incubation for 4 days, the major portion of the 203 Hg in the water column was found to be associated with the microparticulate fraction, corresponding to a rise in total viable count. Mercury accumulation in the oysters was significantly higher in the gill and fisceral tissue than other tissues. Mercury concentrations were 200 times greater in tissue fractions of oysters dosed with mercury-metabolizing bacteria compared with the oysters held under control conditions without mercury-metabolizing bacteria. (U.S.)

  6. Parasites infecting the cultured oyster Crassostrea gasar (Adanson, 1757) in Northeast Brazil.

    Science.gov (United States)

    Queiroga, Fernando Ramos; Vianna, Rogério Tubino; Vieira, Cairé Barreto; Farias, Natanael Dantas; Da Silva, Patricia Mirella

    2015-05-01

    The oyster Crassostrea gasar is a species widely used as food and a source of income for the local population of the estuaries of Northeast Brazil. Perkinsus marinus and Perkinsus olseni are deleterious parasites for oyster farming and were recently detected in Brazil. In this study, a histopathologic survey of the oyster C. gasar cultured in the estuary of the River Mamanguape (Paraíba State) was performed. Adult oysters were collected in December 2011 and March, May, August and October 2012 and processed for histology and Perkinsus sp. identification by molecular analyses. Histopathological analysis revealed the presence of parasitic organisms including viral gametocytic hypertrophy, prokaryote-like colonies, protozoans (Perkinsus sp. and Nematopsis sp.) and metazoans (Tylocephalum sp. and cestodes). Other commensal organisms were also detected (the protozoan Ancistrocoma sp. and the turbellarian Urastoma sp.). The protozoan parasite Perkinsus sp. had the highest overall prevalence among the symbiotic organisms studied (48.9%), followed by Nematopsis sp. (36.3%). The other organisms were only sporadically observed. Only the protozoan Perkinsus sp. caused alterations in the oysters' infected organs. Molecular analyses confirmed the presence of P. marinus, P. olseni and Perkinsus beihaiensis infecting the oyster C. gasar. This is the first report of P. beihaiensis in this oyster species.

  7. Growth of Crassostrea gasar cultured in marine and estuary environments in Brazilian waters

    Directory of Open Access Journals (Sweden)

    Gustavo Ruschel Lopes

    2013-08-01

    Full Text Available The objective of this work was to evaluate the growth of the mangrove oyster Crassostrea gasar cultured in marine and estuarine environments. Oysters were cultured for 11 months in a longline system in two study sites - São Francisco do Sul and Florianópolis -, in the state of Santa Catarina, Southern Brazil. Water chlorophyll-α concentration, temperature, and salinity were measured weekly. The oysters were measured monthly (shell size and weight gain to assess growth. At the end of the culture period, the average wet flesh weight, dry flesh weight, and shell weight were determined, as well as the distribution of oysters per size class. Six nonlinear models (logistic, exponential, Gompertz, Brody, Richards, and Von Bertalanffy were adjusted to the oyster growth data set. Final mean shell sizes were higher in São Francisco do Sul than in Florianópolis. In addition, oysters cultured in São Francisco do Sul were more uniformly distributed in the four size classes than those cultured in Florianópolis. The highest average values of wet flesh weight and shell weight were observed in São Francisco do Sul, whereas dry flesh weight did not differ between the sites. The estuary environment is more promising for the cultivation of oysters.

  8. Effects of High Hydrostatic Pressure on the Physical, Microbial, and Chemical Attributes of Oysters (Crassostrea virginica).

    Science.gov (United States)

    Lingham, Talaysha; Ye, Mu; Chen, Haiqiang; Chintapenta, Lathadevi Karuna; Handy, Eunice; Zhao, Jing; Wu, Changqing; Ozbay, Gulnihal

    2016-05-01

    The change in the quality attributes (physical, microbial, and chemical) of oysters (Crassostrea virginica) after high hydrostatic pressure (HHP) treatment at 300 MPa at room temperature (RT, 25 °C) 300, 450, and 500 MPa at 0 °C for 2 min and control oysters without treatment were evaluated over 3 wk. The texture and tissue yield percentages of oysters HHP treated at 300 MPa, RT increased significantly (P oysters reached the spoilage point of 7 log CFU/g after 15 d. Coliform counts (log MPN/g) were low during storage with total and fecal coliforms less than 3.5 and 1.0. High pressure treated oysters at 500 MPa at 0 °C were significantly higher (P oysters HHP treated at 300 MPa at 0 °C in lipid oxidation values. The highest pressure (500 MPa) treatment in this study, significantly (P oysters at 3 wk was significantly higher (P oysters [300 MPa, (RT); 450 MPa (0 °C); and 500 MPa (0 °C)]. HHP treatments of oysters were not significantly different in pH, percent salt extractable protein (SEP), and total lipid values compared to control. Based on our results, HHP prolongs the physical, microbial, and chemical quality of oysters. © 2016 Institute of Food Technologists®

  9. Quantitative assessment of viable Cryptosporidium parvum load in commercial oysters (Crassostrea virginica) in the Chesapeake Bay.

    Science.gov (United States)

    Graczyk, Thaddeus K; Lewis, Earl J; Glass, Gregory; Dasilva, Alexandre J; Tamang, Leena; Girouard, Autumn S; Curriero, Frank C

    2007-01-01

    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 parvum oocysts by combined fluorescent in situ hybridization (FISH) and IFA. The mean cumulative numbers of Cryptosporidium sp. oocysts in six oysters (overall, 42.1+/-4.1) were significantly higher than in the numbers of viable C. parvum oocysts (overall, 28.0+/-2.9). Of 265 oyster groups, 221 (83.4%) contained viable C. parvum oocysts, and overall, from 10-32% (mean, 23%) of the total viable oocysts were identified in the hemolymph as distinct from gill washings. The amount of viable C. parvum oocysts was not related to oyster size or to the level of fecal coliforms at the sampling site. This study demonstrated that, although oysters are frequently contaminated with oocysts, the levels of viable oocysts may be too low to cause infection in healthy individuals. FISH assay for identification can be retrospectively applied to properly stored samples.

  10. 108mAg and 110mAg in crassostrea gigas

    International Nuclear Information System (INIS)

    Ishikawa, Y.; Sato, N.; Nakamura, E.; Sekine, T.; Yoshihara, K.

    1992-01-01

    Accumulation of radiosilver 108m Ag and 110m Ag in oysters (Crassostrea gigas) and their behavior in marine environments has been studied in the northeast Pacific coast in Japan. Enrichment of radiosilver in oysters depends on topographical conditions; significant bioaccumulation occurred in open bays, while it was hardly observed in bays with narrow shaped entrances. From these observations difference of the behavior of radiosilver between open and nearly closed bays is suggested. 110m Ag in oysters decayed with an effective half-life of about 150 days for both the Chinese nuclear weapon test and the Chernobyl accident. In contrast to radiosilver, the fission product nuclide 137 Cs was almost independent of topographical conditions, and its concentration was constant. 110m Ag bioaccumulation in oysters after the Chernobyl accident in 1986 was found in both open and nearly closed bays, the lattershowing much lower concentration of radiosilver than the former. Specific activity of 108m Ag in oysters was determined in bays open to the Pacific Oceans. (author) 13 refs.; 4 figs.; 3 tabs

  11. Ostreid herpesvirus type 1 replication and host response in adult Pacific oysters, Crassostrea gigas.

    Science.gov (United States)

    Segarra, Amélie; Baillon, Laury; Tourbiez, Delphine; Benabdelmouna, Abdellah; Faury, Nicole; Bourgougnon, Nathalie; Renault, Tristan

    2014-10-08

    Since 2008, massive mortality outbreaks associated with OsHV-1 detection have been reported in Crassostrea gigas spat and juveniles in several countries. Nevertheless, adult oysters do not demonstrate mortality in the field related to OsHV-1 detection and were thus assumed to be more resistant to viral infection. Determining how virus and adult oyster interact is a major goal in understanding why mortality events are not reported among adult Pacific oysters. Dual transcriptomics of virus-host interactions were explored by real-time PCR in adult oysters after a virus injection. Thirty-nine viral genes and five host genes including MyD88, IFI44, IkB2, IAP and Gly were measured at 0.5, 10, 26, 72 and 144 hours post infection (hpi). No viral RNA among the 39 genes was detected at 144 hpi suggesting the adult oysters are able to inhibit viral replication. Moreover, the IAP gene (oyster gene) shows significant up-regulation in infected adults compared to control adults. This result suggests that over-expression of IAP could be a reaction to OsHV-1 infection, which may induce the apoptotic process. Apoptosis could be a main mechanism involved in disease resistance in adults. Antiviral activity of haemolymph against herpes simplex virus (HSV-1) was not significantly different between infected adults versus control.

  12. Biofiltration, growth and body composition of oyster Crassostrea rhizophorae in effluents from shrimp Litopenaeus vannamei1

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    Rafael Vieira de Azevedo

    Full Text Available The objective of this study was to use oyster as biofilter to improve the quality of effluent from shrimp farming and to assess its growth performance and body composition. It was distributed 1,080 oysters into lanterns in fiberglass tanks (170 L in a completely randomized design with three treatments (0, 60 and 120 oysters and six replicates. It was used the effluent from the sedimentation tank. It was measured weekly: temperature, salinity, dissolved oxygen and pH, and it was analyzed ammonia-N, nitrite-N, nitrate-N, orthophosphate-P, suspended solids and chlorophyll-α of the input effluent. The control tanks (without oysters were more efficient at removing ammonia-N, nitrite-N, nitrate-N and orthophosphate-P. The tanks containing oysters were more efficient at removing suspended solids and chlorophyll-α. Stocking density influenced the height growth of oysters, but not width. Wet and daily weight, condition and yield index were not affected by stocking density, and a significant increase in comparison to the initials values was observed. Body composition was not affected by stocking density, and a significant difference (p0.05. Under the conditions evaluated, the oyster Crassostrea rhizophorae improves water quality and presents growth rates and body composition similar to those obtained in traditional crops.

  13. First characterization of three cyclophilin family proteins in the oyster, Crassostrea ariakensis Gould.

    Science.gov (United States)

    Xu, Ting; Xie, Jiasong; Yang, Shoubao; Ye, Shigen; Luo, Ming; Wu, Xinzhong

    2016-08-01

    Cyclophilins (CyPs) are a family of proteins that bind the immunosuppressive agent cyclosporin A (CsA) with high-affinity and belong to one of the three superfamilies of peptidyl-prolyl cis-trans isomerases (PPIase). In this report, three cyclophilin genes (Ca-CyPs), including Ca-CyPA, Ca-CyPB and Ca-PPIL3, were identified from oyster, Crassostrea ariakensis Gould in which Ca-CyPA encodes a protein with 165 amino acid sequences, Ca-CyPB encodes a protein with 217 amino acid sequences and Ca-PPIL3 encodes a protein with 162 amino acid sequences. All of the three Ca-CyPs genes contain a typical CyP-PPIase domain with its signature sequences and Ca-CyPB contains an N-signal peptide sequences. Tissue distribution study revealed that Ca-CyPs were ubiquitously expressed in all examined tissues and the highest levels were observed in hemocytes. RLO incubation upregulated the mRNA expression levels of Ca-CyPs, indicating that three Ca-CyPs might be involved in oyster immune response against RLO infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. pH controls spermatozoa motility in the Pacific oyster (Crassostrea gigas

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    Myrina Boulais

    2018-03-01

    Full Text Available Investigating the roles of chemical factors stimulating and inhibiting sperm motility is required to understand the mechanisms of spermatozoa movement. In this study, we described the composition of the seminal fluid (osmotic pressure, pH, and ions and investigated the roles of these factors and salinity in initiating spermatozoa movement in the Pacific oyster, Crassostrea gigas. The acidic pH of the gonad (5.82±0.22 maintained sperm in the quiescent stage and initiation of flagellar movement was triggered by a sudden increase of spermatozoa external pH (pHe when released in seawater (SW. At pH 6.4, percentage of motile spermatozoa was three times higher when they were activated in SW containing 30 mM NH4Cl, which alkalinizes internal pH (pHi of spermatozoa, compared to NH4Cl-free SW, revealing the role of pHi in triggering sperm movement. Percentage of motile spermatozoa activated in Na+-free artificial seawater (ASW was highly reduced compared to ASW, suggesting that change of pHi triggering sperm motility was mediated by a Na+/H+ exchanger. Motility and swimming speed were highest in salinities between 33.8 and 42.7‰ (within a range of 0 to 50 ‰, and pH values above 7.5 (within a range of 4.5 to 9.5.

  15. Culture conditions improvement of Crassostrea gigas using a potential probiotic Bacillus sp strain.

    Science.gov (United States)

    Fdhila, Kais; Haddaji, Najla; Chakroun, Ibtissem; Dhiaf, Amel; Macherki, Mohammed Ezz Edine; Khouildi, Bochra; Lamari, Faouzi; Chaieb, Kamel; Abid, Nabil; Marzougui, Hajer; Khouadja, Sadok; Missaoui, Hechmi

    2017-09-01

    It is well demonstrated that some probiotics improve rearing water quality and thereby have beneficial effects on reared organisms. We conducted this study to determine the effect of Bacillus consortium on Crassostrea gigas reared in contemned seawater with indigo dye priory treated with Bacillus or no treated. This effect was studied by assessing hemocytes death using flow cytometry analysis. We found that the percentage of decolorization of indigo dye in polluted seawater in presence of C. gigas increased from 41% to 90% when using Bacillus consortium. In these conditions, the hemocytes mortality of reared C. gigas decreased from 87% to 56%. We have demonstrated also that seawater contemned with priory treated indigo with Bacillus consortium is less toxic than seawater contemned with the no treated indigo. The percentage of hemocytes death is 81% for the contemned seawater with indigo and 56% for no contemned seawater. This consortium shows a protector effect of C. gigas against Vibrio harveyi contemning reared seawater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Role of dissolved and particulate cadmium in the accumulation of cadmium in cultured oysters (Crassostrea gigas)

    International Nuclear Information System (INIS)

    Lekhi, Priyanka; Cassis, D.; Pearce, C.M.; Ebell, N.; Maldonado, M.T.; Orians, K.J.

    2008-01-01

    Pacific oysters (Crassostrea gigas) collected on the coast of British Columbia, Canada have occasionally shown cadmium (Cd) concentrations at or above 2 μg g -1 (wet weight), which has resulted in the loss of some international markets. This study investigated the source and transfer of Cd to oysters by focusing on the role of dissolved and particulate Cd in seawater. Parameters monitored for 1 year at two oyster farm sites on Vancouver Island included: oyster tissue mass and shell length, Cd in oysters, dissolved Cd, particulate Cd, temperature and salinity. Results show that dissolved Cd was the main source of Cd to the oysters and that Cd was mainly concentrated in the gut tissues. A seasonal trend was observed in Cd in oysters, in which levels were lowest during periods of higher temperatures. Results also indicate that the local oceanographic inputs and sediment diagenesis directly affect dissolved Cd and thereby influence the Cd levels in oysters. Particulate matter was not found to be a source of Cd in oysters, and was actually negatively correlated. This was likely due to the uptake of dissolved Cd by phytoplankton and the effect of phytoplankton on oyster tissue mass

  17. Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

    Science.gov (United States)

    Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

    2015-07-01

    A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P0.05), and the quadratic effects of copper ion concentration were significant ( P0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

  18. Effects of cadmium on aneuploidy and hemocyte parameters in the Pacific oyster, Crassostrea gigas

    International Nuclear Information System (INIS)

    Bouilly, Karine; Gagnaire, Beatrice; Bonnard, Marc; Thomas-Guyon, Helene; Renault, Tristan; Miramand, Pierre; Lapegue, Sylvie

    2006-01-01

    Pacific oysters, Crassostrea gigas, are commonly reared in estuaries where they are exposed to anthropogenic pollution. Much research has been made on the toxicity of cadmium to aquatic organisms because the compound recurrently contaminates their environment. Our study examined the influence of cadmium on aneuploidy level (lowered chromosome number in a percentage of somatic cells) and hemocyte parameters in C. gigas at different stages of life. Adults and juveniles were exposed to two different concentrations of cadmium. The first concentration applied was equivalent to a peak value found in Marennes-Oleron bay (Charente-Maritime, France; 50 ng L -1 ) and the second was 10 times higher (500 ng L -1 ). Exposure to 50 ng L -1 cadmium caused a significant decrease in the survival time of C. gigas, but exposure to 500 ng L -1 surprisingly affected the survival time positively. Significant differences in aneuploidy level were observed between the cadmium treatments and the control in adults but not in juveniles or the offspring of the adult groups. The effects of cadmium on hemocyte parameters were analyzed by flow cytometry. Several hemocyte parameters increased significantly after 21 days of cadmium exposure and subsequently decreased. Phenoloxidase-like activity, evaluated by spectrophotometry, varied over the time of the experiment and increased after 66 days of contact with 500 ng L -1 cadmium. Taken together, cadmium at environmentally relevant concentrations seems to have only moderate effects on aneuploidy and hemocyte parameters

  19. Antimicrobial histones and DNA traps in invertebrate immunity: evidences in Crassostrea gigas.

    Science.gov (United States)

    Poirier, Aurore C; Schmitt, Paulina; Rosa, Rafael D; Vanhove, Audrey S; Kieffer-Jaquinod, Sylvie; Rubio, Tristan P; Charrière, Guillaume M; Destoumieux-Garzón, Delphine

    2014-09-05

    Although antimicrobial histones have been isolated from multiple metazoan species, their role in host defense has long remained unanswered. We found here that the hemocytes of the oyster Crassostrea gigas release antimicrobial H1-like and H5-like histones in response to tissue damage and infection. These antimicrobial histones were shown to be associated with extracellular DNA networks released by hemocytes, the circulating immune cells of invertebrates, in response to immune challenge. The hemocyte-released DNA was found to surround and entangle vibrios. This defense mechanism is reminiscent of the neutrophil extracellular traps (ETs) recently described in vertebrates. Importantly, oyster ETs were evidenced in vivo in hemocyte-infiltrated interstitial tissues surrounding wounds, whereas they were absent from tissues of unchallenged oysters. Consistently, antimicrobial histones were found to accumulate in oyster tissues following injury or infection with vibrios. Finally, oyster ET formation was highly dependent on the production of reactive oxygen species by hemocytes. This shows that ET formation relies on common cellular and molecular mechanisms from vertebrates to invertebrates. Altogether, our data reveal that ET formation is a defense mechanism triggered by infection and tissue damage, which is shared by relatively distant species suggesting either evolutionary conservation or convergent evolution within Bilateria. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Identification and Functional Characterization of the Glycogen Synthesis Related Gene Glycogenin in Pacific Oysters (Crassostrea gigas).

    Science.gov (United States)

    Li, Busu; Meng, Jie; Li, Li; Liu, Sheng; Wang, Ting; Zhang, Guofan

    2017-09-06

    High glycogen levels in the Pacific oyster (Crassostrea gigas) contribute to its flavor, quality, and hardiness. Glycogenin (CgGN) is the priming glucosyltransferase that initiates glycogen biosynthesis. We characterized the full sequence and function of C. gigas CgGN. Three CgGN isoforms (CgGN-α, β, and γ) containing alternative exon regions were isolated. CgGN expression varied seasonally in the adductor muscle and gonadal area and was the highest in the adductor muscle. Autoglycosylation of CgGN can interact with glycogen synthase (CgGS) to complete glycogen synthesis. Subcellular localization analysis showed that CgGN isoforms and CgGS were located in the cytoplasm. Additionally, a site-directed mutagenesis experiment revealed that the Tyr200Phe and Tyr202Phe mutations could affect CgGN autoglycosylation. This is the first study of glycogenin function in marine bivalves. These findings will improve our understanding of glycogen synthesis and accumulation mechanisms in mollusks. The data are potentially useful for breeding high-glycogen oysters.

  1. Refining the tethering of American oysters (Crassostrea virginica) to measure the effects of two environmental stressors.

    Science.gov (United States)

    Poirier, Luke A; Gilbert, Shane T C; St-Hilaire, Sophie; Davidson, Jeff; Cox, Ruth; Quijón, Pedro A

    2018-02-01

    Tethering assays, or the physical restraint of test organisms, has been used in the past to measure selected organisms' response to stressors while removing the observer from the experimental setting. Although informative for monitoring and hypothesis testing, these assays often used microfilaments that have been found to be too invasive or prone to biases given their effects on test organisms' behavior. Here, we describe a new variation of tethering using American oysters (Crassostrea virginica) and illustrate its use in the study of their mortality rates as a result of two stressors: siltation and predation by a non-indigenous species. Our protocol identified a resistant (non-toxic) glue that could be used to attach oysters to stone slabs, thus partially mimicking the natural cementation of the shell to natural substrates. This variation of tethering was harmless and maintained oysters' body position and natural ability to filter feed. Using tethered oysters in separate two-week field cage experiments, we also show how siltation and predation by a non-indigenous species (the European green crab, Carcinus maenas), caused a gradual, easily measurable increase in oyster mortality rates. We argue that this variation of tethering is a cost-effective and advantageous way to monitor or test the effects of these and other stressors on oysters and similar species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Viral gametocytic hypertrophy of Crassostrea gigas in France: from occasional records to disease emergence?

    Science.gov (United States)

    Garcia, Céline; Robert, Maeva; Arzul, Isabelle; Chollet, Bruno; Joly, Jean-Pierre; Miossec, Laurence; Comtet, Thierry; Berthe, Franck

    2006-06-23

    Viral gametocytic hypertrophy was reported for the first time in 2001 in Pacific oyster Crassostrea gigas in France. Since this date, the number of reported cases and the distribution area have increased every year; however, the cases are not associated with macroscopic signs or increased mortality rates. Both male and female gametes were hypertrophied and basophilic inclusions were observed in gamete nuclei. Transmission electron microscopy revealed the presence of viral particles in these intranuclear basophilic inclusions. These particles had characteristics similar to those of the Papillomaviridae and Polyoma viridae families: they were small, non-enveloped, icosahedral, and 44 to 56 nm in diameter. The viral particles were found in male, female and hermaphrodite oysters and no significant difference in viral infection was observed between those groups. The frequency of detection and the intensity of infection were low and no host defence reaction was recognised, suggesting that the viral particles had a weak impact on C. gigas. The viral particles described in the present study seem to be similar to these described in C. virginica in the USA and Canada and in C. gigas in Korea, but further studies are required to confirm their identity. The issue of a possible emergence of this infection is discussed.

  3. Radiosensitivity of Salmonella spp and Vibrio parahaemolyticus artificially incorporated by oysters (Crassostrea brasiliana)

    International Nuclear Information System (INIS)

    Jakabi, Miyoko

    2001-01-01

    Irradiation is considered one of the most efficient technological process to reduce the number of microorganisms in food. It can be used to improve the safety of food products as well as their shelf life. Oysters are considered one of the most important vehicle of pathogenic bacteria due to their feeding characteristic and because they are usually ingested raw. The aim of this study was to evaluate the influence of gamma radiation process on high levels of Salmonella Enteritidis, Salmonella Infantis and Vibrio parahaemolyticus incorporated by oysters (Crassostrea brasiliana) as well as on the survival of the animals and sensory attributes. The oysters were submitted to gamma radiation treatment ( 60 Co) with doses ranging from 0.5 kGy to 3.0 kGy. At least four trials were conducted for each serotype. The dose of 3.0 kGy was, generally, sufficient to reduce the level of Salmonella serotypes in 6 log while for V.parahaemolyticus the dose as 1.o kGy. Animals were not killed and sensory attributes were not changed by the highest irradiation dose. Therefore, 3.0 kGy is a dose that is effective on the inactivation of Salmonella spp and V.parahaemolyticus in oysters without changing their odour, flavour and appearance. (author)

  4. Metals concentrations in sediments and oyster Crassostrea gigas from La Pitahaya lagoon, Sinaloa, NW Mexico

    Science.gov (United States)

    Luna Varela, R.; Muñoz Sevilla, N.; Campos Villegas, L.; Rodriguez Espinosa, P.; Gongora Gomez, A.; MP, J.

    2013-05-01

    This present study was performed in a culture of Crassostrea gigas in La Pitahaya, Sinaloa, México. The main objective is to identify the enrichment pattern of trace elements (Cu, Cd, Cr, Ni, Pb, Zn, Hg, As, V) also was determine concentrations thereof in oyster. Four sampling sites were selected, two smaller channels which connect the lagoon directly , the region of culture and connection with the sea ; and each sampling consisted of 4 sample sediments and 50 oysters of commercial size per mounth . Concentrations of trace metals were determined using atomic absorption spectrophotometry (AAS). The higher concentration of elements in certain samples clearly suggests that they are directly fed by the smaller channels which connect the lagoon directly. These small channels often carry the contaminants which are absorbed and deposited in the sediments. The results were also compared with the Effect Range Low (ERL) and Effect Range Medium (ERM) of NOAA and it indicates that Ni is above the ERL values. Cadmium, lead, chrome and copper concentrations exceeded the limits permissible of bivalbe mollusks established by the sanitary regulations

  5. Transmission of the haplosporidian parasite MSX Haplosporidium nelsoni to the eastern oyster Crassostrea virginica in an upweller system.

    Science.gov (United States)

    Sunila, I; Karolus, J; Lang, E P; Mroczka, M E; Volk, J

    2000-08-31

    The haplosporidian oyster parasite MSX (Multinucleated Sphere X) Haplosporidium nelsoni was transmitted to eastern oysters Crassostrea virginica. Hatchery-raised, MSX-free juvenile oysters were placed in upweller tanks. Water to the tanks was filtered through a screen with 1 mm2 openings and originated from the water column overlaying naturally infected oysters beds (MSX prevalence 17 to 57%). MSX was diagnosed by histopathological analysis. MSX-disease (57% prevalence) with increased mortality (19%) was observed 11 wk after the beginning of the exposure and mortality of 80% after 16 wk. The study demonstrates transmission of MSX via water-borne infectious agents capable of passing through a 1 mm filter.

  6. Microbiological quality of oysters (Crassostrea gigas) produced and commercialized in the coastal region of Florianópolis - Brazil

    OpenAIRE

    Pereira,Murilo Anderson; Nunes,Márcia Menezes; Nuernberg,Leonardo; Schulz,Denys; Batista,Cleide Rosana Vieira

    2006-01-01

    Oysters are filter feeders able to ingest particles in suspension that may carry pathogenic microorganisms. In this respect, the consumption of raw oysters can cause foodborne diseases in humans. The aim of the present study was to evaluate the microbiological quality of Crassostrea gigas oysters cultivated and commercialized in the coastal region of Florianópolis, SC, Brazil. The study comprised counts of coliforms at 35ºC and at 45ºC, Escherichia coli and coagulase-positive staphylococci, a...

  7. Observations of Crassostrea virginica cultured in the heated effluent and discharged radionuclides of a nuclear power reactor

    International Nuclear Information System (INIS)

    Price, A.H.; Hess, C.T.; Smith, C.W.

    1976-06-01

    American oysters (Crassostrea virginica) were rafted for 26 months at four sites in the effluent waters near Maine Yankee Nuclear Power Reactor in Montsweag Bay and at a control site in the adjacent Damariscotta River. In an evaluation of the thermal effluent for aquaculture, comparisons are made among the sites of the effects of heated effluent on oyster growth and condition, and the uptake and retention of gamma-ray emitting radionuclides. Growth and uptake of radionuclides were observed to be accelerated at the warmer water sites. Both experimental results and calculations for 58 Co and 54 Mn are presented

  8. Vibrios patogênicos em ostras (Crassostrea rhizophorae servidas em restaurantes no Rio de Janeiro: um alerta para a Saúde Pública Pathogenic Vibrios in oysters (Crassostrea rhizophorae served at restaurants in Rio de Janeiro: a public health warning

    Directory of Open Access Journals (Sweden)

    Christiane Soares Pereira

    2007-06-01

    Full Text Available Avaliaram-se 40 amostras de ostras (Crassostrea rhizophorae servidas in natura em 15 restaurantes da Cidade do Rio de Janeiro, a fim de investigar a presença de Vibrio spp. As amostras de ostras foram analisadas e submetidas a enriquecimento em água peptonada alcalina adicionada de 1 e 3% de NaCl, incubadas a 37°C por 24 horas. Em seguida, os cultivos foram semeados em agar tiossulfato citrato bile sacarose e as colônias suspeitas foram submetidas à caracterização bioquímica. Vibrio parahaemolyticus, Vibrio carchariae, Vibrio alginolyticus e Vibrio vulnificus representaram as principais espécies (> 60% isoladas a partir das ostras in natura.Forty oyster samples (Crassostrea rhizophorae served raw in 15 restaurants in the city of Rio de Janeiro were evaluated in order to investigate the presence of Vibrio spp. The oyster samples were analyzed and subjected to enrichment in alkaline peptone water with the addition of 1 and 3% NaCl and incubated at 37°C for 24 hours. Following this, the cultures were seeded onto thiosulfate citrate bile sucrose agar (TCBS and the suspected colonies were subjected to biochemical characterization. Vibrio parahaemolyticus, Vibrio carchariae, Vibrio alginolyticus and Vibrio vulnificus were the main species (> 60% isolated from raw oysters.

  9. Ostreid herpesvirus OsHV-1 μVar in Pacific oysters Crassostrea gigas (Thunberg 1793) of the Wadden Sea, a UNESCO world heritage site

    NARCIS (Netherlands)

    Gittenberger, A.; Voorbergen-Laarman, M.A.; Engelsma, M.Y.

    2016-01-01

    The Wadden Sea is an extensive wetland area, recognized as UNESCO world heritage site of international importance. Since the mid-1990s, the invasive Pacific oyster Crassostrea gigas (Thunberg 1793) population in the area has grown exponentially, having a distinct impact on the ecosystem. The

  10. Evaluating the performance of selective-bred lines of eastern oysters, Crassostrea virginica, at different locations along the east coast of the United States

    Science.gov (United States)

    Populations of the economically important eastern oyster, Crassostrea virginica have been severely affected in the last few decades by diseases such as Dermo, MSX, SSO, and ROD. As the demand for a fast-growing, disease-resistant oyster increases, so has the need for effective breeding programs that...

  11. INVESTIGATIONS INTO THE EFFECTS OF SEASON AND WATER QUALITY ON OYSTERS (CRASSOSTREA VIRGINICA) AND ASSOCIATED FISH ASSEMBLAGES IN THE CALOOSAHATCHEE RIVER ESTUARY, FLORIDA: IMPLICATIONS OF ALTERED FRESHWATER INFLOW

    Science.gov (United States)

    A suite of biological and ecological responses of a Valued Ecosystem Component species, Crassostrea virginica, was used to investigate ecosystem-wide health effects of watershed alterations in the Caloosahatchee River estuary, Florida. The influence of water quality and season on...

  12. Coexistence of Pacific oyster Crassostrea gigas (Thunberg, 1793) and blue mussels Mytilus edulis Linnaeus, 1758 on a sheltered intertidal bivalve bed?

    DEFF Research Database (Denmark)

    Holm, M.W.; Davids, J.K.; Dolmer, Per

    2016-01-01

    The invasive Pacific oyster, Crassostrea gigas Thunberg, 1793 was introduced in Denmark for aquaculture in the 1970s. Presently, feral populations are found in many parts of the country, with the largest populations established on existing beds of blue mussel, Mytilus edulis Linnaeus, 1758...

  13. Biochemical and volatile organic compound profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea gigas) cultivated in the Eastern Scheldt and Lake Grevelingen, the Netherlands

    NARCIS (Netherlands)

    Houcke, van Jasper; Medina, Isabel; Linssen, Jozef; Luten, Joop

    2016-01-01

    The aim of this study was to evaluate the effect of two important different geographical cultivation areas in the Netherlands (Eastern Scheldt and Lake Grevelingen) on the volatile organic compound (VOC) profile of European flat oyster (Ostrea edulis) and Pacific cupped oyster (Crassostrea

  14. Feeding current characteristics of three morphologically different bivalve suspension feeders, Crassostrea gigas, Mytilus edulis and Cerastoderma edule, in relation to food competition

    NARCIS (Netherlands)

    Troost, K.; Stamhuis, E.J.; van Duren, L.A; Wolff, W.J.

    Introduced Pacific oysters (Crassostrea gigas) have shown rapid expansion in the Oosterschelde estuary, while stocks of native bivalves declined slightly or remained stable. This indicates that they might have an advantage over native bivalve filter feeders. Hence, at the scale of individual

  15. Feeding current characteristics of three morphologically different bivalve suspension feeders, Crassostrea gigas Mytilus edulis and Cerastoderma edule , in relation to food competition

    NARCIS (Netherlands)

    Troost, K.; Stamhuis, E.J.; Duren, L.A.; Wolff, W.

    2009-01-01

    Introduced Pacific oysters (Crassostrea gigas) have shown rapid expansion in the Oosterschelde estuary, while stocks of native bivalves declined slightly or remained stable. This indicates that they might have an advantage over native bivalve filter feeders. Hence, at the scale of individual

  16. First report of Perkinsus beihaiensis in Crassostrea madrasensis from the Indian subcontinent.

    Science.gov (United States)

    Sanil, N K; Suja, G; Lijo, J; Vijayan, K K

    2012-04-26

    Protozoan parasites of the genus Perkinsus are considered important pathogens responsible for mass mortalities in many wild and farmed bivalve populations. The present study was initiated to screen populations of the Indian edible oyster Crassostrea madrasensis, a promising candidate for aquaculture along the Indian coasts, for the presence of Perkinsus spp. The study reports the presence of P. beihaiensis for the first time in C. madrasensis populations from the Indian subcontinent and south Asia. Samples collected from the east and west coasts of India were subjected to Ray's fluid thioglycollate medium (RFTM) culture and histology which indicated the presence of Perkinsus spp. PCR screening of the tissues using specific primers amplified the product specific to the genus Perkinsus. The taxonomic affinities of the parasites were determined by sequencing both internal transcribed spacer (ITS) and actin genes followed by basic local alignment search tool (BLAST) analysis. Analysis based on the ITS sequences showed 98 to 100% identity to Perkinsus spp. (P. beihaiensis and Brazilian Perkinsus sp.). The pairwise genetic distance values and phylogenetic analysis confirmed that 2 of the present samples belonged to the P. beihaiensis clade while the other 4 showed close affinities with the Brazilian Perkinsus sp. clade. The genetic divergence data, close affinity with the Brazilian Perkinsus sp., and co-existence with P. beihaiensis in the same host species in the same habitat show that the remaining 4 samples exhibit some degree of variation from P. beihaiensis. As expected, the sequencing of actin genes did not show any divergence among the samples studied. They probably could be intraspecific variants of P. beihaiensis having a separate lineage in the process of evolution.

  17. Reactive oxygen species in unstimulated hemocytes of the pacific oyster Crassostrea gigas: a mitochondrial involvement.

    Directory of Open Access Journals (Sweden)

    Ludovic Donaghy

    Full Text Available The Pacific oyster Crassostrea gigas is a sessile bivalve mollusc whose homeostasis relies, at least partially, upon cells circulating in hemolymph and referred to as hemocytes. Oyster's hemocytes have been reported to produce reactive oxygen species (ROS, even in absence of stimulation. Although ROS production in bivalve molluscs is mostly studied for its defence involvement, ROS may also be involved in cellular and tissue homeostasis. ROS sources have not yet been described in oyster hemocytes. The objective of the present work was to characterize the ROS sources in unstimulated hemocytes. We studied the effects of chemical inhibitors on the ROS production and the mitochondrial membrane potential (Δψ(m of hemocytes. First, this work confirmed the specificity of JC-10 probe to measure Δψ(m in oyster hemocytes, without being affected by ΔpH, as reported in mammalian cells. Second, results show that ROS production in unstimulated hemocytes does not originate from cytoplasmic NADPH-oxidase, nitric oxide synthase or myeloperoxidase, but from mitochondria. In contrast to mammalian cells, incubation of hemocytes with rotenone (complex I inhibitor had no effect on ROS production. Incubation with antimycin A (complex III inhibitor resulted in a dose-dependent ROS production decrease while an over-production is usually reported in vertebrates. In hemocytes of C. gigas, the production of ROS seems similarly dependent on both Δψ(m and ΔpH. These findings point out differences between mammalian models and bivalve cells, which warrant further investigation about the fine characterization of the electron transfer chain and the respective involvement of mitochondrial complexes in ROS production in hemocytes of bivalve molluscs.

  18. Construction and evaluation of a high-density SNP array for the Pacific oyster (Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Haigang Qi

    Full Text Available Single nucleotide polymorphisms (SNPs are widely used in genetics and genomics research. The Pacific oyster (Crassostrea gigas is an economically and ecologically important marine bivalve, and it possesses one of the highest levels of genomic DNA variation among animal species. Pacific oyster SNPs have been extensively investigated; however, the mechanisms by which these SNPs may be used in a high-throughput, transferable, and economical manner remain to be elucidated. Here, we constructed an oyster 190K SNP array using Affymetrix Axiom genotyping technology. We designed 190,420 SNPs on the chip; these SNPs were selected from 54 million SNPs identified through re-sequencing of 472 Pacific oysters collected in China, Japan, Korea, and Canada. Our genotyping results indicated that 133,984 (70.4% SNPs were polymorphic and successfully converted on the chip. The SNPs were distributed evenly throughout the oyster genome, located in 3,595 scaffolds with a length of ~509.4 million; the average interval spacing was 4,210 bp. In addition, 111,158 SNPs were distributed in 21,050 coding genes, with an average of 5.3 SNPs per gene. In comparison with genotypes obtained through re-sequencing, ~69% of the converted SNPs had a concordance rate of >0.971; the mean concordance rate was 0.966. Evaluation based on genotypes of full-sib family individuals revealed that the average genotyping accuracy rate was 0.975. Carrying 133 K polymorphic SNPs, our oyster 190K SNP array is the first commercially available high-density SNP chip for mollusks, with the highest throughput. It represents a valuable tool for oyster genome-wide association studies, fine linkage mapping, and population genetics.

  19. Inter-site differences of zinc susceptibility of the oyster Crassostrea hongkongensis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fengjie [Division of Life Science, State Key Laboratory of Marine Pollution, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Rainbow, Philip S. [Department of Life Sciences, The Natural History Museum, Cromwell Rd., London SW7 5BD (United Kingdom); Wang, Wen-Xiong, E-mail: wwang@ust.hk [Division of Life Science, State Key Laboratory of Marine Pollution, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2013-05-15

    Highlights: ► Zn sensitivity and detoxification in oysters are related to the history of metal exposure. ► The lethal threshold concentration of total body Zn varied significantly among oyster populations. ► Total body Zn concentration could not serve as a suitable toxicity indicator in oysters. ► Zn toxicity is related to a threshold concentration of metabolically available metal. -- Abstract: Understanding the underlying mechanisms governing metal toxicity is crucial for predicting the risks and effects of metal pollutants. We hypothesized that metal toxicity is related to a threshold concentration of metabolically available metal but not to the total body metal concentration. Following a two-month laboratory Zn exposure, we characterized mortality and Zn bioaccumulation and subcellular partitioning in the oyster Crassostrea hongkongensis sampled from three sites with contrasting histories of Zn exposure and one multiple-metal contaminated site. Large differences in Zn sensitivity, lethal body concentration, and detoxification capability between sites were observed. Specifically, the oysters from the highly Zn-contaminated site were more tolerant to Zn exposure than those from the relatively clean ones, and the former accumulated and detoxified more Zn and had a significantly higher lethal body Zn concentration. The accumulation of Zn in the metabolically available pool (operationally defined as the metal-sensitive fraction) in the oysters from the multiple-metal contaminated site was relatively fast, and correspondingly they were highly sensitive to Zn exposure. The lethal threshold concentration of total body Zn varied significantly within the four sites, and thus total body Zn concentration could not serve as a suitable toxicity indicator. Importantly, Zn accumulation within the operationally defined metabolically available pool better explained variances in mortality than Zn accumulation in the whole body. Our results suggested that Zn toxicity is

  20. Transcriptomic responses to salinity stress in the Pacific oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Xuelin Zhao

    Full Text Available BACKGROUND: Low salinity is one of the main factors limiting the distribution and survival of marine species. As a euryhaline species, the Pacific oyster Crassostrea gigas is considered to be tolerant to relative low salinity. The genes that regulate C. gigas responses to osmotic stress were monitored using the next-generation sequencing of whole transcriptome with samples taken from gills. By RNAseq technology, transcript catalogs of up- and down-regulated genes were generated from the oysters exposed to low and optimal salinity seawater. METHODOLOGY/PRINCIPAL FINDINGS: Through Illumina sequencing, we reported 1665 up-regulated transcripts and 1815 down-regulated transcripts. A total of 45771 protein-coding contigs were identified from two groups based on sequence similarities with known proteins. As determined by GO annotation and KEGG pathway mapping, functional annotation of the genes recovered diverse biological functions and processes. The genes that changed expression significantly were highly represented in cellular process and regulation of biological process, intracellular and cell, binding and protein binding according to GO annotation. The results highlighted genes related to osmoregulation, signaling and interactions of osmotic stress response, anti-apoptotic reactions as well as immune response, cell adhesion and communication, cytoskeleton and cell cycle. CONCLUSIONS/SIGNIFICANCE: Through more than 1.5 million sequence reads and the expression data of the two libraries, the study provided some useful insights into signal transduction pathways in oysters and offered a number of candidate genes as potential markers of tolerance to hypoosmotic stress for oysters. In addition, the characterization of C. gigas transcriptome will not only provide a better understanding of the molecular mechanisms about the response to osmotic stress of the oysters, but also facilitate research into biological processes to find underlying physiological

  1. A survey of oysters (Crassostrea gigas) in New Zealand for Vibrio parahaemolyticus and Vibrio vulnificus.

    Science.gov (United States)

    Kirs, M; Depaola, A; Fyfe, R; Jones, J L; Krantz, J; Van Laanen, A; Cotton, D; Castle, M

    2011-05-27

    A microbiological survey was conducted to determine the levels of total and pathogenic Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) in Pacific oysters (Crassostrea gigas) collected from commercial growing areas in the North Island, New Zealand. The survey was intended to be geographically representative of commercial growing areas of Pacific oysters in New Zealand, while selecting the time frame most likely to coincide with the increased abundance of pathogenic vibrio species. Vp was detected in 94.8% of oyster samples examined (n=58) with a geometric mean concentration of 99.3 MPN/g, while Vv was detected in 17.2% of oyster samples examined with a geometric mean concentration of 7.4 MPN/g. The frequency of Vp positive samples was 1.7 fold greater than reported in a study conducted three decades ago in New Zealand. Potentially virulent (tdh positive) Vp was detected in two samples (3.4%, n=58) while no trh (another virulence marker) positive samples were detected. 16S rRNA genotype could be assigned only to 58.8% of Vv isolates (8:1:1 A:B:AB ratio, n=10). There was a good agreement [98.2% of Vp (n=280) and 94.4% of Vv (n=18) isolates] between molecular tests and cultivation based techniques used to identify Vibrio isolates and there was a significant (R(2)=0.95, Pcultivation. There was no significant correlation between any of the environmental parameters tested and Vp or Vv concentrations. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Evolution and functional analysis of the Pif97 gene of the Pacific oyster Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Xiaotong WANG, Xiaorui SONG, Tong WANG, Qihui ZHU, Guoying MIAO, Yuanxin CHEN, Xiaodong FANG, Huayong QUE, Li LI, Guofan ZHANG

    2013-02-01

    Full Text Available Mollusc shell matrix proteins (SMPs are important functional components embedded in the shell and play a role in shell formation. A SMP (Pif177 was identified previously from the nacreous layer of the Japanese pearl oyster Pinctada fucata, and its cleavage products (named pfPif97 and pfPif80 proteins were found to bind to the chitin framework and induce aragonite crystal formation and orient the c axis. In this study, a homologue of pfPif177 was cloned from the mantle of the Pacific oyster Crassostrea gigas, containing the homologue of pfPif97 only and not pfPif80. This finding hints at the large divergence in gene structure between the two species. This homologue (cgPif97 shares characteristics with pfPif97, and suggests that the biological functions of these two proteins may be similar. The expression pattern of cgPif97 in different tissues and development stages indicates that it may play an important role in shell formation of the adult oyster. The morphology of the inner shell surface was affected by injected siRNA of cgPif97 and the calcite laths of the shell became thinner and narrower when the siRNA dose increased, suggesting that the cgPif97 gene plays an important role in calcite shell formation in C. gigas. In conclusion, we found evidence that the Pif177 gene evolved very fast but still retains a similar function among species [Current Zoology 59 (1: 109–115, 2013].

  3. Effect of carbonate chemistry alteration on the early embryonic development of the Pacific oyster (Crassostrea gigas).

    Science.gov (United States)

    Gazeau, Frédéric; Gattuso, Jean-Pierre; Greaves, Mervyn; Elderfield, Henry; Peene, Jan; Heip, Carlo H R; Middelburg, Jack J

    2011-01-01

    Ocean acidification, due to anthropogenic CO₂ absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportions of abnormal development under low pH conditions, they did not allow attribution to pH induced changes in physiology or changes due to a decrease in aragonite saturation state. This study aims to assess the impact of several carbonate-system perturbations on the growth of Pacific oyster (Crassostrea gigas) larvae during the first 3 days of development (until shelled D-veliger larvae). Seawater with five different chemistries was obtained by separately manipulating pH, total alkalinity and aragonite saturation state (calcium addition). Results showed that the developmental success and growth rates were not directly affected by changes in pH or aragonite saturation state but were highly correlated with the availability of carbonate ions. In contrast to previous studies, both developmental success into viable D-shaped larvae and growth rates were not significantly altered as long as carbonate ion concentrations were above aragonite saturation levels, but they strongly decreased below saturation levels. These results suggest that the mechanisms used by these organisms to regulate calcification rates are not efficient enough to compensate for the low availability of carbonate ions under corrosive conditions.

  4. D1 dopamine receptor is involved in shell formation in larvae of Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Liu, Zhaoqun; Wang, Lingling; Yan, Yunchen; Zheng, Yan; Ge, Wenjing; Li, Meijia; Wang, Weilin; Song, Xiaorui; Song, Linsheng

    2018-07-01

    Dopamine (DA), a significant member of catecholamines, is reported to induce biomineralization of calcium carbonate vaterite microspheres via dopamine receptor (DR) in bivalves, implying the modulation of dopaminergic system on shell formation during larval development. In this research, a homologue of D1 type DR (CgD1DR-1) was identified from oyster Crassostrea gigas, whose full length cDNA was 1197 bp. It was widely expressed in various tissues of C. gigas, with the significantly higher levels in hepatopancreas, mantle, muscle and gill. During developmental stages, the mRNA transcripts of CgD1DR-1 in D-shape larvae were obviously higher (p < 0.05) than those in trochophore and umbo larvae, and CO 2 exposure could inhibit the synthesis of DA and mRNA expression of CgD1DR-1. After cell transfection and DA treatment, intracellular cAMP in cells with the expression of CgD1DR-1 increased significantly (p < 0.05). Furthermore, the incubation with SCH 23390 for the blockage of CgD1DR-1 significantly restrained the expressions of six shell formation-related genes including CgTyrosinase-1, CgTyrosinase-3, CgChitinaseLP, CgAMC, CgBMP and CgBMPR in trochophore and D-shape larvae. These results jointly suggested that DA together with its receptor CgD1DR-1 might be involved in shell formation during oyster larval development from trochophore to D-shape larvae, and CO 2 -induced ocean acidification (OA) might influence marine bivalves by inhibiting the DA-D1DR pathway to prohibit their shell formation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Antioxidant deficit in gills of Pacific oyster (Crassostrea gigas) exposed to chlorodinitrobenzene increases menadione toxicity

    International Nuclear Information System (INIS)

    Trevisan, Rafael; Arl, Miriam; Sacchet, Cássia Lopes; Engel, Cristiano Severino; Danielli, Naissa Maria; Mello, Danielle Ferraz; Brocardo, Caroline; Maris, Angelica Francesca; Dafre, Alcir Luiz

    2012-01-01

    Disturbances in antioxidant defenses decrease cellular protection against oxidative stress and jeopardize cellular homeostasis. To knock down the antioxidant defenses of Pacific oyster Crassostrea gigas, animals were pre-treated with 1-chloro-2,4-dinitrobenzene (CDNB) and further challenged with pro-oxidant menadione (MEN). CDNB pre-treatment (10 μM for 18 h) was able to consume cellular thiols in gills, decreasing GSH (53%) and decrease protein thiols (25%). CDNB pre-treatment also disrupted glutathione reductase and thioredoxin reductase activity in the gills, but likewise strongly induced glutathione S-transferase activity (270% increase). Surprisingly, hemocyte viability was greatly affected 24 h after CDNB removal, indicating a possible vulnerability of the oyster immune system to electrophilic attack. New in vivo approaches were established, allowing the identification of higher rates of GSH–CDNB conjugate export to the seawater and enabling the measurement of the organic peroxide consumption rate. CDNB-induced impairment in antioxidant defenses decreased the peroxide removal rate from seawater. After showing that CDNB decreased gill antioxidant defenses and increased DNA damage in hemocytes, oysters were further challenged with 1 mM MEN over 24 h. MEN treatment did not affect thiol homeostasis in gills, while CDNB pre-treated animals recovered GSH and PSH to the control level after 24 h of depuration. Interestingly, MEN intensified GSH and PSH loss and mortality in CDNB-pre-treated animals, showing a clear synergistic effect. The superoxide-generating one-electron reduction of MEN was predominant in gills and may have contributed to MEN toxicity. These results support the idea that antioxidant-depleted animals are more susceptible to oxidative attack, which can compromise survival. Data also corroborate the idea that gills are an important detoxifying organ, able to dispose of organic peroxides, induce phase II enzymes, and efficiently export GSH

  6. Antioxidant deficit in gills of Pacific oyster (Crassostrea gigas) exposed to chlorodinitrobenzene increases menadione toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Trevisan, Rafael; Arl, Miriam [Departamento de Bioquimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Sacchet, Cassia Lopes [Universidade do Oeste do Estado de Santa Catarina, 89600-000 Joacaba, SC (Brazil); Engel, Cristiano Severino; Danielli, Naissa Maria; Mello, Danielle Ferraz [Departamento de Bioquimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Brocardo, Caroline [Universidade do Oeste do Estado de Santa Catarina, 89600-000 Joacaba, SC (Brazil); Maris, Angelica Francesca [Departamento de Biologia Celular, Embriologia e Genetica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil); Dafre, Alcir Luiz, E-mail: alcir@ccb.ufsc.br [Departamento de Bioquimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil)

    2012-02-15

    Disturbances in antioxidant defenses decrease cellular protection against oxidative stress and jeopardize cellular homeostasis. To knock down the antioxidant defenses of Pacific oyster Crassostrea gigas, animals were pre-treated with 1-chloro-2,4-dinitrobenzene (CDNB) and further challenged with pro-oxidant menadione (MEN). CDNB pre-treatment (10 {mu}M for 18 h) was able to consume cellular thiols in gills, decreasing GSH (53%) and decrease protein thiols (25%). CDNB pre-treatment also disrupted glutathione reductase and thioredoxin reductase activity in the gills, but likewise strongly induced glutathione S-transferase activity (270% increase). Surprisingly, hemocyte viability was greatly affected 24 h after CDNB removal, indicating a possible vulnerability of the oyster immune system to electrophilic attack. New in vivo approaches were established, allowing the identification of higher rates of GSH-CDNB conjugate export to the seawater and enabling the measurement of the organic peroxide consumption rate. CDNB-induced impairment in antioxidant defenses decreased the peroxide removal rate from seawater. After showing that CDNB decreased gill antioxidant defenses and increased DNA damage in hemocytes, oysters were further challenged with 1 mM MEN over 24 h. MEN treatment did not affect thiol homeostasis in gills, while CDNB pre-treated animals recovered GSH and PSH to the control level after 24 h of depuration. Interestingly, MEN intensified GSH and PSH loss and mortality in CDNB-pre-treated animals, showing a clear synergistic effect. The superoxide-generating one-electron reduction of MEN was predominant in gills and may have contributed to MEN toxicity. These results support the idea that antioxidant-depleted animals are more susceptible to oxidative attack, which can compromise survival. Data also corroborate the idea that gills are an important detoxifying organ, able to dispose of organic peroxides, induce phase II enzymes, and efficiently export GSH

  7. The biofilteration ability of oysters (Crassostrea gigas) to reduce Aeromonas salmonicida in salmon culture.

    Science.gov (United States)

    Ma, Xiaona; Li, Xian; Sun, Guoxiang; Sharawy, Zaki Zaki; Qiu, Tianlong; Du, Yishuai; Liu, Ying

    2017-07-01

    Pathogen contamination in the environment is inevitable with the rapid development of intensive aquaculture. Therefore, alternative ecofriendly biological strategies to control pathogenic bacteria are required. However, our aim was to investigate the ability of oysters (Crassostrea gigas) to filter the important opportunistic pathogen, Aeromonas salmonicida (strain C4), using a green fluorescent protein tag (GFP) in the Atlantic salmon (Salmo salar) farming wastewater. Hence, A. salmonicida removal efficiency and ingestion rate were detected in two different oyster stages (larvae and adults). To evaluate the practical performance of oysters as A. salmonicida biofilter, adult oysters were applied to an integrated constructed wetlands system (ICWS) and their long-term C4-GFP removal efficiency was recorded for 60 days. Overall, our results clearly indicated that oysters had substantial A. salmonicida removal ability via their ingestion process when observed under a fluorescent microscope. Approximately 88-95% of C4-GFP was removed by oyster larvae at an ingestion rate of 6.4 × 10 3 -6.2 × 10 5  CFU/h·ind, while 79-92% of C4-GFP was removed by adult oysters at an ingestion rate of 2.1 × 10 4 -3.1 × 10 6  CFU/h·ind. Furthermore, 57.9 ± 17.2% of C4-GFP removal efficiency was achieved when oysters were applied to ICWS. We, therefore, concluded that using oysters as a biofilter represents an effective alternative for removing A. salmonicida from aquaculture wastewater. However, the fate of oysters after ingesting the pathogenic bacteria, acting as a potential reservoir or vector for pathogens, is still debatable. This research provides the basis for the application of oysters as a biofilter to remove pathogens from aquaculture wastewater in industrialized production.

  8. Exploitable Lipids and Fatty Acids in the Invasive Oyster Crassostrea gigas on the French Atlantic Coast

    Directory of Open Access Journals (Sweden)

    Flore Dagorn

    2016-05-01

    Full Text Available Economic exploitation is one means to offset the cost of controlling invasive species, such as the introduced Pacific oyster (Crassostrea gigas Thunberg on the French Atlantic coast. Total lipid and phospholipid (PL fatty acids (FAs and sterols were examined in an invasive population of C. gigas in Bourgneuf Bay, France, over four successive seasons, with a view to identify possible sources of exploitable substances. The total lipid level (% dry weight varied from 7.1% (winter to 8.6% (spring. Of this, PLs accounted for 28.1% (spring to 50.4% (winter. Phosphatidylcholine was the dominant PL throughout the year (up to 74% of total PLs in winter. Plasmalogens were identified throughout the year as a series of eleven dimethylacetals (DMAs with chain lengths between C16 and C20 (up to 14.5% of PL FAs + DMAs in winter. Thirty-seven FAs were identified in the PL FAs. Eicosapentaenoic acid (20:5n-3 EPA/7.53% to 14.5% and docosahexaenoic acid (22:6n-3 DHA/5.51% to 9.5% were the dominant polyunsaturated FAs in all seasons. Two non-methylene-interrupted dienoic (NMID FAs were identified in all seasons: 7,13-docosadienoic and 7,15-docosadienoic acids, the latter being present at relatively high levels (up to 9.6% in winter. Twenty free sterols were identified, including cholesterol at 29.9% of the sterol mixture and about 33% of phytosterols. C. gigas tissues thus contained exploitable lipids for health benefits or as a potential source of high-quality commercial lecithin.

  9. Exploitable Lipids and Fatty Acids in the Invasive Oyster Crassostrea gigas on the French Atlantic Coast

    Science.gov (United States)

    Dagorn, Flore; Couzinet-Mossion, Aurélie; Kendel, Melha; Beninger, Peter G.; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

    2016-01-01

    Economic exploitation is one means to offset the cost of controlling invasive species, such as the introduced Pacific oyster (Crassostrea gigas Thunberg) on the French Atlantic coast. Total lipid and phospholipid (PL) fatty acids (FAs) and sterols were examined in an invasive population of C. gigas in Bourgneuf Bay, France, over four successive seasons, with a view to identify possible sources of exploitable substances. The total lipid level (% dry weight) varied from 7.1% (winter) to 8.6% (spring). Of this, PLs accounted for 28.1% (spring) to 50.4% (winter). Phosphatidylcholine was the dominant PL throughout the year (up to 74% of total PLs in winter). Plasmalogens were identified throughout the year as a series of eleven dimethylacetals (DMAs) with chain lengths between C16 and C20 (up to 14.5% of PL FAs + DMAs in winter). Thirty-seven FAs were identified in the PL FAs. Eicosapentaenoic acid (20:5n-3 EPA/7.53% to 14.5%) and docosahexaenoic acid (22:6n-3 DHA/5.51% to 9.5%) were the dominant polyunsaturated FAs in all seasons. Two non-methylene-interrupted dienoic (NMID) FAs were identified in all seasons: 7,13-docosadienoic and 7,15-docosadienoic acids, the latter being present at relatively high levels (up to 9.6% in winter). Twenty free sterols were identified, including cholesterol at 29.9% of the sterol mixture and about 33% of phytosterols. C. gigas tissues thus contained exploitable lipids for health benefits or as a potential source of high-quality commercial lecithin. PMID:27231919

  10. Transcriptional changes in Crassostrea gigas oyster spat following a parental exposure to the herbicide diuron.

    Science.gov (United States)

    Rondon, R; Akcha, F; Alonso, P; Menard, D; Rouxel, J; Montagnani, C; Mitta, G; Cosseau, C; Grunau, C

    2016-06-01

    The Pacific oyster Crassostrea gigas is the main oyster species produced in the world, and a key coastal economic resource in France. High mortalities affect Pacific oysters since 2008 in France and Europe. Their origins have been attributed to a combination of biotic and abiotic factors, underlining the importance of environment quality. The impact of water pollution has been pointed out and one of the pollutants, the genotoxic herbicide diuron, occurs at high concentrations all along the French coasts. Previous work has revealed that a parental exposure to diuron had a strong impact on hatching rates and offspring development even if spats were not exposed to diuron themselves. In this study, we explored for the first time the transcriptional changes occurring in oyster spats (non exposed) originating from genitors exposed to an environmentally relevant concentration of diuron during gametogenesis using the RNAseq methodology. We identified a transcriptomic remodeling revealing an effect of the herbicide. Different molecular pathways involved in energy production, translation and cell proliferation are particularly disturbed. This analysis revealed modulated candidate genes putatively involved in response to oxidative stress and mitochondrial damage in offspring of genitors exposed to diuron. Complementary measures of the activity of enzymes involved in these latter processes corroborate the results obtained at the transcriptomic level. In addition, our results suggested an increase in energy production and mitotic activity in 5-month-spats from diuron-exposed genitors. These results could correspond to a "catch-up growth" phenomenon allowing the spats from diuron-exposed genitors, which displayed a growth delay at 3 months, to gain a normal size when they reach the age of 6 months. These results indicate that exposure to a concentration of diuron that is frequently encountered in the field during the oyster's gametogenesis stage can impact the next generation

  11. Inter-site differences of zinc susceptibility of the oyster Crassostrea hongkongensis

    International Nuclear Information System (INIS)

    Liu, Fengjie; Rainbow, Philip S.; Wang, Wen-Xiong

    2013-01-01

    Highlights: ► Zn sensitivity and detoxification in oysters are related to the history of metal exposure. ► The lethal threshold concentration of total body Zn varied significantly among oyster populations. ► Total body Zn concentration could not serve as a suitable toxicity indicator in oysters. ► Zn toxicity is related to a threshold concentration of metabolically available metal. -- Abstract: Understanding the underlying mechanisms governing metal toxicity is crucial for predicting the risks and effects of metal pollutants. We hypothesized that metal toxicity is related to a threshold concentration of metabolically available metal but not to the total body metal concentration. Following a two-month laboratory Zn exposure, we characterized mortality and Zn bioaccumulation and subcellular partitioning in the oyster Crassostrea hongkongensis sampled from three sites with contrasting histories of Zn exposure and one multiple-metal contaminated site. Large differences in Zn sensitivity, lethal body concentration, and detoxification capability between sites were observed. Specifically, the oysters from the highly Zn-contaminated site were more tolerant to Zn exposure than those from the relatively clean ones, and the former accumulated and detoxified more Zn and had a significantly higher lethal body Zn concentration. The accumulation of Zn in the metabolically available pool (operationally defined as the metal-sensitive fraction) in the oysters from the multiple-metal contaminated site was relatively fast, and correspondingly they were highly sensitive to Zn exposure. The lethal threshold concentration of total body Zn varied significantly within the four sites, and thus total body Zn concentration could not serve as a suitable toxicity indicator. Importantly, Zn accumulation within the operationally defined metabolically available pool better explained variances in mortality than Zn accumulation in the whole body. Our results suggested that Zn toxicity is

  12. Heterologous expression of the Crassostrea gigas (Pacific oyster) alternative oxidase in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Robertson, Aaron; Schaltz, Kyle; Neimanis, Karina; Staples, James F; McDonald, Allison E

    2016-10-01

    Alternative oxidase (AOX) is a terminal oxidase within the inner mitochondrial membrane (IMM) present in many organisms where it functions in the electron transport system (ETS). AOX directly accepts electrons from ubiquinol and is therefore capable of bypassing ETS Complexes III and IV. The human genome does not contain a gene coding for AOX, so AOX expression has been suggested as a gene therapy for a range of human mitochondrial diseases caused by genetic mutations that render Complex III and/or IV dysfunctional. An effective means of screening mutations amenable to AOX treatment remains to be devised. We have generated such a tool by heterologously expressing AOX from the Pacific oyster (Crassostrea gigas) in the yeast Saccharomyces cerevisiae under the control of a galactose promoter. Our results show that this animal AOX is monomeric and is correctly targeted to yeast mitochondria. Moreover, when expressed in yeast, Pacific oyster AOX is a functional quinol oxidase, conferring cyanide-resistant growth and myxothiazol-resistant oxygen consumption to yeast cells and isolated mitochondria. This system represents a high-throughput screening tool for determining which Complex III and IV genetic mutations in yeast will be amenable to AOX gene therapy. As many human genes are orthologous to those found in yeast, our invention represents an efficient and cost-effective way to evaluate viable research avenues. In addition, this system provides the opportunity to learn more about the localization, structure, and regulation of AOXs from animals that are not easily reared or manipulated in the lab.

  13. The nuclear receptor gene family in the Pacific oyster, Crassostrea gigas, contains a novel subfamily group.

    Science.gov (United States)

    Vogeler, Susanne; Galloway, Tamara S; Lyons, Brett P; Bean, Tim P

    2014-05-15

    Nuclear receptors are a superfamily of transcription factors important in key biological, developmental and reproductive processes. Several of these receptors are ligand- activated and through their ability to bind endogenous and exogenous ligands, are potentially vulnerable to xenobiotics. Molluscs are key ecological species in defining aquatic and terrestrial habitats and are sensitive to xenobiotic compounds in the environment. However, the understanding of nuclear receptor presence, function and xenobiotic disruption in the phylum Mollusca is limited. Here, forty-three nuclear receptor sequences were mined from the genome of the Pacific oyster, Crassostrea gigas. They include members of NR0-NR5 subfamilies, notably lacking any NR6 members. Phylogenetic analyses of the oyster nuclear receptors have been conducted showing the presence of a large novel subfamily group not previously reported, which is named NR1P. Homologues to all previous identified nuclear receptors in other mollusc species have also been determined including the putative heterodimer partner retinoid X receptor, estrogen receptor and estrogen related receptor. C. gigas contains a highly diverse set of nuclear receptors including a novel NR1 group, which provides important information on presence and evolution of this transcription factor superfamily in invertebrates. The Pacific oyster possesses two members of NR3, the sex steroid hormone receptor analogues, of which there are 9 in humans. This provides increasing evidence that steroid ligand specific expansion of this family is deuterostome specific. This new knowledge on divergence and emergence of nuclear receptors in C. gigas provides essential information for studying regulation of molluscan gene expression and the potential effects of xenobiotics.

  14. Shotgun proteomics reveals physiological response to ocean acidification in Crassostrea gigas.

    Science.gov (United States)

    Timmins-Schiffman, Emma; Coffey, William D; Hua, Wilber; Nunn, Brook L; Dickinson, Gary H; Roberts, Steven B

    2014-11-03

    Ocean acidification as a result of increased anthropogenic CO2 emissions is occurring in marine and estuarine environments worldwide. The coastal ocean experiences additional daily and seasonal fluctuations in pH that can be lower than projected end-of-century open ocean pH reductions. In order to assess the impact of ocean acidification on marine invertebrates, Pacific oysters (Crassostrea gigas) were exposed to one of four different p CO2 levels for four weeks: 400 μatm (pH 8.0), 800 μatm (pH 7.7), 1000 μatm (pH 7.6), or 2800 μatm (pH 7.3). At the end of the four week exposure period, oysters in all four p CO2 environments deposited new shell, but growth rate was not different among the treatments. However, micromechanical properties of the new shell were compromised by elevated p CO2. Elevated p CO2 affected neither whole body fatty acid composition, nor glycogen content, nor mortality rate associated with acute heat shock. Shotgun proteomics revealed that several physiological pathways were significantly affected by ocean acidification, including antioxidant response, carbohydrate metabolism, and transcription and translation. Additionally, the proteomic response to a second stress differed with p CO2, with numerous processes significantly affected by mechanical stimulation at high versus low p CO2 (all proteomics data are available in the ProteomeXchange under the identifier PXD000835). Oyster physiology is significantly altered by exposure to elevated p CO2, indicating changes in energy resource use. This is especially apparent in the assessment of the effects of p CO2 on the proteomic response to a second stress. The altered stress response illustrates that ocean acidification may impact how oysters respond to other changes in their environment. These data contribute to an integrative view of the effects of ocean acidification on oysters as well as physiological trade-offs during environmental stress.

  15. Effect of carbonate chemistry alteration on the early embryonic development of the Pacific oyster (Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Frédéric Gazeau

    Full Text Available Ocean acidification, due to anthropogenic CO₂ absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportions of abnormal development under low pH conditions, they did not allow attribution to pH induced changes in physiology or changes due to a decrease in aragonite saturation state. This study aims to assess the impact of several carbonate-system perturbations on the growth of Pacific oyster (Crassostrea gigas larvae during the first 3 days of development (until shelled D-veliger larvae. Seawater with five different chemistries was obtained by separately manipulating pH, total alkalinity and aragonite saturation state (calcium addition. Results showed that the developmental success and growth rates were not directly affected by changes in pH or aragonite saturation state but were highly correlated with the availability of carbonate ions. In contrast to previous studies, both developmental success into viable D-shaped larvae and growth rates were not significantly altered as long as carbonate ion concentrations were above aragonite saturation levels, but they strongly decreased below saturation levels. These results suggest that the mechanisms used by these organisms to regulate calcification rates are not efficient enough to compensate for the low availability of carbonate ions under corrosive conditions.

  16. Effects of heavy metals on the oyster (Crassostrea virginica at Mandinga Lagoon, Veracruz, Mexico

    Directory of Open Access Journals (Sweden)

    X Guzmán-García

    2009-12-01

    Full Text Available 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 within the Mexican legal limits. The recorded values in sediments corresponded to those not producing biological effects (ERL. In the tissues, the highest concentrations corresponded to Pb, above 5.84 μgg-1 dry weight (d.w.; Cd was of 2.23 μgg-1 d.w., and Cr above 6 μgg-1 d.w. The metal levels detected in oysters exceeded the maximum permissible limits (MPL for Cd and Pb, and oysters were unable to eliminate the concentrations of the bioaccumulated metals during the detoxification stage. The histopathological analysis revealed lesions in the digestive gland, edema, atrophy of epithelia in the digestive tubules, the presence of brown vesicles, hemocytic reaction, and necrosis. During detoxification, a higher number of epithelia were observed in the tubules, as well as an increase in brown vesicles and hemocytic reaction. Forty seven percent of oysters presented histopathological lesions related to metal concentrations. It is important to monitor metal concentrations, to detect the source of pollution, andto evaluate the effects on organisms to establish culture areas and adequate criteria for the exploitation of such an important fishery resource. Rev. Biol. Trop. 57 (4: 955-962. Epub 2009 December 01.

  17. Impacts of ocean acidification on gene expression and biomineralisation in the Pacific oyster Crassostrea gigas Thunberg, 1793

    Science.gov (United States)

    Bagusche, F.; Pouvreau, S.; Trueman, C.; Long, S.; Hauton, C.

    2012-04-01

    The published evidence of impacts of ocean acidification and on marine calcifiers has emphasized the need to understand the molecular mechanisms of biomineralisation. Crassostrea gigas is an ideal organism to examine these processes as: 1) the hatchery rearing of larval stages is well constrained, 2) studies have established an ontogenetic switch in deposition of carbonate polymorphs from aragonite in larval shells to calcite in adults and 3) it is a globally-important commercial species. Research summarized in this presentation will identify some of the molecular mechanisms involved in calcification processes during ontogeny of Crassostrea gigas, as well as possible impacts of changes in environmental conditions such as temperature and pH. Data will be presented from a quantitative real-time PCR study of the changes in gene expression during development in different environments. Additionally scanning electron microscopy and infrared spectroscopy analyses of shell microstructures and composition will be summarised to correlate changes in gene expression with end-point differences in shell structure. Preliminary results suggest that changes in the environmental conditions lead to differences in expression patterns of genes involved in biomineralisation processes. The combined effects of ambient seawater temperature and low pH show the greatest negative effect on larval shell development, identified as malformations, eroded shell surfaces and a significant decrease in shell size. However, the effect of higher seawater temperature seems to amend the effects of ocean acidification on larval shell development.

  18. Growth, mortality and susceptibility of oyster Crassostrea spp. to Perkinsus spp. infection during on growing in northeast Brazil

    Directory of Open Access Journals (Sweden)

    Marcos Paiva Scardua

    2017-11-01

    Full Text Available Abstract Crassostrea rhizophorae and C. gasar oysters are cultivated in the northeast region. Perkinsus parasites infect bivalves, and their effects on oysters from tropical regions are poorly understood. This study evaluated the impact of Perkinsus infection on the productive traits of native oysters. Oysters were sampled bimonthly during 7 months, from July 2010 to February 2011, to evaluate growth rate, mortality and shell color patterns (white and dark-gray (n = 500, and to determine the prevalence and intensity of Perkinsus (n = 152. Perkinsus and Crassostrea species were determined using molecular tools. Results showed that most dark-gray (90%, n = 20 and white (67%, n = 18 oysters were C. gasar and C. rhizophorae, respectively. Oysters showed a high growth rate and moderate cumulative mortality (44%. C. gasar oysters grew better and showed lower mortality and lower incidence of Perkinsus compared to C. rhizophorae. The mean prevalence of Perkinsus was moderate (48%, but the infection intensity was light (2.2. Perkinsosis affected very small oysters (19.4 mm. In conclusion, native oysters, especially C. gasar, have a great potential for culture, mortality is not associated with perkinsosis, and the shell color of oysters can be used to improve selection for spats with better performance.

  19. High pressure treatment changes spoilage characteristics and shelf life of Pacific oysters ( Crassostrea gigas) during refrigerated storage

    Science.gov (United States)

    Cao, Rong; Zhao, Ling; Liu, Qi

    2017-04-01

    The effects of high pressure (HP) treatment on spoilage characteristic and shelf life extension of Pacific oysters ( Crassostrea gigas) during refrigerated storage were studied. Results showed that HP treatment of 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle, pressures higher than 350 MPa caused excessive release as the shells of oysters were broken, thus use of higher pressures should be cautious in oyster processing industry because of its adverse impact on the appearance of shells. HP treatment (300 MPa, 2 min) was proper for the shucking of Pacific oyster ( Crassostrea gigas) in China. This treatment caused no organoleptic disadvantage. Moreover, HP treatment resulted in obvious differences in biochemical spoilage indicators (pH, TVB-N and TBARS) changes and volatile compounds profile determined by electronic nose during storage. HP treatment (300 MPa, 2 min) also led to a reduction of aerobic bacterial count (APC) by 1.27 log cycles. Furthermore, the APC values of oysters treated by HP were always lower than those of the control samples during storage. Based on the organoleptic, biochemical and microbiological indicators, shelf life of 6-8 d for control and 12 d for HP-treated oysters could be expected. HP treatment showed great potential in oyster processing and preservation.

  20. Treatment of shrimp effluent by sedimentation and oyster filtration using Crassostrea gigas and C. rhizophorae

    Directory of Open Access Journals (Sweden)

    Roberto Ramos

    2009-06-01

    Full Text Available Efficiency in removing particulate matter from Litopenaeus vannamei shrimp culture effluent was assessed in laboratory scale employing sedimentation and oysters Crassostrea gigas and C. rhizophorae filtration processes. Cylindroconical tanks (100 L were used in duplicate for sedimentation and 50-L in triplicate for oyster filtration. Fifteen oysters of each species weighing 76-80 g were stocked in each of the filtration treatment experimental units (biomass of 1065 - 1174 g oyster per unit. The control treatment was a tank similar to those used in the filtration treatment but with empty oyster shells. Hydraulic retention time of the effluent was of 6 hours in each treatment. First, effluent went through sedimentation, and then the supernatant went through the filtration tanks. Temperature, pH, dissolved oxygen, salinity, turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5 were evaluated. During sedimentation and filtration, temperature, pH, salinity and dissolved oxygen concentration remained stable. Sedimentation removed 18, 5.6, 27.5, 45.40 and 23.2% of turbidity, total suspended solids, total volatile solids, chlorophyll a and BOD5, respectively. Chlorophyll a and BOD5 after sedimentation presented significant difference (PEm escala laboratorial, foi comparada a eficiência de remoção de material particulado presente no efluente do cultivo de camarão branco Litopenaeus vannamei, mediante o processo de sedimentação e filtração com ostra nativa Crassostrea rhizophorae e com ostra do pacifico Crassostrea gigas. No processo de sedimentação foram empregados tanques cilindro cônico, em duplicata, de cor preta com 100 L de capacidade total. Para o processo de filtração foram empregados tanques cilindro cônicos, em triplicata, de cor preta de 50 L de volume total. No tratamento de filtração cada unidade experimental foi estocada com 15 indivíduos de ostras de ambas as espécies, com peso médio entre 76

  1. EFFECT OF SALINITY, TEMPERATURE, AND FOOD VALUE OF FOUR MICROALGAE TO OYSTER, Crassostrea iredalei LARVAL GROWTH

    Directory of Open Access Journals (Sweden)

    Achmad Sudradjat

    2006-12-01

    Full Text Available Published accounts of Crassostrea iredalei are only of its distribution in the Philippines. In Indonesia, this species is known to occur on the coast of South Sulawesi as well as in Banten. The purposes of the present studies were to investigate effect of salinity, temperature and food value of four microalgae to C. iredalei larval growth. Fine filtration of water was carried out using Sartorius capsule filter cartridge (1.2 ìm and 0.2 ìm and sterilization was achieved by passing the water through an ultraviolet light unit. Low-salinity water was prepared by diluting filtered seawater with distilled water. High-salinity water was made by adding synthetic sea salts. All cultures were kept in constant temperature baths. Experiments of 8-days (for temperature and salinity trials and 10-days (for diet trial duration were duplicated in 500 mL glass beakers with larval density of 104 per liter. Seawater was changed every 48 h. The algae, Isochrysis galbana, I. galbana clone T-ISO, and Pavlova lutheri were added to the glass beakers at a rate of 100 cells/ìL; cell density of Chaetoceros calsitrans was 250 cells/ìl at the start of the experiment and after every water change. Using thermostat chambers, 5 temperatures were tested, ranging from 14o to 34o in 5 steps. Four salinities were used, they ranged from 10 to 35‰ in 5‰ steps. For environmental condition trial, I. galbana as food was used. In diet trials, 4 species of algae were tested e.g. I. galbana, I. galbana T-ISO, P. lutheri, C. calcitrans and a mixture of algae, T-ISO/C. calcitrans. The optimum salinity range for growth of larvae was recorded at 20‰—30‰ at which the mean shell length was 85.1—87.7 ìm. The highest survival rate was recorded at salinity of 25‰—30‰, it was 91.6%—92.7%. There were significant differences in larval growth between temperature treatments. The optimum temperature for larval growth was at 24°C—29°C, with survival rate of 91.6%—93.0%. P

  2. Transcriptional changes in Crassostrea gigas oyster spat following a parental exposure to the herbicide diuron

    International Nuclear Information System (INIS)

    Rondon, R.; Akcha, F.; Alonso, P.; Menard, D.; Rouxel, J.; Montagnani, C.; Mitta, G.; Cosseau, C.; Grunau, C.

    2016-01-01

    Highlights: • Remodeling of the transcriptome of the offspring of oysters exposed to diuron (838 gene which expression is modulated). • Functions related to cytoskeleton organization, translation, ATP synthesis were activated. • Functions linked to transcription and protein degradation were altered. • Up-regulation of genes involved in energy production, protein synthesis and mitosis. • Catch-up growth phenomenon could allow the spats to compensate for slower growth. - Abstract: The Pacific oyster Crassostrea gigas is the main oyster species produced in the world, and a key coastal economic resource in France. High mortalities affect Pacific oysters since 2008 in France and Europe. Their origins have been attributed to a combination of biotic and abiotic factors, underlining the importance of environment quality. The impact of water pollution has been pointed out and one of the pollutants, the genotoxic herbicide diuron, occurs at high concentrations all along the French coasts. Previous work has revealed that a parental exposure to diuron had a strong impact on hatching rates and offspring development even if spats were not exposed to diuron themselves. In this study, we explored for the first time the transcriptional changes occurring in oyster spats (non exposed) originating from genitors exposed to an environmentally relevant concentration of diuron during gametogenesis using the RNAseq methodology. We identified a transcriptomic remodeling revealing an effect of the herbicide. Different molecular pathways involved in energy production, translation and cell proliferation are particularly disturbed. This analysis revealed modulated candidate genes putatively involved in response to oxidative stress and mitochondrial damage in offspring of genitors exposed to diuron. Complementary measures of the activity of enzymes involved in these latter processes corroborate the results obtained at the transcriptomic level. In addition, our results suggested an

  3. Hemolymph chemistry and histopathological changes in Pacific oysters (Crassostrea gigas) in response to low salinity stress.

    Science.gov (United States)

    Knowles, Graeme; Handlinger, Judith; Jones, Brian; Moltschaniwskyj, Natalie

    2014-09-01

    This study described seasonal differences in the histopathological and hemolymph chemistry changes in different family lines of Pacific oysters, Crassostrea gigas, in response to the stress of an abrupt change to low salinity, and mechanical grading. The most significant changes in pallial cavity salinity, hemolymph chemistry and histopathological findings occurred in summer at low salinity. In summer (water temperature 18°C) at low salinity, 9 (25.7% of full salinity), the mean pallial cavity salinity in oysters at day 3 was 19.8±1.6 (SE) and day 10 was 22.8±1.6 (SE) lower than oysters at salinity 35. Associated with this fall in pallial cavity salinity, mean hemolymph sodium for oysters at salinity 9 on day 3 and 10 were 297.2mmol/L±20(SE) and 350.4mmol/L±21.3(SE) lower than oysters at salinity 35. Similarly mean hemolymph potassium in oysters held at salinity 9 at day 3 and 10 were 5.6mmol/L±0.6(SE) and 7.9mmol/L±0.6 (SE) lower than oysters at salinity 35. These oysters at low salinity had expanded intercellular spaces and significant intracytoplasmic vacuolation distending the cytoplasm of epithelial cells in the alimentary tract and kidney and hemocyte infiltrate (diapedesis) within the alimentary tract wall. In contrast, in winter (water temperature 8°C) oyster mean pallial cavity salinity only fell at day 10 and this was by 6.0±0.6 (SE) compared to that of oysters at salinity 35. There were limited histopathological changes (expanded intercellular spaces and moderate intracytoplasmic vacuolation of renal epithelial cells) in these oysters at day 10 in low salinity. Mechanical grading and family line did not influence the oyster response to sudden low salinity. These findings provide additional information for interpretation of non-lethal, histopathological changes associated with temperature and salinity variation. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Proteomic and metabolomic responses of Pacific oyster Crassostrea gigas to elevated pCO2 exposure.

    Science.gov (United States)

    Wei, Lei; Wang, Qing; Wu, Huifeng; Ji, Chenglong; Zhao, Jianmin

    2015-01-01

    The gradually increased atmospheric CO2 partial pressure (pCO2) has thrown the carbonate chemistry off balance and resulted in decreased seawater pH in marine ecosystem, termed ocean acidification (OA). Anthropogenic OA is postulated to affect the physiology of many marine calcifying organisms. However, the susceptibility and metabolic pathways of change in most calcifying animals are still far from being well understood. In this work, the effects of exposure to elevated pCO2 were characterized in gills and hepatopancreas of Crassostrea gigas using integrated proteomic and metabolomic approaches. Metabolic responses indicated that high CO2 exposure mainly caused disturbances in energy metabolism and osmotic regulation marked by differentially altered ATP, glucose, glycogen, amino acids and organic osmolytes in oysters, and the depletions of ATP in gills and the accumulations of ATP, glucose and glycogen in hepatopancreas accounted for the difference in energy distribution between these two tissues. Proteomic responses suggested that OA could not only affect energy and primary metabolisms, stress responses and calcium homeostasis in both tissues, but also influence the nucleotide metabolism in gills and cytoskeleton structure in hepatopancreas. This study demonstrated that the combination of proteomics and metabolomics could provide an insightful view into the effects of OA on oyster C. gigas. The gradually increased atmospheric CO2 partial pressure (pCO2) has thrown the carbonate chemistry off balance and resulted in decreased seawater pH in marine ecosystem, termed ocean acidification (OA). Anthropogenic OA is postulated to affect the physiology of many marine calcifying organisms. However, the susceptibility and metabolic pathways of change in most calcifying animals are still far from being understood. To our knowledge, few studies have focused on the responses induced by pCO2 at both protein and metabolite levels. The pacific oyster C. gigas, widely distributed

  5. Cultivo de la ostra Crassostrea gigas (Thunberg, 1795 en un vivero artesanal, La arena, Casma

    Directory of Open Access Journals (Sweden)

    Paul Baltazar

    2014-06-01

    Full Text Available El presente trabajo describe la metodología empleada para el cultivo de la ostra del Pacífico Crassostrea gigas en un vivero artesanal, en el Centro Acuícola La Arena, Casma. Se utilizó reproductores en fase intermedia de madurez gonádica procedentes de líneas de cultivo del Centro Acuícola. El acondicionamiento se realizó en tanques de fibra de vidrio de 1000 L, con agua de mar sin filtrar a una temperatura de 27 ± 0,9 oC; adicionalmente se les alimentó con fécula de maíz y microalgas obtenidas en el lugar y cultivadas al aire libre. El desove se indujo para un grupo sólo por estimulación térmica (30 a 31 oC y para el otro se añadió además peróxido de hidrógeno, a lo cual se presentaron respuestas diferentes. A los 20 minutos después de la fertilización se observó, en el 100% de huevos fecundados, el cuerpo polar definido y a las 24 horas las larvas veliger. Las larvas alcanzaron el estado de pediveliger luego de 20 días de cultivo, con tallas promedios de 237 ± 10 µm. Para la fijación de las larvas se utilizó conchuela molida (300 µm, plástico negro lijado y valvas de ostras. A los 33 días se obtuvieron semillas con tallas medias de 1262 ± 204 µm las que fueron colocadas en pearl net para su desarrollo en el mar. A los 30 días de la siembra en el mar, la talla promedio de las postlarvas alcanzó los 13,4 ± 3,4 mm. El trabajo muestra las ventajas de la metodología descrita en la producción masiva de semillas en un vivero artesanal.

  6. Purification and characterization of a salt-tolerant cellulase from the mangrove oyster, Crassostrea rivularis.

    Science.gov (United States)

    An, Tianchen; Dong, Zhu; Lv, Junchen; Liu, Yujun; Wang, Manchuriga; Wei, Shuangshuang; Song, Yanting; Zhang, Yingxia; Deng, Shiming

    2015-04-01

    A cellulase with wide range of pH resistance and high salt tolerance was isolated from the digestive gland of the oyster Crassostrea rivularis living in mangrove forests. The 27 kDa cellulase named as CrCel was purified 40.6 folds by anion exchange chromatography and extraction from the gel after non-reducing sodium dodecylsufate-polyacrylamide gel electrophoresis. The specific activity of the purified cellulase was 23.4 U/mg against carboxymethyl cellulose (CMC). The N-terminal amino acid sequence of CrCel was determined to be NQKCQANSRV. CrCel preferably hydrolyzes β-1,4-glucosidic bonds in the amorphous parts of cellulose materials and displays degradation activity toward xylan. The Km and Vmax values of CrCel for CMC were determined to be 2.1% ± 0.4% and 73.5 ± 3.3 U mg(-1), respectively. The optimal pH value and temperature of CrCel were 5.5 and 40°C, respectively. The enzyme was stable in a wide range of pH, retaining over 60% activity after incubation for 80 min in the pH range of 3.0-9.0. In addition, CrCel showed remarkable tolerance to salt and remained active at high NaCl concentrations, but also retained over 70% activity after incubation in 0.5-2 M NaCl for up to 24 h. On the basis of the N-terminal sequence alignment and its similar properties to other animal cellulases, CrCel was regarded as a member of glycosyl hydrolase family 45 β-1,4-glucanases. CrCel is the first reported cellulase isolated from mangrove invertebrates, which suggests that it may participate in the assimilation of cellulolytic materials derived from the food sources of the oyster and contribute to the consumption of mangrove primary production. The unique properties of this enzyme make it a potential candidate for further industrial application. © The Author 2015. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

  7. Copper induces expression and methylation changes of early development genes in Crassostrea gigas embryos.

    Science.gov (United States)

    Sussarellu, Rossana; Lebreton, Morgane; Rouxel, Julien; Akcha, Farida; Rivière, Guillaume

    2018-03-01

    Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L -1 Cu 2+ ) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval bioassay at the D-larva stage 24 h post fertilization (hpf) and genotoxicity at gastrulation 7 hpf. In parallel, the relative expression of 15 genes encoding putative homeotic, biomineralization and DNA methylation proteins was measured at three developmental stages (3 hpf morula stage, 7 hpf gastrula stage, 24 hpf D-larvae stage) using RT-qPCR. Global DNA content in methylcytosine and hydroxymethylcytosine were measured by HPLC and gene-specific DNA methylation levels were monitored using MeDIP-qPCR. A significant increase in larval abnormalities was observed from copper concentrations of 10 μg L -1 , while significant genotoxic effects were detected at 1 μg L -1 and above. All the selected genes presented a stage-dependent expression pattern, which was impaired for some homeobox and DNA methylation genes (Notochord, HOXA1, HOX2, Lox5, DNMT3b and CXXC-1) after copper exposure. While global DNA methylation (5-methylcytosine) at gastrula stage didn't show significant changes between experimental conditions, 5-hydroxymethylcytosine, its degradation product, decreased upon copper treatment. The DNA methylation of exons and the transcript levels were correlated in control samples for HOXA1 but such

  8. Transcriptomics Analysis of Crassostrea hongkongensis for the Discovery of Reproduction-Related Genes

    Science.gov (United States)

    Tong, Ying; Zhang, Yang; Huang, Jiaomei; Xiao, Shu; Zhang, Yuehuan; Li, Jun; Chen, Jinhui; Yu, Ziniu

    2015-01-01

    Background The reproductive mechanisms of mollusk species have been interesting targets in biological research because of the diverse reproductive strategies observed in this phylum. These species have also been studied for the development of fishery technologies in molluscan aquaculture. Although the molecular mechanisms underlying the reproductive process have been well studied in animal models, the relevant information from mollusks remains limited, particularly in species of great commercial interest. Crassostrea hongkongensis is the dominant oyster species that is distributed along the coast of the South China Sea and little genomic information on this species is available. Currently, high-throughput sequencing techniques have been widely used for investigating the basis of physiological processes and facilitating the establishment of adequate genetic selection programs. Results The C.hongkongensis transcriptome included a total of 1,595,855 reads, which were generated by 454 sequencing and were assembled into 41,472 contigs using de novo methods. Contigs were clustered into 33,920 isotigs and further grouped into 22,829 isogroups. Approximately 77.6% of the isogroups were successfully annotated by the Nr database. More than 1,910 genes were identified as being related to reproduction. Some key genes involved in germline development, sex determination and differentiation were identified for the first time in C.hongkongensis (nanos, piwi, ATRX, FoxL2, β-catenin, etc.). Gene expression analysis indicated that vasa, nanos, piwi, ATRX, FoxL2, β-catenin and SRD5A1 were highly or specifically expressed in C.hongkongensis gonads. Additionally, 94,056 single nucleotide polymorphisms (SNPs) and 1,699 simple sequence repeats (SSRs) were compiled. Conclusions Our study significantly increased C.hongkongensis genomic information based on transcriptomics analysis. The group of reproduction-related genes identified in the present study constitutes a new tool for research

  9. Transcriptomics Analysis of Crassostrea hongkongensis for the Discovery of Reproduction-Related Genes.

    Directory of Open Access Journals (Sweden)

    Ying Tong

    Full Text Available The reproductive mechanisms of mollusk species have been interesting targets in biological research because of the diverse reproductive strategies observed in this phylum. These species have also been studied for the development of fishery technologies in molluscan aquaculture. Although the molecular mechanisms underlying the reproductive process have been well studied in animal models, the relevant information from mollusks remains limited, particularly in species of great commercial interest. Crassostrea hongkongensis is the dominant oyster species that is distributed along the coast of the South China Sea and little genomic information on this species is available. Currently, high-throughput sequencing techniques have been widely used for investigating the basis of physiological processes and facilitating the establishment of adequate genetic selection programs.The C.hongkongensis transcriptome included a total of 1,595,855 reads, which were generated by 454 sequencing and were assembled into 41,472 contigs using de novo methods. Contigs were clustered into 33,920 isotigs and further grouped into 22,829 isogroups. Approximately 77.6% of the isogroups were successfully annotated by the Nr database. More than 1,910 genes were identified as being related to reproduction. Some key genes involved in germline development, sex determination and differentiation were identified for the first time in C.hongkongensis (nanos, piwi, ATRX, FoxL2, β-catenin, etc.. Gene expression analysis indicated that vasa, nanos, piwi, ATRX, FoxL2, β-catenin and SRD5A1 were highly or specifically expressed in C.hongkongensis gonads. Additionally, 94,056 single nucleotide polymorphisms (SNPs and 1,699 simple sequence repeats (SSRs were compiled.Our study significantly increased C.hongkongensis genomic information based on transcriptomics analysis. The group of reproduction-related genes identified in the present study constitutes a new tool for research on bivalve

  10. The Molecular Differentiation of Anatomically Paired Left and Right Mantles of the Pacific Oyster Crassostrea gigas.

    Science.gov (United States)

    Wei, Lei; Xu, Fei; Wang, Yuzhi; Cai, Zhongqiang; Yu, Wenchao; He, Cheng; Jiang, Qiuyun; Xu, Xiqiang; Guo, Wen; Wang, Xiaotong

    2018-03-28

    Left-right (L-R) asymmetry is controlled by gene regulation pathways for the L-R axis, and in vertebrates, the gene Pitx2 in TGF-β signaling pathway plays important roles in the asymmetrical formation of organs. However, less is known about the asymmetries of anatomically identical paired organs, as well as the transcriptional regulation mechanism of the gene Pitx in invertebrates. Here, we report the molecular biological differences between the left and right mantles of an invertebrate, the Pacific oyster Crassostrea gigas, and propose one possible mechanism underlying those differences. RNA sequencing (RNA-seq) analysis indicated that the paired organs showed different gene expression patterns, suggesting possible functional differences in shell formation, pheromone signaling, nerve conduction, the stress response, and other physiological processes. RNA-seq and real-time qPCR analysis indicated high right-side expression of the Pitx homolog (cgPitx) in oyster mantle, supporting a conserved role for Pitx in controlling asymmetry. Methylation-dependent restriction-site associated DNA sequencing (MethylRAD) identified a methylation site in the promoter region of cgPitx and showed significantly different methylation levels between the left and right mantles. This is the first report, to our knowledge, of such a difference in methylation in spiralians, and it was further confirmed in 18 other individuals by using a pyrosequencing assay. The miRNome analysis and the TGF-β receptor/Smad inhibition experiment further supported that several genes in TGF-β signaling pathway may be related with the L/R asymmetry of oyster mantles. These results suggested that the molecular differentiation of the oyster's paired left and right mantles is significant, TGF-β signaling pathway could be involved in establishing or maintaining the asymmetry, and the cgPitx gene as one of genes in this pathway; the different methylation levels in its promoter regions between L/R mantles was

  11. Transcriptional changes in Crassostrea gigas oyster spat following a parental exposure to the herbicide diuron

    Energy Technology Data Exchange (ETDEWEB)

    Rondon, R. [Ifremer, IHPE UMR 5244, Univ. Perpignan Via Domitia, CNRS, Univ. Montpellier, F-34095 Montpellier (France); Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan (France); Akcha, F. [Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France); Alonso, P. [CNRS, IHPE UMR 5244, Univ. Perpignan Via Domitia, IFREMER, Univ. Montpellier, F-34095 Montpellier (France); Menard, D.; Rouxel, J. [Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l’ile d’Yeu, BP 21105, 44311 Nantes Cedex 03 (France); Montagnani, C., E-mail: cmontagn@ifremer.fr [Ifremer, IHPE UMR 5244, Univ. Perpignan Via Domitia, CNRS, Univ. Montpellier, F-34095 Montpellier (France); Mitta, G.; Cosseau, C.; Grunau, C. [Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan (France)

    2016-06-15

    Highlights: • Remodeling of the transcriptome of the offspring of oysters exposed to diuron (838 gene which expression is modulated). • Functions related to cytoskeleton organization, translation, ATP synthesis were activated. • Functions linked to transcription and protein degradation were altered. • Up-regulation of genes involved in energy production, protein synthesis and mitosis. • Catch-up growth phenomenon could allow the spats to compensate for slower growth. - Abstract: The Pacific oyster Crassostrea gigas is the main oyster species produced in the world, and a key coastal economic resource in France. High mortalities affect Pacific oysters since 2008 in France and Europe. Their origins have been attributed to a combination of biotic and abiotic factors, underlining the importance of environment quality. The impact of water pollution has been pointed out and one of the pollutants, the genotoxic herbicide diuron, occurs at high concentrations all along the French coasts. Previous work has revealed that a parental exposure to diuron had a strong impact on hatching rates and offspring development even if spats were not exposed to diuron themselves. In this study, we explored for the first time the transcriptional changes occurring in oyster spats (non exposed) originating from genitors exposed to an environmentally relevant concentration of diuron during gametogenesis using the RNAseq methodology. We identified a transcriptomic remodeling revealing an effect of the herbicide. Different molecular pathways involved in energy production, translation and cell proliferation are particularly disturbed. This analysis revealed modulated candidate genes putatively involved in response to oxidative stress and mitochondrial damage in offspring of genitors exposed to diuron. Complementary measures of the activity of enzymes involved in these latter processes corroborate the results obtained at the transcriptomic level. In addition, our results suggested an

  12. Aeromonas spp. isolated from oysters (Crassostrea rhizophorea from a natural oyster bed, Ceará, Brazil Aeromonas spp. isoladas de ostras (Crassostrea rhizophorea coletadas em um criadouro natural, Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Norma S. Evangelista-Barreto

    2006-06-01

    Full Text Available Between April and October 2002, thirty fortnightly collections of oysters (Crassostrea rhizophorea from a natural oyster bed at the Cocó River estuary in the Sabiaguaba region (Fortaleza, Ceará, Brazil were carried out, aiming to isolate Aeromonas spp. strains. Oyster samples were submitted to the direct plating (DP and the presence/absence (P/A methods. Aeromonas were identified in 15 (50% samples analyzed by the DP method and in 13 (43% analyzed by the P/A method. A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii and Aeromonas sp. were isolated. The predominant species was A. veronii (both biovars, which was identified in 13 (43% samples, followed by A. media in 11 (37% and A. caviae in seven (23%. From the 59 strains identified, 28 (48% presented resistance to at least one of the eight antibiotics tested.Foram realizadas 30 coletas quinzenais, entre abril e outubro de 2002, de ostras (Crassostrea rhizophorea de um criadouro natural, no estuário do rio Cocó (Fortaleza/Ceará/Brasil, objetivando-se isolar cepas de Aeromonas spp. As amostras de ostras foram submetidas aos métodos de plaqueamento direto (PD e presença/ausência (P/A. Foram identificadas Aeromonas em 15 (50% amostras analisadas pelo método PD e em 13 (43% pelo método P/A. Foram isoladas: A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii e Aeromonas sp. A espécie predominate foi A. veronii (ambos biovars, identificada em 13 (43% amostras, seguida de A. media em 11 (37% e A. caviae em 7 (23%. Das 59 cepas identificadas, 28 (48% apresentaram resistência a pelo menos um, dos oitos antibióticos testados.

  13. A 1-year investigation of the parasite Haplosporidium nelsoni (MSX) in the Pacific oyster Crassostrea gigas from Dayaowan Bay, China.

    Science.gov (United States)

    Wang, Zhongwei; Lu, Xin; Liang, Yubo

    2010-06-01

    The infection prevalence of the protozoan parasite Haplosporidium nelsoni (MSX) in Pacific oysters (Crassostrea gigas), collected from Dayaowan Bay on the north coast of the Yellow Sea, China, was investigated in 2007. The traditional histological method of diagnosing H. nelsoni infection in oysters was compared to that of polymerase chain reaction (PCR). Histology and the first PCR analysis detected infection in 21 (a total of 240 oysters) (8.75%) oysters, and the second PCR revealed infection in 26 oysters (10.83%). Only local or epithelial infections were found; no systemic infections were detected. Infection by H. nelsoni mostly occurred from April through October, and the monthly prevalence ranged from 5% to 25%, with a peak in August. These results suggest that the prevalence of the parasite is low in Dayaowan Bay. The prevalence of H. nelsoni is thought to be controlled in some way by temperature and salinity.

  14. Larvae of the Commercial Tropical Oyster Crassostrea belcheri (Sowerby) are induced to settle by Pheromones from the Adults

    DEFF Research Database (Denmark)

    Bussarawit, Somchai; Cedhagen, Tomas

    2012-01-01

    Pediveliger larvae of the commercial tropical oyster Crassostrea belcheri were allowed to settle under different conditions. Two types of seawater were used for the experiments: aged seawater (1 month) and aged seawater conditioned by the presence of adult oysters for 24 hours. Two groups of five...... other species within the same genus or from a different genus. Settling frequency was increased by the presence of living oysters together with soaked spatfall collectors in commercial aquaculture. The fact that larvae are induced to settle by pheromones released from the adults is an important...... mechanism that favours the gregariousness of the oysters in nature. Settling behaviour of oyster larvae was observed and the behaviour of the three main stages was described: free swimming searching stage, crawling stage and cementing stage....

  15. Nuclear microprobe and Raman investigation of the chemistry of the shell of the pacific oyster, Crassostrea gigas

    International Nuclear Information System (INIS)

    Markwitz, A.; Gauldie, R.W.; Pithie, J.; Sharma, S.K.; Jamieson, D.J.

    1999-01-01

    High-resolution nuclear microscopy was used to study the layered structure in the shell of the pacific oyster, Crassostrea gigas. In cross section, the layers appear as opaque white zones and clearer translucent zones. Raman spectroscopy indicates that the zones consist of alternating layers of the aragonite and calcite morphs of calcium carbonate, the mineral constituent of the shell. The chemistry of the shell varies from individual to individual but generally the predominant metal ion is Ca, with varying amounts of Si, Cl, Cr, Mn, Fe, Zn, Sb, Ni, Fe, As and Sr. Two dimensional maps of these major, minor and trace elements were measured in many shells with nuclear microscopy to identify the patterns of Zn and Sr deposition reflecting the calcite and aragonite layers. The significant difference in the patterns identified by ion beam analyses are possibly a result of isostructural exclusion of these metal ions between the different aragonite and calcite polymorphic forms of calcium carbonate. (author)

  16. Perkinsus beihaiensis infecting the oyster Crassostrea rhizophorae under cultivation and in natural stock in Camamu Bay, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Mariane dos Santos Aguiar Luz

    2016-07-01

    Full Text Available This study investigated the infection of Perkinsus beihaiensis (Perkinsozoa in the oyster Crassostrea rhizophorae, both from a long-line cultivation system and from a nearby intertidal zone of mangrove, both in the state of Bahia, northeastern Brazil. The collections were performed in October and November 2012, and in January 2013. The oysters (n = 300 were measured, examined macroscopically for signs of infection and then submitted to the following laboratory techniques: histology, Ray's fluid thioglycollate medium assay (RFTM, polymerase chain reaction (PCR and sequencing, which confirmed the identification of the pathogen. Histological and RFTM analyses showed, respectively, a mean prevalence of 93.3% and of 69%. The infection was usually mild or very mild. There was no significant difference (p > 0.05 between the environments in terms of infection prevalence or severity. This is the first record of P. beihaiensis in the state of Bahia and the second in oysters from Brazil and South America.

  17. Potencial cosechable de la Ostra Crassostrea rhizophorae (Guilding, en la ciénaga grande de Santa Marta, Colombia

    Directory of Open Access Journals (Sweden)

    Carlos A. Hernández J.

    1987-01-01

    Full Text Available The potencial standing crop of oyster Crassostrea rhizophorae has been calculated as 938,6 tons oyster meat per year (wet-weight for market sized oyster, in the northern zone of the Cienaga Grande de Santa Marta. It has been estimated that the oyster-bank area within this zones covers 3.000.000 sq.m. The calculated actual oyster standing crop for that area during this research (April-November 1982 was 3,9 tons of oyster-meat (wet-weight and the actual catch 2,0 tons (in the same period. This reduction in the actual standing crop of oyster is mainly the result of: 1. The low prolonged salinity and the sediment causes mass mortality on oyster population; 2. Deterioration of the quality and available amounts of supporting shell substratum, required by oyster seedling attach and growth until they reach comercial size.

  18. Influence of salinity on uptake rate and bioaccumulation of /sup 137/Cs in the oyster crassostrea glomerata

    International Nuclear Information System (INIS)

    Mashiatullah, A.; Qureshi, R.M.; Khan, S.; Chaghtai, F.; Akhter, P.; Jabbar, A.

    2008-01-01

    This paper describes results of experiment on bioaccumulation and uptake rate of radiocesium /sup 137/Cs from dissolved phase in the flesh of the Oysters (Crassostrea glomerata) collected off Karachi coast. A radiotracer experiment was conducted under laboratory conditions to determine the uptake rate and bioaccumulation of /sup 137/Cs from dissolved phase in the flesh of the Oyster. Oysters (size: 6-7 cm) were subjected to radiocesium activity of 24 Kilobecquerel per liter (kBq L/sup -1/) under three salinity Ievels (25, 30 and 35 ppt). The uptake of /sup 137/Cs was monitored for a period of seven days. The results showed that bioaccumulation and uptake of /sup 137/Cs in oysters were considerably dependent of salinity levels. Higher bioaccumulation factors and uptake rates were found at low salinity levels. (author)

  19. Aliphatic hydrocarbons and triterpane biomarkers in mangrove oyster (Crassostrea belcheri) from the west coast of Peninsular Malaysia.

    Science.gov (United States)

    Vaezzadeh, Vahab; Zakaria, Mohamad Pauzi; Bong, Chui Wei

    2017-11-15

    The Straits of Malacca is one of the world's busiest shipping routes where frequent oil spills occur. Rapid development in the west coast of Peninsular Malaysia is the other major source of petroleum pollution in this narrow waterway. In order to identify occurrence and origin of hydrocarbons in the Straits, mangrove oysters (Crassostrea belcheri) were collected from five sampling locations and analysed for n-alkanes and biomarkers. Soxhlet apparatus and two step column chromatography were used for extraction, purification and fractionation of the oysters. Petroleum origin n-alkanes were detected in majority of the sampling locations which is indicative of anthropogenic activities in this region. Using source and maturity diagnostic ratios for hopanes revealed used crankcase oil as the main source of petroleum hydrocarbons in oysters from all sampling locations except for the Pulau Merambong where signature of South East Asia crude oil (SEACO) was detected. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Evaluation of pollution in Camichin estuary (Mexico): pro-oxidant and antioxidant response in oyster (Crassostrea corteziensis).

    Science.gov (United States)

    Girón-Pérez, M I; Romero-Bañuelos, C A; Toledo-Ibarra, G A; Rojas-García, A E; Medina-Diaz, I M; Robledo-Marenco, M L; Vega-López, A

    2013-08-01

    The physiological system of molluscs, particularly pro-oxidant and antioxidant mechanisms, could be altered by pollutants and induce disturbance on health status and productive parameters of aquatic organisms, such as oyster. Therefore, the aim of this study was to evaluate the chemical contamination in water (total metals and polycyclic aromatic hydrocarbons) and oxidative stress parameters in oysters (Crassostrea corteziensis) in Camichin estuary, located in Mexican Tropical Pacific. The results obtained showed the presence of arsenic, lead and zinc, as well as naphthalene, pyrene and benzo[a]pyrene in concentrations relatively higher than criteria established by local and international guidelines. Regarding the biomarkers of oxidative stress response (H2O2 and O2 concentration, catalase activity, lipid peroxidation, and hydroperoxide concentration), differences between oyster from estuary and control group were significant. These results indicate that these pollutants could be related with oxidative stress detected in oyster. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Relationship between single nucleotide polymorphism of glycogen synthase gene of Pacific oyster Crassostrea gigas and its glycogen content

    Science.gov (United States)

    Liu, Siwei; Li, Qi; Yu, Hong; Kong, Lingfeng

    2017-02-01

    Glycogen is important not only for the energy supplementary of oysters, but also for human consumption. High glycogen content can improve the stress survival of oyster. A key enzyme in glycogenesis is glycogen synthase that is encoded by glycogen synthase gene GYS. In this study, the relationship between single nucleotide polymorphisms (SNPs) in coding regions of Crassostrea gigas GYS (Cg-GYS) and individual glycogen content was investigated with 321 individuals from five full-sib families. Single-strand conformation polymorphism (SSCP) procedure was combined with sequencing to confirm individual SNP genotypes of Cg-GYS. Least-square analysis of variance was performed to assess the relationship of variation in glycogen content of C. gigas with single SNP genotype and SNP haplotype. As a consequence, six SNPs were found in coding regions to be significantly associated with glycogen content ( P glycogen content ( P glycogen content and provided molecular biological information for the selective breeding of good quality traits of C. gigas.

  2. Viral gametocytic hypertrophy caused by a papova-like virus infection in the Pacific oyster Crassostrea gigas in Korea.

    Science.gov (United States)

    Choi, Dong Lim; Lee, Nam-Sil; Choi, Hee Jung; Park, Myoung-Ae; McGladdery, Sharon E; Park, Mi Seon

    2004-06-11

    During a routine survey of the Pacific oyster Crassostrea gigas in Tongyoung (previously Chungmu) on the southern coast of Korea, basophilic inclusions were observed in the gonadal tissues. They were detected from March to May at a prevalence rate of 3.3 to 7.1%. The inclusion bodies were Feulgen-positive and stained orange-red with phloxine tartrazine. Electron microscopic observation revealed non-enveloped, icosahedral particles 40 to 45 nm in diameter. These morphological characteristics resemble those of papova virus-like inclusions previously described from Pacific and eastern (American) oysters C. virginica in North America. Although many mitochondrial bodies and intact sperm cells were observed around the inclusion body, no host reaction, such as hemocytic infiltration, was detected.

  3. Developing tools for the study of molluscan immunity: The sequencing of the genome of the eastern oyster, Crassostrea virginica.

    Science.gov (United States)

    Gómez-Chiarri, Marta; Warren, Wesley C; Guo, Ximing; Proestou, Dina

    2015-09-01

    The eastern oyster, Crassostrea virginica, provides important ecological and economical services, making it the target of restoration projects and supporting a significant fishery/aquaculture industry with landings valued at more than $100 million in 2012 in the United States of America. Due to the impact of infectious diseases on wild, restored, and cultured populations, the eastern oyster has been the focus of studies on host-pathogen interactions and immunity, as well as the target of selective breeding efforts for disease resistant oyster lines. Despite these efforts, relatively little is known about the genetic basis of resistance to diseases or environmental stress, not only in eastern oyster, but also in other molluscan species of commercial interest worldwide. In order to develop tools and resources to assist in the elucidation of the genomic basis of traits of commercial, biological, and ecological interest in oysters, a team of genome and bioinformatics experts, in collaboration with the oyster research community, is sequencing, assembling, and annotating the first reference genome for the eastern oyster and producing an exhaustive transcriptome from a variety of oyster developmental stages and tissues in response to a diverse set of environmentally-relevant stimuli. These transcriptomes and reference genome for the eastern oyster, added to the already available genome and transcriptomes for the Pacific oyster (Crassostrea gigas) and other bivalve species, will be an essential resource for the discovery of candidate genes and markers associated with traits of commercial, biological, and ecologic importance in bivalve molluscs, including those related to host-pathogen interactions and immunity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Spatial genetic features of eastern oysters (Crassostrea virginica Gmelin) in the Gulf of Mexico: northward movement of a secondary contact zone

    OpenAIRE

    Anderson, Joel D; Karel, William J; Mace, Christopher E; Bartram, Brian L; Hare, Matthew P

    2014-01-01

    The eastern oyster (Crassostrea virginica Gmelin) is an economically and ecologically valuable marine bivalve occurring in the Gulf of Mexico. This study builds upon previous research that identified two divergent populations of eastern oysters in the western Gulf of Mexico. Allelic and genotypic patterns from 11 microsatellite markers were used to assess genetic structure and migration between the previously described oyster populations in Texas. The main findings are as follows: (1) there a...

  5. Bacteria of fecal origin in mangrove oysters (Crassostrea rhizophorae) in the Cocó River estuary, Ceará State, Brazil

    OpenAIRE

    Silva,Ana I.M.; Vieira,Regine H.S.F.; Menezes,Francisca G.R.; Fonteles-Filho,Antonio A.; Torres,Regina C.O.; Sant'Anna,Ernani S.

    2004-01-01

    This study was aimed at evaluating the microbiological quality of mangrove oysters (Crassostrea rhizophorae), collected at a natural oyster bed in the estuary of Cocó river (Fortaleza, Ceará, Brazil). MPN values were used for estimating the total (TC) and fecal (FC) coliforms and Enterococcus spp. TC and FC MPN values in the whole muscle and intervalve liquid ranged from 1,600/g and from

  6. Effects of chronic exposure to ionising radiation in the Pacific oyster Crassostrea gigas

    Energy Technology Data Exchange (ETDEWEB)

    Fievet, B.; Devos, A.; Voiseux, C.; Leconte-Pradines, C. [Institut de Radioprotection et de Surete' Nucleaire (France); Dallas, L.; Jha, A. [University of Plymouth (United Kingdom)

    2014-07-01

    The Cotentin peninsula (Normandy, France) hosts nuclear industry facilities which operate with controlled discharges of radionuclides in the marine environment. Compared to natural radioactivity, the increase by artificial radionuclides is small but constant. As a consequence, marine species are chronically exposed to low additional doses of ionizing radiation (IR). The effects of chronic exposure to radionuclides were investigated in early stages of development of the Japanese oyster Crassostrea gigas. On the basis of literature, mollusks are expected to be particularly resistant to acute IR (UNSCEAR, 1996. Sources and effects of ionizing radiation. Report to the General Assembly, with Scientific Annex. 86 p). Two different chronic exposure conditions consisted in external ({sup 137}Cs) and internal ({sup 241}Am) irradiation for two weeks. Biological endpoints were analyzed in parallel at both the integrated (growth) and molecular (target stress gene expression) levels. To identify potential biological targets of IR, oysters were first exposed to very high dose rates and radionuclide activities with the perspective to reduce the levels and to derive dose-response curves. Although the initial exposure levels ({sup 137}Cs 30 000 μGy.h{sup -1}; {sup 241}Am 57 000 Bq.L{sup -1}) were many orders of magnitude higher than those encountered in the natural environment, no significant change in the measured parameters was observed. This result was surprising because data from the literature showed that exposure of mussel Mytilus edulis to {sup 3}H at lower doses rates (10-100 μGy.h{sup -1}) induced DNA damage in hemocytes (Jha et al., 2005. Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 586, 47-57). To understand this apparent discrepancy between those two filtering bivalves, a new experiment was performed to compare the response

  7. Bioaccumulation of arsenic and other heavy metals in the oyster crassostrea virginica: a radiotracer study

    International Nuclear Information System (INIS)

    Gomez Batista, M.; Alonso Hernandez, M. C.; Metian, A.; Buschiazzo, E.; Teyssie, J. L.; Cotret, O.; Fowler, S.W.; Warnau, M.

    2006-01-01

    Cienfuegos Bay, situated in the Southern part of Cuba, is a semi enclosed bay of important as natural resource for the country, due to industrial and artesian fishing activities, maritime transport, tourism industry and natural parks. During the last decade important economic and social development, around the bay has resulted in a significant increase in inputs of industrial and domestic wastes to its waters. Regarding arsenic, direct input occurred through the Nitrogen Fertilizer Factory, which was operating until 1989 and where two important accidental spills took place, in 1979 and 2001. Therefore, understanding the behaviour and fate of As in this region is of prime importance in order to be able to develop coastal zone monitoring programs and improve local marine resource protection and management. The objective of this work was to investigate the bioaccumulation behaviour of As and other co occurring metals in the edible oyster Crassostrea virginica, a specie that is abundant, widely distributed in the bay, and frequently eaten by local populations. Seven different metals (As, Ag, Cr, Co, Cd, Mn and Zn) were considered and their bioconcentration was studied using γ emitting radiotracers ( 73 As, 110m Ag, 51 Cr, 57 Co, 109 Cd, 54 Mn and 65 Zn). The organisms were exposed for 14 d to background concentrations of the seven metals via seawater and then held for 21 d under non contaminated conditions. During these periods, uptake and loss kinetics of the metal radiotracers were determined in whole body individuals. In addition, tissue distribution of the metals was determined at the end of both exposure and depuration periods. In another experiment, C. virginica was exposed to four increasing concentrations of As dissolved in seawater in order to determine possible differences in As bioaccumulation according to ambient contamination level. Uptake kinetics were expressed as the variation of the concentration factor (CF, ratio between radioactivity in the organism

  8. Health assessment of the oyster Crassostrea rhizophorae on the southern coast of Bahia, northeastern Brazil Avaliação da saúde da ostra Crassostrea rhizophorae no Litoral Sul da Bahia, nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Rosana Pinho Brandão

    Full Text Available This study investigated the health of natural stocks of the oyster Crassostrea rhizophorae on the southern coast of Bahia in northeastern Brazil, during summer and winter 2010, at three localities (sampling points in the estuaries of the Maraú (Camamu Bay and Graciosa rivers. A total of 180 oysters (30/sampling point/season were examined macroscopically for the presence of pathogens and anatomical changes. The specimens were subsequently fixed in Davidson solution, processed for paraffin embedding, sectioned and stained with Harris' hematoxylin and eosin. Histological analysis revealed the presence of Rickettsia-like organisms (RLOs, Ancistrocoma, Trichodina, Sphenophrya, Nematopsis, Urastoma, Bucephalus in the sporocyst phase, a nonspecific metacercaria, and a metacestode of genus Tylocephalum. The prevalence of infection was low except for parasitism by Nematopsis sp. which also caused histopathological changes. The presence of Bucephalus sp. caused parasitic castration. These two pathogens significantly affect the health of C. rhizophorae.Este estudo investigou a saúde de ostras da espécie Crassostrea rhizophorae de estoques naturais do Litoral Sul do Estado da Bahia, Nordeste do Brasil, durante o verão e o inverno de 2010, em três pontos amostrais distribuídos nos estuários dos rios Maraú (Baía de Camamu e Graciosa. Um total de 180 ostras (30/ponto amostral/período foram examinadas macroscopicamente para a presença de patógenos e alterações anatômicas e posteriormente fixadas em solução de Davidson, processadas para inclusão em parafina, seccionadas e coradas com hematoxilina de Harris e eosina. A análise histológica evidenciou a presença de organismos com características similares a Rickettsia (RLOs, Ancistrocoma, Trichodina, Sphenophrya, Nematopsis, Urastoma, Bucephalus em fase esporocística, metacercária inespecífica e metacestóide de Tylocephalum. As prevalências de infecção foram baixas, com exceção do

  9. Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster (Crassostrea gigas) and culture broth under different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Pil-Mun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Park, Jae Seok [Korea Food and Drug Administration, Seoul 122-704 (Korea, Republic of); Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Baek, Min [Atomic Energy Policy Division, Ministry of Education, Science and Technology, Gwacheon 427-715 (Korea, Republic of); Chung, Young-Jin [Department of Food and Nutrition, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster (Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D{sub 10} value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

  10. Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster (Crassostrea gigas) and culture broth under different conditions

    International Nuclear Information System (INIS)

    Jung, Pil-Mun; Park, Jae Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Baek, Min; Chung, Young-Jin; Lee, Ju-Woon

    2009-01-01

    Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster (Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D 10 value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

  11. Assessment of bioavailability of weathered oil residues using caged bivalves (Crassostrea gigas and Mytilus edulis) as indicator organisms

    International Nuclear Information System (INIS)

    Bleczinski, C.F.; Costa, H.J.; Rigatti, M.J.; Wong, M.C.; Boehm, P.D.

    1993-01-01

    In April 1988, an estimated 400,000 gallons of San Joaquin Valley crude oil spilled into Peyton Slough and subsequently into Suisun Bay from an oil refinery in Martinez, California. The crude oil initially impacted a number of ecologically sensitive environments including estuarine water, marsh grasses, marsh and shoreline sediment, and intertidal sediment. A four-year oil weathering study was performed to determine the concentrations of environmentally important compounds in the stranded oil, to monitor changes in these concentrations over time, and to assess the potential long-term impact of the spilled oil in these various environments. As a result of marked differences in the rate of weathering at the different sites, a bioaccumulation component was added to the original study design in order to assess the bioavailability of crude oil residues remaining four-years post spill. Caged bivalves (Crassostrea gigas and Mytilus edulis) were deployed at the three study sites as sentinel organisms and exposed for three months. Sediments and organism tissues were analyzed using gas chromatography/mass spectrometry for polynuclear aromatic hydrocarbon (PAH) assemblages characteristics of the spilled oil. Advanced hydrocarbon fingerprinting techniques (e.g., double ratio plots of characteristic alkyl PAHs) were used to match distributions in the organisms and in the study site sediments

  12. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster (Crassostrea belcheri) in Thailand

    International Nuclear Information System (INIS)

    Thupila, Nunticha; Ratana-arporn, Pattama; Wilaipun, Pongtep

    2011-01-01

    In Thailand, white scar oyster (Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses (D 10 ) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D 10 values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10 5 CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  13. Assessment of sediment contamination by spermiotoxicity and embryotoxicity bioassays with sea urchins (Paracentrotus lividus) and oysters (Crassostrea gigas).

    Science.gov (United States)

    Geffard, O; Budzinski, H; Augagneur, S; Seaman, M N; His, E

    2001-07-01

    Gametes (sperm) and fertilized eggs (embryos) of the Mediterranean sea urchin, Paracentrotus lividus, and the Japanese oyster, Crassostrea gigas, were used to investigate the toxicity of two marine sediments, one polluted by polycyclic aromatic hydrocarbons (PAH) and the other by heavy metals. The sediment samples were freeze-dried for storage, and three different treatments were used for analysis: whole sediment, unfiltered elutriate, and filtered elutriate. The two sediments were toxic to sea urchin spermatozoa but not to oyster spermatozoa, and embryotoxicity was almost always the more sensitive endpoint for toxicity assessment. As a rule, whole sediment was more toxic than the elutriates by nearly two orders of magnitude. With respect to embryotoxicity, the whole sediments and the elutriates of the PAH-contaminated sediment were more toxic to oyster embryos, whereas the elutriates of the sediment polluted by heavy metals had stronger effects on sea urchin embryos. The results confirm that bioassays with Japanese oyster embryos provide a more sensitive appraisal of toxicity in the marine environment than bioassays with other developmental stages. As a whole, Mediterranean sea urchins and Japanese oysters were similar in overall sensitivity and are therefore both equally suited as bioassay organisms, but tests with oysters are more reproducible because of the better performance of the controls.

  14. Use of Competitive PCR to Detect and Quantify Haplosporidium nelsoni Infection (MSX disease) in the Eastern Oyster (Crassostrea virginica).

    Science.gov (United States)

    Day, J Michael; Franklin, Dean E.; Brown, Bonnie L.

    2000-09-01

    This study was undertaken to develop a quantitative polymerase chain reaction assay that would improve the utility of PCR for detecting Haplosporidium nelsoni (MSX), a serious parasite of the eastern oyster Crassostrea virginica. A competitive PCR sequence was generated from the H. nelsoni small subunit ribosomal DNA fragment, originally described by Stokes and colleagues, that was amplified by the same PCR primers and had similar amplification performance. Assays performed using competitor dilutions ranging from 0.05 to 500 pg/µl DNA were used to test oyster samples designated using histological techniques as having "light" or "heavy" MSX infections. Visual diagnoses were confirmed equally well with three methods: densitometry of ethidium-bromide-stained agarose, densitometry of SYBRGreen-stained polyacrylamide gels, and analysis by GeneScan 3.0 of fluorescent products detected in ultrathin gels. Oysters diagnosed as negative for MSX tested as negative or light by PCR. Oysters with light MSX infections generally had less than 5 pg/µl infectious DNA. Oysters with heavy infections generally corresponded to 5 pg/µl or greater competitor dilutions.

  15. Microflora in the Soft Tissue of the Pacific Oyster Crassostrea gigas Exposed to the Harmful Microalga Heterosigma akashiwo.

    Science.gov (United States)

    Takenaka, Shinkuro; Yoshikawa, Takeshi; Kadowaki, Shusaku; Okunishi, Suguru; Maeda, Hiroto

    2017-01-01

     A marine raphidophyte Heterosigma akashiwo is a causative agent of harmful microalgal blooms, which often cause the massive mortality of aquacultured finfish. In the present study, the Pacific oyster Crassostrea gigas was reared with H. akashiwo, and effect of the microalga on filter-feeding behavior and microflora of the gastrointestinal tract was investigated. The intake of the raphidophyte cells inhibited the molluscan filter-feeding activities, suggesting the negative physiological effect of the microalgal cell contents. However, the bivalves ingested the H. akashiwo cells to the same extent as the diatom Chaetoceros calcitrans, a non-harmful indicator to estimate the filtration rate, showing a continuation of their non-selective ingestion of the phytoplankton. Microflora of the oyster soft tissue was dominated by bacteria affiliated with the family Rhodobacteraceae, some of which are associated with microalgae. In addition, the Bacteroidetes species, in which algicidal bacteria are included, were also found in the bivalve individuals exposed to H. akashiwo. These results suggested that the ingested phytoplankton affected the microbial flora in the gastrointestinal tracts, some constituents of which helped the mollusc assimilate the ingested red tide phytoplankton. This study will provide beneficial information to clarify mechanisms by which the oyster evades the ichthyotoxicity of harmful microalgae and the participation of the intestinal microorganisms in these processes.

  16. Genetic variation assessed with microsatellites in mass selection lines of the Pacific oyster ( Crassostrea gigas) in China

    Science.gov (United States)

    Wang, Xubo; Li, Qi; Yu, Hong; Kong, Lingfeng

    2016-12-01

    Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding programs in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a relatively large number of broodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided important information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.

  17. Radiation sensitivity of poliovirus, a model for norovirus, inoculated in oyster ( Crassostrea gigas) and culture broth under different conditions

    Science.gov (United States)

    Jung, Pil-Mun; Park, Jae Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Baek, Min; Chung, Young-Jin; Lee, Ju-Woon

    2009-07-01

    Poliovirus is a recognized surrogate for norovirus, pathogen in water and food, due to the structural and genetic similarity. Although radiation sensitivity of poliovirus in water or media had been reported, there has been no research in food model such as shellfish. In this study, oyster ( Crassostrea gigas) was incubated in artificial seawater contaminated with poliovirus, and thus radiation sensitivity of poliovirus was determined in inoculated oyster. The effects of ionizing radiation on the sensitivity of poliovirus were also evaluated under different conditions such as pH (4-7) and salt concentration (1-15%) in culture broth, and temperature during irradiation. The D10 value of poliovirus in PBS buffer, virus culture broth and oyster was determined to 0.46, 2.84 and 2.94 kGy, respectively. The initial plaque forming unit (PFU) of poliovirus in culture broth was slightly decreased as the decrease of pH and the increase of salt concentration, but radiation sensitivity was not affected by pH and salt contents. However, radiation resistance of poliovirus was increased at frozen state. These results provide the basic information for the inactivation of pathogenic virus in foods by using irradiation.

  18. Rising water temperatures, reproduction and recruitment of an invasive oyster, Crassostrea gigas, on the French Atlantic coast.

    Science.gov (United States)

    Dutertre, Mickaël; Beninger, Peter G; Barillé, Laurent; Papin, Mathias; Haure, Joël

    2010-02-01

    The recent appearance and invasion of feral oysters (Crassostrea gigas) along the northern European Atlantic coast, underscores the necessity to investigate the relationship between environmental variables, reproductive physiology, larval development and recruitment. We studied these relationships at both high (HT) and intermediate (IT) - turbidity sites, through historical data on water temperatures, multi-parameter environmental probes, histological analyses, and field collections of planktonic larvae and settled post-larvae in 2005 and 2006. A progressive warming trend was observed, especially since 1995, when oyster proliferation first became severe. Threshold temperatures for oocyte growth, larval development and settlement were achieved in both 2005 and 2006. The HT site showed greater numbers of larvae and post-larvae than the IT site for both years, with the highest numbers of post-larvae observed at both sites during the warmer summer of 2006. These results suggest that increased temperatures in northern European waters allow successful reproduction, larval development, and recruitment of C. gigas. High turbidity conditions further enhance this success. 2009 Elsevier Ltd. All rights reserved.

  19. Isostructural exclusion of elements between aragonite and calcite layers in the shell of the Pacific oyster Crassostrea gigas

    International Nuclear Information System (INIS)

    Markwitz, A.; Gauldie, R.W.; Trompetter, W.J.; Pithie, J.; Jamieson, D.N.; Sharma, S.K.

    1999-01-01

    Sections of the shell of the farmed Pacific oyster 'Crassostrea gigas' that are available commercially in Wellington, New Zealand, showed a distinct alternating pattern in the shell mineral when observed by reflected light. The layers were identified by Raman scattering as alternating bands of the calcite and aragonite mineral forms of calcium carbonate using the micro-Raman facility at the Hawaii Institute of Geophysics and Planetology. The differences in the unit cell structure of calcite and aragonite favour different trace elements in the two minerals. Aragonite is isostructural with Strontianite SrCO 3 , and calcite is isostructural with Smithsonite ZnCO 3 . As a result, Sr deposition should be favoured in the aragonite layer and is excluded from the calcite layer; and, conversely, Zn deposition should be favoured in the calcite layer and is excluded from the aragonite layer. However, up to today, significant differences in the pattern of Sr and Zn in microprobe scans are not discovered. By ion microprobe analysis, it was shown that differences in the unit cell structure of calcite and aragonite favor different trace elements in the two minerals

  20. Are oysters being bored to death? Influence of Cliona celata on Crassostrea virginica condition, growth and survival.

    Science.gov (United States)

    Carroll, John M; O'Shaughnessy, Kathryn A; Diedrich, Grant A; Finelli, Christopher M

    2015-11-17

    The boring sponge Cliona celata is a nuisance species that can have deleterious effects on eastern oyster Crassostrea virginica growth, condition, and survival. Surprisingly, however, these effects have not been well documented and when examined, results have been equi-vocal. In this study, we provide a direct comparison of growth, condition, and survival of sponge-colonized and uncolonized oysters in southeast North Carolina in 2 separate experiments. In the first experiment, sponge-colonized oysters exhibited significantly slower growth rates, reduced condition, and lower survival relative to uncolonized oysters, although results may have been confounded by oyster source. In the second experiment, using smaller oysters from the same source population, growth rate was again significantly reduced in colonized oysters relative to uncolonized oysters, however neither condition nor survival differed. In field surveys of the same population, colonized individuals across a range of sizes demonstrated significantly reduced condition. Further, condition index was negatively correlated with sponge biomass, which was positively correlated with oyster size, suggesting that the impact of the sponge changes with ontogeny. By investigating clearance rates, tissue isotopic and nutrient content, as well as caloric value, this study provides further evidence that sponge presence causes the oysters to divert energy into costly shell maintenance and repair at the expense of shell and somatic growth. Thus, although variable, our results demonstrate negative impacts of sponge infestation on oyster demographics, particularly as oysters grow larger.

  1. Probing for heavy element impurities in the shell of the Pacific oyster, Crassostrea gigas, with nuclear microscopy

    International Nuclear Information System (INIS)

    Markwitz, A.; Barry, B.; Gauldie, R.W.; Roberts, R.D.

    2003-01-01

    Nuclear microscopy was performed on shells of the Pacific oyster, Crassostrea gigas, to probe for heavy element impurities. For the studies 14 shells from the Auckland and the Marlborough Sounds region were chosen. In sections, the shells appear as opaque with white and grey zones, which are related to alternating layers of calcite and aragonite. Raster scans with 2.5 MeV protons over the sections (scan area 5 x 5 mm) were used in the experiment to measure trace elements in the ppm region using proton induced X-ray spectroscopy. Two dimensional maps and line scans revealed the presence of bromine in all shells investigated. Bromine was found to be related with the pattern of calcium. Hot spots of iron proved to be a common feature in the shells as well. In some shells, copper and zinc were also measured in hot spots of a few micrometers in diameter. Spatially resolved results on the micrometer level indicate the usefulness of nuclear microscopy for the detection of heavy elements in shells of the Pacific oyster

  2. Microbiological quality and bacterial diversity of the tropical oyster Crassostrea rhizophorae in a monitored farming system and from natural stocks.

    Science.gov (United States)

    Silva Neta, M T; Maciel, B M; Lopes, A T S; Marques, E L S; Rezende, R P; Boehs, G

    2015-12-02

    Microbiological evaluation is one of the most important parameters for analyzing the viability of an oyster farming system, which addresses public health and ecological concerns. Here, the microbiological quality of the oyster Crassostrea rhizophorae cultivated in a monitored environment and from natural beds in Bahia, northeastern Brazil, was determined. Bacterial diversity in oysters was measured by polymerase chain reaction-denaturing gradient gel electrophoresis. Sequence analysis revealed that most bacterial species showed similarity with uncultured or unidentified bacteria from environmental samples, and were clustered into the phylum Proteobacteria. Diverse bacteria from cultivated (monitored) oyster samples were grouped in the same cluster with a high similarity index (above 79%). Microbiological analyses revealed that these oysters did not contain pathogens. These results reflect the natural balance of the microbial communities essential to the maintenance of health and in inhibiting pathogen colonization in the oyster. On the other hand, bacterial diversity of samples from native stocks in extractive areas displayed a similarity index varying between 55 and 77%, and all samples were clustered separately from each other and from the cluster of samples derived from the cultivation area. Microbiological analyses showed that oysters from the extractive area were not fit for human consumption. This reflected a different composition of the microbial community in this area, probably resulting from anthropic impact. Our study also demonstrated that low temperatures and high rainfall limits the bacterial concentration in tropical oysters. This is the first study analyzing the total bacterial community profiles of the oyster C. rhizophorae.

  3. Parasites in the mangrove oyster Crassostrea rhizophorae cultivated in the estuary of the Graciosa River in Taperoá, Bahia.

    Science.gov (United States)

    Cova, Aliane Watanabe; Serafim Júnior, Moacyr; Boehs, Guisla; Souza, Jackson Moreira de

    2015-01-01

    In this work, parasites associated with the mangrove oyster Crassostrea rhizophorae were studied at a cultivation unit in the estuary of the Graciosa River in Taperoá, Bahia. On a monthly basis, between April 2011 and March 2012, 20 oysters were collected, measured and fixed in 10% formaldehyde. In order to identify the parasites, routine histological techniques were used. The specimens were embedded in paraffin and sections, 7 µm thick, were cut. These were then stained with Harris hematoxylin and eosin and were examined using an optical microscope. The parameters analyzed to investigate water quality showed that the temperature ranged from 23.9 °C to 29.3 °C, water salinity from 0.4 to 24.2 Practical Salinity Units PSU and recorded rainfall from 80 mm to 406.4 mm/month. During the parasitological analyses, infestation of the polychaete Neanthes succinea was observed in 41% of the oysters. Through histological techniques, the following parasites were identified: colonies of Rickettsia-like organisms (RLOs); the protozoa Nematopsis sp. and Ancistrocoma sp.; the turbellarian Urastoma sp.; the metacestode Tylocephalum sp. and an unidentified tapeworm. The data collected showed that there was low-intensity infection with and prevalence of parasites, except for Nematopsis sp., thus attesting that these cultivated oysters were in a healthy condition.

  4. Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae).

    Science.gov (United States)

    Christo, S W; Absher, T M; Boehs, G

    2010-08-01

    In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM). Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.

  5. In situ distribution and characterization of the organic content of the oyster shell Crassostrea gigas (Mollusca, Bivalvia).

    Science.gov (United States)

    Dauphin, Yannicke; Ball, Alexander D; Castillo-Michel, Hiram; Chevallard, Corinne; Cuif, Jean-Pierre; Farre, Bastien; Pouvreau, Stéphane; Salomé, Murielle

    2013-01-01

    Cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". In order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. The left and right valves of the oyster shell Crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular. The shell layers of juvenile C. gigas are studied using a variety of highly spatially resolved techniques to establish their composition and structure. Our results confirm the presence of three different calcitic structural types. The role of the lenses of chalky layers is not yet deciplered. Despite a common mineralogy, the elemental composition of the layers differs. The sulphur aminoacids and sulphated polysaccharide contents of the intracrystalline and intercrystalline matrices differ, as well as those of the structural types. The possible different sensitivity of these structures to environmental changes is still unknown. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Microbiological quality of oysters (Crassostrea gigas produced and commercialized in the coastal region of Florianópolis - Brazil

    Directory of Open Access Journals (Sweden)

    Pereira Murilo Anderson

    2006-01-01

    Full Text Available Oysters are filter feeders able to ingest particles in suspension that may carry pathogenic microorganisms. In this respect, the consumption of raw oysters can cause foodborne diseases in humans. The aim of the present study was to evaluate the microbiological quality of Crassostrea gigas oysters cultivated and commercialized in the coastal region of Florianópolis, SC, Brazil. The study comprised counts of coliforms at 35ºC and at 45ºC, Escherichia coli and coagulase-positive staphylococci, and detection of Salmonella sp, Vibrio cholerae and Vibrio parahaemolyticus. Ninety samples were analyzed, 45 of them collected at seafood commercial establishments and the other 45 were collected in the cultivation area. All analyses were performed according to methods of the American Public Health Association. Vibrio cholerae, V. parahaemolyticus and Salmonella sp. were not detected in any of the samples. Coagulase-positive staphylococci were observed in only one sample (80 CFU/g. The counts of coliforms at 35 and 45ºC indicated that samples obtained from both the cultivation area and place of sale were contaminated. E. coli was detected in 4 (9% samples collected in the cultivation area and in 16 (35.5% samples obtained from commercial establishments. These results indicate the need for monitoring the quality of raw oysters, including the implantation of programs for good mollusk manipulation and management practices.

  7. Molecular Cloning and Characterization of Full-Length cDNA of Calmodulin Gene from Pacific Oyster Crassostrea gigas.

    Science.gov (United States)

    Li, Xing-Xia; Yu, Wen-Chao; Cai, Zhong-Qiang; He, Cheng; Wei, Na; Wang, Xiao-Tong; Yue, Xi-Qing

    2016-01-01

    The shell of the pearl oyster ( Pinctada fucata ) mainly comprises aragonite whereas that of the Pacific oyster ( Crassostrea gigas ) is mainly calcite, thereby suggesting the different mechanisms of shell formation between above two mollusks. Calmodulin (CaM) is an important gene for regulating the uptake, transport, and secretion of calcium during the process of shell formation in pearl oyster. It is interesting to characterize the CaM in oysters, which could facilitate the understanding of the different shell formation mechanisms among mollusks. We cloned the full-length cDNA of Pacific oyster CaM (cgCaM) and found that the cgCaM ORF encoded a peptide of 113 amino acids containing three EF-hand calcium-binding domains, its expression level was highest in the mantle, hinting that the cgCaM gene is probably involved in shell formation of Pacific oyster, and the common ancestor of Gastropoda and Bivalvia may possess at least three CaM genes. We also found that the numbers of some EF hand family members in highly calcified species were higher than those in lowly calcified species and the numbers of these motifs in oyster genome were the highest among the mollusk species with whole genome sequence, further hinting the correlation between CaM and biomineralization.

  8. Molecular Cloning and Characterization of Full-Length cDNA of Calmodulin Gene from Pacific Oyster Crassostrea gigas

    Directory of Open Access Journals (Sweden)

    Xing-Xia Li

    2016-01-01

    Full Text Available The shell of the pearl oyster (Pinctada fucata mainly comprises aragonite whereas that of the Pacific oyster (Crassostrea gigas is mainly calcite, thereby suggesting the different mechanisms of shell formation between above two mollusks. Calmodulin (CaM is an important gene for regulating the uptake, transport, and secretion of calcium during the process of shell formation in pearl oyster. It is interesting to characterize the CaM in oysters, which could facilitate the understanding of the different shell formation mechanisms among mollusks. We cloned the full-length cDNA of Pacific oyster CaM (cgCaM and found that the cgCaM ORF encoded a peptide of 113 amino acids containing three EF-hand calcium-binding domains, its expression level was highest in the mantle, hinting that the cgCaM gene is probably involved in shell formation of Pacific oyster, and the common ancestor of Gastropoda and Bivalvia may possess at least three CaM genes. We also found that the numbers of some EF hand family members in highly calcified species were higher than those in lowly calcified species and the numbers of these motifs in oyster genome were the highest among the mollusk species with whole genome sequence, further hinting the correlation between CaM and biomineralization.

  9. Identification two novel nacrein-like proteins involved in the shell formation of the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Song, Xiaorui; Wang, Xiaotong; Li, Li; Zhang, Guofan

    2014-07-01

    Nacrein-like proteins have carbonic anhydrase (CA)-like domains, but their coding regions are flanked by inserted repeat sequence, such as Gly-X-Asn. Reportedly, nacrein-like proteins show the highest similarity to human carbonic anhydrase 1(α-CA1), possess CA catalytic functions, and play a key role in shell biomineralization. In the present study, two novel nacrein-like proteins were firstly identified from the shell-forming mantle of the Pacific oyster Crassostrea gigas. With numerous analyses, it was identified and characterized that both the nacrein-like proteins F1 and F2 were secreted and most closely related to the nacrein-like protein of California mussel Mytilus californianus via phylogenetic analysis. RT-PCR analysis showed that the nacrein-like proteins F1 and F2 were expressed in multiple tissues and the expression levels remarkably rose after entering the spat stage, which were basically consistent with the increase of calcite fractions in the total shell volume. Surprisingly, the Gly-X-Asn repeat domain, which is distinctive in most nacrein-like proteins, was absent in the two newly identified nacrein-like proteins in C. gigas and replaced with a series of acidic amino acids (D/E). Regardless, nacrein-like proteins in mollusks seem to be vital to the deposition of calcium carbonate and likely perform diverse functions.

  10. Gonad Transcriptome Analysis of the Pacific Oyster Crassostrea gigas Identifies Potential Genes Regulating the Sex Determination and Differentiation Process.

    Science.gov (United States)

    Yue, Chenyang; Li, Qi; Yu, Hong

    2018-04-01

    The Pacific oyster Crassostrea gigas is a commercially important bivalve in aquaculture worldwide. C. gigas has a fascinating sexual reproduction system consisting of dioecism, sex change, and occasional hermaphroditism, while knowledge of the molecular mechanisms of sex determination and differentiation is still limited. In this study, the transcriptomes of male and female gonads at different gametogenesis stages were characterized by RNA-seq. Hierarchical clustering based on genes differentially expressed revealed that 1269 genes were expressed specifically in female gonads and 817 genes were expressed increasingly over the course of spermatogenesis. Besides, we identified two and one gene modules related to female and male gonad development, respectively, using weighted gene correlation network analysis (WGCNA). Interestingly, GO and KEGG enrichment analysis showed that neurotransmitter-related terms were significantly enriched in genes related to ovary development, suggesting that the neurotransmitters were likely to regulate female sex differentiation. In addition, two hub genes related to testis development, lncRNA LOC105321313 and Cg-Sh3kbp1, and one hub gene related to ovary development, Cg-Malrd1-like, were firstly investigated. This study points out the role of neurotransmitter and non-coding RNA regulation during gonad development and produces lists of novel relevant candidate genes for further studies. All of these provided valuable information to understand the molecular mechanisms of C. gigas sex determination and differentiation.

  11. First record of parasitism in the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae at Jaguaribe River estuary - Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    RC Sabry

    Full Text Available Mangrove oysters Crassostrea rhizophorae were sampled monthly in the estuary of Jaguaribe River, on the east coast of Ceará State, Brazil, between August, 2000 and December, 2001, making up 170 individuals. The water temperature varied from 26 to 30 °C and salinity from 21 to 42‰. The animals' size ranged from 3.4 to 7.2 cm height. Macroscopical and histopathological analyses were carried out in the oysters' tissues. The histological exams showed protozoans and metazoans of genera Nematopsis and Tylocephalum, respectively. Nematopsis prevalence varied from 60 to 100% and it was higher in the gills and mantle. The oocysts presented a mean size of 11.5 µm (±1.32 length and 9.1 µm (±1.06 width (n = 30, up to 3 oocysts/phagocyte having been observed. Several animals presented focal hemocitical reaction. The percentage of Tylocephalum was 1.7%. In spite of the high infection prevalence by Nematopsis, infected animals did not have their reproductive cycle impaired.

  12. Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae

    Directory of Open Access Journals (Sweden)

    SW. Christo

    Full Text Available In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM. Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.

  13. Parasites in the mangrove oyster Crassostrea rhizophorae cultivated in the estuary of the Graciosa River in Taperoá, Bahia

    Directory of Open Access Journals (Sweden)

    Aliane Watanabe Cova

    Full Text Available In this work, parasites associated with the mangrove oyster Crassostrea rhizophorae were studied at a cultivation unit in the estuary of the Graciosa River in Taperoá, Bahia. On a monthly basis, between April 2011 and March 2012, 20 oysters were collected, measured and fixed in 10% formaldehyde. In order to identify the parasites, routine histological techniques were used. The specimens were embedded in paraffin and sections, 7 µm thick, were cut. These were then stained with Harris hematoxylin and eosin and were examined using an optical microscope. The parameters analyzed to investigate water quality showed that the temperature ranged from 23.9 °C to 29.3 °C, water salinity from 0.4 to 24.2 Practical Salinity Units PSU and recorded rainfall from 80 mm to 406.4 mm/month. During the parasitological analyses, infestation of the polychaete Neanthes succinea was observed in 41% of the oysters. Through histological techniques, the following parasites were identified: colonies of Rickettsia-like organisms (RLOs; the protozoa Nematopsis sp. and Ancistrocoma sp.; the turbellarian Urastoma sp.; the metacestode Tylocephalum sp. and an unidentified tapeworm. The data collected showed that there was low-intensity infection with and prevalence of parasites, except for Nematopsis sp., thus attesting that these cultivated oysters were in a healthy condition.

  14. Experimental infection of Pacific oyster Crassostrea gigas spat by ostreid herpesvirus 1: demonstration of oyster spat susceptibility

    Directory of Open Access Journals (Sweden)

    Schikorski David

    2011-02-01

    Full Text Available Abstract In 2008 and 2009, acute mortalities occurred in France among Pacific cupped oyster, Crassostrea gigas, spat. Different hypothesis including the implication of environmental factors, toxic algae and/or pathogens have been explored. Diagnostic tests indicated that OsHV-1 including a particular genotype, termed OsHV-1 μVar, was detected in most of samples and especially in moribund oysters with the highlighting of virus particles looking like herpes viruses by TEM examination. In this study, an experimental protocol to reproduce OsHV-1 infection in laboratory conditions was developed. This protocol was based on the intramuscular injection of filtered (0.22 μm tissue homogenates prepared from naturally OsHV-1 infected spat collected on French coasts during mortality outbreaks in 2008. Results of the experimental trials showed that mortalities were induced after injection. Moreover, filtered tissue homogenates induced mortalities whereas the same tissue homogenates exposed to an ultraviolet (UV treatment did not induce any mortality suggesting that oyster spat mortalities require the presence of a UV sensitive agent. Furthermore, analysis of injected oyster spat revealed the detection of high amounts of OsHV-1 DNA by real-time quantitative PCR. Finally, TEM analysis demonstrated the presence of herpes virus particles. The developed protocol allowed to maintain sources of infective virus which can be useful for the development of further studies concerning the transmission and the development of OsHV-1 infection.

  15. Pacific oyster (Crassostrea gigas) hemocyte are not affected by a mixture of pesticides in short-term in vitro assays.

    Science.gov (United States)

    Moreau, Pierrick; Burgeot, Thierry; Renault, Tristan

    2014-04-01

    Pesticides are frequently detected in estuaries among the pollutants found in estuarine and coastal areas and may have major ecological consequences. They could endanger organism growth, reproduction, or survival. In the context of high-mortality outbreaks affecting Pacific oysters, Crassostrea gigas, in France since 2008, it appears of importance to determine the putative effects of pesticides on oyster susceptibility to infectious agents. Massive mortality outbreaks reported in this species, mainly in spring and summer, may suggest an important role played by the seasonal use of pesticides and freshwater input in estuarine areas where oyster farms are frequently located. To understand the impact of some pesticides detected in French waters, their effects on Pacific oyster hemocytes were studied through short-term in vitro experiments. Bivalve immunity is mainly supported by hemocytes eliminating pathogens by phagocytosis and producing compounds including lysosomal enzymes and antimicrobial molecules. In this study, oyster hemocytes were incubated with a mixture of 14 pesticides and metaldehyde alone, a molecule used to eliminate land mollusks. Hemocyte parameters including dead/alive cells, nonspecific esterase activities, intracytoplasmic calcium, lysosome number and activity, and phagocytosis were monitored by flow cytometry. No significant effect of pesticides tested at different concentrations was reported on oyster hemocytes maintained in vitro for short-term periods in the present study. It could be assumed that these oyster cells were resistant to pesticide exposure in tested conditions and developing in vivo assays appears as necessary to better understand the effects of pollutants on immune system in mollusks.

  16. The Kinome of Pacific Oyster Crassostrea gigas, Its Expression during Development and in Response to Environmental Factors.

    Directory of Open Access Journals (Sweden)

    Yanouk Epelboin

    Full Text Available Oysters play an important role in estuarine and coastal marine habitats, where the majority of humans live. In these ecosystems, environmental degradation is substantial, and oysters must cope with highly dynamic and stressful environmental constraints during their lives in the intertidal zone. The availability of the genome sequence of the Pacific oyster Crassostrea gigas represents a unique opportunity for a comprehensive assessment of the signal transduction pathways that the species has developed to deal with this unique habitat. We performed an in silico analysis to identify, annotate and classify protein kinases in C. gigas, according to their kinase domain taxonomy classification, and compared with kinome already described in other animal species. The C. gigas kinome consists of 371 protein kinases, making it closely related to the sea urchin kinome, which has 353 protein kinases. The absence of gene redundancy in some groups of the C. gigas kinome may simplify functional studies of protein kinases. Through data mining of transcriptomes in C. gigas, we identified part of the kinome which may be central during development and may play a role in response to various environmental factors. Overall, this work contributes to a better understanding of key sensing pathways that may be central for adaptation to a highly dynamic marine environment.

  17. The enkephalinergic nervous system and its immunomodulation on the developing immune system during the ontogenesis of oyster Crassostrea gigas.

    Science.gov (United States)

    Liu, Zhaoqun; Zhou, Zhi; Wang, Lingling; Song, Xiaorui; Chen, Hao; Wang, Weilin; Liu, Rui; Wang, Mengqiang; Wang, Hao; Song, Linsheng

    2015-08-01

    Enkephalinergic neuroendocrine-immune regulatory system is one of the most important neuroendocrine-immune systems in both vertebrates and invertebrates for its significant role in the immune regulation. In the present study, the early onset of enkephalinergic nervous system and its immunomodulation on the developing immune system during the ontogenesis of oyster Crassostrea gigas were investigated to illustrate the function of neural regulation on the innate immune system in oyster larvae. [Met(5)]-enkephalin (Met-ENK) was firstly observed on the marginal of the dorsal half of D-hinged larvae. Six immune-related molecules, including four PRRs (CgCTL-1, CgCTL-2, CgCTL-4, CgNatterin-3) and two immune effectors (CgTNF-1 and CgEcSOD) were detected in the early developmental stages of trochophore, D-hinged and umbo larvae of oyster. After incubated with [Met(5)]-enkephalin, the mRNA expression level of all the PRRs changed significantly (p immune effectors were up-regulated significantly at 3 h and 6 h in trochophore larvae (p system of oyster was firstly appeared in D-hinged larvae, while the primitive immune defense system existed in the region of prototroch in trochophore larvae and developed maturely after D-hinged larvae. The developing immune system could be regulated by the neurotransmitter [Met(5)]-enkephalin released by the neuroendocrine system in oyster C. gigas. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Temperature Effect Study on Growth and Survival of Pathogenic Vibrio parahaemolyticus in Jinjiang Oyster (Crassostrea rivularis with Rapid Count Method

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    Yuan Wang

    2018-01-01

    Full Text Available The growth of Vibrio parahaemolyticus (V. parahaemolyticus in oysters during postharvest storage increases the possibility of its infection in humans. In this work, to investigate the growth or survival profiles in different media, pathogenic V. parahaemolyticus in APW, Jinjiang oyster (JO, Crassostrea rivularis slurry, and live JO were studied under different temperatures. All the strain populations were counted through our double-layer agar plate (DLAP method. In APW, the pathogenic V. parahaemolyticus showed continuous growth under 15, 25, and 35°C, while a decline in behavior was displayed under 5°C. The similar survival trend of pathogenic V. parahaemolyticus in JO slurry and live JO was observed under 5, 25, and 35°C, except the delayed growth or decline profile compared to APW. Under 15°C, they displayed decline and growth profile in JO slurry and live JO, respectively. These results indicate the different sensitivity of pathogenic V. parahaemolyticus in these matrices to temperature variation. Furthermore, nonpathogenic V. parahaemolyticus displayed little difference in survival profiles when inoculated in live JO under corresponding temperatures. The results indicate that inhibition or promotion effect could be regulated under different storage temperature for both pathogenic and nonpathogenic strains. Besides, the DLAP method showed the obvious quickness and efficiency during the bacteria count.

  19. Effects of air-exposure gradients on spatial infection patterns of Perkinsus marinus in the eastern oyster Crassostrea virginica.

    Science.gov (United States)

    Malek, Jennafer C; Breitburg, Denise L

    2016-02-25

    Spatial distributions of species can be shaped by factors such as parasites, mortality, and reproduction, all of which may be influenced by differences in physical factors along environmental gradients. In nearshore tidal waters, an elevational gradient in aerial exposure during low tide can shape the spatial distributions of benthic marine organisms. The eastern oyster Crassostrea virginica is an ecologically and economically important species that can dominate both subtidal and intertidal habitats along the east coast of the USA. Our goal was to determine whether prevalence and intensity of Perkinsus marinus (the causative agent of Dermo disease) infections vary along intertidal to subtidal gradients during summer. We used (1) field experiments conducted at 4 sites in the Chesapeake Bay and a Virginia coastal bay, (2) a controlled air-exposure experiment, and (3) field surveys from 7 sites ranging from Maine to North Carolina to test for effects of tidal exposure on infection. Results from our field surveys suggested that high intertidal oysters tend to have higher infection prevalence than subtidal oysters, but there was no effect on infection intensity. Field experiments rarely yielded significant effects of tidal exposure on infection prevalence and intensity. Overall, our study shows that exposure to air may not be a strong driver of infection patterns in this host-parasite system.

  20. Effect of linear alkylbenzene mixtures and sanitary sewage in biochemical and molecular responses in pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Flores-Nunes, Fabrício; Mattos, Jacó J; Zacchi, Flávia L; Serrano, Miguel A S; Piazza, Clei E; Sasaki, Silvio T; Taniguchi, Satie; Bicego, Márcia C; Melo, Cláudio M R; Bainy, Afonso C D

    2015-11-01

    Urban effluents are rich in nutrients, organic matter, pharmaceuticals and personal care products (PPCPs), pesticides, hydrocarbons, surfactants, and others. Previous studies have shown that oysters Crassostrea gigas accumulate significant levels of linear alkylbenzenes (LABs) in sanitary sewage contaminated sites, but there is little information about its toxicological effects in marine bivalves. The aim of this study was to analyze the transcription of genes in two tissues of C. gigas exposed for 12, 24, and 36 h to LABs or sanitary sewage. Likewise, the activity of antioxidant and biotransformation enzymes was measured in oysters exposed for 36 h in all groups. Oysters exposed to LABs and oysters exposed to sanitary sewage showed different patterns of transcriptional responses. LAB-exposed oysters showed lower level of biological responses than the oysters exposed to sanitary sewage. Despite the ability of the oyster C. gigas to accumulate LABs (28-fold), the data indicate that these contaminants are not the cause for the transcriptional responses observed in oysters exposed to sanitary sewage. Possibly, the biological changes observed in the sanitary sewage-exposed oysters are associated with the presence of other contaminants, which might have caused synergistic, additive, or antagonistic effects. The results show that FABP-like and GST-ω-like messenger RNAs (mRNAs) have a rapid response in tissues of oyster C. gigas exposed to sanitary sewage, suggesting a possible protective response and a role in maintaining homeostasis of these organisms.

  1. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster ( Crassostrea belcheri) in Thailand

    Science.gov (United States)

    Thupila, Nunticha; Ratana-arporn, Pattama; Wilaipun, Pongtep

    2011-07-01

    In Thailand, white scar oyster ( Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses ( D10) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D10 values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10 5 CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  2. Biodisponibilidade de zinco de ostras (Crassostrea gigas cultivadas em fl orianópolis / SC
    bioavailability of oysters (crassostrea gigas cultivated in Florianopólis / SC

    Directory of Open Access Journals (Sweden)

    R. CAETANO

    2010-05-01

    Full Text Available

    O objetivo deste trabalho foi avaliar a biodisponibilidade do zinco presente nas ostras Crassostrea gigas cultivadas na região de Florianópolis, SC em ratas adultas (Rattus norvegicus, pois nessa região as ostras são fontes de zinco biodisponível. Foi realizado ensaio biológico durante 49 dias, sendo que os 24 animais foram distribuídos em três grupos: G1: dieta controle (AIN-93M, G2: dieta isenta de zinco (AIN-93M modifi cada; G3: dieta isenta de zinco e acrescida de ostras. Ao fi nal do experimento foram coletados os fêmures dos animais para análise do teor de zinco, por espectrofotometria de absorção atômica. As ostras in natura apresentaram 4,38mg% de zinco. Quanto ao teor de zinco no fêmur, os grupos G1 (246,62 ± 9,97μg Zn/g osso e G3 (221,41 ± 15,80 μg apresentaram elevadas concentrações (p < 0,05 quando comparados ao grupo G0 (155,0 ± 32,80 μg e G2 (110,12 ± 32,88 μg.

  3. The effects of x-ray treatments on bioaccumulated murine norovirus-1 (MNV-1) and survivability, inherent microbiota, color, and firmness of Atlantic oysters (Crassostrea virginica) during storage at 5°C for 20 days

    Science.gov (United States)

    In this study, we investigated the inactivation of human norovirus (HuNoV) surrogate Murine norovirus (MNV-1) by X-ray in whole-shell Atlantic oysters (Crassostrea virginica). We also investigated the effects of X-ray treatments on the survivability, inherent microbiota, color, and firmness of treat...

  4. Seasonal variation in mitochondrial responses to cadmium and temperature in eastern oysters Crassostrea virginica (Gmelin) from different latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Cherkasov, A.S. [Department of Biology, University of North Carolina at Charlotte, Charlotte, NC (United States); Taylor, C. [Department of Biology, University of North Carolina at Charlotte, Charlotte, NC (United States); Johnson C. Smith University, 100 Beatties Ford Rd., Charlotte, NC 28216 (United States); Sokolova, I.M., E-mail: isokolov@uncc.edu [Department of Biology, University of North Carolina at Charlotte, Charlotte, NC (United States)

    2010-04-01

    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 seasonal variability of mitochondrial responses to elevated temperatures and Cd stress in eastern oysters Crassostrea virginica from populations adapted to different thermal regimes (subtropical Texas (TX), warm temperate North Carolina (NC) and cold temperate Washington (WA) areas). Seasonality had a strong effect on mitochondrial function in oysters from the two studied southern populations (TX and NC) but not in their northern (WA) counterparts, with decreased mitochondrial abundance and increased rates of mitochondrial proton leak in gill tissues of TX and NC oysters in summer. Compared to WA oysters, oysters from the two southern populations accumulated Cd faster in their tissues, and their mitochondria were more sensitive to Cd inhibition in resting and ADP-stimulated states at 20 and 28 {sup o}C. At 12 {sup o}C, inter-populational differences in Cd accumulation rates and sensitivity of mitochondrial respiration to Cd were not significant. Within each of the three studied populations, sensitivity of mitochondrial ADP-stimulated respiration to Cd inhibition increased with increasing temperatures (28 > 20 > 12 {sup o}C). This indicates that oysters from the two southern sites may be more vulnerable to Cd toxicity due to exposure to high environmental temperatures in summer, elevated rates of Cd accumulation and high intrinsic sensitivity of their mitochondria to Cd. This study suggests that data on sensitivity to pollutants obtained for one population of oysters should be

  5. Human norovirus RNA persists in seawater under simulated winter conditions but does not bioaccumulate efficiently in Pacific Oysters (Crassostrea gigas).

    Science.gov (United States)

    Dancer, D; Rangdale, R E; Lowther, J A; Lees, D N

    2010-11-01

    Norovirus (NoV) is the principal agent of bivalve molluscan shellfish-associated gastroenteric illness worldwide. Currently, noncultivable human NoVs can be detected in bivalve molluscan shellfish by using molecular methods such as real-time reverse transcription PCR assays (qRT-PCR). In addition to infectious viruses, this methodology may also detect noninfectious NoV, including fragments of the NoV genome. This study addresses, in part, the implications of qRT-PCR results for the detection of NoV in shellfish in the absence of an infectivity assay. To evaluate environmental persistence, the stability of a short fragment of the NoV genome, spanning the qRT-PCR target in the open reading frame 1/2 junction, was assessed in seawater under artificial environmental conditions simulating winter in the United Kingdom (1 mW/cm² UV irradiation, 8°C) during a 4-week period. Detectable RNA levels decreased exponentially (T₉₀ of approximately 141 h); however, sequences were still detectable for up to 2 weeks. The ability of Pacific oysters (Crassostrea gigas) to bioaccumulate NoV particles (from human feces) and RNA fragments was also compared using qRT-PCR. Oysters exposed to NoV particles subsequently were positive for NoV by qRT-PCR at levels several orders of magnitude in excess of the theoretical limit of detection, whereas oysters exposed to similar quantities of NoV RNA were either negative or positive at significantly lower levels. Therefore, although noninfectious fragments of NoV RNA may persist in the environment under winter conditions, this type of material will not be efficiently bioaccumulated by Pacific oysters and should not significantly contribute to positive qRT-PCR results.

  6. Parental exposure to the herbicide diuron results in oxidative DNA damage to germinal cells of the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Barranger, Audrey; Heude-Berthelin, Clothilde; Rouxel, Julien; Adeline, Béatrice; Benabdelmouna, Abdellah; Burgeot, Thierry; Akcha, Farida

    2016-02-01

    Chemical pollution by pesticides has been identified as a possible contributing factor to the massive mortality outbreaks observed in Crassostrea gigas for several years. A previous study demonstrated the vertical transmission of DNA damage by subjecting oyster genitors to the herbicide diuron at environmental concentrations during gametogenesis. This trans-generational effect occurs through damage to genitor-exposed gametes, as measured by the comet-assay. The presence of DNA damage in gametes could be linked to the formation of DNA damage in other germ cells. In order to explore this question, the levels and cell distribution of the oxidized base lesion 8-oxodGuo were studied in the gonads of exposed genitors. High-performance liquid chromatography coupled with UV and electrochemical detection analysis showed an increase in 8-oxodGuo levels in both male and female gonads after exposure to diuron. Immunohistochemistry analysis showed the presence of 8-oxodGuo at all stages of male germ cells, from early to mature stages. Conversely, the oxidized base was only present in early germ cell stages in female gonads. These results indicate that male and female genitors underwent oxidative stress following exposure to diuron, resulting in DNA oxidation in both early germ cells and gametes, such as spermatozoa, which could explain the transmission of diuron-induced DNA damage to offspring. Furthermore, immunostaining of early germ cells seems indicates that damages caused by exposure to diuron on germ line not only affect the current sexual cycle but also could affect future gametogenesis. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. High salinity relay as a post-harvest processing method for reducing Vibrio vulnificus levels in oysters (Crassostrea virginica).

    Science.gov (United States)

    Audemard, Corinne; Kator, Howard I; Reece, Kimberly S

    2018-08-20

    High salinity relay of Eastern oysters (Crassostrea virginica) was evaluated as a post-harvest processing (PHP) method for reducing Vibrio vulnificus. This approach relies on the exposure of oysters to natural high salinity waters and preserves a live product compared to previously approved PHPs. Although results of prior studies evaluating high salinity relay as a means to decrease V. vulnificus levels were promising, validation of this method as a PHP following approved guidelines is required. This study was designed to provide data for validation of this method following Food and Drug Administration (FDA) PHP validation guidelines. During each of 3 relay experiments, oysters cultured from 3 different Chesapeake Bay sites of contrasting salinities (10-21 psu) were relayed without acclimation to high salinity waters (31-33 psu) for up to 28 days. Densities of V. vulnificus and densities of total and pathogenic Vibrio parahaemolyticus (as tdh positive strains) were measured using an MPN-quantitative PCR approach. Overall, 9 lots of oysters were relayed with 6 exhibiting initial V. vulnificus >10,000/g. As recommended by the FDA PHP validation guidelines, these lots reached both the 3.52 log reduction and the levels ranged from 2 to 61% after 28 days of relay. Although the identification of the factors implicated in oyster mortality will require further examination, this study strongly supports the validation of high salinity relay as an effective PHP method to reduce levels of V. vulnificus in oysters to endpoint levels approved for human consumption. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Parasitological survey of mangrove oyster, Crassostrea rhizophorae, in the Pacoti River Estuary, Ceará State, Brazil.

    Science.gov (United States)

    Sabry, Rachel Costa; Gesteira, Tereza Cristina Vasconcelos; Magalhães, Aimê Rachel Magenta; Barracco, Margherita Anna; Guertler, Cristhiane; Ferreira, Liana Pinho; Vianna, Rogério Tubino; da Silva, Patrícia Mirella

    2013-01-01

    The mangrove oyster, Crassostrea rhizophorae (Bivalvia, Ostreidae) is commonly collected by fisherwomen in the estuaries of the Ceará State (CE), Northeastern Brazil. Despite the socioeconomic importance of this natural resource, there are few studies on the health of the oysters in this region. This study aimed to survey pathological changes in the mangrove oyster C. rhizophorae in the estuary of the Pacoti River, CE. Adult oysters were collected in August 2008 (N=450) and December 2009 (N=450) at three sites of the Pacoti estuary and in 2010 (N=600) samplings were done quarterly at one site which has showed the higher prevalence de Perkinsus. Macroscopical and histological analyses were used to evaluate pathological changes, Ray's Fluid Thioglycollate Medium (RFTM) to detect Perkinsus spp. and polymerase chain reactions (PCR) and DNA sequencing to identify Perkinsus species. In 2009, RFTM assay detected Perkinsus sp. infecting the tissues of C. rhizophorae with low prevalences of 1.3%, 6.7% e 7.3% in sites 1, 2 and 3, respectively, and in 2010, in site 3, prevalence was 2% (12 of 600 oysters). PCR did not confirm any positive case in 2009 and only 5 in 2010. The phylogenetic analyses strongly indicate that the Perkinsus species infecting oysters C. rhizophorae of this study belongs to Perkinsus beihaiensis. The histology confirmed 11 cases of Perkinsus sp. infecting the C. rhizophorae in 2009, and only two cases in 2010. Nematopsis sp. was the protozoan observed with greater prevalence (up 96.7%). Other found protozoa were: Trichodina, Sphenophrya, Ancistrocoma - like and an unknown ovarian parasite. The metazoa found were the polychaete Polydora with high prevalences, a turbellarian, possibly of the genus Urastoma, an unidentified digenean metacercariae and larvae of cestode Tylocephalum. A continuous monitoring of diseases in bivalves from this natural population is recommended, since the phylogenetic analyses indicate the occurrence of P. beihaiensis

  9. Cellular and biochemical responses of the oyster Crassostrea gigas to controlled exposures to metals and Alexandrium minutum

    Energy Technology Data Exchange (ETDEWEB)

    Haberkorn, Hansy; Lambert, Christophe; Le Goïc, Nelly [Laboratoire des Sciences de l‘Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané (France); Quéré, Claudie [IFREMER Centre de Brest, Laboratoire de Physiologie des Invertébrés, Unité Physiologie Fonctionnelle des Organismes Marins, BP 70, 29280 Plouzané (France); Bruneau, Audrey; Riso, Ricardo; Auffret, Michel [Laboratoire des Sciences de l‘Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané (France); Soudant, Philippe, E-mail: Philippe.Soudant@univ-brest.fr [Laboratoire des Sciences de l‘Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané (France)

    2014-02-15

    Highlights: •Oysters, C. gigas, were exposed to both metals and PST-producer A. minutum. •Oysters exposed to metals accumulated about thirty-six times less PSTs. •Exposure to both metals and A. minutum induced antagonistic or synergetic effects. -- Abstract: Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd–Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd–Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd–Cu induced significant changes in neutral lipids (increase in diacylglycerol – DAG – and decrease in sterols) and phospholipids (decreases in phosphatidylcholine, phosphatidylethanolamine, cardiolipin and ceramide aminoethylphosphonate) of digestive gland suggesting that lipid metabolism disruptions and/or lipid peroxidation have occurred. Simultaneously, concentrations, percentages of dead cells and phenoloxidase activity of hemocytes increased in oysters exposed to metals while reactive oxygen species production of hemocytes decreased. Feeding on the harmful dinoflagellate A. minutum resulted in significant decreases in monoacylglycerol (MAG) and DAG and ether glycerides (EG), as well as significant increases in hemocyte concentration and phagocytic activity as compared to oysters fed T. lutea. Finally, the present study revealed that short-term, simultaneous exposure to Cd–Cu and A. minutum may induce antagonistic (i.e. hemocyte concentration and phagocytosis) or synergic (i.e. DAG content in

  10. Seasonal variation in mitochondrial responses to cadmium and temperature in eastern oysters Crassostrea virginica (Gmelin) from different latitudes

    International Nuclear Information System (INIS)

    Cherkasov, A.S.; Taylor, C.; Sokolova, I.M.

    2010-01-01

    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 seasonal variability of mitochondrial responses to elevated temperatures and Cd stress in eastern oysters Crassostrea virginica from populations adapted to different thermal regimes (subtropical Texas (TX), warm temperate North Carolina (NC) and cold temperate Washington (WA) areas). Seasonality had a strong effect on mitochondrial function in oysters from the two studied southern populations (TX and NC) but not in their northern (WA) counterparts, with decreased mitochondrial abundance and increased rates of mitochondrial proton leak in gill tissues of TX and NC oysters in summer. Compared to WA oysters, oysters from the two southern populations accumulated Cd faster in their tissues, and their mitochondria were more sensitive to Cd inhibition in resting and ADP-stimulated states at 20 and 28 o C. At 12 o C, inter-populational differences in Cd accumulation rates and sensitivity of mitochondrial respiration to Cd were not significant. Within each of the three studied populations, sensitivity of mitochondrial ADP-stimulated respiration to Cd inhibition increased with increasing temperatures (28 > 20 > 12 o C). This indicates that oysters from the two southern sites may be more vulnerable to Cd toxicity due to exposure to high environmental temperatures in summer, elevated rates of Cd accumulation and high intrinsic sensitivity of their mitochondria to Cd. This study suggests that data on sensitivity to pollutants obtained for one population of oysters should be extrapolated to

  11. Effects of Antifouling Biocides on Molecular and Biochemical Defense System in the Gill of the Pacific Oyster Crassostrea gigas

    Science.gov (United States)

    Park, Mi Seon; Kim, Young Dae; Kim, Bo-Mi; Kim, Youn-Jung; Kim, Jang Kyun; Rhee, Jae-Sung

    2016-01-01

    Antifouling biocides such as organotin compounds and their alternatives are potent toxicants in marine ecosystems. In this study, we employed several molecular and biochemical response systems of the Pacific oyster Crassostrea gigas to understand a potential mode of action of antifouling biocides (i.e. tributyltin (TBT), diuron and irgarol) after exposure to different concentrations (0.01, 0.1, and 1 μg L-1) for 96 h. As a result, all the three antifouling biocides strongly induced the antioxidant defense system. TBT reduced both enzymatic activity and mRNA expression of Na+/K+-ATPase and acetylcholinesterase (AChE). Lower levels of both Na+/K+-ATPase activity and AChE mRNA expression were observed in the diuron-exposed oysters compared to the control, while the irgarol treatment reduced only the transcriptional expression of AChE gene. We also analyzed transcript profile of heat shock protein (Hsp) superfamily in same experimental conditions. All antifouling biocides tested in this study significantly modulated mRNA expression of Hsp superfamily with strong induction of Hsp70 family. Taken together, overall results indicate that representative organotin TBT and alternatives have potential hazardous effects on the gill of C. gigas within relatively short time period. Our results also suggest that analyzing a series of molecular and biochemical parameters can be a way of understanding and uncovering the mode of action of emerging antifouling biocides. In particular, it was revealed that Pacific oysters have different sensitivities depend on the antifouling biocides. PMID:28006823

  12. Effects of Antifouling Biocides on Molecular and Biochemical Defense System in the Gill of the Pacific Oyster Crassostrea gigas.

    Science.gov (United States)

    Park, Mi Seon; Kim, Young Dae; Kim, Bo-Mi; Kim, Youn-Jung; Kim, Jang Kyun; Rhee, Jae-Sung

    2016-01-01

    Antifouling biocides such as organotin compounds and their alternatives are potent toxicants in marine ecosystems. In this study, we employed several molecular and biochemical response systems of the Pacific oyster Crassostrea gigas to understand a potential mode of action of antifouling biocides (i.e. tributyltin (TBT), diuron and irgarol) after exposure to different concentrations (0.01, 0.1, and 1 μg L-1) for 96 h. As a result, all the three antifouling biocides strongly induced the antioxidant defense system. TBT reduced both enzymatic activity and mRNA expression of Na+/K+-ATPase and acetylcholinesterase (AChE). Lower levels of both Na+/K+-ATPase activity and AChE mRNA expression were observed in the diuron-exposed oysters compared to the control, while the irgarol treatment reduced only the transcriptional expression of AChE gene. We also analyzed transcript profile of heat shock protein (Hsp) superfamily in same experimental conditions. All antifouling biocides tested in this study significantly modulated mRNA expression of Hsp superfamily with strong induction of Hsp70 family. Taken together, overall results indicate that representative organotin TBT and alternatives have potential hazardous effects on the gill of C. gigas within relatively short time period. Our results also suggest that analyzing a series of molecular and biochemical parameters can be a way of understanding and uncovering the mode of action of emerging antifouling biocides. In particular, it was revealed that Pacific oysters have different sensitivities depend on the antifouling biocides.

  13. Transcriptomic profiling of gametogenesis in triploid Pacific Oysters Crassostrea gigas: towards an understanding of partial sterility associated with triploidy.

    Directory of Open Access Journals (Sweden)

    Nolwenn M Dheilly

    Full Text Available Triploidy can occur in many animal species but is often lethal. Among invertebrates, amphibians and fishes, triploids are viable although often sterile or infertile. Most triploids of the Pacific oyster Crassostrea gigas are almost sterile (named "3nβ" yet a low but significant proportion show an advanced gametogenesis (named "3nα". These oysters thus constitute an interesting model to study the effect of triploidy on germ cell development. We used microarrays to compare the gonad transcriptomes of diploid 2n and the abovementioned triploid 3nβ and 3nα male and female oysters throughout gametogenesis.All triploids displayed an upregulation of genes related to DNA repair and apoptosis and a downregulation of genes associated with cell division. The comparison of 3nα and 3nβ transcriptomes with 2n revealed the likely involvement of a cell cycle checkpoint during mitosis in the successful but delayed development of gonads in 3nα individuals. In contrast, a disruption of sex differentiation mechanisms may explain the sterility of 3nβ individuals with 3nβ females expressing male-specific genes and 3nβ males expressing female-specific genes.The disruption of sex differentiation and mitosis may be responsible for the impaired gametogenesis of triploid Pacific oysters. The function of the numerous candidate genes identified in our study should now be studied in detail in order to elucidate their role in sex determination, mitosis/meiosis control, pachytene cell cycle checkpoint, and the control of DNA repair/apoptosis.

  14. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster (Crassostrea belcheri) in Thailand

    Energy Technology Data Exchange (ETDEWEB)

    Thupila, Nunticha [Department of Fishery Products, Faculty of Fisheries, Kasetsart University, 50 Ngamwongwan Rd. Ladyao, Chatuchak, Bangkok (Thailand); Ratana-arporn, Pattama, E-mail: ffispmr@ku.ac.t [Department of Fishery Products, Faculty of Fisheries, Kasetsart University, 50 Ngamwongwan Rd. Ladyao, Chatuchak, Bangkok (Thailand); Wilaipun, Pongtep [Department of Fishery Products, Faculty of Fisheries, Kasetsart University, 50 Ngamwongwan Rd. Ladyao, Chatuchak, Bangkok (Thailand)

    2011-07-15

    In Thailand, white scar oyster (Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses (D{sub 10}) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D{sub 10} values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10{sup 5} CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  15. Pesticide residues, heavy metals, and DNA damage in sentinel oysters Crassostrea gigas from Sinaloa and Sonora, Mexico.

    Science.gov (United States)

    Vázquez-Boucard, Celia; Anguiano-Vega, Gerardo; Mercier, Laurence; Rojas del Castillo, Emilio

    2014-01-01

    Pesticides and heavy metals were analyzed in sentinel Crassostrea gigas oysters placed in six aquaculture sites close to a contaminated agricultural region. Each site was sampled twice. Tests revealed the presence of organochlorine (OC) pesticides in the oysters at concentrations varying from 31.8 to 72.5 μg/kg for gamma-hexachlorocyclohexane (γ-HCH); from 1.2 to 3.1 μg/kg for dichlorodiphenyldichloroethylene (4,4-DDE); from 1.6 to 2.3 μg/kg for endosulfan I; and from 1.4 to 41.2 μg/kg for endosulfan II, as well as heavy metals in concentrations that exceeded Mexican tolerance levels (405.5 to 987.8 μg/g for zinc; 4.2 to 7.3 μg/g for cadmium; and 7.2 to 9.9 μg/g for lead). Significant levels of DNA damage in oyster hemocytes were also detected. There was a significant, positive correlation between genotoxic damage and concentration of nickel or the presence of endosulfan II. Cellular viability evaluated by cytotoxic analyses was found to be high at 80%. Marked inhibition in activity of acetylcholinesterase (AChE ) and induction of glutathione S-transferase (GST) activity was noted. Data demonstrated a significant relation between AChE activity inhibition and presence of endosulfan II, γ-HCH, copper, lead, and 4,4-DDE, as well as between AChE and GST activity at different sites.

  16. Evaluation of the concentration of heavy metals in sea water, silt and rock oysters, Crassostrea iridescens, from Manzanillo bay

    International Nuclear Information System (INIS)

    Guerrero Carbajal, Y.C.

    1993-01-01

    Some essential metals such as Fe, Ni, Cu and Zn were evaluated by X-ray spectroscopy in water, soil and rock oyster Crassostrea iridescens from Manzanillo Bay. Four samplings were taken every two months during 1991. Concentration range on liofilized oysters for Fe was determined between 76 and 172 μ g/g dry weight, Ni 9-21 μ g/g dry weight, Cu 21-123 μ g/g dry weight and Zn 216-885 μ g/g dry weight. Ni concentration was above the toxicological tolerance level for crustaceans (5 μ g/g); Cu was above maxima permission limited (MPL) from FAO for molluscs (70 μ g/g); Zn was below MPL for oysters (1000 μ g/g). For Fe there is no MPL for oyster or any other aquatic organisms. Concentration and accumulation factors for the elements measured suggested the filtration oyster activity. Fe concentration range in water was 27-2266 μ g/l. This value is above the ecological aquatic life criteria in Mexico (50 μ g/l). For Cu the concentration range was 4-536 μ g/l., which is above the MPL for Mexican Legislation (5 μ g/l). Chemical elements detected in soil were the essential metal mentioned before. However, the heavy metals concentrations for soil, from Manzanillo Bay, were higher than those reported in other polluted regions in both Mexican coasts. Concentration range for Fe was 30661-76332 μ g/g, Ni 19-180 μ g/g, Cu 56-270 μ g/g and Zn 33-1377 μ g/g. Contamination problem in Manzanillo Bay must be considered as an evidence of potential risk, since the essential metals are reaching levels that could endanger aquatic life. (Author). 87 refs, 20 figs, 6 tabs

  17. Counting the dead to determine the source and transmission of the marine herpesvirus OsHV-1 in Crassostrea gigas.

    Science.gov (United States)

    Whittington, Richard J; Paul-Pont, Ika; Evans, Olivia; Hick, Paul; Dhand, Navneet K

    2018-04-10

    Marine herpesviruses are responsible for epizootics in economically, ecologically and culturally significant taxa. The recent emergence of microvariants of Ostreid herpesvirus 1 (OsHV-1) in Pacific oysters Crassostrea gigas has resulted in socioeconomic losses in Europe, New Zealand and Australia however, there is no information on their origin or mode of transmission. These factors need to be understood because they influence the way the disease may be prevented and controlled. Mortality data obtained from experimental populations of C. gigas during natural epizootics of OsHV-1 disease in Australia were analysed qualitatively. In addition we compared actual mortality data with those from a Reed-Frost model of direct transmission and analysed incubation periods using Sartwell's method to test for the type of epizootic, point source or propagating. We concluded that outbreaks were initiated from an unknown environmental source which is unlikely to be farmed oysters in the same estuary. While direct oyster-to-oyster transmission may occur in larger oysters if they are in close proximity (< 40 cm), it did not explain the observed epizootics, point source exposure and indirect transmission being more common and important. A conceptual model is proposed for OsHV-1 index case source and transmission, leading to endemicity with recurrent seasonal outbreaks. The findings suggest that prevention and control of OsHV-1 in C. gigas will require multiple interventions. OsHV-1 in C. gigas, which is a sedentary animal once beyond the larval stage, is an informative model when considering marine host-herpesvirus relationships.

  18. Effects of storage on microbial loads of two commercially important shellfish species, Crassostrea virginica and Mercenaria campechiensis.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-04-01

    The effects of storage on the microbial load in two commercially important species of shellfish were examined. Oysters (Crassostrea virginica) were stored as shellstock, shucked meats, and fully processed meats at four temperatures for up to 21 days, and clams (Mercenaria campechiensis) were stored only as shellstock. The concentrations of most microbiological groups of organisms increased with the duration and temperature of storage in both shellfish species, although the increases were significantly lower in claims. Concentrations of Vibrio cholerae rose by approximately 1 log in oysters stored as shellstock after 7 days at 2 degrees C, and Lac+ vibrios increased 2 logs at 8 degrees C. Total counts of bacteria, fungi, coliforms, fecal streptococci, Aeromonas hydrophila, and clostridia were significantly higher in shucked oysters than in those stored as shellstock. Fecal coliforms were statistically the same, but V. cholerae, Vibrio parahaemolyticus, and the Lac+ vibrios were higher in oysters stored as shellstock. The concentrations of all microbial groups were higher in fully processed oysters than in shucked meats, with the exception of the vibrios, which showed no significant difference among the treatments. The results showed that although traditional methods of storing shellfish resulted in an overall increase in the microbial load, vibrio levels increased only in oysters stored as shellstock. Although fecal coliform and total bacterial counts did not correlate with those for vibrios in fresh oysters, strong correlations were observed in oysters stored for 7 days, suggesting that these indicators may be useful in monitoring oyster quality when meats are stored for a limited time as shellstock.

  19. Elimination of fecal coliforms and F-specific RNA coliphage from oysters (Crassostrea virginica) relaid in floating containers.

    Science.gov (United States)

    Kator, H; Rhodes, M

    2001-06-01

    Declining oyster (Crassostrea virginica) production in the Chesapeake Bay has stimulated aquaculture based on floats for off-bottom culture. While advantages of off-bottom culture are significant, the increased use of floating containers raises public health and microbiological concerns, because oysters in floats may be more susceptible to fecal contamination from storm runoff compared to those cultured on-bottom. We conducted four commercial-scale studies with market-size oysters naturally contaminated with fecal coliforms (FC) and a candidate viral indicator, F-specific RNA (FRNA) coliphage. To facilitate sampling and to test for location effects, 12 replicate subsamples, each consisting of 15 to 20 randomly selected oysters in plastic mesh bags, were placed at four characteristic locations within a 0.6- by 3.0-m "Taylor" float, and the remaining oysters were added to a depth not exceeding 15.2 cm. The float containing approximately 3,000 oysters was relaid in the York River, Virginia, for 14 days. During relay, increases in shellfish FC densities followed rain events such that final mean levels exceeded initial levels or did not meet an arbitrary product end point of 50 FC/100 ml. FRNA coliphage densities decreased to undetectable levels within 14 days (16 to 28 degrees C) in all but the last experiment, when temperatures fell between 12 and 16 degrees C. Friedman (nonparametric analysis of variance) tests performed on FC/Escherichia coli and FRNA densities indicated no differences in counts as a function of location within the float. The public health consequences of these observations are discussed, and future research and educational needs are identified.

  20. Surveillance of Enteric Viruses and Microbial Indicators in the Eastern Oysters (Crassostrea virginica) and Harvest Waters along Louisiana Gulf Coast.

    Science.gov (United States)

    Montazeri, Naim; Maite, Morgan; Liu, Da; Cormier, Jiemin; Landry, Matthew; Shackleford, John; Lampila, Lucina E; Achberger, Eric C; Janes, Marlene E

    2015-05-01

    Noroviruses are the most common causative agent of viral gastroenteritis in humans, and are responsible for major foodborne illnesses in the United States. Filter-feeding molluscan shellfish exposed to sewage-contaminated waters bioaccumulate viruses, and if consumed raw, transmit the viruses to humans and cause illness. We investigated the occurrence of norovirus GI and GII and microbial indicators of fecal contamination in the eastern oysters (Crassostrea virginica) and water from commercial harvesting areas along the Louisiana Gulf Coast (January to November of 2013). Microbial indicators (aerobic plate count, enterococci, fecal coliforms, Escherichia coli, male-specific coliphages, and somatic coliphages) were detected at the densities lower than public health concerns. Only one oyster sample was positive for norovirus GII at 3.5 ± 0.2 log10 genomic equivalent copies/g digestive tissues. A stool specimen obtained from an infected individual associated with a norovirus outbreak and the suspected oysters (Cameron Parish, La., area 30, January 2013) were also analyzed. The norovirus strain in the stool belonged to GII.4 Sydney; however, the oysters were negative and could not be linked. In general, no temporal trend was observed in the microbial indicators. Low correlation among bacterial indicators was observed in oysters. Strongest correlations among microbial indicators were observed between enterococci and fecal coliforms (r = 0.63) and between enterococci and E. coli (r = 0.64) in water (P oysters (r oysters and harvest water (r ≤ 0.36, P > 0.05). Our results emphasize the need for regular monitoring of pathogenic viruses in commercial oyster harvesting areas to reduce the risks of viral gastroenteritis incidences. © 2015 Institute of Food Technologists®

  1. In vivo effects of metaldehyde on Pacific oyster, Crassostrea gigas: comparing hemocyte parameters in two oyster families.

    Science.gov (United States)

    Moreau, Pierrick; Burgeot, Thierry; Renault, Tristan

    2015-06-01

    Pollutants via run-off into the ocean represent a potential threat to marine organisms, especially bivalves such as oysters living in coastal environments. These organisms filter large volumes of seawater and may accumulate contaminants within their tissues. Pesticide contamination in water could have a direct or indirect toxic action on tissues or cells and could induce alteration of immune system. Bivalve immunity is mainly supported by hemocytes and participates directly by phagocytosis to eliminate pathogens. Some studies have shown that pesticides can reduce immune defences and/or modify genomes in vertebrates and invertebrates. Metaldehyde is used to kill slugs, snails and other terrestrial gastropods. Although metaldehyde has been detected in surface waters, its effects on marine bivalves including the Pacific oyster, Crassostrea gigas, have never been studied. Given the mode of action of this molecule and its targets (molluscs), it could be potentially more toxic to oysters than other pesticides (herbicides, fungicides, insecticides, etc.). Effects of metaldehyde on oyster hemocyte parameters were thus monitored through in vivo experiments based on a short-term exposure. In this work, metaldehyde at 0.1 μg/L, which corresponds to an average concentration detected in the environment, modulated hemocyte activities of Pacific oysters after an in vivo short-term contact. Individuals belonging to two families showed different behaviours for some hemocyte activities after contamination by metaldehyde. These results suggested that effects of pollutants on oysters may differ from an individual to another in relation to genetic diversity. Finally, it appears essential to take an interest in the effects of metaldehyde on a wide variety of aquatic invertebrates including those that have a significant economic impact.

  2. In situ localization and tissue distribution of ostreid herpesvirus 1 proteins in infected Pacific oyster, Crassostrea gigas.

    Science.gov (United States)

    Martenot, Claire; Segarra, Amélie; Baillon, Laury; Faury, Nicole; Houssin, Maryline; Renault, Tristan

    2016-05-01

    Immunohistochemistry (IHC) assays were conducted on paraffin sections from experimentally infected spat and unchallenged spat produced in hatchery to determine the tissue distribution of three viral proteins within the Pacific oyster, Crassostrea gigas. Polyclonal antibodies were produced from recombinant proteins corresponding to two putative membrane proteins and one putative apoptosis inhibitor encoded by ORF 25, 72, and 87, respectively. Results were then compared to those obtained by in situ hybridization performed on the same individuals, and showed a substantial agreement according to Landis and Koch numeric scale. Positive signals were mainly observed in connective tissue of gills, mantle, adductor muscle, heart, digestive gland, labial palps, and gonads of infected spat. Positive signals were also reported in digestive epithelia. However, few positive signals were also observed in healthy appearing oysters (unchallenged spat) and could be due to virus persistence after a primary infection. Cellular localization of staining seemed to be linked to the function of the viral protein targeted. A nucleus staining was preferentially observed with antibodies targeting the putative apoptosis inhibitor protein whereas a cytoplasmic localization was obtained using antibodies recognizing putative membrane proteins. The detection of viral proteins was often associated with histopathological changes previously reported during OsHV-1 infection by histology and transmission electron microscopy. Within the 6h after viral suspension injection, positive signals were almost at the maximal level with the three antibodies and all studied organs appeared infected at 28h post viral injection. Connective tissue appeared to be a privileged site for OsHV-1 replication even if positive signals were observed in the epithelium cells of different organs which may be interpreted as a hypothetical portal of entry or release for the virus. IHC constitutes a suited method for analyzing the

  3. Haemocytes from Crassostrea gigas and OsHV-1: A promising in vitro system to study host/virus interactions.

    Science.gov (United States)

    Morga, Benjamin; Faury, Nicole; Guesdon, Stéphane; Chollet, Bruno; Renault, Tristan

    2017-11-01

    Since 2008, mass mortality outbreaks associated with the detection of particular variants of OsHV-1 have been reported in Crassostrea gigas spat and juveniles in several countries. Recent studies have reported information on viral replication during experimental infection. Viral DNA and RNA were also detected in the haemolymph and haemocytes suggesting that the virus could circulate through the circulatory system. However, it is unknown if the virus is free in the haemolymph, passively associated at the surface of haemocytes, or able to infect and replicate inside these cells inducing (or not) virion production. In the present study, we collected haemocytes from the haemolymphatic sinus of the adductor muscle of healthy C. gigas spat and exposed them in vitro to a viral suspension. Results showed that viral RNAs were detectable one hour after contact and the number of virus transcripts increased over time in association with an increase of viral DNA detection. These results suggested that the virus is able to initiate replication rapidly inside haemocytes maintained in vitro. These in vitro trials were also used to carry out a dual transcriptomic study. We analyzed concomitantly the expression of some host immune genes and 15 viral genes. Results showed an up regulation of oyster genes currently studied during OsHV-1 infection. Additionally, transmission electron microscopy examination was carried out and did not allow the detection of viral particles. Moreover, All the results suggested that the in vitro model using haemocytes can be valuable for providing new perspective on virus-oyster interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. New Insight for the Genetic Evaluation of Resistance to Ostreid Herpesvirus Infection, a Worldwide Disease, in Crassostrea gigas.

    Science.gov (United States)

    Dégremont, Lionel; Lamy, Jean-Baptiste; Pépin, Jean-François; Travers, Marie-Agnès; Renault, Tristan

    2015-01-01

    The Pacific oyster, Crassostrea gigas, is the most important commercial oyster species cultivated in the world. Meanwhile, the ostreid herpesvirus 1 (OsHV-1) is one of the major pathogens affecting the Pacific oyster, and numerous mortality outbreaks related to this pathogen are now reported worldwide. To assess the genetic basis of resistance to OsHV-1 infection in spat C. gigas and to facilitate breeding programs for such a trait, if any exist, we compared the mortality of half- and full-sib families using three field methods and a controlled challenge by OsHV-1 in the laboratory. In the field, three methods were tested: (A) one family per bag; (B) one family per small soft mesh bag and all families inside one bag; (C) same as the previous methods but the oysters were individually labelled and then mixed. The mean mortality ranged from 80 to 82% and was related to OsHV-1 based on viral DNA detection. The narrow-sense heritability for mortality, and thus OsHV-1 resistance, ranged from 0.49 to 0.60. The high positive genetic correlations across the field methods suggested no genotype by environment interaction. Ideally, selective breeding could use method B, which is less time- and space-consuming. The narrow sense heritability for mortality under OsHV-1 challenge was 0.61, and genetic correlation between the field and the laboratory was ranged from 0.68 to 0.75, suggesting a weak genotype by environment interaction. Thus, most of families showing the highest survival performed well in field and laboratory conditions, and a similar trend was also observed for families with the lowest survival. In conclusion, this is the first study demonstrating a large additive genetic variation for resistance to OsHV-1 infection in C. gigas, regardless of the methods used, which should help in selective breeding to improve resistance to viral infection in C. gigas.

  5. Thiol oxidation of hemolymph proteins in oysters Crassostrea brasiliana as markers of oxidative damage induced by urban sewage exposure.

    Science.gov (United States)

    Trevisan, Rafael; Flores-Nunes, Fabrício; Dolores, Euler S; Mattos, Jacó J; Piazza, Clei E; Sasaki, Sílvio T; Taniguchi, Satie; Montone, Rosalinda C; Bícego, Márcia C; Dos Reis, Isis M M; Zacchi, Flávia L; Othero, Bárbara N M; Bastolla, Camila L V; Mello, Danielle F; Fraga, Ana Paula M; Wendt, Nestor; Toledo-Silva, Guilherme; Razzera, Guilherme; Dafre, Alcir L; de Melo, Cláudio M R; Bianchini, Adalto; Marques, Maria R F; Bainy, Afonso C D

    2017-07-01

    Urban sewage is a concerning issue worldwide, threatening both wildlife and human health. The present study investigated protein oxidation in mangrove oysters (Crassostrea brasiliana) exposed to seawater from Balneário Camboriú, an important tourist destination in Brazil that is affected by urban sewage. Oysters were exposed for 24 h to seawater collected close to the Camboriú River (CAM1) or 1 km away (CAM2). Seawater from an aquaculture laboratory was used as a reference. Local sewage input was marked by higher levels of coliforms, nitrogen, and phosphorus in seawater, as well as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), linear alkylbenzenes (LABs), and fecal steroid in sediments at CAM1. Exposure of oysters to CAM1 caused marked bioaccumulation of LABs and decreased PAH and PCB concentrations after exposure to both CAM1 and CAM2. Protein thiol oxidation in gills, digestive gland, and hemolymph was evaluated. Lower levels of reduced protein thiols were detected in hemolymph from CAM1, and actin, segon, and dominin were identified as targets of protein thiol oxidation. Dominin susceptibility to oxidation was confirmed in vitro by exposure to peroxides and hypochlorous acid, and 2 cysteine residues were identified as potential sites of oxidation. Overall, these data indicate that urban sewage contamination in local waters has a toxic potential and that protein thiol oxidation in hemolymph could be a useful biomarker of oxidative stress in bivalves exposed to contaminants. Environ Toxicol Chem 2017;36:1833-1845. © 2016 SETAC. © 2016 SETAC.

  6. Integrated application of transcriptomics and metabolomics provides insights into glycogen content regulation in the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Li, Busu; Song, Kai; Meng, Jie; Li, Li; Zhang, Guofan

    2017-09-11

    The Pacific oyster Crassostrea gigas is an important marine fishery resource, which contains high levels of glycogen that contributes to the flavor and the quality of the oyster. However, little is known about the molecular and chemical mechanisms underlying glycogen content differences in Pacific oysters. Using a homogeneous cultured Pacific oyster family, we explored these regulatory networks at the level of the metabolome and the transcriptome. Oysters with the highest and lowest natural glycogen content were selected for differential transcriptome and metabolome analysis. We identified 1888 differentially-expressed genes, seventy-five differentially-abundant metabolites, which are part of twenty-seven signaling pathways that were enriched using an integrated analysis of the interaction between the differentially-expressed genes and the differentially-abundant metabolites. Based on these results, we found that a high expression of carnitine O-palmitoyltransferase 2 (CPT2), indicative of increased fatty acid degradation, is associated with a lower glycogen content. Together, a high level of expression of phosphoenolpyruvate carboxykinase (PEPCK), and high levels of glucogenic amino acids likely underlie the increased glycogen production in high-glycogen oysters. In addition, the higher levels of the glycolytic enzymes hexokinase (HK) and pyruvate kinase (PK), as well as of the TCA cycle enzymes malate dehydrogenase (MDH) and pyruvate carboxylase (PYC), imply that there is a concomitant up-regulation of energy metabolism in high-glycogen oysters. High-glycogen oysters also appeared to have an increased ability to cope with stress, since the levels of the antioxidant glutathione peroxidase enzyme 5 (GPX5) gene were also increased. Our results suggest that amino acids and free fatty acids are closely related to glycogen content in oysters. In addition, oysters with a high glycogen content have a greater energy production capacity and a greater ability to cope with

  7. Whole transcriptome profiling of successful immune response to Vibrio infections in the oyster Crassostrea gigas by digital gene expression analysis.

    Directory of Open Access Journals (Sweden)

    Julien de Lorgeril

    Full Text Available The cultivated Pacific oyster Crassostrea gigas has suffered for decades large scale summer mortality phenomenon resulting from the interaction between the environment parameters, the oyster physiological and/or genetic status and the presence of pathogenic microorganisms including Vibrio species. To obtain a general picture of the molecular mechanisms implicated in C. gigas immune responsiveness to circumvent Vibrio infections, we have developed the first deep sequencing study of the transcriptome of hemocytes, the immunocompetent cells. Using Digital Gene Expression (DGE, we generated a transcript catalog of up-regulated genes from oysters surviving infection with virulent Vibrio strains (Vibrio splendidus LGP32 and V. aestuarianus LPi 02/41 compared to an avirulent one, V. tasmaniensis LMG 20012(T. For that an original experimental infection protocol was developed in which only animals that were able to survive infections were considered for the DGE approach. We report the identification of cellular and immune functions that characterize the oyster capability to survive pathogenic Vibrio infections. Functional annotations highlight genes related to signal transduction of immune response, cell adhesion and communication as well as cellular processes and defence mechanisms of phagocytosis, actin cytosqueleton reorganization, cell trafficking and autophagy, but also antioxidant and anti-apoptotic reactions. In addition, quantitative PCR analysis reveals the first identification of pathogen-specific signatures in oyster gene regulation, which opens the way for in depth molecular studies of oyster-pathogen interaction and pathogenesis. This work is a prerequisite for the identification of those physiological traits controlling oyster capacity to survive a Vibrio infection and, subsequently, for a better understanding of the phenomenon of summer mortality.

  8. Bioaccumulation of trace metals in farmed pacific oysters Crassostrea gigas from SW Gulf of California coast, Mexico.

    Science.gov (United States)

    Jonathan, M P; Muñoz-Sevilla, N P; Góngora-Gómez, Andrés Martin; Luna Varela, Raquel Gabriela; Sujitha, S B; Escobedo-Urías, D C; Rodríguez-Espinosa, P F; Campos Villegas, Lorena Elizabeth

    2017-11-01

    The aim of the study was to evaluate the bioavailability of trace metals (Chromium, Copper, Nickel, Lead, Zinc, Cadmium, Arsenic, and Mercury) in the commercially consumed Crassostrea gigas oysters collected over a 12-month growth period (2011-12) from an experimental cultivation farm in La Pitahaya, Sinaloa State, Mexico. Sediment and water samples were also collected from four different zones adjacent to the cultivation area to identify the concentration patterns of metals. The results revealed that sewage disposals, fertilizers used for agricultural practices and shrimp culture are the major sources for the enrichment of certain toxic metals. The metal concentrations in oysters presented a decreasing order of abundance (all values in mg Kg -1 ): Zn (278.91 ± 93.03) > Cu (63.13 ± 31.72) > Cr (22.29 ± 30.23) > Cd (14.54 ± 4.28) > Ni (9.41 ± 11.33) > Pb (2.22 ± 1.33) > As (0.58 ± 0.91) > Hg (0.04 ± 0.06). Bioconcentration Factor (BCF) and Biota Sediment Accumulation Factor (BSAF) exhibited that C. gigas in the region are strong accumulators for Zn and Cd respectively. Thus, the present study proves to fulfill the gap in understanding the rate of bioaccumulation of metals in C. gigas which is regarded as the most sought after oyster species globally. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Chemical contamination assessment in mangrove-lined Caribbean coastal systems using the oyster Crassostrea rhizophorae as biomonitor species.

    Science.gov (United States)

    Aguirre-Rubí, Javier R; Luna-Acosta, Andrea; Etxebarría, Nestor; Soto, Manu; Espinoza, Félix; Ahrens, Michael J; Marigómez, Ionan

    2018-05-01

    This paper aims to contribute to the use of mangrove cupped oyster, Crassostrea rhizophorae, as a biomonitor species for chemical contamination assessment in mangrove-lined Caribbean coastal systems. Sampling was carried out in eight localities (three in Nicaragua and five in Colombia) with different types and levels of contamination. Oysters were collected during the rainy and dry seasons of 2012-2013 and the tissue concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), and persistent organic pollutants (POPs) were determined. Low tissue concentrations of metals (except Hg) and PAHs; moderate-to-high tissue concentrations of Hg, hexachlorocyclohexanes (HCHs), and dichlorodiphenyl-trichloroethanes (DDTs); detectable levels of chlorpyrifos, polychlorinated biphenyls (PCBs) (mainly CB28, CB118, CB138 and CB 153) and brominated diphenyl ethers 85 (BDE85); and negligible levels of musks were recorded in Nicaraguan oysters. A distinct profile of POPs was identified in Colombia, where the tissue concentrations of PCBs and synthetic musk fragrances were low to moderate, and Ag, As, Cd, Pb, and PAHs ranged from moderate to extremely high. Overall, the values recorded for HCHs, DDTs and PCBs in Nicaraguan mangrove cupped oysters greatly exceeded the reference values in tissues of C. rhizophorae from the Wider Caribbean Region, whereas only the levels of PCBs were occasionally surpassed in Colombia. Different contaminant profiles were distinguished between oysters from Nicaragua and Colombia in radar plots constructed using the main groups of contaminants (metals, PAHs, musks, PCBs, and organochlorine pesticides (OCPs)). Likewise, integrated pollution indices revealed differences in the levels of contaminants. Moreover, the profiles and levels in oyster tissues also varied with season. Thus, principal component analysis clearly discriminated Nicaraguan and Colombian localities and, especially in Colombia, seasonal trends in chemical contamination and differences

  10. Generation and analysis of ESTs from the eastern oyster, Crassostrea virginica Gmelin and identification of microsatellite and SNP markers

    Directory of Open Access Journals (Sweden)

    Wallace Richard

    2007-06-01

    Full Text Available Abstract Background 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 been lacking for this species. Efficient generation of EST resources from this species has been hindered by a high redundancy of transcripts. The objectives of this study were to construct a normalized cDNA library for efficient EST analysis, to generate thousands of ESTs, and to analyze the ESTs for microsatellites and potential single nucleotide polymorphisms (SNPs. Results A normalized and subtracted C. virginica cDNA library was constructed from pooled RNA isolated from hemocytes, mantle, gill, gonad and digestive tract, muscle, and a whole juvenile oyster. A total of 6,528 clones were sequenced from this library generating 5,542 high-quality EST sequences. Cluster analysis indicated the presence of 635 contigs and 4,053 singletons, generating a total of 4,688 unique sequences. About 46% (2,174 of the unique ESTs had significant hits (E-value ≤ 1e-05 to the non-redundant protein database; 1,104 of which were annotated using Gene Ontology (GO terms. A total of 35 microsatellites were identified from the ESTs, with 18 having sufficient flanking sequences for primer design. A total of 6,533 putative SNPs were also identified using all existing and the newly generated EST resources of the eastern oysters. Conclusion A high quality normalized cDNA library was constructed. A total of 5,542 ESTs were generated representing 4,688 unique sequences. Putative microsatellite and SNP markers were identified. These genome resources provide the

  11. Crecimiento del ostión Crassostrea gigas (Thunberg, 1795 cultivado en el estero La Piedra, Sinaloa, México

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    A. M. Góngora-Gómez

    2012-01-01

    Full Text Available Se realizó un ciclo de engorda (noviembre 2004- mayo 2005 con el ostión Crassostrea gigas en el estero La Piedra, Guasave (Sinaloa, México, usando canastas suspendidas en una línea madre para evaluar su crecimiento y supervivencia. Se utilizaron 10,000 semillas (3.5 ± 0.5 mm de altura inicial. Los valores promedios de los parámetros del agua fueron: temperatura, 22.2 ± 3.2°C; oxígeno disuelto, 6.8 ± 2.3 mg/l; y salinidad, 32.8 ± 3.14 ups; mientras que el promedio de la concentración de clorofila a fue de 3.2 ± 0.8 mg/m3. Los animales mostraron un crecimiento de 0.26 mm/día para la altura de su concha y 0.42 g/día de peso corporal. El índice de condición mostró un ligero descenso en el último mes de cultivo de 9.54 a 8.68. La fórmula: Peso = -15.4352 + 0.7968 Altura (r2 = 88.29; = 12.88; F = 37,71; P = 0.0017 describe la relación entre el peso y la altura de C. gigas en el cultivo. Se obtuvieron diferencias significativas entre el peso e índice de condición (P = 0.0023. Se registró una mortalidad total de 12%. Los resultados obtenidos indican que la temporada otoño-pri-mavera es favorable para el cultivo del ostión del Pacífico C. gigas en el estero La Piedra, Guasave, Sinaloa, ya que alcanzó la talla comercial (109.8 mm y 88.7 g en siete meses de cultivo.

  12. Effects of cadmium exposure on expression and activity of P-glycoprotein in eastern oysters, Crassostrea virginica Gmelin

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, Anna V. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Sokolova, Inna M. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)], E-mail: isokolov@uncc.edu

    2008-06-02

    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 (50 {mu}g L{sup -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 suggest that in the gills, mitochondrial P-gp pumps substrates from cytosol into the mitochondria, while cell membrane P-gp pumps substrates from cytosol out of the cell. Cd exposure resulted in a 2-2.5-fold increase in P-gp protein expression in cell membranes and a 3.5-7-fold increase in transport activity measured as the inhibitor-sensitive rhodamine B extrusion rate. In contrast, p-gp mRNA levels were similar in control and Cd-exposed oysters. No difference in P-gp protein expression was observed between mitochondria of control and Cd-exposed oysters but the apparent transport activity was higher in mitochondria from Cd-exposed oysters. Overall, a stronger increase in substrate transport activity in Cd-exposed oysters compared to a relatively weaker change in P-gp protein levels suggests that P-gp activity is post-translationally regulated. Our data show that direct determination of P-gp transport activity may be the best measure of the xenobiotic-resistant phenotype, whereas p-gp mRNA levels are not a good marker due to the likely involvement of multiple post-transcriptional regulatory steps. Cd exposure resulted in a significantly elevated rate of oxygen consumption of isolated oyster gills by 46%. Specific inhibitors of ATPase function of P-gp (cyclosporine A and JS-2190) had no significant effect on tissue oxygen consumption indicating that P-gp contribution to energy budget is negligible and supporting indirect estimates based on the ATP stoichiometry of substrate

  13. Effects of elevated temperature and cadmium exposure on stress protein response in eastern oysters Crassostrea virginica (Gmelin)

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, A.V. [Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Taylor, C. [Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Johnson C. Smith University, 100 Beatties Ford Rd., Charlotte, NC 28216 (United States); Sokolova, I.M. [Department of Biology, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)], E-mail: isokolov@uncc.edu

    2009-02-19

    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 populations adapted to different thermal regimes (Washington, North Carolina and Texas) at a common temperature of 12 deg. C, and analyzed their expression of MTs and HSPs (cytosolic HSP69, HSC72-77, HSP90 and mitochondrial HSP60) in response to the combined acute temperature stress and long-term Cd exposure. Overall, HSP and MT induction patterns were similar in oysters from the three studied geographically distant populations. HSP69 and MTs were significantly up-regulated by Cd and temperature stress implying their important role in cellular stress protection. In contrast, HSC72-77, HSP60 and HSP90 were not consistently induced by either acute heat or Cd exposure. The induction temperature for MTs was higher than for HSP69 (>28 deg. C vs. 20 deg. C, respectively), and MTs were more strongly induced by Cd than by temperature stress (to up to 38-94-fold compared by 3.5-7.5-fold, respectively) consistent with their predominant role in metal detoxification. Notably, heat stress did not result in an additional increase in metallothionein expression in Cd-exposed oysters suggesting a capacity limitation during the combined exposure to Cd and temperature stress. Levels of HSP69 and in some cases, HSC72-77 and HSP90 were lower in Cd-exposed oysters as compared to their control counterparts during heat stress indicating that simultaneous exposure to these two stressors may have partially suppressed the cytoprotective upregulation of molecular chaperones. These limitations of stress

  14. Gametogenesis in the Pacific oyster Crassostrea gigas: a microarrays-based analysis identifies sex and stage specific genes.

    Directory of Open Access Journals (Sweden)

    Nolwenn M Dheilly

    Full Text Available BACKGROUND: The Pacific oyster Crassostrea gigas (Mollusca, Lophotrochozoa is an alternative and irregular protandrous hermaphrodite: most individuals mature first as males and then change sex several times. Little is known about genetic and phenotypic basis of sex differentiation in oysters, and little more about the molecular pathways regulating reproduction. We have recently developed and validated a microarray containing 31,918 oligomers (Dheilly et al., 2011 representing the oyster transcriptome. The application of this microarray to the study of mollusk gametogenesis should provide a better understanding of the key factors involved in sex differentiation and the regulation of oyster reproduction. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression was studied in gonads of oysters cultured over a yearly reproductive cycle. Principal component analysis and hierarchical clustering showed a significant divergence in gene expression patterns of males and females coinciding with the start of gonial mitosis. ANOVA analysis of the data revealed 2,482 genes differentially expressed during the course of males and/or females gametogenesis. The expression of 434 genes could be localized in either germ cells or somatic cells of the gonad by comparing the transcriptome of female gonads to the transcriptome of stripped oocytes and somatic tissues. Analysis of the annotated genes revealed conserved molecular mechanisms between mollusks and mammals: genes involved in chromatin condensation, DNA replication and repair, mitosis and meiosis regulation, transcription, translation and apoptosis were expressed in both male and female gonads. Most interestingly, early expressed male-specific genes included bindin and a dpy-30 homolog and female-specific genes included foxL2, nanos homolog 3, a pancreatic lipase related protein, cd63 and vitellogenin. Further functional analyses are now required in order to investigate their role in sex differentiation in oysters

  15. Changing seasonality patterns in Central Europe from Miocene Climate Optimum to Miocene Climate Transition deduced from the Crassostrea isotope archive

    Science.gov (United States)

    Harzhauser, Mathias; Piller, Werner E.; Müllegger, Stefan; Grunert, Patrick; Micheels, Arne

    2011-03-01

    The Western Tethyan estuarine oyster Crassostrea gryphoides is an excellent climate archive due to its large size and rapid growth. It is geologically long lived and allows a stable isotope-based insight into climatic trends during the Miocene. Herein we utilised the climate archive of 5 oyster shells from the Miocene Climate Optimum (MCO) and the subsequent Miocene Climate Transition (MCT) to evaluate changes of seasonality patterns. MCO shells exhibit highly regular seasonal rhythms of warm-wet and dry-cool seasons. Optimal conditions resulted in extraordinary growth rates of the oysters. δ 13C profiles are in phase with δ 18O although phytoplankton blooms may cause a slight offset. Estuarine waters during the MCO in Central Europe display a seasonal temperature range of c. 9-10 °C. Absolute water temperatures have ranged from 17 to 19 °C during cool seasons and up to 28 °C in warm seasons. Already during the early phase of the MCO, the growth rates are distinctly declining, although gigantic and extremely old shells have been formed at that time. Still, a very regular and well expressed seasonality is dominating the isotope profiles, but episodically occurring extreme climate events influence the environments. The seasonal temperature range is still c. 9 °C but the cool season temperature seems to be slightly lower (16 °C) and the warm season water temperature does not exceed c. 25 °C. In the later MCT at c. 12.5-12.0 Ma the seasonality pattern is breaking down and is replaced by successions of dry years with irregular precipitation events. No correlation between δ 18O and δ 13C is documented maybe due to a suboptimal nutrition level which would explain the low growth rates and small sizes. The amplitude of seasonal temperature range is decreasing to 5-8 °C. No clear cooling trend can be postulated for that time as the winter season water temperatures range from 15 to 20 °C. This may point to unstable precipitation rhythms on a multi-annual to

  16. Determination of Cesium - 137 in the Oyster (Crassostrea belcheri) Meat and Seawater Samples from the Lower Gulf of Thailand

    International Nuclear Information System (INIS)

    Pakkong, P.; Phaopeng, N.; Tumnoi, Y.

    2014-01-01

    Cs-137 radioactivity was determined in the oyster (Crassostrea belcheri) meat samples which were collected on October 2010 and August 2011. The seawater samples were collected in 3 different provinces of the Lower Gulf of Thailand. The oyster meat samples were prepared as oven dried at 80±C. The seawater samples were prepared with AMP precipitation technique. The results of Cs-137 radioactivity in oyster meat samples in October 2010 were 3.179±2.2929, 3.1797±2.2929 and 3.1797±2.2929 mBq/kg-ww respectively and in August 2011 were 2.5437±2.2029, 1.9078±2.1091 and 3.1797±2.2929 mBq/kg-ww respectively. The Minimum Detectable Activity (MDA) of oyster meat samples were estimated to be 10.4723 mBq/kg-ww. Statistic calculation of critical limit (Lc) values of 2.9634mBq/kg-ww was used to confirm the value of Cs-137 radioactivity in oyster meat samples. The Cs-137 radioactivity in seawater samples which had been collected on October 2010 were 4.7806±0.1113, 3.7161±0.0868 and 3.19330.0745 mBq/L, respectively and the average of MDA was 0.4562 mBq/L, on March 2011 were 3.2213±0.0756, 2.7824±0.0653 and 1.9566±0.0462 mBq/L respectively and the average of MDA was 0.3142 mBq/L. The third collection of seawater samples on August 2011 after Fukushima Daiichi crisis accident were 4.9673±0.1155, 3.8469±0.0897 and 3.5294±0.0826 mBq/L respectively and the average of MDA was 0.4793 mBq/L) The results from calculation of radiation dose assessment for general public consumption were found lower than the accepted value (1 mSv/y).

  17. New Insight for the Genetic Evaluation of Resistance to Ostreid Herpesvirus Infection, a Worldwide Disease, in Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Lionel Dégremont

    Full Text Available The Pacific oyster, Crassostrea gigas, is the most important commercial oyster species cultivated in the world. Meanwhile, the ostreid herpesvirus 1 (OsHV-1 is one of the major pathogens affecting the Pacific oyster, and numerous mortality outbreaks related to this pathogen are now reported worldwide. To assess the genetic basis of resistance to OsHV-1 infection in spat C. gigas and to facilitate breeding programs for such a trait, if any exist, we compared the mortality of half- and full-sib families using three field methods and a controlled challenge by OsHV-1 in the laboratory. In the field, three methods were tested: (A one family per bag; (B one family per small soft mesh bag and all families inside one bag; (C same as the previous methods but the oysters were individually labelled and then mixed. The mean mortality ranged from 80 to 82% and was related to OsHV-1 based on viral DNA detection. The narrow-sense heritability for mortality, and thus OsHV-1 resistance, ranged from 0.49 to 0.60. The high positive genetic correlations across the field methods suggested no genotype by environment interaction. Ideally, selective breeding could use method B, which is less time- and space-consuming. The narrow sense heritability for mortality under OsHV-1 challenge was 0.61, and genetic correlation between the field and the laboratory was ranged from 0.68 to 0.75, suggesting a weak genotype by environment interaction. Thus, most of families showing the highest survival performed well in field and laboratory conditions, and a similar trend was also observed for families with the lowest survival. In conclusion, this is the first study demonstrating a large additive genetic variation for resistance to OsHV-1 infection in C. gigas, regardless of the methods used, which should help in selective breeding to improve resistance to viral infection in C. gigas.

  18. Effects of cadmium exposure on expression and activity of P-glycoprotein in eastern oysters, Crassostrea virginica Gmelin

    International Nuclear Information System (INIS)

    Ivanina, Anna V.; Sokolova, Inna M.

    2008-01-01

    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 (50 μg L -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 suggest that in the gills, mitochondrial P-gp pumps substrates from cytosol into the mitochondria, while cell membrane P-gp pumps substrates from cytosol out of the cell. Cd exposure resulted in a 2-2.5-fold increase in P-gp protein expression in cell membranes and a 3.5-7-fold increase in transport activity measured as the inhibitor-sensitive rhodamine B extrusion rate. In contrast, p-gp mRNA levels were similar in control and Cd-exposed oysters. No difference in P-gp protein expression was observed between mitochondria of control and Cd-exposed oysters but the apparent transport activity was higher in mitochondria from Cd-exposed oysters. Overall, a stronger increase in substrate transport activity in Cd-exposed oysters compared to a relatively weaker change in P-gp protein levels suggests that P-gp activity is post-translationally regulated. Our data show that direct determination of P-gp transport activity may be the best measure of the xenobiotic-resistant phenotype, whereas p-gp mRNA levels are not a good marker due to the likely involvement of multiple post-transcriptional regulatory steps. Cd exposure resulted in a significantly elevated rate of oxygen consumption of isolated oyster gills by 46%. Specific inhibitors of ATPase function of P-gp (cyclosporine A and JS-2190) had no significant effect on tissue oxygen consumption indicating that P-gp contribution to energy budget is negligible and supporting indirect estimates based on the ATP stoichiometry of substrate

  19. Tratamiento de efluentes del cultivo de Litopenaeus vannamei por sedimentación y filtración por la ostra Crassostrea rhizophorae Treatment of Litopenaeus vannamei farming effluents by sedimentation and oyster Crassostrea rhizophorae filtration

    Directory of Open Access Journals (Sweden)

    Roberto Ramos

    2008-01-01

    Full Text Available A escala de laboratorio se evaluaron las eficiencias de remoción del material particulado y nutrientes disueltos desde efluentes de cultivo de Litopenaeus vannamei, utilizando un sistema combinado de dos fases, sedimentación y filtración por la ostra Crassostrea rhizophorae, empleando tres tiempos de retención hidráulica (TRH del efluente, 6, 12 y 24 h. En la fase de sedimentación, se emplearon estanques de 100 L en los cuales fueron colocados 90 L de efluente. En la fase de filtración, se utilizaron estanques de 50 L en los cuales se colocaron 20 L del efluente sobrenadante correspondiente a cada TRH de la fase de sedimentación. Cada unidad experimental de la fase de filtración fue sembrada con 15 ejemplares adultos de ostras con un peso promedio de 80 g manteniendo una biomasa de 1.200 g estanque-1 . Se utilizó un estanque control para cada TRH, conteniendo solamente conchas de ostras sin animal. Los resultados indicaron que en la fase de sedimentación el mejor desempeño fue alcanzado en el tiempo de 24 h, con 56,1% de remoción para la turbidez, 36,3% para los sólidos volátiles totales, la DB0(5 con 31,0% y el amonio con 21,4%. En la fase de filtración, la mayor eficiencia de remoción fue alcanzada en el tiempo de 6 h, con valores de 62,1% para la turbidez, 69,4% para los sólidos disueltos totales, 35,4% para los sólidos volátiles totales, 100% para la clorofila a y 17,2% para la DB0(5, en relación a los valores del estanque control. En esta fase, el amonio presentó un aumento en su concentración en todos los TRH. Calculadas las eficiencias de remoción con las dos fases integradas: sedimentación y filtración, en el tiempo de 6 h, en relación al efluente bruto, el desempeño mejoró significativamente alcanzando valores de 69,3% para la turbidez, 69,0% para los sólidos disueltos totales, 41,3% para los sólidos volátiles totales y 100% para la clorofila a.Efficiency in removing particulate matter and dissolved

  20. Mangrove oyster (Crassostrea spp.) (Sacco, 1897) extractivism in Cananéia estuary (São Paulo, Brazil) from 1999 to 2006: capture and management evaluation.

    Science.gov (United States)

    Mendonça, J T; Machado, I C

    2010-02-01

    The oyster Crassostrea spp. is one of the main fisheries resources in the southern portion of São Paulo State. This paper aims to evaluate the extractivism of that resource, supplying subsidies to the implementation of management regulations. This study was developed in Cananéia, from February 1999 to December 2006. The oyster production data in dozens was obtained through weekly or monthly interviews. The annual and average CPUE in dozens per day was analysis to verify significant differences along years. There are no regulations that limit the fishing effort or organize the admission in the fishermen. The admission is controlled by the condition of the market and there is a risk of increasing the fishing effort above the sustainable yield, which demands measures that control the number of fishermen engaged in the activity. Those measures, to be effective, must be created in discussion with the fisheries sector, based on technical information.

  1. Effects of a bio-invasion of the Pacific oyster, Crassostrea gigas (Thunberg, 1793) in five shallow water habitats in Scandinavia

    DEFF Research Database (Denmark)

    Mortensen, Stein; Bodvin, Torjan; Strand, Åsa

    2017-01-01

    Management of invasive species is addressed in both national and international regulations regarding the protection of marine habitats and biodiversity and in regulations of aquaculture. The geographical range of the invasive Pacific oyster, Crassostrea gigas, is expanding, both through human...... mediated vectors and by natural dispersal. The species is now spreading in Scandinavia. In order to optimize the management of the oyster, including targeted monitoring and mitigation activities, knowledge on the present and future distribution and impact on the ecosystem is important. The development...... of habitats where Pacific oysters are found in Scandinavia (Low energy rock, Littoral sand and mudflats, Littoral biogenic reefs, Sublittoral sand and Sublittoral biogenic reefs) to a predicted development, thereafter assessed in relation to impact on the habitats. The assessment was done as a function...

  2. Identification of Proteins with Potential Osteogenic Activity Present in the Water-Soluble Matrix Proteins from Crassostrea gigas Nacre Using a Proteomic Approach

    Directory of Open Access Journals (Sweden)

    Daniel V. Oliveira

    2012-01-01

    Full Text Available Nacre, when implanted in vivo in bones of dogs, sheep, mice, and humans, induces a biological response that includes integration and osteogenic activity on the host tissue that seems to be activated by a set of proteins present in the nacre water-soluble matrix (WSM. We describe here an experimental approach that can accurately identify the proteins present in the WSM of shell mollusk nacre. Four proteins (three gigasin-2 isoforms and a cystatin A2 were for the first time identified in WSM of Crassostrea gigas nacre using 2DE and LC-MS/MS for protein identification. These proteins are thought to be involved in bone remodeling processes and could be responsible for the biocompatibility shown between bone and nacre grafts. These results represent a contribution to the study of shell biomineralization process and opens new perspectives for the development of new nacre biomaterials for orthopedic applications.

  3. Mangrove oyster (Crassostrea spp. (Sacco, 1897 extractivism in Cananéia estuary (São Paulo, Brazil from 1999 to 2006: capture and management evaluation

    Directory of Open Access Journals (Sweden)

    JT. Mendonça

    Full Text Available The oyster Crassostrea spp. is one of the main fisheries resources in the southern portion of São Paulo State. This paper aims to evaluate the extractivism of that resource, supplying subsidies to the implementation of management regulations. This study was developed in Cananéia, from February 1999 to December 2006. The oyster production data in dozens was obtained through weekly or monthly interviews. The annual and average CPUE in dozens per day was analysis to verify significant differences along years. There are no regulations that limit the fishing effort or organize the admission in the fishermen. The admission is controlled by the condition of the market and there is a risk of increasing the fishing effort above the sustainable yield, which demands measures that control the number of fishermen enganged in the activity. Those measures, to be effective, must be created in discussion with the fisheries sector, based on technical information.

  4. Development of an in situ hybridization assay for the detection of ostreid herpesvirus type 1 mRNAs in the Pacific oyster, Crassostrea gigas.

    Science.gov (United States)

    Corbeil, Serge; Faury, Nicole; Segarra, Amélie; Renault, Tristan

    2015-01-01

    An in situ hybridization protocol for detecting mRNAs of ostreid herpesvirus type 1 (OsHV-1) which infects Pacific oysters, Crassostrea gigas, was developed. Three RNA probes were synthesized by cloning three partial OsHV-1 genes into plasmids using three specific primer pairs, and performing a transcription in the presence of digoxigenin dUTP. The RNA probes were able to detect the virus mRNAs in paraffin sections of experimentally infected oysters 26 h post-injection. The in situ hybridization showed that the OsHV-1 mRNAs were mainly present in connective tissues in gills, mantle, adductor muscle, digestive gland and gonads. DNA detection by in situ hybridization using a DNA probe and viral DNA quantitation by real-time PCR were also performed and results were compared with those obtained using RNA probes. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Use of side-scan sonar for estimations of Crassostrea brasiliana (Lamarck, 1819 stocks in subtidal banks on the south coast of Brazil

    Directory of Open Access Journals (Sweden)

    Gisela Geraldine Castilho Westphal

    2016-03-01

    Full Text Available Abstract Uncontrolled extractivism has led to a worldwide reduction in oyster stocks. The use of new and more efficient management tools for impacted environments must increase. The application of such tools requires previous biological and environmental knowledge of the resident populations of these bivalve mollusks. Technical difficulties are usually associated with studies of submerged oyster banks, and these difficulties result in a considerable lack of biological data on the oysters that inhabit subtidal zones. This study aimed to survey Crassostrea brasiliana (also known as C. gasar stocks in submerged banks and to evaluate a method with which to measure the extent of the banks and identify and quantify the oysters in the banks with the use of side-scan sonar. This study was conducted on 10 oysters banks located in the subtidal zone of Guaratuba Bay, on the south coast of Brazil. The prospection of all these banks was later validated by diving, and oyster samples (n = 20/bank were collected for species identification with a molecular method. Only one bank contained oysters that were generically classified as Crassostrea sp.; those in the remaining banks being identified as C. brasiliana. The prospected banks contained oysters of various sizes (average 1.5 m, n = 1,107 that were heterogeneously scattered in the riverbeds. The total number of oysters in the 10 sampled banks was estimated to be 21,159.13 oysters or 1 oyster/4.5 m², which represents a low oyster density in the study site. The results validate the use of side-scan sonar as an efficient means with which to prospect for oysters in banks located within subtidal zones.

  6. Gills are an initial target of zinc oxide nanoparticles in oysters Crassostrea gigas, leading to mitochondrial disruption and oxidative stress

    International Nuclear Information System (INIS)

    Trevisan, Rafael; Delapedra, Gabriel; Mello, Danielle F.; Arl, Miriam; Schmidt, Éder C.; Meder, Fabian; Monopoli, Marco; Cargnin-Ferreira, Eduardo; Bouzon, Zenilda L.; Fisher, Andrew S.; Sheehan, David; Dafre, Alcir L.

    2014-01-01

    Graphical abstract: - Highlights: • ZnONP exposure causes an initial accumulation of zinc in gills and later in digestive gland. • Zinc burden occurs by ZnONP endocytosis or uptake of ionic zinc after dissociation. • ZnONP exposure disrupts mitochondrial ultrastructure in both tissues. • Mitochondrial damage and oxidative stress are major features of ZnONP acute toxicity. - Abstract: The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnONP) was investigated in Pacific oysters Crassostrea gigas. The nanoscale of ZnONP, in vehicle or ultrapure water, was confirmed, presenting an average size ranging from 28 to 88 nm. In seawater, aggregation was detected by TEM and DLS analysis, with an increased average size ranging from 1 to 2 μm. Soluble or nanoparticulated zinc presented similar toxicity, displaying a LC 50 (96 h) around 30 mg/L. High zinc dissociation from ZnONP, releasing ionic zinc in seawater, is a potential route for zinc assimilation and ZnONP toxicity. To investigate mechanisms of toxicity, oysters were treated with 4 mg/L ZnONP for 6, 24 or 48 h. ZnONP accumulated in gills (24 and 48 h) and digestive glands (48 h). Ultrastructural analysis of gills revealed electron-dense vesicles near the cell membrane and loss of mitochondrial cristae (6 h). Swollen mitochondria and a more conspicuous loss of mitochondrial cristae were observed after 24 h. Mitochondria with disrupted membranes and an increased number of cytosolic vesicles displaying electron-dense material were observed 48 h post exposure. Digestive gland showed similar changes, but these were delayed relative to gills. ZnONP exposure did not greatly affect thiol homeostasis (reduced and oxidized glutathione) or immunological parameters (phagocytosis, hemocyte viability and activation and total hemocyte

  7. Interactive effects of pH and metals on mitochondrial functions of intertidal bivalves Crassostrea virginica and Mercenaria mercenaria

    International Nuclear Information System (INIS)

    Ivanina, Anna V.; Sokolova, Inna M.

    2013-01-01

    Highlights: •Interactive effects of trace metals Cd and Cu and pH were studied in mitochondria of clams and oysters. •Mitochondrial respiration and membrane potential of bivalves were robust to pH variation (6.6–7.8). •Elevated levels of Cd and Cu inhibited mitochondrial respiration in the pH-dependent manner but did not affect the membrane potential. •Negative effects of Cd and Cd on mitochondrial respiration were alleviated at low pH (7.0 and below). •Moderate acidosis may protect molluscan mitochondria from metal toxicity. -- Abstract: Intertidal bivalves experience broad fluctuations of environmental temperature, pH and oxygen content which could change their intracellular pH. They are also exposed to trace metals such as cadmium (Cd) and copper (Cu) that accumulate in their tissues and may negatively affect mitochondrial functions and bioenergetics. We determined the interactive effects of pH and trace metals (25 μM Cd or Cu) on mitochondrial functions (including respiration and membrane potentials in both ADP-stimulated (state 3) and resting (state 4) states) of two common marine bivalves, the hard clams (Mercenaria mercenaria) and eastern oysters (Crassostrea virginica). In the absence of the trace metals, mitochondrial functions of C. virginica and M. mercenaria were insensitive to pH in a broad physiologically relevant range (6.6–7.8). Mitochondrial respiration was generally suppressed by 25 μM Cd or Cu (with the stronger effects observed for ADP-stimulated compared to the resting respiration) while the mitochondrial membrane potential was unaffected. pH modulated the effects of Cu and Cd on mitochondrial respiration of the bivalves. In oysters, Cu suppressed ADP-stimulated mitochondrial respiration at high and low pH values (6.6 and 7.8, respectively), but had no effect in the intermediate pH range (7.0–7.4). In clams, the negative effect of Cu on ADP-stimulated respiration was only observed at extremely high pH (7.8). A decrease in p

  8. Effects of cadmium exposure on critical temperatures of aerobic metabolism in eastern oysters Crassostrea virginica (Gmelin, 1791)

    International Nuclear Information System (INIS)

    Bagwe, Rita; Beniash, Elia; Sokolova, Inna M.

    2015-01-01

    Highlights: • Effects of Cd exposure on thermal tolerance of oysters were studied. • Temperature rise (20–36 °C) led to transition to partial anaerobiosis at critical temperature T_cII. • Exposure to Cd reduced thermal tolerance indicated by a downward shift of T_cII. • Cellular energy status was maintained but oxidative stress occurred at extreme temperatures. • Onset of anaerobiosis is a sensitive biomarker of temperature- and Cd-induced energetic stress. - Abstract: Cadmium (Cd) and elevated temperatures are common stressors in estuarine and coastal environments. Elevated temperature can sensitize estuarine organisms to the toxicity of metals such as Cd and vice versa, but the physiological mechanisms of temperature–Cd interactions are not well understood. We tested a hypothesis that interactive effects of elevated temperature and Cd stress involve Cd-induced reduction of the aerobic scope of an organism thereby narrowing the thermal tolerance window of oysters. We determined the effects of prolonged Cd exposure (50 μg Cd l"−"1 for 30 days) on the upper critical temperature of aerobic metabolism (assessed by accumulation of anaerobic end products L-alanine, succinate and acetate), cellular energy status (assessed by the tissue levels of adenylates, phosphagen/aphosphagen and glycogen and lipid reserves) and oxidative damage during acute temperature rise (20–36 °C) in the eastern oysters Crassostrea virginica. The upper critical temperature (T_cII) was shifted to lower values (from 28 to 24 °C) in Cd-exposed oysters in spring and was lower in both control and Cd-exposed groups in winter (24 and <20 °C, respectively). This indicates a reduction of thermal tolerance of Cd-exposed oysters associated with a decrease of the aerobic scope of the organism and early transition to partial anaerobiosis. Acute warming had no negative effects on tissue energy reserves or parameters of cellular energy status of oysters (except a decrease in adenylate

  9. Effects of cadmium exposure on critical temperatures of aerobic metabolism in eastern oysters Crassostrea virginica (Gmelin, 1791)

    Energy Technology Data Exchange (ETDEWEB)

    Bagwe, Rita [Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC (United States); Great Basin College, Pahrump Valley Center, Elko, NV (United States); Beniash, Elia [Department of Oral Biology, University of Pittsburgh, Pittsburgh, PA (United States); Sokolova, Inna M., E-mail: isokolov@uncc.edu [Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC (United States)

    2015-10-15

    Highlights: • Effects of Cd exposure on thermal tolerance of oysters were studied. • Temperature rise (20–36 °C) led to transition to partial anaerobiosis at critical temperature T{sub c}II. • Exposure to Cd reduced thermal tolerance indicated by a downward shift of T{sub c}II. • Cellular energy status was maintained but oxidative stress occurred at extreme temperatures. • Onset of anaerobiosis is a sensitive biomarker of temperature- and Cd-induced energetic stress. - Abstract: Cadmium (Cd) and elevated temperatures are common stressors in estuarine and coastal environments. Elevated temperature can sensitize estuarine organisms to the toxicity of metals such as Cd and vice versa, but the physiological mechanisms of temperature–Cd interactions are not well understood. We tested a hypothesis that interactive effects of elevated temperature and Cd stress involve Cd-induced reduction of the aerobic scope of an organism thereby narrowing the thermal tolerance window of oysters. We determined the effects of prolonged Cd exposure (50 μg Cd l{sup −1} for 30 days) on the upper critical temperature of aerobic metabolism (assessed by accumulation of anaerobic end products L-alanine, succinate and acetate), cellular energy status (assessed by the tissue levels of adenylates, phosphagen/aphosphagen and glycogen and lipid reserves) and oxidative damage during acute temperature rise (20–36 °C) in the eastern oysters Crassostrea virginica. The upper critical temperature (T{sub c}II) was shifted to lower values (from 28 to 24 °C) in Cd-exposed oysters in spring and was lower in both control and Cd-exposed groups in winter (24 and <20 °C, respectively). This indicates a reduction of thermal tolerance of Cd-exposed oysters associated with a decrease of the aerobic scope of the organism and early transition to partial anaerobiosis. Acute warming had no negative effects on tissue energy reserves or parameters of cellular energy status of oysters (except a

  10. Gills are an initial target of zinc oxide nanoparticles in oysters Crassostrea gigas, leading to mitochondrial disruption and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Trevisan, Rafael; Delapedra, Gabriel; Mello, Danielle F.; Arl, Miriam [Department of Biochemistry, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Schmidt, Éder C. [Department of Cell Biology, Embryology and Genetic, Federal University of Santa Catarina, 88049-900 Florianópolis, SC (Brazil); Meder, Fabian; Monopoli, Marco [Centre for Bionano Interactions, University College Dublin, Dublin (Ireland); Cargnin-Ferreira, Eduardo [Federal Institute of Santa Catarina, Campus Garopaba, Laboratory of Histological Markers, 88495-000 Garopaba, SC (Brazil); Bouzon, Zenilda L. [Department of Cell Biology, Embryology and Genetic, Federal University of Santa Catarina, 88049-900 Florianópolis, SC (Brazil); Fisher, Andrew S. [School of Geography, Earth and Environmental Sciences, University of Plymouth, PL4 8AA Plymouth (United Kingdom); Sheehan, David [Department of Biochemistry, University College Cork, Cork (Ireland); Dafre, Alcir L., E-mail: alcir.dafre@ufsc.br [Department of Biochemistry, Federal University of Santa Catarina, 88040-900 Florianópolis, SC (Brazil)

    2014-08-15

    Graphical abstract: - Highlights: • ZnONP exposure causes an initial accumulation of zinc in gills and later in digestive gland. • Zinc burden occurs by ZnONP endocytosis or uptake of ionic zinc after dissociation. • ZnONP exposure disrupts mitochondrial ultrastructure in both tissues. • Mitochondrial damage and oxidative stress are major features of ZnONP acute toxicity. - Abstract: The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnONP) was investigated in Pacific oysters Crassostrea gigas. The nanoscale of ZnONP, in vehicle or ultrapure water, was confirmed, presenting an average size ranging from 28 to 88 nm. In seawater, aggregation was detected by TEM and DLS analysis, with an increased average size ranging from 1 to 2 μm. Soluble or nanoparticulated zinc presented similar toxicity, displaying a LC{sub 50} (96 h) around 30 mg/L. High zinc dissociation from ZnONP, releasing ionic zinc in seawater, is a potential route for zinc assimilation and ZnONP toxicity. To investigate mechanisms of toxicity, oysters were treated with 4 mg/L ZnONP for 6, 24 or 48 h. ZnONP accumulated in gills (24 and 48 h) and digestive glands (48 h). Ultrastructural analysis of gills revealed electron-dense vesicles near the cell membrane and loss of mitochondrial cristae (6 h). Swollen mitochondria and a more conspicuous loss of mitochondrial cristae were observed after 24 h. Mitochondria with disrupted membranes and an increased number of cytosolic vesicles displaying electron-dense material were observed 48 h post exposure. Digestive gland showed similar changes, but these were delayed relative to gills. ZnONP exposure did not greatly affect thiol homeostasis (reduced and oxidized glutathione) or immunological parameters (phagocytosis, hemocyte viability and activation and total

  11. Interactive effects of pH and metals on mitochondrial functions of intertidal bivalves Crassostrea virginica and Mercenaria mercenaria

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, Anna V.; Sokolova, Inna M., E-mail: isokolov@uncc.edu

    2013-11-15

    Highlights: •Interactive effects of trace metals Cd and Cu and pH were studied in mitochondria of clams and oysters. •Mitochondrial respiration and membrane potential of bivalves were robust to pH variation (6.6–7.8). •Elevated levels of Cd and Cu inhibited mitochondrial respiration in the pH-dependent manner but did not affect the membrane potential. •Negative effects of Cd and Cd on mitochondrial respiration were alleviated at low pH (7.0 and below). •Moderate acidosis may protect molluscan mitochondria from metal toxicity. -- Abstract: Intertidal bivalves experience broad fluctuations of environmental temperature, pH and oxygen content which could change their intracellular pH. They are also exposed to trace metals such as cadmium (Cd) and copper (Cu) that accumulate in their tissues and may negatively affect mitochondrial functions and bioenergetics. We determined the interactive effects of pH and trace metals (25 μM Cd or Cu) on mitochondrial functions (including respiration and membrane potentials in both ADP-stimulated (state 3) and resting (state 4) states) of two common marine bivalves, the hard clams (Mercenaria mercenaria) and eastern oysters (Crassostrea virginica). In the absence of the trace metals, mitochondrial functions of C. virginica and M. mercenaria were insensitive to pH in a broad physiologically relevant range (6.6–7.8). Mitochondrial respiration was generally suppressed by 25 μM Cd or Cu (with the stronger effects observed for ADP-stimulated compared to the resting respiration) while the mitochondrial membrane potential was unaffected. pH modulated the effects of Cu and Cd on mitochondrial respiration of the bivalves. In oysters, Cu suppressed ADP-stimulated mitochondrial respiration at high and low pH values (6.6 and 7.8, respectively), but had no effect in the intermediate pH range (7.0–7.4). In clams, the negative effect of Cu on ADP-stimulated respiration was only observed at extremely high pH (7.8). A decrease in p

  12. estructura de tallas, crecimiento y mortalidad de Crassostrea rhizophorae en la laguna de la r estinga, isla de margarita, Venezuela I size structure , gro W tH and mortality o F Crassostrea rhizophorae at la restinga lagoon , margarita island , V enezuela

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    Carmen González

    2018-05-01

    Full Text Available The size structure, height - weight relationship and growth rate and mortality of the mangrove oyster Crassostrea rhizophorae were evaluated in the area La Tortuga, La Restinga Lagoon, during the period march 2012 - february 2013. Monthly ramdom samples of oysters were taken. The annual size composition consisted of individuals between 15 and 95 mm in length, with a larger number of individuals in the range 45 to 60 mm. The length-weight relationship showed a positive relationship, with a correlation coefficient r = 0.66 and a slope b = 1.80, indicating that the species has a negative allometric growth. The model of growth in length was represented by the equation Lt = 103.41 [1 - exp (-1.59 (t-0, 31], showing a fast growth which allows the oyster to reach commercial size (60 mm at 6 months, with a maximum estimated longevity of 2 years.

  13. Immunological responses of the mangrove oysters Crassostrea gasar naturally infected by Perkinsus sp. in the Mamanguape Estuary, Paraíba state (Northeastern, Brazil).

    Science.gov (United States)

    Queiroga, Fernando Ramos; Marques-Santos, Luis Fernando; Hégaret, Hélène; Soudant, Philippe; Farias, Natanael Dantas; Schlindwein, Aline Daiane; Mirella da Silva, Patricia

    2013-08-01

    Perkinsus genus includes protozoan parasites of marine mollusks, especially bivalves. In the last four years, this parasite has been detected in mangrove oysters Crassostrea rhizophorae and Crassostrea gasar from the Northeastern region of Brazil. Hemocytes are the key cells of the oyster immune system, being responsible for a variety of cellular and humoral reactions, such as phagocytosis, encapsulation and the release of several effector molecules that control the invasion and proliferation of microorganisms. In Brazil, there is little information on perkinsosis and none on the immune responses of native oysters' species against Perkinsus spp. The objective of this study was to determine the effects of natural infection by Perkinsus sp. on the immunological parameters of mangrove oysters C. gasar cultured in the Mamanguape River Estuary (Paraíba, Brazil). Adults oysters (N = 40/month) were sampled in December 2011, March, May, August and October 2012. Gills were removed and used to determine the presence and intensity of the Perkinsus sp. infection, according to a scale of four levels (1-4), using the Ray's fluid thioglycollate medium assay. Immunological parameters were measured in hemolymph samples by flow cytometry, including: total hemocyte count (THC), differential hemocyte count (DHC), cell mortality, phagocytic capacity, and production of Reactive Oxygen Species (ROS). The plasma was used to determine the hemagglutination activity. The results showed the occurrence of Perkinsus sp. with the highest mean prevalence (93.3%) seen so far in oyster populations in Brazil. Despite that, no oyster mortality was associated. In contrast, we observed an increase in hemocyte mortality and a suppression of two of the main defense mechanisms, phagocytosis and ROS production in infected oysters. The increase in the percentage of blast-like cells on the hemolymph, and the increase in THC in oysters heavily infected (at the maximum intensity, 4) suggest an induction of

  14. Non-additive effects of ocean acidification in combination with warming on the larval proteome of the Pacific oyster, Crassostrea gigas.

    Science.gov (United States)

    Harney, Ewan; Artigaud, Sébastien; Le Souchu, Pierrick; Miner, Philippe; Corporeau, Charlotte; Essid, Hafida; Pichereau, Vianney; Nunes, Flavia L D

    2016-03-01

    Increasing atmospheric carbon dioxide results in ocean acidification and warming, significantly impacting marine invertebrate larvae development. We investigated how ocean acidification in combination with warming affected D-veliger larvae of the Pacific oyster Crassostrea gigas. Larvae were reared for 40h under either control (pH8.1, 20 °C), acidified (pH7.9, 20 °C), warm (pH8.1, 22 °C) or warm acidified (pH7.9, 22 °C) conditions. Larvae in acidified conditions were significantly smaller than in the control, but warm acidified conditions mitigated negative effects on size, and increased calcification. A proteomic approach employing two-dimensional electrophoresis (2-DE) was used to quantify proteins and relate their abundance to phenotypic traits. In total 12 differentially abundant spots were identified by nano-liquid chromatography-tandem mass spectrometry. These proteins had roles in metabolism, intra- and extra-cellular matrix formations, stress response, and as molecular chaperones. Seven spots responded to reduced pH, four to increased temperature, and six to acidification and warming. Reduced abundance of proteins such as ATP synthase and GAPDH, and increased abundance of superoxide dismutase, occurred when both pH and temperature changes were imposed, suggesting altered metabolism and enhanced oxidative stress. These results identify key proteins that may be involved in the acclimation of C. gigas larvae to ocean acidification and warming. Increasing atmospheric CO2 raises sea surface temperatures and results in ocean acidification, two climatic variables known to impact marine organisms. Larvae of calcifying species may be particularly at risk to such changing environmental conditions. The Pacific oyster Crassostrea gigas is ecologically and commercially important, and understanding its ability to acclimate to climate change will help to predict how aquaculture of this species is likely to be impacted. Modest, yet realistic changes in pH and

  15. A Preliminary Study on the Pattern, the Physiological Bases and the Molecular Mechanism of the Adductor Muscle Scar Pigmentation in Pacific Oyster Crassostrea gigas

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    Wenchao Yu

    2017-09-01

    Full Text Available The melanin pigmentation of the adductor muscle scar and the outer surface of the shell are among attractive features and their pigmentation patterns and mechanism still remains unknown in the Pacific oyster Crassostrea gigas. To study these pigmentation patterns, the colors of the adductor muscle scar vs. the outer surface of the shell on the same side were compared. No relevance was found between the colors of the adductor muscle scars and the corresponding outer surface of the shells, suggesting that their pigmentation processes were independent. Interestingly, a relationship between the color of the adductor muscle scars and the dried soft-body weight of Pacific oysters was found, which could be explained by the high hydroxyl free radical scavenging capacity of the muscle attached to the black adductor muscle scar. After the transcriptomes of pigmented and unpigmented adductor muscles and mantles were studied by RNAseq and compared, it was found that the retinol metabolism pathway were likely to be involved in melanin deposition on the adductor muscle scar and the outer surface of the shell, and that the different members of the tyrosinase or Cytochrome P450 gene families could play a role in the independent pigmentation of different organs.

  16. Spatial genetic features of eastern oysters (Crassostrea virginica Gmelin) in the Gulf of Mexico: northward movement of a secondary contact zone.

    Science.gov (United States)

    Anderson, Joel D; Karel, William J; Mace, Christopher E; Bartram, Brian L; Hare, Matthew P

    2014-05-01

    The eastern oyster (Crassostrea virginica Gmelin) is an economically and ecologically valuable marine bivalve occurring in the Gulf of Mexico. This study builds upon previous research that identified two divergent populations of eastern oysters in the western Gulf of Mexico. Allelic and genotypic patterns from 11 microsatellite markers were used to assess genetic structure and migration between the previously described oyster populations in Texas. The main findings are as follows: (1) there are two distinct populations (F ST = 0.392, P turbidity and depth are not correlated with allele frequencies on reefs in the contact zone or when analyzed across Texas, and (4) there is little evidence of directional selection acting on the loci assayed here, although patterns at four markers suggested the influence of balancing selection based on outlier analyses. These results are consistent with long-term historical isolation between populations, followed by secondary contact. Recent hydrological changes in the area of secondary contact may be promoting migration in areas that were previously inhospitable to eastern oysters, and observed differences in the timing of spawning may limit hybridization between populations. Comparison of these findings with the results of an earlier study of oysters in Texas suggests that the secondary contact zone has shifted approximately 27 km north, in as little as a 23-year span.

  17. Environmental parameters influence on the dynamics of total and pathogenic Vibrio parahaemolyticus densities in Crassostrea virginica harvested from Mexico's Gulf coast.

    Science.gov (United States)

    López-Hernández, Karla M; Pardío-Sedas, Violeta T; Lizárraga-Partida, Leonardo; Williams, José de J; Martínez-Herrera, David; Flores-Primo, Argel; Uscanga-Serrano, Roxana; Rendón-Castro, Karla

    2015-02-15

    The influence of environmental parameters on the total and pathogenic Vibrio parahaemolyticus seasonal densities in American oysters (Crassostrea virginica) was evaluated for 1 year. Harvesting site A yielded the highest mean densities of V. parahaemolyticus tlh+, tdh+/trh-, tdh-/trh+ and tdh+/trh+ during spring season at 2.57, 1.74, 0.36, and -0.40 log10 MPN/g, respectively, and tdh+/orf8+ during winter season (0.90 log10 MPN/g). V. parahaemolyticus tlh+ densities were associated to salinity (R(2)=0.372, Pturbidity (R(2)=0.597, P<0.035), and orf8+ to temperature, salinity, and pH (R(2)=0.964, P<0.001). The exposure to salinity and temperature conditions during winter and spring seasons regulated the dynamics of V. parahaemolyticus harboring potentially pathogenic genotypes within the oyster. The adaptive response of V. parahaemolyticus to seasonal environmental changes may lead to an increase in survival and virulence, threatening the seafood safety and increasing the risk of illness. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Ostreid herpesvirus OsHV-1 μVar in Pacific oysters Crassostrea gigas (Thunberg 1793) of the Wadden Sea, a UNESCO world heritage site.

    Science.gov (United States)

    Gittenberger, A; Voorbergen-Laarman, M A; Engelsma, M Y

    2016-01-01

    The Wadden Sea is an extensive wetland area, recognized as UNESCO world heritage site of international importance. Since the mid-1990s, the invasive Pacific oyster Crassostrea gigas (Thunberg 1793) population in the area has grown exponentially, having a distinct impact on the ecosystem. The recent spread of the emerging oyster pathogen Ostreid herpesvirus OsHV-1 μVar worldwide and specifically in the oyster culture areas in the south of the Netherlands raised the question whether the virus may also be present in the Wadden Sea. In the summer of 2012 juvenile Pacific oysters were collected from five locations in the Dutch Wadden Sea. The virus was shown to be present in three of the five locations by real-time PCR and sequencing. It was concluded that OsHV-1 μVar has settled itself in Pacific oyster reefs in the Wadden Sea. These results and the recent discoveries of OsHV-1 microvariants in Australia and Korea indicate that OsHV-1 μVar and related variants might be more widespread than can be deduced from current literature. In particular in regions with no commercial oyster culture, similar to the Wadden Sea, the virus may go undetected as wild beds with mixed age classes hamper the detection of mortality among juvenile oysters. © 2015 John Wiley & Sons Ltd.

  19. Levels of Platinum Group Metals in Selected Species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa in Some Estuaries and Lagoons Along the Coast of Ghana

    Directory of Open Access Journals (Sweden)

    D. K. Essumang

    2010-01-01

    Full Text Available The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae, brown goby (Chonophorus lateristriga Gobiidae, shrimp (Macrobrachium vollenhovenii Palaemonidae, and mangrove oysters (Crassostrea tulipa Ostreidae in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μ/g (dry weight Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

  20. Quantitative PCR assay to determine prevalence and intensity of MSX (Haplosporidium nelsoni) in North Carolina and Rhode Island oysters Crassostrea virginica.

    Science.gov (United States)

    Wilbur, Ami E; Ford, Susan E; Gauthier, Julie D; Gomez-Chiarri, Marta

    2012-12-27

    The continuing challenges to the management of both wild and cultured eastern oyster Crassostrea virginica populations resulting from protozoan parasites has stimulated interest in the development of molecular assays for their detection and quantification. For Haplosporidium nelsoni, the causative agent of multinucleated sphere unknown (MSX) disease, diagnostic evaluations depend extensively on traditional but laborious histological approaches and more recently on rapid and sensitive (but not quantitative) end-point polymerase chain reaction (PCR) assays. Here, we describe the development and application of a quantitative PCR (qPCR) assay for H. nelsoni using an Applied Biosystems TaqMan® assay designed with minor groove binder (MGB) probes. The assay was highly sensitive, detecting as few as 20 copies of cloned target DNA. Histologically evaluated parasite density was significantly correlated with the quantification cycle (Cq), regardless of whether quantification was categorical (r2 = 0.696, p < 0.0001) or quantitative (r2 = 0.797, p < 0.0001). Application in field studies conducted in North Carolina, USA (7 locations), revealed widespread occurrence of the parasite with moderate to high intensities noted in some locations. In Rhode Island, USA, application of the assay on oysters from 2 locations resulted in no positives.

  1. First report of the protozoan parasite Perkinsus marinus in South America, infecting mangrove oysters Crassostrea rhizophorae from the Paraíba River (NE, Brazil).

    Science.gov (United States)

    da Silva, Patricia Mirella; Vianna, Rogério Tubino; Guertler, Cristhiane; Ferreira, Liana Pinho; Santana, Lucas Nunes; Fernández-Boo, Sergio; Ramilo, Andrea; Cao, Asunción; Villalba, Antonio

    2013-05-01

    The present work aimed to study the infection by Perkinsus sp. in the mangrove oysters Crassostrea rhizophorae from the estuary of the Paraíba River (Paraíba State, Brazil). Perkinsosis was detected by incubation of oyster gill pieces in Ray's fluid thioglycollate medium. The monthly prevalence values were all above 70%, thus infection was not likely to be a transient event. Perkinsus sp. parasites isolated from eight oysters were propagated in vitro. PCR-RFLP analysis of in vitro cultured cells as well as the sequences of the rDNA ITS region allowed the identification of the in vitro propagated parasites as Perkinsus marinus. Phylogenetic analyses using rDNA ITS region sequences strongly supported the Perkinsus sp. from Paraíba in a monophyletic group with P. marinus. Thus, the results confirmed the species affiliation of Paraíba Perkinsus sp. as P. marinus. This is the first report of P. marinus in Brazil and South America and the first report of P. marinus naturally infecting C. rhizophorae. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Paralytic Toxins Accumulation and Tissue Expression of α-Amylase and Lipase Genes in the Pacific Oyster Crassostrea gigas Fed with the Neurotoxic Dinoflagellate Alexandrium catenella

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    Mohamed Laabir

    2012-11-01

    Full Text Available The pacific oyster Crassostrea gigas was experimentally exposed to the neurotoxic Alexandrium catenella and a non-producer of PSTs, Alexandrium tamarense (control algae, at concentrations corresponding to those observed during the blooming period. At fixed time intervals, from 0 to 48 h, we determined the clearance rate, the total filtered cells, the composition of the fecal ribbons, the profile of the PSP toxins and the variation of the expression of two α-amylase and triacylglecerol lipase precursor (TLP genes through semi-quantitative RT-PCR. The results showed a significant decrease of the clearance rate of C. gigas fed with both Alexandrium species. However, from 29 to 48 h, the clearance rate and cell filtration activity increased only in oysters fed with A. tamarense. The toxin concentrations in the digestive gland rose above the sanitary threshold in less than 48 h of exposure and GTX6, a compound absent in A. catenella cells, accumulated. The α-amylase B gene expression level increased significantly in the time interval from 6 to 48 h in the digestive gland of oysters fed with A. tamarense, whereas the TLP gene transcript was significantly up-regulated in the digestive gland of oysters fed with the neurotoxic A. catenella. All together, these results suggest that the digestion capacity could be affected by PSP toxins.

  3. Distribution, Condition and Gonad Maturity of the Invasive Pacific Oysters (Crassostrea Gigas, Thunberg 1793 in Cimanuk Delta, Indramayu, West Java, Indonesia

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    Selia Hermawati

    2017-11-01

    Full Text Available Pacific oyster (Crassostrea gigas is an invasive species which is able to adapt a wide range of environmental conditions. The study was conducted from August to October 2014. Objective of this study was to asses the distribution pattern, condition and gonad maturity length (Lm 50% of the Pacific oysters in mangrove ecosystem of Cimanuk Delta, Indramayu, West Java, Indonesia.  This study was conducted in two adjacent areas:  Pabean Ilir and Pagirikan subdeltas. The oysters were collected from the estuary, brackish water ponds and the coastal flat, and  observed for their abundance, total length (mm and weight (g. Morphological and histological methods were used to estimate the gonad maturity stage. Analysis were carried out to estimate distribution pattern and condition factor. According to the study, the Pacific oyster distribution pattern was clumped. The condition factor of the oyster was higher in the brackish water pond and estuary than in the coastal flat.  The Pacific oyster was found in gonad maturity stage (GMS I – IV. The oyster was hermaprodit protandry and had length maturity (Lm 50% of 47,46-48,43 mm (male and 75,27-75,50  mm (female.

  4. Crassostrea gigas mortality in France: the usual suspect, a herpes virus, may not be the killer in this polymicrobial opportunistic disease

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    Bruno ePetton

    2015-07-01

    Full Text Available Successive disease outbreaks in oyster (Crassostrea gigas beds in France have resulted in dramatic losses in production, and subsequent decline in the oyster-farming industry. Deaths of juvenile oysters have been associated with the presence of a herpes virus (OsHV-1 µvar and bacterial populations of the genus Vibrio. Although the pathogenicity of OsHV-1 µvar, as well as several strains of Vibrio has been demonstrated by experimental infections, our understanding of the complexity of infections occurring in the natural environment remains limited. In the present study, we use specific-pathogen-free (SPF oysters infected in an estuarine environment to study the diversity and dynamics of cultured microbial populations during disease expression. We observe that rapid Vibrio colonization followed by viral replication precedes oyster death. No correlation was found between the vibrio concentration and viral load in co-infected animals. We show that the quantity of viral DNA is a predictor of mortality, however, in the absence of bacteria, a high load of herpes virus is not sufficient to induce the full expression of the disease. In addition, we demonstrate that juvenile mortalities can occur in the absence of herpes virus, indicating that the herpes virus appears neither essential nor sufficient to cause juvenile deaths; whereas bacteria are necessary for the disease. Finally, we demonstrate that oysters are a reservoir of putative pathogens, and that the geographic origin, age, and cultivation method of oysters influence disease expression.

  5. Crassostrea gigas mortality in France: the usual suspect, a herpes virus, may not be the killer in this polymicrobial opportunistic disease.

    Science.gov (United States)

    Petton, Bruno; Bruto, Maxime; James, Adèle; Labreuche, Yannick; Alunno-Bruscia, Marianne; Le Roux, Frédérique

    2015-01-01

    Successive disease outbreaks in oyster (Crassostrea gigas) beds in France have resulted in dramatic losses in production, and subsequent decline in the oyster-farming industry. Deaths of juvenile oysters have been associated with the presence of a herpes virus (OsHV-1 μvar) and bacterial populations of the genus Vibrio. Although the pathogenicity of OsHV-1 μvar, as well as several strains of Vibrio has been demonstrated by experimental infections, our understanding of the complexity of infections occurring in the natural environment remains limited. In the present study, we use specific-pathogen-free (SPF) oysters infected in an estuarine environment to study the diversity and dynamics of cultured microbial populations during disease expression. We observe that rapid Vibrio colonization followed by viral replication precedes oyster death. No correlation was found between the vibrio concentration and viral load in co-infected animals. We show that the quantity of viral DNA is a predictor of mortality, however, in the absence of bacteria, a high load of herpes virus is not sufficient to induce the full expression of the disease. In addition, we demonstrate that juvenile mortalities can occur in the absence of herpes virus, indicating that the herpes virus appears neither essential nor sufficient to cause juvenile deaths; whereas bacteria are necessary for the disease. Finally, we demonstrate that oysters are a reservoir of putative pathogens, and that the geographic origin, age, and cultivation method of oysters influence disease expression.

  6. Gene expression correlated with delay in shell formation in larval Pacific oysters (Crassostrea gigas) exposed to experimental ocean acidification provides insights into shell formation mechanisms.

    Science.gov (United States)

    De Wit, Pierre; Durland, Evan; Ventura, Alexander; Langdon, Chris J

    2018-02-22

    Despite recent work to characterize gene expression changes associated with larval development in oysters, the mechanism by which the larval shell is first formed is still largely unknown. In Crassostrea gigas, this shell forms within the first 24 h post fertilization, and it has been demonstrated that changes in water chemistry can cause delays in shell formation, shell deformations and higher mortality rates. In this study, we use the delay in shell formation associated with exposure to CO 2 -acidified seawater to identify genes correlated with initial shell deposition. By fitting linear models to gene expression data in ambient and low aragonite saturation treatments, we are able to isolate 37 annotated genes correlated with initial larval shell formation, which can be categorized into 1) ion transporters, 2) shell matrix proteins and 3) protease inhibitors. Clustering of the gene expression data into co-expression networks further supports the result of the linear models, and also implies an important role of dynein motor proteins as transporters of cellular components during the initial shell formation process. Using an RNA-Seq approach with high temporal resolution allows us to identify a conceptual model for how oyster larval calcification is initiated. This work provides a foundation for further studies on how genetic variation in these identified genes could affect fitness of oyster populations subjected to future environmental changes, such as ocean acidification.

  7. Ocean acidification stimulates alkali signal pathway: A bicarbonate sensing soluble adenylyl cyclase from oyster Crassostrea gigas mediates physiological changes induced by CO2 exposure.

    Science.gov (United States)

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Wang, Hao; Jiang, Shuai; Chen, Hao; Wang, Lingling; Song, Linsheng

    2016-12-01

    Ocean acidification (OA) has been demonstrated to have severe effects on marine organisms, especially marine calcifiers. However, the impacts of OA on the physiology of marine calcifiers and the underlying mechanisms remain unclear. Soluble adenylyl cyclase (sAC) is an acid-base sensor in response to [HCO 3 - ] and an intracellular source of cyclic AMP (cAMP). In the present study, an ortholog of sAC was identified from pacific oyster Crassostrea gigas (designated as CgsAC) and the catalytic region of CgsAC was cloned and expressed. Similar to the native CgsAC from gill tissues, the recombinant CgsAC protein (rCgsAC) exhibited [HCO 3 - ] mediated cAMP-forming activity, which could be inhibited by a small molecule KH7. After 16days of CO 2 exposure (pH=7.50), the mRNA transcripts of CgsAC increased in muscle, mantle, hepatopancreas, gill, male gonad and haemocytes, and two truncated CgsAC forms of 45kD and 20kD were produced. Cytosolic CgsAC could be translocated from the cytoplasm and nuclei to the membrane in response to CO 2 exposure. Besides, CO 2 exposure could increase the production of cAMP and intracellular pH of haemocytes, which was regulated by CgsAC (pocean acidification on marine calcifiers. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Environmental parameters influence on the dynamics of total and pathogenic Vibrio parahaemolyticus densities in Crassostrea virginica harvested from Mexico’s Gulf coast

    International Nuclear Information System (INIS)

    López-Hernández, Karla M.; Pardío-Sedas, Violeta T.; Lizárraga-Partida, Leonardo; Williams, José de J.; Martínez-Herrera, David; Flores-Primo, Argel; Uscanga-Serrano, Roxana; Rendón-Castro, Karla

    2015-01-01

    Highlights: • V. parahaemolyticus densities in oysters were isolated in spring and winter seasons. • Pathogenic genes abundances varied with environmental parameters seasonal changes. • Water temperature modulated V. parahaemolyticus abundance during reduced salinities. • V. parahaemolyticus with potentially pathogenic genes raises important health issues. - Abstract: The influence of environmental parameters on the total and pathogenic Vibrio parahaemolyticus seasonal densities in American oysters (Crassostrea virginica) was evaluated for 1 year. Harvesting site A yielded the highest mean densities of V. parahaemolyticus tlh+, tdh+/trh−, tdh−/trh+ and tdh+/trh+ during spring season at 2.57, 1.74, 0.36, and −0.40 log 10 MPN/g, respectively, and tdh+/orf8+ during winter season (0.90 log 10 MPN/g). V. parahaemolyticus tlh+ densities were associated to salinity (R 2 = 0.372, P < 0.022), tdh+/trh+ to turbidity (R 2 = 0.597, P < 0.035), and orf8+ to temperature, salinity, and pH (R 2 = 0.964, P < 0.001). The exposure to salinity and temperature conditions during winter and spring seasons regulated the dynamics of V. parahaemolyticus harboring potentially pathogenic genotypes within the oyster. The adaptive response of V. parahaemolyticus to seasonal environmental changes may lead to an increase in survival and virulence, threatening the seafood safety and increasing the risk of illness

  9. SEASONAL VARIATION OF Perkinsus marinus IN THE AMERICAN OYSTER Crassostrea virginica FROM THE CARMEN-MACHONA PAJONAL LAGOON SYSTEM IN TABASCO, MEXICO

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    Sergio Curiel-Ramírez-Gutiérrez

    2012-11-01

    Full Text Available In the Gulf of Mexico, the fishery of the oyster Crassostrea virginica is the main resource for you capture volume (42, 796 t. This resource is affected by the disease of the Dermo, which has been little studied in the Gulf of Mexico. The objective of the study was to determine the prevalence and grade of infection of Perkinsus marinus in Tabasco. Samples were realized by Fluid Thioglycolate medium (MFT, histopathology and PCR in oysters of six banks in the lagoon system Carmen-Machona-Pajonal, Tabasco. The results of the MFT after incubation, showed hipnosporas of blue-black. The histopathological analysis revealed alterations in the tissues connective and epithelial, as well as the forms characteristic of P. marinus, such as tomontes and trophozoites. The identity of the parasite was confirmed by PCR analysis. The prevalence of P. marinus registered in times of rain, north-wind and dry was 73.3, 90 and 100%; the degree of infection was 2, 3 and 5 on the scale of Mackin, respectively. There is a relationship of the prevalence and intensity of the infection with respect to increased temperature and salinity, where the dry season was most critical.

  10. Factibilidad económico-ambiental para el cultivo sostenible de ostión de mangle Crassostrea rhizophorae (Güilding, 1828, en Cuba

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    Abel Betanzos-Vega

    2014-11-01

    Full Text Available Se analizaron dos variantes en la producción de ostión de mangle Crassostrea rhizophorae en Cuba: 1 extracción pesquera tradicional (EP en bancos naturales, apoyada en menor grado con acuicultura artesanal por agregación de colectores de mangle suspendidos en el manglar, y 2 cultivo artesanal (CA, obteniendo semillas del medio natural en colectores de "concha madre", con engorde y cosecha en el mismo colector y en canastas o cajas ostrícolas. Se determinó la factibilidad económico-ambiental de ambas variantes proyectadas a cinco años, a partir del análisis de costo-beneficio económico basado en datos de operación pesquera y se incluyeron costos estimados por daño ambiental. La variante extractiva (EP mostró una rentabilidad negativa durante el periodo proyectado (US$-1.388,39 en el quinto año, con impacto negativo sobre el ecosistema de manglar. La variante productiva (CA mostró ganancias a partir del tercer año y una rentabilidad positiva durante el periodo proyectado (US$731,78 al quinto año, con reducción de daños al ecosistema de manglar. De acuerdo a estos resultados, se recomienda desarrollar el cultivo y manejo sustentable de la ostra nativa C. rhizophorae en Cuba.

  11. Assessment of pollution of the Boca de Camichin Estuary in Nayarit (Mexico) and its influence on oxidative stress in Crassostrea corteziensis oysters.

    Science.gov (United States)

    Toledo-Ibarra, G A; Díaz Resendiz, K J G; Ventura-Ramón, G H; Romero-Bañuelos, C A; Medina-Díaz, I M; Rojas-García, A E; Vega-López, A; Girón-Pérez, M I

    2016-10-01

    Boca de Camichin Estuary is one of the main producers of Crassostrea corteziensis oysters in Mexico, but the presence of pollutants can affect oyster production. Molluscs produce reactive oxygen species (ROS) in response to changes in the environment and pollution. These ROS induce oxidative damage in biomolecules. The main objective of this study was to evaluate pollution in the estuary and the subsequent oxidative stress in C. corteziensis oysters during the 2010 production cycle. For this aim, we performed monthly samplings in the oyster farms from January to May. We took water samples to quantify polycyclic aromatic hydrocarbon (PAH) and metal content; also, we evaluated oxidative damage (lipoperoxidation, lipidic hydroperoxides, protein oxidation) and enzyme activity (CAT, SOD, GPx, GST and AChE) in oyster gills. The results show the presence of Cu, Fe, Mn, naphthalene, benz[a]anthracene, pyrene, benz[a]pyrene and benzo[k]fluoranthene. On the other hand, AChE activity was not inhibited, which suggests that organophosphorus pollutants or carbamates were absent. Regarding oxidative stress, oysters from the estuary had oxidative damage in lipids, not proteins, and altered antioxidant enzyme activity, when compared to control organisms. Interestingly, we did not observe any correlation between the pollutants and the oxidative stress parameters evaluated in this study. Thus, we cannot rule out that a synergistic effect between the environmental variables and the pollutants is causing the oxidative stress in these oysters. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. First evidence of a potential antibacterial activity involving a laccase-type enzyme of the phenoloxidase system in Pacific oyster Crassostrea gigas haemocytes.

    Science.gov (United States)

    Luna-Acosta, Andrea; Saulnier, Denis; Pommier, Mylène; Haffner, Philippe; De Decker, Sophie; Renault, Tristan; Thomas-Guyon, Hélène

    2011-12-01

    Phenoloxidases (POs) are a group of copper proteins including tyrosinase, catecholase and laccase. In several insects and crustaceans, antibacterial substances are produced through the PO cascade, participating in the direct killing of invading microorganisms. However, although POs are widely recognised as an integral part of the invertebrate immune defence system, experimental evidence is lacking that these properties are conserved in molluscs, and more particularly in the Pacific oyster Crassostrea gigas. In the present study, Vibrio splendidus LGP32 and Vibrio aestuarianus 02/041 growths were affected, after being treated with C. gigas haemocyte lysate supernatant (HLS), and either a common substrate of POs, l-3,4-dihydroxyphenylalanine (L-DOPA), to detect catecholase-type PO activity, or a specific substrate of laccase, p-phenylenediamine (PPD), to detect laccase-type PO activity. Interestingly, a higher bacterial growth inhibition was observed in the presence of PPD than in the presence of L-DOPA. These effects were suppressed when the specific PO inhibitor, phenylthiourea (PTU), was added to the medium. Results of the present study suggest, for the first time in a mollusc species, that antibacterial activities of HLS from C. gigas potentially involve POs, and more particularly laccase catalysed reactions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Impact of Environment and Ontogeny on Relative Fecundity and Egg Quality of Female Oysters (Crassostrea virginica) from Four Sites in Northern Chesapeake Bay.

    Science.gov (United States)

    Glandon, Hillary Lane; Michaelis, Adriane K; Politano, Vincent A; Alexander, Stephanie T; Vlahovich, Emily A; Reece, Kimberly S; Koopman, Heather N; Meritt, Donald W; Paynter, Kennedy T

    2016-12-01

    Resource allocation to reproduction is a primary physiological concern for individuals, and can vary with age, environment, or a combination of both factors. In this study we quantified the impact of environment and individual age on the reproductive output of female oysters Crassostrea virginica. We determined the relative fecundity, egg total lipid content, and overall and omega-3/omega-6 (ω3/ω6) fatty acid signatures (FAS) of eggs spawned by female oysters over a 2-year period (n = 32 and n = 64). Variation was quantified spatially and ontogenetically by sampling young and old oyster populations from two rivers in Chesapeake Bay, totaling four collection sites. During Year 1, when oysters underwent oogenesis in different locations, overall and ω3/ω6 egg FAS varied significantly by river, with no significant differences observed in the FAS of oysters by age in Year 1. In Year 2, when oysters from different sites underwent oogenesis in a single location, no significant differences in the overall egg FAS or ω3/ω6 egg FAS by river or age were observed. These findings suggest that oysters integrate environment into their reproductive output, but that time spent growing at a specific location (in this case, represented by oyster age) plays a relatively minor role in the biochemical composition of oyster eggs. These results have consequences for our understanding of how resources are allocated from the female oyster to eggs and, more generally, the impact of environment and ontogeny on reproductive physiology.

  14. Oocyte maturation and origin of the germline as revealed by the expression of Nanos-like in the Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Xu, Rui; Li, Qi; Yu, Hong; Kong, Lingfeng

    2018-04-13

    Nanos gene plays an important role in germline development in animals. However, the molecular mechanisms involved in germline development in Mollusca, the second largest animal phylum, are still poorly understood. Here we identified the Nanos orthologue from the Pacific oyster Crassostrea gigas (Cg-Nanos-like), and investigated the expression patterns of Nanos during gametogenesis and embryogenesis in C. gigas. Tissue expression analysis showed that Cg-Nanos-like was specifically expressed in female gonads. During the reproductive cycle, the expression of Cg-Nanos-like mRNA increased matching the seasonal development of the ovarian tissues in diploids, while the expression levels were significantly lower in the ovaries of sterile triploids compared to diploids. High expression of Cg-Nanos-like transcripts were detected in early embryonic stages, while the expression significantly dropped at gastrulation and was barely detectable in veliger stages. In situ hybridization showed that Cg-Nanos-like was expressed at different stages of developing oocytes, whereas positive signals were detected only in spermatogonia during the spermatogenic cycle. These findings indicated that Cg-Nanos-like was involved in the development of germ cells, and maintenance of oocyte maturation. In early embryogenesis, the transcripts were broadly expressed; following gastrulation, the expression was restricted to two cell clumps, which might be the putative primordial germ cells (PGCs) or their precursors. Based on the results, the formation of the PGCs in C. gigas was consistent with the model of transition from epigenesis to preformation. Copyright © 2017. Published by Elsevier B.V.

  15. Hemocyte parameters of the Pacific oyster Crassostrea gigas a year after the Hebei Spirit oil spill off the west coast of Korea

    Science.gov (United States)

    Donaghy, Ludovic; Hong, Hyun-Ki; Lee, Hee-Jung; Jun, Je-Cheon; Park, Young-Je; Choi, Kwang-Sik

    2010-12-01

    In marine bivalves, hemocytes support various physiological functions, including immune defense, nutrient transport, shell repair, and homeostatic maintenance. Although the effects of marine contaminants on the immunological functions of bivalves have been extensively investigated, the impacts of oil spills are not well understood. Therefore, we investigated hemocyte parameters in the Pacific oyster Crassostrea gigas 13 months after the Hebei Spirit oil spill (December 2007) off the west coast of Korea. The parameters studied included hemocyte concentration and mortality, relative proportion of hemocyte populations, and immunological functions such as phagocytosis and oxidative activity using flow cytometry. These immune-related parameters in oysters damaged by the oil spill were also compared to control oysters that were collected from an area unaffected by the spill. The flow cytometry study indicated that granulocyte population, phagocytic capacity, and reactive oxygen species production in oysters exposed to crude oil 13 months prior were depressed compared to the unexposed control oysters. Our data suggest that immunocompetence in oysters affected by the oil spill had not fully recovered 1 year after the accident, although more detailed studies on the physiology and disease resistance should be performed.

  16. 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.

    Science.gov (United States)

    Crawford, Sherine; Davis, Kiyya; Saddler, Claudette; Joseph, Jevaun; Catapane, Edward J; Carroll, Margaret A

    2011-01-01

    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 dysfunction in the brain's dopaminergic system. In this study we utilized micro-batch chambers and oxygen probes to measure oyster gill mitochondrial respiration in the presence of Mn and potential Mn blockers. The addition of Mn to respiring mitochondria caused a dose dependent decrease in mitochondrial O(2) consumption. Pretreating mitochondria with calcium disodium EDTA (caEDTA), p aminosalicylic acid (PAS) or acetylsalicylic acid (ASA) before Mn additions, provided full protection against the toxic effects of Mn. While mitochondrial pretreatment with any of the 3 drugs effectively blocked Mn toxicity, none of the drugs tested was able to reverse the decrease in mitochondrial O(2) consumption seen in Mn treated mitochondria. The study found that high levels of Mn had a toxic effect on gill mitochondrial O(2) consumption and that this effect could be blocked by the drugs caEDTA, PAS and ASA. C. virginica continues to be a good model with which to investigate the mechanism that underlies manganese neurotoxcity and in the pharmacological study of drugs to treat or prevent Manganism.

  17. Mangrove oyster (Crassostrea rhizophorae (Guilding, 1928 farming areas as artificial reefs for fish: A case study in the State of Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Lima de Freitas

    2006-03-01

    Full Text Available A type of platform, known as a table, is now being used for mangrove oyster farming. In Fortim, Ceará, Brazil, this activity was begun in June 2000 and covers an area of 50 m² overlying a sand-clay substrate. The present study has the following main objectives: to identify and catalogue the ichthyofauna colonizing the Crassostrea rhizophorae farming platforms; to evaluate ecological aspects, such as the possible correlation between the physical and chemical variables for water quality and the occurrence of the ichthyofauna; and to observe the differences in the fish species found during tidal variations. Specimens were identified and quantified using the linear-transect, visual census methodology. The ichthyofauna observed comprised 3,030 individuals belonging to 28 species and 20 families. Of the 28 species found in the area studied, 14 were marine transients, 12 marine dependent, and only 2 permanent residents. A significant association was observed between the abundance of 11 species and the physical and chemical variables studied. Based on these results, it may be concluded that the platforms act as artificial reefs for the ichthyofauna, being colonized by at least 28 species, and providing protection from predators as well as a source of food and a reproductive substrate.Um tipo de plataforma, conhecido como mesas, estão sendo utilizadas para o cultivo de ostras. Em Fortim, Ceará, este cultivo teve início em junho de 2000 e abrange uma área total de 50m² sobre um substrato argilo-arenoso. A presente pesquisa tem como objetivo identificar e catalogar a ictiofauna colonizadora das mesas de cultivo de ostras do mangue (Crassostrea rhizophorae, avaliar aspectos ecológicos tais como as possíveis correlações de parâmetros físico-químicos da água com a ocorrência da ictiofauna, além de observar as diferenças na composição da mesma durante as variações de marés. Os exemplares foram identificados visualmente e quantificados

  18. Seasonal and geographical variability in some trace elements of Pacific oysters (Crassostrea Gigas) cultured in two different bays of Northern Chile

    International Nuclear Information System (INIS)

    Gras, N.; Thieck, M.; Munoz, L.

    1991-01-01

    Chile has approximately 4,500 kilometers of continental coastline on the Pacific Ocean. It is therefore in a favorable position to develop fishing activities, since its waters contain a great variety of marine resources, namely, fish, shellfish and seaweeds. Fishing in Chile plays an important role in production. Metal contamination of the marine ecosystem is a pervasive and worldwide problem. Consequently, seafood consuming and exporting countries have gradually increased the need to improve the quality of their products in order to meet the required standards. In turn, this implies the need to adopt more efficient methods to analyze these resources by carrying out studies that will provide greater integral knowledge on the levels of essential and toxic trace elements found in seafood. In the present study, seasonal and geographical variability of some trace elements content of Pacific Oysters (Crassostrea Gigas) cultured, greatly demanded on the international market, are investigated. Samples for the analysis were collected from two different bays of Northern Chile, where heavy-metal pollution is already recognized as a problem. The trace elements content of this mollusk was studied at monthly intervals for 12 months (September 1987-August 1988). The determination of Cu was carried out using radiochemical neutron activation analysis and the other trace elements like Cd, As, Br, Na, Se, Cr, Fe, Zn and Co, were determined through neutron activation analysis in its purely instrumental form. NBS Standard Reference Materials were used to determine the accuracy of both methods. Significant differences were found comparing the content of copper and cadmium at the different seasons and locations of capture

  19. Response of an estuarine benthic community to application of the pesticide carbaryl and cultivation of Pacific oysters (Crassostrea gigas) in Willapa Bay, Washington.

    Science.gov (United States)

    Dumbauld, B R; Brooks, K M; Posey, M H

    2001-10-01

    Oyster culture operations on the West coast of North America have developed into complete farming operations for the introduced Japanese oyster, Crassostrea gigas, which now covers vast areas of the intertidal landscape, particularly in Washington State where the pesticide carbaryl has also been used to control burrowing thalassinid shrimp for more than 30 years. Field experiments were conducted to examine the effects of these habitat modifications on the benthic community in Willapa, Bay Washington (124 degrees 06'W,46 degrees 24'N) where 50% of the state's oyster production occurs. Results indicated that the primary long-term effect of carbaryl application was removal of the two species of thalassinid shrimp (Neotrypaea californiensis and Upogebia pugettensis), which dominated the community at the start of the experiment and clearly influenced community composition themselves. Small peracarid crustaceans like the amphipods Corophium acherusicum and Eohaustorius estuarius experienced the most significant short-term mortalities, but generally recruited back to treated sites within 3 months, and were often more abundant on treated than untreated sites 1 year after carbaryl application. Results for molluscs were mixed, with no significant effect on Macoma spp, but a significant effect on the commensal clam Crytomya californica and mixed results for the cockle Clinocardium nutalli. Polychaetes were the least susceptible to carbaryl and with the exception of a short-term effect on oligochaetes, no significant negative effects were observed. The addition of oysters did not affect the infaunal community in this study, however greater abundance of epifaunal organisms like mussels, scaleworms, and the amphipod Amphithoe valida, which builds tubes in algae attached to shells, was observed. Carbaryl, which is currently applied to roughly 242 ha (oyster culture operations like the addition of oysters themselves to a community often dominated by burrowing thalassinid shrimp

  20. Neuropeptides encoded by the genomes of the Akoya pearl oyster Pinctata fucata and Pacific oyster Crassostrea gigas: a bioinformatic and peptidomic survey.

    Science.gov (United States)

    Stewart, Michael J; Favrel, Pascal; Rotgans, Bronwyn A; Wang, Tianfang; Zhao, Min; Sohail, Manzar; O'Connor, Wayne A; Elizur, Abigail; Henry, Joel; Cummins, Scott F

    2014-10-02

    Oysters impart significant socio-ecological benefits from primary production of food supply, to estuarine ecosystems via reduction of water column nutrients, plankton and seston biomass. Little though is known at the molecular level of what genes are responsible for how oysters reproduce, filter nutrients, survive stressful physiological events and form reef communities. Neuropeptides represent a diverse class of chemical messengers, instrumental in orchestrating these complex physiological events in other species. By a combination of in silico data mining and peptide analysis of ganglia, 74 putative neuropeptide genes were identified from genome and transcriptome databases of the Akoya pearl oyster, Pinctata fucata and the Pacific oyster, Crassostrea gigas, encoding precursors for over 300 predicted bioactive peptide products, including three newly identified neuropeptide precursors PFGx8amide, RxIamide and Wx3Yamide. Our findings also include a gene for the gonadotropin-releasing hormone (GnRH) and two egg-laying hormones (ELH) which were identified from both oysters. Multiple sequence alignments and phylogenetic analysis supports similar global organization of these mature peptides. Computer-based peptide modeling of the molecular tertiary structures of ELH highlights the structural homologies within ELH family, which may facilitate ELH activity leading to the release of gametes. Our analysis demonstrates that oysters possess conserved molluscan neuropeptide domains and overall precursor organization whilst highlighting many previously unrecognized bivalve idiosyncrasies. This genomic analysis provides a solid foundation from which further studies aimed at the functional characterization of these molluscan neuropeptides can be conducted to further stimulate advances in understanding the ecology and cultivation of oysters.

  1. Seasonal changes in mRNA encoding for cell stress markers in the oyster Crassostrea gigas exposed to radioactive discharges in their natural environment

    International Nuclear Information System (INIS)

    Farcy, Emilie; Voiseux, Claire; Lebel, Jean-Marc; Fievet, Bruno

    2007-01-01

    The North Cotentin area (Normandy, France) hosts several nuclear facilities among which the AREVA reprocessing plant of La Hague is responsible for controlled discharges of liquid radioactive wastes into the marine environment. The resulting increase in radioactivity is very small compared to natural radioactivity. However, concerns about environment protection prompted the scientific community to focus on the effects of the chronic exposure to low concentrations of radionuclides in non-human biota. This study contributes to the evaluation of the possible impact of radioactive discharges on the oyster Crassostrea gigas in the field. Real-time polymerase chain reaction was used to quantify the expression levels of genes involved in cell stress in the oyster. They included members of the heat shock protein family (Hsp70, Hsc72, Hsp90), superoxide dismutase (SOD) and metallothionein (MT). Times series measurements were built from periodic samplings in the natural environment in order to characterize the natural variability as well as possible seasonal fluctuations. The genes studied exhibited a general seasonal expression pattern with a peak value in winter. The data inversely correlated with seawater temperature and the nature of the relationship between gene expression and temperature is discussed. In parallel, oysters were collected in four locations on the French shores, exposed or not to radioactive liquid wastes from the nuclear facilities hosted in the North Cotentin. The comparison of data obtained in the reference location on the Atlantic coast (not exposed) and data from oysters of the English Channel (exposed) gave no evidence for any statistical difference. However, because of the complexity of the natural environment, we cannot rule out the possibility that other parameters may have masked the impact of radioactive discharges. This dense set of data is a basis for the use of the expression levels of those genes as biomarkers to address the question of the

  2. Ciclo reproductivo del ostión de manglar Crassostrea rhizophorae (Bivalvia: Ostreidae en la Bahía de Camamu, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Tiago Lenz

    2011-03-01

    Full Text Available El ostión de manglar es un importante recurso pesquero que se distribuye por toda la costa brasileña y una de las especies nativas con mayor potencial para maricultura. Este estudio tuvo como objetivo conocer las características reproductivas del ostión de manglar Crassostrea rhizophorae en el estero del Río Maraú, Bahía de Camamu, Bahia, Brasil. Las muestras fueran recolectadas mensualmente, entre agosto de 2006 y septiembre de 2007, en dos sitios. Las metodologías utilizadas fueron el análisis histológico de las gónadas y el cálculo de rendimiento de carne. La temperatura del agua durante el período de estudio varió de 23.5°C a 30°C y la salinidad osciló entre 15 y 35ups. La altura de los ostiones examinados varió de 27 a 102mm (n=437. Hubo predominancia de hembras en las poblaciones de ambos sitios. Los análisis de estadios gonádicos demostraron que el proceso de reproducción de C. rhizophorae en el estero del Río Maraú es continuo durante el año, sin período de reposo sexual. El rendimiento de carne (R fue de 8.0% a 17.7% (n=669. Los resultados de este estudio proveen informaciones para la captación de semilla e implantación de la ostricultura en la Bahía de Camamu.

  3. Integrating the effects of salinity on the physiology of the eastern oyster, Crassostrea virginica, in the northern Gulf of Mexico through a Dynamic Energy Budget model

    Science.gov (United States)

    Lavaud, Romain; LaPeyre, Megan K.; Casas, Sandra M.; Bacher, C.; La Peyre, Jerome F.

    2017-01-01

    We present a Dynamic Energy Budget (DEB) model for the eastern oyster, Crassostrea virginica, which enables the inclusion of salinity as a third environmental variable, on top of the standard foodr and temperature variables. Salinity changes have various effects on the physiology of oysters, potentially altering filtration and respiration rates, and ultimately impacting growth, reproduction and mortality. We tested different hypotheses as to how to include these effects in a DEB model for C. virginica. Specifically, we tested two potential mechanisms to explain changes in oyster shell growth (cm), tissue dry weight (g) and gonad dry weight (g) when salinity moves away from the ideal range: 1) a negative effect on filtration rate and 2) an additional somatic maintenance cost. Comparative simulations of shell growth, dry tissue biomass and dry gonad weight in two monitored sites in coastal Louisiana experiencing salinity from 0 to 28 were statistically analyzed to determine the best hypothesis. Model parameters were estimated through the covariation method, using literature data and a set of specifically designed ecophysiological experiments. The model was validated through independent field studies in estuaries along the northern Gulf of Mexico. Our results suggest that salinity impacts C. virginica’s energy budget predominantly through effects on filtration rate. With an overwhelming number of environmental factors impacting organisms, and increasing exposure to novel and extreme conditions, the mechanistic nature of the DEB model with its ability to incorporate more than the standard food and temperature variables provides a powerful tool to verify hypotheses and predict individual organism performance across a range of conditions.

  4. Development of genomic microsatellite multiplex PCR using dye-labeled universal primer and its validation in pedigree analysis of Pacific oyster ( Crassostrea gigas)

    Science.gov (United States)

    Liu, Ting; Li, Qi; Song, Junlin; Yu, Hong

    2017-02-01

    There is an increasing requirement for traceability of aquaculture products, both for consumer protection and for food safety. There are high error rates in the conventional traceability systems depending on physical labels. Genetic traceability technique depending on DNA-based tracking system can overcome this problem. Genealogy information is essential for genetic traceability, and microsatellite DNA marker is a good choice for pedigree analysis. As increasing genotyping throughput of microsatellites, microsatellite multiplex PCR has become a fast and cost-effective technique. As a commercially important cultured aquatic species, Pacific oyster Crassostrea gigas has the highest global production. The objective of this study was to develop microsatellite multiplex PCR panels with dye-labeled universal primer for pedigree analysis in C. gigas, and these multiplex PCRs were validated using 12 full-sib families with known pedigrees. Here we developed six informative multiplex PCRs using 18 genomic microsatellites in C. gigas. Each multiplex panel contained a single universal primer M13(-21) used as a tail on each locus-specific forward primer and a single universal primer M13(-21) labeled with fluorophores. The polymorphisms of the markers were moderate, with an average of 10.3 alleles per locus and average polymorphic information content of 0.740. The observed heterozygosity per locus ranged from 0.492 to 0.822. Cervus simulations revealed that the six panels would still be of great value when massive families were analysed. Pedigree analysis of real offspring demonstrated that 100% of the offspring were unambiguously allocated to their parents when two multiplex PCRs were used. The six sets of multiplex PCRs can be an important tool for tracing cultured individuals, population genetic analysis, and selective breeding program in C. gigas.

  5. Ostreid herpesvirus 1 infection among Pacific oyster (Crassostrea gigas) Spat: relevance of water temperature to virus replication and circulation prior to the onset of mortality.

    Science.gov (United States)

    Renault, Tristan; Bouquet, Anne Lise; Maurice, Julien-Thomas; Lupo, Coralie; Blachier, Philippe

    2014-09-01

    A number of bivalve species worldwide, including the Pacific oyster, Crassostrea gigas, have been affected by mass mortality events associated with herpesviruses, resulting in significant losses. A particular herpesvirus was purified from naturally infected larval Pacific oysters, and its genome was completely sequenced. This virus has been classified as Ostreid herpesvirus 1 (OsHV-1) within the family Malacoherpesviridae. Since 2008, mass mortality outbreaks among C. gigas in Europe have been related to the detection of a variant of OsHV-1 called μVar. Additional data are necessary to better describe mortality events in relation to environmental-parameter fluctuations and OsHV-1 detection. For this purpose, a single batch of Pacific oyster spat was deployed in 4 different locations in the Marennes-Oleron area (France): an oyster pond ("claire"), a shellfish nursery, and two locations in the field. Mortality rates were recorded based on regular observation, and samples were collected to search for and quantify OsHV-1 DNA by real-time PCR. Although similar massive mortality rates were reported at the 4 sites, mortality was detected earlier in the pond and in the nursery than at both field sites. This difference may be related to earlier increases in water temperature. Mass mortality was observed among oysters a few days after increases in the number of PCR-positive oysters and viral-DNA amounts were recorded. An initial increment in the number of PCR-positive oysters was reported at both field sites during the survey in the absence of significant mortality. During this period, the water temperature was below 16°C. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  6. Genomics study of the exposure effect of Gymnodinium catenatum, a paralyzing toxin producer, on Crassostrea gigas' defense system and detoxification genes.

    Science.gov (United States)

    García-Lagunas, Norma; Romero-Geraldo, Reyna; Hernández-Saavedra, Norma Y

    2013-01-01

    Crassostrea gigas accumulates paralytic shellfish toxins (PST) associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response. We found that 24 h feeding on toxic dinoflagellate cells (acute exposure) induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense (copper/zinc superoxide dismutase, Cu/Zn-SOD), cell detoxification (glutathione S-transferase, GST and cytochrome P450, CPY450), intermediate immune response activation (lipopolysaccharide and beta glucan binding protein, LGBP), and stress responses (glutamine synthetase, GS) in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days (30×10³ cells mL⁻¹) showed higher gene expression levels. A significant increase was observed in Cu/Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum (3×10³ cells mL⁻¹ produced a significant increase on the transcription level than in a mixed diet (3×10³ cells mL⁻¹ of G. catenatum+0.75×10⁶ cells mL⁻¹ I. galbana) in all the analyzed genes. Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to stress generated by toxic dinoflagellate exposure.

  7. Genomics study of the exposure effect of Gymnodinium catenatum, a paralyzing toxin producer, on Crassostrea gigas' defense system and detoxification genes.

    Directory of Open Access Journals (Sweden)

    Norma García-Lagunas

    Full Text Available BACKGROUND: Crassostrea gigas accumulates paralytic shellfish toxins (PST associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response. PRINCIPAL FINDINGS: We found that 24 h feeding on toxic dinoflagellate cells (acute exposure induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense (copper/zinc superoxide dismutase, Cu/Zn-SOD, cell detoxification (glutathione S-transferase, GST and cytochrome P450, CPY450, intermediate immune response activation (lipopolysaccharide and beta glucan binding protein, LGBP, and stress responses (glutamine synthetase, GS in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days (30×10³ cells mL⁻¹ showed higher gene expression levels. A significant increase was observed in Cu/Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum (3×10³ cells mL⁻¹ produced a significant increase on the transcription level than in a mixed diet (3×10³ cells mL⁻¹ of G. catenatum+0.75×10⁶ cells mL⁻¹ I. galbana in all the analyzed genes. CONCLUSIONS: Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to

  8. Determination and Quantification of metals in the shells of Crassostrea virginica after the Deepwater Horizon oil spill utilizing Atomic Absorption Spectrometry.

    Science.gov (United States)

    Roopnarine, D.; Patel, S.; Roopnarine, P.; Giarikos, D.; Anderson, L. C.

    2017-12-01

    The Deepwater Horizon (DWH) oil rig explosion on April 20, 2010 resulted in the release of 685,000 tons of crude oil into the Gulf of Mexico (GOM) over a period of three months. There were obvious immediate effects, but the long-term ramifications are still being studied. The primary constituent of crude oil is hydrocarbons with other organic compounds containing nitrogen, oxygen and sulfur. There are also a number of trace metals with the most abundant frequently being iron, nickel, copper and vanadium. These do not degrade like organic materials. However, the exact composition varies among the production sites. The oil from the DWH rig was classified as light crude which is moderately volatile. Natural oil seeps occur in the environment, but the DWH spill represented an acute impact. Trace amounts of heavy metals are a normal part of the composition of marine organisms, but can be toxic in high concentrations. Bivalved molluscs bioaccumulate heavy metals in their tissues and shells, and are therefore often useful as monitors of environmental pollution. We thus used the Eastern oyster Crassostrea virginica to determine the impact of the spill by measuring the concentrations of metals in the shells utilizing flame emission atomic absorption spectrometry. We focused on the hypothesis that DWH spill exposure resulted in an increase in metal uptake into the shells. Specimens spanned the years 2010 to 2014 and ranged from Grand Isle, LA to Apalachicola Bay, Fl. Vanadium had the greatest concentration in the shells, and along with copper, cadmium, zinc and iron displayed an upward trend of increase from 2010 to 2013, with a decline in 2014. However there was unexpected variability, as the specimens from Apalachicola Bay, Fl had higher levels of vanadium when compared to those from Grand Isle, LA. Ongoing work includes an increase of sample sizes from the same geographic localities and time period.

  9. Study of the impact of radionuclides discharges from nuclear industry in the northern Cotentin area on the oyster Crassostrea gigas: expression of cellular stress molecular markers

    International Nuclear Information System (INIS)

    Farcy, E.

    2006-11-01

    This thesis explores the potential radiological impact of radionuclide discharges from the nuclear industry on the Pacific oyster, Crassostrea gigas. One of the major goals of this research was to identify markers that could be used to monitor the effects of low-level chronic irradiation. We decided to focalize on the expression of stress-induced genes involved in the regulation of cellular stress, focusing on transcription. First, homology cloning was used to identify four new cDNAs encoding stress markers. Then data collected at various sites enabled to evidence that mRNA levels for each of the genes of interest naturally vary to a significant degree, based on individual differences and seasonal factors. Comparing oysters from exposed sites with those from a reference site located on the Atlantic coast did not suggest any relationship between mRNA levels changes and the oysters exposure to liquid radioactive waste from the A.R.E.V.A. reprocessing plant. In the environment, we found that those radionuclide releases resulted in a very small increase in radioactivity in oysters, especially compared with their natural radioactivity. In the laboratory, by exposing the oysters to higher radionuclide concentrations than those found in the environment, we were able to identify two genes as potential candidates for studying the effects of chronic exposure to low doses of ionizing radiations in the oyster: genes encoding MT and MXR. We confirmed that transcriptional induction of these two genes occurs in response to high doses of acute irradiation. Finally, the comparison between environmental results and the laboratory results underlined the complementarity of these two approaches. In particular, it revealed that seasonal variations in mRNA levels probably have a significant effect on the stress response. (author)

  10. Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas harvested in the south bay of Santa Catarina island, Brazil Ocorrência de Vibrio spp., estafilococos coagulase positivo e bactérias entéricas em ostras (Crassostrea gigas cultivadas na baía sul da ilha de Santa Catarina, Brasil

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    Roberta Juliano Ramos

    2012-09-01

    Full Text Available The aim of this study was to assess the contamination of oysters (Crassostrea gigas, harvested in six different regions of the South Bay of Santa Catarina Island, with Coliforms at 45 ºC, Escherichia coli, Vibrio spp., positive coagulase staphylococci, and Salmonella sp. over a period of one year. One hundred eighty oyster samples were collected directly from their culture sites and analyzed. Each sample consisted of a pool of 12 oysters. All of the samples analyzed showed absence of Salmonella, 18 (10% samples showed presence of Escherichia coli, 15 (8.3% samples were positive for V. alginolyticus, and Vibriocholerae was detected in 4 samples (2.2%. The counts of positive-coagulase staphylococci varied from O objetivo deste estudo foi avaliar a contaminação de ostras (Crassostrea gigas cultivadas em diferentes regiões da Baía Sul da Ilha de Santa Catarina, por coliformes a 45 ºC, Escherichia coli, Vibrio spp. Estafilococos coagulase positiva e Salmonella sp., durante o período de um ano. Foram analisadas 180 amostras, coletadas diretamente no local de cultivo. Todas as amostras analisadas apresentaram ausência de Salmonella, 18 (10% amostras apresentaram presença de Escherichia coli, 15 (8,3% amostras positivas para Vibrio alginolyticus e V. cholerae foi detectado em 4 amostras (2,2%. As contagens de Estafilococos coagulase positiva variaram de <10 a 1,9 x 102 UFC.g-1, enquanto que as contagens de coliformes a 45 ºC e E. coli variaram de <3 a 1,5 x 102 NMP.g-1 e <3 e 4,3 x 10 NMP.g-1, respectivamente. As contagens de V. parahaemolyticus e V. vulnificus variaram de <3 a 7 NMP.g-1, para ambos os microrganismos, sugerindo um monitoramento tanto destas espécies quanto da temperatura das águas marinhas nas regiões de cultivo. Com base nos resultados das análises microbiológicas, as amostras analisadas mostraram qualidade bacteriológica aceitável, ou seja, dentro dos parâmetros estabelecidos na legislação brasileira.

  11. Bacteria of fecal origin in mangrove oysters (Crassostrea rhizophorae in the Cocó River estuary, Ceará State, Brazil Bactérias de origem fecal contaminantes de ostra Crassostrea rhizophorae, oriundas do estuário do Rio Cocó, Estado do Ceará, Brasil

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    Ana I.M. Silva

    2004-06-01

    Full Text Available This study was aimed at evaluating the microbiological quality of mangrove oysters (Crassostrea rhizophorae, collected at a natural oyster bed in the estuary of Cocó river (Fortaleza, Ceará, Brazil. MPN values were used for estimating the total (TC and fecal (FC coliforms and Enterococcus spp. TC and FC MPN values in the whole muscle and intervalve liquid ranged from 1,600/g and from 1,100/g. No correlation was found between the physico-chemical parameters (temperature, salinity and pH of the surrounding water and the bacteriological contamination levels found in the tested oysters. The only correlation found was between TC and FC values. Enterococcus spp. strains were isolated and subjected to biochemical tests for species identification. The capacity of those strains for production of a bacteriocin-like inhibitory substance was tested using the Escherichia coli strain ATCC 25922 as a testing organism. Only one, E. faecalis, out of 121 Enterococcus strains tested, presented the inhibitory activity.O objetivo deste trabalho foi avaliar a qualidade microbiológica da ostra de mangue (Crassostrea rhizophorae originária de um criadouro natural no estuário do Rio Cocó, Fortaleza, Ceará, Brasil. Para isso, foram realizadas as estimativas do Número Mais Provável (NMP de Coliformes Totais (CT e de Fecais (CF e de Enterococcus spp. Os valores encontrados para CT e CF no músculo (com líquido intervalvar variaram de 1.600 e 1.100/g. Não houve correlação entre os parâmetros físico-químicos (temperatura, salinidade e pH da água na área do criadouro e os níveis de contaminação encontrados nas ostras. Somente houve correlação entre os valores de CT e CF. Cepas de Enterococcus spp. foram isoladas e submetidas a testes bioquímicos para identificação das espécies e, posteriormente, foram testadas para verificar a produção de substância inibitória semelhante à bacteriocina utilizando a cepa-teste Escherichia coli ATCC 25922. De um

  12. Ciclo reproductivo del ostión de manglar Crassostrea rhizophorae (Bivalvia: Ostreidae en la Bahía de Camamu, Bahia, Brasil

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    Tiago Lenz

    2011-03-01

    Full Text Available El ostión de manglar es un importante recurso pesquero que se distribuye por toda la costa brasileña y una de las especies nativas con mayor potencial para maricultura. Este estudio tuvo como objetivo conocer las características reproductivas del ostión de manglar Crassostrea rhizophorae en el estero del Río Maraú, Bahía de Camamu, Bahia, Brasil. Las muestras fueran recolectadas mensualmente, entre agosto de 2006 y septiembre de 2007, en dos sitios. Las metodologías utilizadas fueron el análisis histológico de las gónadas y el cálculo de rendimiento de carne. La temperatura del agua durante el período de estudio varió de 23.5°C a 30°C y la salinidad osciló entre 15 y 35ups. La altura de los ostiones examinados varió de 27 a 102mm (n=437. Hubo predominancia de hembras en las poblaciones de ambos sitios. Los análisis de estadios gonádicos demostraron que el proceso de reproducción de C. rhizophorae en el estero del Río Maraú es continuo durante el año, sin período de reposo sexual. El rendimiento de carne (R fue de 8.0% a 17.7% (n=669. Los resultados de este estudio proveen informaciones para la captación de semilla e implantación de la ostricultura en la Bahía de Camamu.Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Bivalvia: Ostreidae in Camamu Bay, Bahia, Brasil. The mangrove oyster Crassostrea rhizophorae is important fishery resource along the entire Brasilian coast with excellent potential for marine culture. The purpose of this paper was to examine the reproductive characteristics of the oyster of the Maraú river estuary in Camamu Bay, Bahia, Brasil. The samples were collected monthly, from September 2006 to August 2007, at two points (I and II in Camamu Bay. At each site 20 oysters were collected for histological analysis, fixed in Davidson’s solution, embedded in paraffin, dehydrated in an ethanol series, sectioned (7μm thick and stained with Harris hematoxylin and Eosin (HE

  13. MACROECOLOGIA EVOLUTIVA DE LOS BIVALVOS MARINOS DE LA COSTA PACIFICA DE SUDAMERICA.

    OpenAIRE

    RIVADENEIRA VALENZUELA, MARCELO MICHEL; RIVADENEIRA VALENZUELA, MARCELO MICHEL

    2005-01-01

    Los procesos que subyacen a los patrones de biodiversidad observables a escalas regionales y globales no operarían a escalas de tiempo ecológicas, sino geológicas. De este modo, análisis geográficos de los procesos de diversificación de las biotas, arroja 76p.

  14. Fijacion primaria y variaciones morfologicas, durante la metamorfosis de algunos bivalvos chilenos

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    Juan Uribe Barichivith

    1980-12-01

    Full Text Available The larval primary settlement and the changes originated during the metamorphosis of some species of Chilean bivalves, are comparatively studied, being described, the larval and post - larval stages from the veliconcha to late plantigrade. By observing in ropes "anchovetera" nets and plankton samples, in the mitiliculture of Codihué (41º 46'S; 73º 24'W, it was verified for Mytilus chilensis Hupé, 1854 and Aulacomya ater (Molina, 1782, primary settlement on the filamentous algae of genera Enteromorpha with an average size of 33º µ high, minimum average of definitive settlement, byssus positional changes, etc. Information concerning average and number of larval and post - larval attachment to different deep and inmersión period and morphological characters of larval and post - larval of: Bankia martensi Stempell, 1898 (Teredinidae, Pholas chiloensis (Molina, 1782 (Pholadidae y Chlamys patriae Doello Jurado, 1918 (Pectinidae, are also given.

  15. Genetic parameters of resistance to Vibrio aestuarianus, and OsHV-1 infections in the Pacific oyster, Crassostrea gigas, at three different life stages.

    Science.gov (United States)

    Azéma, Patrick; Lamy, Jean-Baptiste; Boudry, Pierre; Renault, Tristan; Travers, Marie-Agnès; Dégremont, Lionel

    2017-02-15

    In France, two main diseases threaten Pacific oyster production. Since 2008, Crassostrea gigas spat have suffered massive losses due to the ostreid herpesvirus OsHV-1, and since 2012, significant mortalities in commercial-size adults have been related to infection by the bacterium Vibrio aestuarianus. The genetic basis for resistance to V. aestuarianus and OsHV-1 and the nature of the genetic correlation between these two traits were investigated by using 20 half-sib sire families, each containing two full-sib families. For each disease, controlled infectious challenges were conducted using naïve oysters that were 3 to 26 months old. In addition, siblings were tested under field, pond and raceway conditions to determine whether laboratory trials reflected mortality events that occur in the oyster industry. First, we estimated the genetic basis of resistance to V. aestuarianus in C. gigas. Susceptibility to the infection was low for oysters in spat stage but increased with later life stages. Second, we confirmed a strong genetic basis of resistance to OsHV-1 infection at early stages and demonstrated that it was also strong at later stages. Most families had increased resistance to OsHV-1 infection from the spat to adult stages, while others consistently showed low or high mortality rates related to OsHV-1 infection, regardless of the life stage. Our third main finding was the absence of genetic correlations between resistance to OsHV-1 infection and resistance to V. aestuarianus infection. Selective breeding to enhance resistance to OsHV-1 infection could be achieved through selective breeding at early stages and would not affect resistance to V. aestuarianus infection. However, our results suggest that the potential to select for improved resistance to V. aestuarianus is lower. Selection for dual resistance to OsHV-1 and V. aestuarianus infection in C. gigas might reduce the impact of these two major diseases by selecting families that have the highest

  16. Estimating the gasoline components and formulations toxicity to microalgae (Tetraselmis chuii) and oyster (Crassostrea rhizophorae) embryos: An approach to minimize environmental pollution risk

    International Nuclear Information System (INIS)

    Paixao, J.F.; Nascimento, I.A.; Pereira, S.A.; Leite, M.B.L.; Carvalho, G.C.; Silveira, J.S.C.; Reboucas, M.; Matias, G.R.A.; Rodrigues, I.L.P.

    2007-01-01

    Even though petrochemical contamination frequently occurs in the form of oil spills, it is thought that a greater danger to coastal habitats is posed by chronic petrochemical toxicity associated with urban run-off, in which gasoline water-soluble-fraction (WSF) plays an important role. The hypothesis of the entrepreneurs, who were associated to the scientists uncharged of this research, was that recycled petrochemical waste may provide different gasoline formulations, having different toxic properties; the correlation between the gasoline formulations and their components' toxicological effects might contribute to the reformulation of the products, in such a way that the gasoline generated could be less toxic and less harmful to the environment. The aim of this research was to determine the toxic effects of 14 different types of gasoline (formulated, in accordance with National Petroleum Agency standards, from petrochemical waste), on Tetraselmis chuii (microalgae culture) and Crassostrea rhizophorae (embryos). Microalgae and oyster embryos were exposed to different gasoline formulations water-soluble fractions (WSF) at a range of concentrations (0%, 4.6%, 10.0%, 22.0%, 46.0%, and 100%), for 96 and 24 h, respectively. The tests were carried out under controlled conditions. End-points have been CI50-96h (concentration causing 50% growth inhibition in microalgae cultures) and EC50-24h (concentration causing abnormalities on 50% of the exposed embryos). Through these procedures, gasoline formulations, which represent the lowest environmental risk, were selected. Bioassays carried out on the 8 different gasoline components aimed to correlate gasoline toxicity with the toxic potential of its components. The analysis of principal components showed that the C9DI, a mixture of aromatic hydrocarbons of 9 carbon atoms, had the highest level of toxic potential, followed by C9S (a mixture of aromatics with 9-11 carbon atoms) and heavy naphtha. The results showed gasoline

  17. Environmental concentrations of irgarol, diuron and S-metolachlor induce deleterious effects on gametes and embryos of the Pacific oyster, Crassostrea gigas.

    Science.gov (United States)

    Mai, Huong; Morin, Bénédicte; Pardon, Patrick; Gonzalez, Patrice; Budzinski, Hélène; Cachot, Jérôme

    2013-08-01

    Irgarol and diuron are the most representative "organic booster biocides" that replace organotin compounds in antifouling paints, and metolachlor is one of the most extensively used chloroacetamide herbicides in agriculture. The toxicity of S-metolachlor, irgarol and diuron was evaluated in Pacific oyster (Crassostrea gigas) gametes or embryos exposed to concentrations of pesticides ranging from 0.1× to 1000×, with 1× corresponding to environmental concentrations of the three studied pesticides in Arcachon Bay (France). Exposures were performed on (1) spermatozoa alone (2) oocytes alone and (3) both spermatozoa and oocytes, and adverse effects on fertilization success and offspring development were recorded. The results showed that the fertilizing capacity of spermatozoa was significantly affected after gamete exposure to pesticide concentrations as low as 1× of irgarol and diuron and 10× of metolachlor. The offspring obtained from pesticide-exposed spermatozoa displayed a dose-dependent increase in developmental abnormalities. In contrast, treating oocytes with pesticide concentrations up to 10× did not alter fertilization rate and offspring quality. However, a significant decline in fertilization success and increase in abnormal D-larvae prevalence were observed at higher concentrations 10× (0.1 μg L(-1)) for S-metolachlor and 100× for irgarol (1.0 μg L(-1)) and diuron (4.0 μg L(-1)). Irgarol, diuron and S-metolachlor also induced a dose-dependent increase in abnormal D-larvae prevalence when freshly fertilized embryos were treated with pesticide concentrations as low as concentration of 1× (0.01 μg L(-1) for irgarol or S-metolachlor, and 0.04 μg L(-1) for diuron). The two bioassays on C. gigas spermatozoa and embryos displayed similar sensitivities to the studied pesticides while oocytes were less sensitive. Diuron, irgarol and S-metolachlor induced spermiotoxicity and embryotoxicity at environmentally relevant concentrations and therefore might be

  18. Predictive models for the effect of storage temperature on Vibrio parahaemolyticus viability and counts of total viable bacteria in Pacific oysters (Crassostrea gigas).

    Science.gov (United States)

    Fernandez-Piquer, Judith; Bowman, John P; Ross, Tom; Tamplin, Mark L

    2011-12-01

    Vibrio parahaemolyticus is an indigenous bacterium of marine environments. It accumulates in oysters and may reach levels that cause human illness when postharvest temperatures are not properly controlled and oysters are consumed raw or undercooked. Predictive models were produced by injecting Pacific oysters (Crassostrea gigas) with a cocktail of V. parahaemolyticus strains, measuring viability rates at storage temperatures from 3.6 to 30.4°C, and fitting the data to a model to obtain parameter estimates. The models were evaluated with Pacific and Sydney Rock oysters (Saccostrea glomerata) containing natural populations of V. parahaemolyticus. V. parahaemolyticus viability was measured by direct plating samples on thiosulfate-citrate-bile salts-sucrose (TCBS) agar for injected oysters and by most probable number (MPN)-PCR for oysters containing natural populations. In parallel, total viable bacterial counts (TVC) were measured by direct plating on marine agar. Growth/inactivation rates for V. parahaemolyticus were -0.006, -0.004, -0.005, -0.003, 0.030, 0.075, 0.095, and 0.282 log₁₀ CFU/h at 3.6, 6.2, 9.6, 12.6, 18.4, 20.0, 25.7, and 30.4°C, respectively. The growth rates for TVC were 0.015, 0.023, 0.016, 0.048, 0.055, 0.071, 0.133, and 0.135 log₁₀ CFU/h at 3.6, 6.2, 9.3, 14.9, 18.4, 20.0, 25.7, and 30.4°C, respectively. Square root and Arrhenius-type secondary models were generated for V. parahaemolyticus growth and inactivation kinetic data, respectively. A square root model was produced for TVC growth. Evaluation studies showed that predictive growth for V. parahaemolyticus and TVC were "fail safe." The models can assist oyster companies and regulators in implementing management strategies to minimize V. parahaemolyticus risk and enhancing product quality in supply chains.

  19. Effects of cadmium on anaerobic energy metabolism and mRNA expression during air exposure and recovery of an intertidal mollusk Crassostrea virginica

    International Nuclear Information System (INIS)

    Ivanina, Anna V.; Sokolov, Eugene P.; Sokolova, Inna M.

    2010-01-01

    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 Crassostrea virginica. In control oysters, prolonged anoxia resulted in a selective suppression of nitric oxide synthase (NOS) and upregulation of cytochrome c oxidase subunit IV (COX4) while the levels of other transcripts remained unchanged. During post-anoxic recovery, mRNA expression of hypoxia inducible factor-1α (HIF-1α) was elevated, phosphoenolpyruvate carboxykinase (PEPCK), NOS and LON protease suppressed, and mRNA expression of other studied genes not changed. Notably, most of the key glycolytic genes that are stimulated by HIF-1 in mammals, either remained unchanged or were downregulated in anoxic oysters suggesting a different mechanism of molecular response to oxygen deficiency. Patterns of transcriptional response during anoxia and reoxygenation were significantly altered by Cd exposure in a gene-specific manner. Anaerobic metabolism (indicated by accumulation of L-alanine, succinate and acetate during anoxia) was also suppressed in Cd-exposed oysters. In control oysters, ATP turnover rate (M ATP ) during anoxia was mostly sustained by anaerobic glycolysis with negligible contributions from ATP and PLA breakdown. In contrast, in Cd-exposed oysters ATP breakdown contributed significantly to anaerobic M ATP . Thus, while control oysters could efficiently defend the ATP levels and tissue energy status during prolonged anoxia, Cd-exposed oysters experienced a disturbance in tissue energy balance indicated by the depletion of ATP, a rapid decline in adenylate energy charge

  20. Effects of cadmium on anaerobic energy metabolism and mRNA expression during air exposure and recovery of an intertidal mollusk Crassostrea virginica

    Energy Technology Data Exchange (ETDEWEB)

    Ivanina, Anna V. [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States); Sokolov, Eugene P. [Department of General Surgery, Carolina' s Medical Center, 1000 Blythe Blvd., Charlotte, NC 28203-5871 (United States); Sokolova, Inna M., E-mail: isokolov@uncc.edu [Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223 (United States)

    2010-09-01

    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 Crassostrea virginica. In control oysters, prolonged anoxia resulted in a selective suppression of nitric oxide synthase (NOS) and upregulation of cytochrome c oxidase subunit IV (COX4) while the levels of other transcripts remained unchanged. During post-anoxic recovery, mRNA expression of hypoxia inducible factor-1{alpha} (HIF-1{alpha}) was elevated, phosphoenolpyruvate carboxykinase (PEPCK), NOS and LON protease suppressed, and mRNA expression of other studied genes not changed. Notably, most of the key glycolytic genes that are stimulated by HIF-1 in mammals, either remained unchanged or were downregulated in anoxic oysters suggesting a different mechanism of molecular response to oxygen deficiency. Patterns of transcriptional response during anoxia and reoxygenation were significantly altered by Cd exposure in a gene-specific manner. Anaerobic metabolism (indicated by accumulation of L-alanine, succinate and acetate during anoxia) was also suppressed in Cd-exposed oysters. In control oysters, ATP turnover rate (M{sub ATP}) during anoxia was mostly sustained by anaerobic glycolysis with negligible contributions from ATP and PLA breakdown. In contrast, in Cd-exposed oysters ATP breakdown contributed significantly to anaerobic M{sub ATP}. Thus, while control oysters could efficiently defend the ATP levels and tissue energy status during prolonged anoxia, Cd-exposed oysters experienced a disturbance in tissue energy balance indicated by the depletion of ATP, a rapid decline in

  1. Big defensins, a diverse family of antimicrobial peptides that follows different patterns of expression in hemocytes of the oyster Crassostrea gigas.

    Science.gov (United States)

    Rosa, Rafael D; Santini, Adrien; Fievet, Julie; Bulet, Philippe; Destoumieux-Garzón, Delphine; Bachère, Evelyne

    2011-01-01

    Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3) that are encoded by distinct genomic sequences. All Cg-BigDefs contain a hydrophobic N-terminal domain and a cationic C-terminal domain that resembles vertebrate β-defensins. Both domains are encoded by separate exons. We found that big defensins form a group predominantly present in mollusks and closer to vertebrate defensins than to invertebrate and fungi CSαβ-containing defensins. Moreover, we showed that Cg-BigDefs are expressed in oyster hemocytes only and follow different patterns of gene expression. While Cg-BigDef3 is non-regulated, both Cg-BigDef1 and Cg-BigDef2 transcripts are strongly induced in response to bacterial challenge. Induction was dependent on pathogen associated molecular patterns but not damage-dependent. The inducibility of Cg-BigDef1 was confirmed by HPLC and mass spectrometry, since ions with a molecular mass compatible with mature Cg-BigDef1 (10.7 kDa) were present in immune-challenged oysters only. From our biochemical data, native Cg-BigDef1 would result from the elimination of a prepropeptide sequence and the cyclization of the resulting N-terminal glutamine residue into a pyroglutamic acid. We provide here the first report showing that big defensins form a family of antimicrobial peptides diverse not only in terms

  2. Big Defensins, a Diverse Family of Antimicrobial Peptides That Follows Different Patterns of Expression in Hemocytes of the Oyster Crassostrea gigas

    Science.gov (United States)

    Rosa, Rafael D.; Santini, Adrien; Fievet, Julie; Bulet, Philippe; Destoumieux-Garzón, Delphine; Bachère, Evelyne

    2011-01-01

    Background Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. Findings Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3) that are encoded by distinct genomic sequences. All Cg-BigDefs contain a hydrophobic N-terminal domain and a cationic C-terminal domain that resembles vertebrate β-defensins. Both domains are encoded by separate exons. We found that big defensins form a group predominantly present in mollusks and closer to vertebrate defensins than to invertebrate and fungi CSαβ-containing defensins. Moreover, we showed that Cg-BigDefs are expressed in oyster hemocytes only and follow different patterns of gene expression. While Cg-BigDef3 is non-regulated, both Cg-BigDef1 and Cg-BigDef2 transcripts are strongly induced in response to bacterial challenge. Induction was dependent on pathogen associated molecular patterns but not damage-dependent. The inducibility of Cg-BigDef1 was confirmed by HPLC and mass spectrometry, since ions with a molecular mass compatible with mature Cg-BigDef1 (10.7 kDa) were present in immune-challenged oysters only. From our biochemical data, native Cg-BigDef1 would result from the elimination of a prepropeptide sequence and the cyclization of the resulting N-terminal glutamine residue into a pyroglutamic acid. Conclusions We provide here the first report showing that big defensins form a family of antimicrobial

  3. Spatial patterns in the condition index of the wild Pacific oyster Crassostrea gigas in a macrotidal coastal ecosystem: Influence of tidal processes and beyond

    Science.gov (United States)

    Gasmi, Sonia; Bernard, Ismaël; Pouvreau, Stéphane; Maurer, Danièle; Schaal, Gauthier; Ganthy, Florian; Cominassi, Louise; Allain, Gwenhael; Sautour, Benoit; David, Valérie

    2017-01-01

    In macrotidal coastal ecosystems, spatial heterogeneity of the water column properties is induced by both oceanic and continental influences. Hydrodynamic processes generate a land-sea gradient of environmental conditions, affecting the biological performances of sedentary organisms. The aim of the present study is to establish an extensive spatial assessment in the reproductive investment of the wild Pacific oyster Crassostrea gigas in Arcachon Bay. This is done by looking for a relationship between the Lawrence and Scott condition index (LSCI) and two tidal processes: the immersion level (IL) and the local oceanic flushing time (LoFt). The LSCI of C. gigas was assessed, just before gamete release, at 68 sampling stations in Arcachon Bay. Oyster performance was overall low and spatially variable. Significant differences in the LSCI were detected between the outer and inner bay. Oyster reefs located toward the mouth of the bay exhibited high LSCI (between 9 and 11), while oyster reefs located in inner bay, especially in south-eastern part around the Eyre River, had low LSCI (below 6). Linear modelling allowed to highlight significant effects of both tidal processes IL and LoFt on the obtained LSCI gradient. IL, LoFt explained 33% of the spatial variability observed on LSCI (IL = 3%; LoFt = 17%; LoFt + IL: 13%), 6% were attributed to the intra-station variation (ISv). Thus, high IL and rapid LoFt favor a better development of somatic-gonadal volume, probably because of longer feeding time and higher supply of food from the ocean by tide flows. Disentangling the effects of IL and LoFt on LSCI allowed to describe the spatial pattern in 61% of variability not explained by both tidal factors. A residual gradient directed southeast-northwest highlighted that others factors, independent from IL and LoFt seems to hamper inner bay oyster reproductive performance. Consequently, investigating on the ecological functioning (Eyre influences), trophic potential and anthropogenic

  4. Molecular cloning, characterization and expression of heat shock protein 70 gene from the oyster Crassostrea hongkongensis responding to thermal stress and exposure of Cu(2+) and malachite green.

    Science.gov (United States)

    Zhang, Zhanhui; Zhang, Qizhong

    2012-04-15

    Heat shock protein 70 (HSP70) acts mostly as a molecular chaperone and plays a key role in the process of protecting cells by facilitating the folding of nascent peptides and the cellular stress response. The cDNA of the oyster Crassostrea hongkongensis hsp70 (designated chhsp70) was cloned with the techniques of homological cloning and rapid amplification of cDNA ends (RACE). The full-length chhsp70 cDNA was 2251bp, consisting of a 130bp 5'-UTR, 216bp 3'-UTR with a canonical polyadenylation signal sequence AATAAA and a poly (A) tail, and an open reading frame of 1905bp, which encoded a polypeptide of 634 amino acids. Three classical HSP signature motifs were detected in ChHSP70, i.e., DLGTT-S-V, IFDLGGGTFDVSIL and VVLVGGSTRIPKIQK. BLAST analysis revealed that the ChHSP70 shared high identity with other bivalve HSP70. The phylogenetic analysis indicated that the ChHSP70 was a member of the HSP70 family. The chhsp70 mRNA transcripts were quantified by fluorescent real time RT-PCR under both unstressed and stressed conditions, i. e., heat shock and exposure to Cu(2+) and malachite green. Basal expression level was similar in mantle, gill, digestive gland, and heart, but higher in muscle than that in the others. A similar trend showed that the chhsp70 mRNA expression significantly increased at 3-6h, then dropped and returned to control level at 24h in the five tissues and organs mentioned above after heat shock. A clearly time-dependent expression pattern of chhsp70 mRNA in digestive gland and gill of the oyster was observed after exposure of Cu(2+) and malachite green. In the two tissues, the chhsp70 mRNA level reached the maximum at 6h after malachite green exposure and on day 4 after Cu(2+) exposure, and then decreased progressively to the control level. The results indicated that ChHSP70 of the oyster is an inducible protein, and plays an important role in response to the Cu(2+) and malachite green polluted stress, so chhsp70 might be used as a potential molecular

  5. Upregulation of biotransformation genes in gills of oyster Crassostrea brasiliana exposed in situ to urban effluents, Florianópolis Bay, Southern Brazil.

    Science.gov (United States)

    Pessatti, Tomás B; Lüchmann, Karim H; Flores-Nunes, Fabrício; Mattos, Jacó J; Sasaki, Sílvio T; Taniguchi, Satie; Bícego, Márcia C; Dias Bainy, Afonso Celso

    2016-09-01

    The release of untreated sanitary sewage, combined with unplanned urban growth, are major factors contributing to degradation of coastal ecosystems in developing countries, including Brazil. Sanitary sewage is a complex mixture of chemicals that can negatively affect aquatic organisms. The use of molecular biomarkers can help to understand and to monitor the biological effects elicited by contaminants. The aim of this study was to evaluate changes in transcript levels of genes related to xenobiotic biotransformation in the gills of oysters Crassostrea brasiliana transplanted and kept for 24h at three areas potentially contaminated by sanitary sewage (Bücheller river, BUC; Biguaçu river, BIG; and Ratones island, RAT), one farming area (Sambaqui beach, SAM) and at one reference site (Forte beach, FOR) in the North Bay of Santa Catarina Island (Florianópolis, Brazil). Transcript levels of four cytochrome P450 isoforms (CYP2AU1, CYP3A-like, CYP356A1-like and CYP20A1-like), three glutathione S-transferase (GST alpha-like, GST pi-like and GST microsomal 3-like) and one sulfotransferase gene (SULT-like) were evaluated by means of quantitative reverse transcription PCR (qRT-PCR). Chemical analysis of the sediment from each site were performed and revealed the presence of aliphatic and polycyclic aromatic hydrocarbons, linear alkylbenzenes and fecal sterols in the contaminated areas (BUC and BIG). Water quality analysis showed that these sites had the highest levels of fecal coliforms and other parameters evidencing the presence of urban sewage discharges. Among the results for gene transcription, CYP2AU1 and SULT-like levels were upregulated by 20 and 50-fold, respectively, in the oysters kept for 24h at the most contaminated site (BUC), suggesting a role of these genes in the detoxification of organic pollutants. These data reinforce that gills possibly have an important role in xenobiotic metabolism and highlight the use of C. brasiliana as a sentinel for monitoring

  6. Characterization of CgHIFα-Like, a Novel bHLH-PAS Transcription Factor Family Member, and Its Role under Hypoxia Stress in the Pacific Oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Ting Wang

    Full Text Available Hypoxia-inducible factor (HIF, a critical member of the basic-helix-loop-helix (bHLH-containing Per-Arnt-Sim (PAS protein family, is a master transcription factor involved in maintaining oxygen homeostasis. In the present study, we isolated and characterized a novel bHLH-PAS family member, CgHIFα-like gene, from the Pacific oyster Crassostrea gigas, and determined its importance during hypoxia stress. The 3020-bp CgHIFα-like cDNA encoded a protein of 888 amino acids. The predicted CgHIFα-like amino acid sequence was conserved in the N-terminal bHLH, PAS, and PAC domains (but not in the C-terminal domain and was most closely related to the HIF family in the bHLH-PAS protein phylogenic tree. Similar to the mammalian HIF-1α, CgHIFα-like could be expressed as four mRNA isoforms containing alternative 5'-untranslated regions and different translation initiation codons. At the mRNA level, these isoforms were expressed in a tissue-specific manner and showed increased transcription to varying degrees under hypoxic conditions. Additionally, the western blot analysis demonstrated that CgHIFα-like was induced by hypoxia. Electrophoretic mobility shift assay indicated that CgHIFα-like could bind to the hypoxia responsive element (HRE, whereas dual-luciferase reporter analysis demonstrated that CgHIFα-like could transactivate the reporter gene containing the HREs. In addition to CgHIFα-like, we identified CgARNT from the C. gigas, analyzed its expression pattern, and confirmed its interaction with CgHIFα-like using a yeast two-hybrid assay. In conclusion, this is the first report on the cloning and characterization of a novel hypoxia transcription factor in mollusks, which could accumulate under hypoxia and regulate hypoxia related gene expression by binding to HRE and dimerizing with CgARNT. As only one member of HIF has been identified in invertebrates to date, our results provide new insights into the unique mechanisms of hypoxia tolerance in

  7. HMGB in mollusk Crassostrea ariakensis Gould: structure, pro-inflammatory cytokine function characterization and anti-infection role of its antibody.

    Directory of Open Access Journals (Sweden)

    Ting Xu

    Full Text Available BACKGROUND: Crassostrea ariakensis Gould is a representative bivalve species and an economically important oyster in China, but suffers severe mortalities in recent years that are caused by rickettsia-like organism (RLO. Prevention and control of this disease is a priority for the development of oyster aquaculture. It has been proven that mammalian HMGB (high mobility group box can be released extracellularly and acts as an important pro-inflammatory cytokine and late mediator of inflammatory reactions. In vertebrates, HMGB's antibody (anti-HMGB has been shown to confer significant protection against certain local and systemic inflammatory diseases. Therefore, we investigated the functions of Ca-HMGB (oyster HMGB and anti-CaHMGB (Ca-HMGB's antibody in oyster RLO/LPS (RLO or LPS-induced disease or inflammation. METHODOLOGY/PRINCIPAL FINDINGS: Sequencing analysis revealed Ca-HMGB shares conserved structures with mammalians. Tissue-specific expression indicates that Ca-HMGB has higher relative expression in hemocytes. Significant continuous up-regulation of Ca-HMGB was detected when the hemocytes were stimulated with RLO/LPS. Recombinant Ca-HMGB protein significantly up-regulated the expression levels of some cytokines. Indirect immunofluorescence study revealed that Ca-HMGB localized both in the hemocyte nucleus and cytoplasm before RLO challenge, but mainly in the cytoplasm 12 h after challenge. Western blot analysis demonstrated Ca-HMGB was released extracellularly 4-12 h after RLO challenge. Anti-CaHMGB was added to the RLO/LPS-challenged hemocyte monolayer and real-time RT-PCR showed that administration of anti-CaHMGB dramatically reduced the rate of RLO/LPS-induced up-regulation of LITAF at 4-12 h after treatment. Flow cytometry analysis indicated that administration of anti-CaHMGB reduced RLO/LPS-induced hemocyte apoptosis and necrosis rates. CONCLUSIONS/SIGNIFICANCE: Ca-HMGB can be released extracellularly and its subcellular localization

  8. Big defensins, a diverse family of antimicrobial peptides that follows different patterns of expression in hemocytes of the oyster Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Rafael D Rosa

    Full Text Available BACKGROUND: Big defensin is an antimicrobial peptide composed of a highly hydrophobic N-terminal region and a cationic C-terminal region containing six cysteine residues involved in three internal disulfide bridges. While big defensin sequences have been reported in various mollusk species, few studies have been devoted to their sequence diversity, gene organization and their expression in response to microbial infections. FINDINGS: Using the high-throughput Digital Gene Expression approach, we have identified in Crassostrea gigas oysters several sequences coding for big defensins induced in response to a Vibrio infection. We showed that the oyster big defensin family is composed of three members (named Cg-BigDef1, Cg-BigDef2 and Cg-BigDef3 that are encoded by distinct genomic sequences. All Cg-BigDefs contain a hydrophobic N-terminal domain and a cationic C-terminal domain that resembles vertebrate β-defensins. Both domains are encoded by separate exons. We found that big defensins form a group predominantly present in mollusks and closer to vertebrate defensins than to invertebrate and fungi CSαβ-containing defensins. Moreover, we showed that Cg-BigDefs are expressed in oyster hemocytes only and follow different patterns of gene expression. While Cg-BigDef3 is non-regulated, both Cg-BigDef1 and Cg-BigDef2 transcripts are strongly induced in response to bacterial challenge. Induction was dependent on pathogen associated molecular patterns but not damage-dependent. The inducibility of Cg-BigDef1 was confirmed by HPLC and mass spectrometry, since ions with a molecular mass compatible with mature Cg-BigDef1 (10.7 kDa were present in immune-challenged oysters only. From our biochemical data, native Cg-BigDef1 would result from the elimination of a prepropeptide sequence and the cyclization of the resulting N-terminal glutamine residue into a pyroglutamic acid. CONCLUSIONS: We provide here the first report showing that big defensins form a family

  9. Study of the impact of radionuclides discharges from nuclear industry in the northern Cotentin area on the oyster Crassostrea gigas: expression of cellular stress molecular markers; Etude de l'impact des radionucleides rejetes par les installations nucleaires du Nord Cotentin sur l'huitre creuse Crassostrea gigas: analyse de l'expression de marqueurs moleculaires de stress

    Energy Technology Data Exchange (ETDEWEB)

    Farcy, E

    2006-11-15

    This thesis explores the potential radiological impact of radionuclide discharges from the nuclear industry on the Pacific oyster, Crassostrea gigas. One of the major goals of this research was to identify markers that could be used to monitor the effects of low-level chronic irradiation. We decided to focalize on the expression of stress-induced genes involved in the regulation of cellular stress, focusing on transcription. First, homology cloning was used to identify four new cDNAs encoding stress markers. Then data collected at various sites enabled to evidence that mRNA levels for each of the genes of interest naturally vary to a significant degree, based on individual differences and seasonal factors. Comparing oysters from exposed sites with those from a reference site located on the Atlantic coast did not suggest any relationship between mRNA levels changes and the oysters exposure to liquid radioactive waste from the A.R.E.V.A. reprocessing plant. In the environment, we found that those radionuclide releases resulted in a very small increase in radioactivity in oysters, especially compared with their natural radioactivity. In the laboratory, by exposing the oysters to higher radionuclide concentrations than those found in the environment, we were able to identify two genes as potential candidates for studying the effects of chronic exposure to low doses of ionizing radiations in the oyster: genes encoding MT and MXR. We confirmed that transcriptional induction of these two genes occurs in response to high doses of acute irradiation. Finally, the comparison between environmental results and the laboratory results underlined the complementarity of these two approaches. In particular, it revealed that seasonal variations in mRNA levels probably have a significant effect on the stress response. (author)

  10. High resolution carbon isotope of Crassostrea cuttakensis: A proxy for seasonally varying carbon dynamics in a tropical delta-estuary system

    Science.gov (United States)

    Sreemany, Arpita

    2017-04-01

    The exponential increase in the atmospheric CO2 concentration and global temperature is becoming a major threat to the existence of the mankind. It has been proposed that the ˜2 ˚ C rise in the average global temperature may lead to a point of no-return where the balance between the climate and the ecosystem collapses. Therefore, detailed understanding of the major carbon reservoirs and their mutual interactions is needed for better future climate prediction. Among all the reservoirs, ocean holds ˜90 % of the exogenic carbon and promotes long term storage in sediments. However, the majority of the sedimentary carbon is of terrestrial origin and transported through rivers, which play an important role in carbon exchange between the atmosphere, terrestrial biosphere, and oceans. The transportation of organic carbon through river does not follow a simple conveyer belt model. Various organic and inorganic reactions (i.e., organic carbon degradation, inorganic carbon precipitation, primary production, community respiration) modify the state of the carbon to form a major sub-reservoir in the river, i.e., Dissolved Inorganic Carbon (DIC). So, identifying the source/s of the DIC is crucial to understand the carbon dynamics in the river. Stable carbon isotopic composition of the DIC (δ13CDIC) has long been extensively used to reveal the dominant source/s of the DIC. The majority of the large rivers, being situated in the tropical belts, show seasonal fluctuation in the DIC sources. However, seasonal sampling in the remotest reaches of these rivers hindered our thorough understanding of the seasonally varying source/s of DIC in these rivers. Many calcifying organisms precipitate their shell carbonate in equilibrium with water and hence likely to record the δ13CDICof ambient water in their shell. In this study, a living oyster (Crassostrea cuttakensis) was collected from Matla River, which is part of the Ganges Brahmaputra river delta system, and analyzed for its stable

  11. Interactive effects of CO2 and trace metals on the proteasome activity and cellular stress response of marine bivalves Crassostrea virginica and Mercenaria mercenaria

    International Nuclear Information System (INIS)

    Götze, Sandra; Matoo, Omera B.; Beniash, Elia; Saborowski, Reinhard; Sokolova, Inna M.

    2014-01-01

    Highlights: • Elevated P CO 2 enhanced accumulation of Cu and Cd in the gills of mollusks. • The proteasome activities were affected by metals but robust to elevated P CO 2 . • Exposure to Cd and Cu had opposite effects on the proteasome activity. • Combined exposure to Cu and elevated P CO 2 negatively affected energy status. - Abstract: Increased anthropogenic emission of CO 2 changes the carbonate chemistry and decreases the pH of the ocean. This can affect the speciation and the bioavailability of metals in polluted habitats such as estuaries. However, the effects of acidification on metal accumulation and stress response in estuarine organisms including bivalves are poorly understood. We studied the interactive effects of CO 2 and two common metal pollutants, copper (Cu) and cadmium (Cd), on metal accumulation, intracellular ATP/ubiquitin-dependent protein degradation, stress response and energy metabolism in two common estuarine bivalves—Crassostrea virginica (eastern oyster) and Mercenaria mercenaria (hard shell clam). Bivalves were exposed for 4–5 weeks to clean seawater (control) and to either 50 μg L −1 Cu or 50 μg L −1 Cd at one of three partial pressures of CO 2 (P CO 2 ∼395, ∼800 and ∼1500 μatm) representative of the present-day conditions and projections of the Intergovernmental Panel for Climate Change (IPCC) for the years 2100 and 2250, respectively. Clams accumulated lower metal burdens than oysters, and elevated P CO 2 enhanced the Cd and Cu accumulation in mantle tissues in both species. Higher Cd and Cu burdens were associated with elevated mRNA expression of metal binding proteins metallothionein and ferritin. In the absence of added metals, proteasome activities of clams and oysters were robust to elevated P CO 2 , but P CO 2 modulated the proteasome response to metals. Cd exposure stimulated the chymotrypsin-like activity of the oyster proteasome at all CO 2 levels. In contrast, trypsin- and caspase-like activities of

  12. Interactive effects of CO₂ and trace metals on the proteasome activity and cellular stress response of marine bivalves Crassostrea virginica and Mercenaria mercenaria

    Energy Technology Data Exchange (ETDEWEB)

    Götze, Sandra [Alfred Wegener Institute, Helmholtz Centre for Polar, Marine Research, Functional Ecology, 27570 Bremerhaven (Germany); Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Matoo, Omera B. [Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Beniash, Elia [Department of Oral Biology, University of Pittsburgh, Pittsburgh, PA (United States); Saborowski, Reinhard [Alfred Wegener Institute, Helmholtz Centre for Polar, Marine Research, Functional Ecology, 27570 Bremerhaven (Germany); Sokolova, Inna M., E-mail: isokolov@uncc.edu [Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States)

    2014-04-01

    Highlights: • Elevated PCO₂ enhanced accumulation of Cu and Cd in the gills of mollusks. • The proteasome activities were affected by metals but robust to elevated PCO₂. • Exposure to Cd and Cu had opposite effects on the proteasome activity. • Combined exposure to Cu and elevated PCO₂ negatively affected energy status. - Abstract: Increased anthropogenic emission of CO₂ changes the carbonate chemistry and decreases the pH of the ocean. This can affect the speciation and the bioavailability of metals in polluted habitats such as estuaries. However, the effects of acidification on metal accumulation and stress response in estuarine organisms including bivalves are poorly understood. We studied the interactive effects of CO₂ and two common metal pollutants, copper (Cu) and cadmium (Cd), on metal accumulation, intracellular ATP/ubiquitin-dependent protein degradation, stress response and energy metabolism in two common estuarine bivalves—Crassostrea virginica (eastern oyster) and Mercenaria mercenaria (hard shell clam). Bivalves were exposed for 4–5 weeks to clean seawater (control) and to either 50 μg L⁻¹ Cu or 50 μg L⁻¹ Cd at one of three partial pressures of CO₂ PCO₂ ~395, ~800 and ~1500 μatm) representative of the present-day conditions and projections of the Intergovernmental Panel for Climate Change (IPCC) for the years 2100 and 2250, respectively. Clams accumulated lower metal burdens than oysters, and elevated PCO₂ enhanced the Cd and Cu accumulation in mantle tissues in both species. Higher Cd and Cu burdens were associated with elevated mRNA expression of metal binding proteins metallothionein and ferritin. In the absence of added metals, proteasome activities of clams and oysters were robust to elevated PCO₂, but PCO₂ modulated the proteasome response to metals. Cd exposure stimulated the chymotrypsin-like activity of the oyster proteasome

  13. Detection of Ostreid herpesvirus-1 microvariants in healthy Crassostrea gigas following disease events and their possible role as reservoirs of infection.

    Science.gov (United States)

    Evans, Olivia; Hick, Paul; Whittington, Richard J

    2017-09-01

    Ostreid herpesvirus-1 microvariants (OsHV-1) cause severe mortalities in farmed Crassostrea gigas in Europe, New Zealand and Australia. Outbreaks are seasonal, recurring in the warmer months of the year in endemic estuaries. The reference genotype and microvariant genotypes of OsHV-1 have been previously detected in the tissues of apparently healthy adult oysters naturally exposed to OsHV-1 in the field. However, the role of such oysters as reservoirs of infection for subsequent mortality outbreaks remains unclear. The aims of this study were: (1) to identify the optimal sample type to use for the detection of OsHV-1 DNA in apparently healthy C. gigas; and (2) to assess whether live C. gigas maintained on-farm after an OsHV-1 related mortality event remain infected and could act as a reservoir host for subsequent outbreaks. OsHV-1 DNA was detected in the hemolymph, gill, mantle, adductor muscle, gonad and digestive gland of apparently healthy adult oysters. The likelihood of detecting OsHV-1 DNA in hemolymph was equivalent to that in gill and mantle, but the odds of detecting OsHV-1 DNA in hemolymph and gill were more than 8 times that of adductor muscle. Gill had the highest viral loads. Compared to testing whole gill homogenates, testing snippets of the gill improved the detection of OsHV-1 DNA by about four fold. The prevalence of OsHV-1 in gill and mantle was highest after the first season of OsHV-1 exposure; it then declined to low or negligible levels in the same cohorts in subsequent seasons, despite repeated seasonal exposure in monitoring lasting up to 4years. The hemolymph of individually identified oysters was repeatedly sampled over 15months, and OsHV-1 prevalence declined over that time frame in the youngest cohort, which had been exposed to OsHV-1 for the first time at the start of that season. In contrast, the prevalence in two cohorts of older oysters, which had been exposed to OsHV-1 in prior seasons, was consistently low (<10%). Viral loads were

  14. Antimicrobial activity of essential oils of Physalis angulata L | Osho ...

    African Journals Online (AJOL)

    The sensitivity of Bacillus Subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus to the essential oils of both the aerial and root parts were determined. Pseudomonas aeruginosa was resistant to the essential oil from both the aerial and root part of the plant. C. torulopsis, C. stellatoidea and ...

  15. Expression of a natural antisense transcript of Cg-Foxl2 during the gonadic differentiation of the oyster Crassostrea gigas: first demonstration in the gonads of a lophotrochozoa species.

    Science.gov (United States)

    Santerre, C; Sourdaine, P; Martinez, A-S

    2012-01-01

    In the oyster Crassostrea gigas, a successive hermaphrodite, Cg-Foxl2, an ortholog of Foxl2, is suspected to be involved in vitellogenesis or female sex determination. The existence of a natural antisense transcript (NAT) of this factor has been suspected in gonads but needs to be confirmed to better understand the early events of the gonadic differentiation. The occurrence of this NAT was studied by orientation-specific RT-PCR. The NAT and its mRNA expressions were investigated during the development and in adults by real-time PCR and in situ hybridization. The presence of stable in vivo RNA-RNA duplexes was also explored by RNase protection-based approach. This work is the first evidence of characterization of a NAT in the gonads of mollusks and Lophotrochozoa. This NAT named Cg-Foxl2os is supposed to be polyadenylated and forms RNA-RNA duplexes with its mRNA. Cg-Foxl2os is significantly more expressed than Cg-Foxl2 in 2-month-old spats and in mature males. It is co-localized with the mRNA in the cytoplasm of spermatogonia and spermatocytes. The results of this study demonstrate the existence of a NAT of Cg-Foxl2 in the gonads of C. gigas. It may regulate its mRNA expression through formation of cytoplasmic RNA-RNA duplexes during the oyster gonadic differentiation. Copyright © 2012 S. Karger AG, Basel.

  16. A Carbonic Anhydrase Serves as an Important Acid-Base Regulator in Pacific Oyster Crassostrea gigas Exposed to Elevated CO2: Implication for Physiological Responses of Mollusk to Ocean Acidification.

    Science.gov (United States)

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Qiu, Limei; Wang, Lingling; Zhang, Anguo; Song, Linsheng

    2017-02-01

    Carbonic anhydrases (CAs) have been demonstrated to play an important role in acid-base regulation in vertebrates. However, the classification and modulatory function of CAs in marine invertebrates, especially their responses to ocean acidification remain largely unknown. Here, a cytosolic α-CA (designated as CgCAII-1) was characterized from Pacific oyster Crassostrea gigas and its molecular activities against CO 2 exposure were investigated. CgCAII-1 possessed a conserved CA catalytic domain, with high similarity to invertebrate cytoplasmic or mitochondrial α-CAs. Recombinant CgCAII-1 could convert CO 2 to HCO 3 - with calculated activity as 0.54 × 10 3  U/mg, which could be inhibited by acetazolamide (AZ). The mRNA transcripts of CgCAII-1 in muscle, mantle, hepatopancreas, gill, and hemocytes increased significantly after exposure to elevated CO 2 . CgCAII-1 could interact with the hemocyte membrane proteins and the distribution of CgCAII-1 protein became more concentrated and dense in gill and mantle under CO 2 exposure. The intracellular pH (pHi) of hemocytes under CO 2 exposure increased significantly (p ocean acidification and participate in acid-base regulation. Such cytoplasmic CA-based physiological regulation mechanism might explain other physiological responses of marine organisms to OA.

  17. Recovery of wild Pacific oyster, Crassostrea gigas in terms of reproduction and gametogenesis two-years after the Hebei Spirit Oil Spill Accident off the West Coast of Korea

    Science.gov (United States)

    Mondol, Mostafizur Rahman; Keshavmurthy, Shashank; Lee, Hee-Jung; Hong, Hyun-Ki; Park, Heung-Sik; Park, Sang-Rul; Kang, Chang-Keun; Choi, Kwang-Sik

    2015-12-01

    The Hebei Spirit oil spill in December 2007 at Taean off the west coast of Korea was the largest oil tanker accident in Korea. However, the impact of the spill on physiology of benthic animals remains largely unknown. Two-years after the accident, we compared reproductive effort and annual gametogenesis of the wild Pacific oyster Crassostrea gigas, residing at oil spill site with a control oyster population in Incheon Bay, North-West coast of Korea. Results showed that the oyster sampled from the oil spill site showed a significantly higher (279.0 mg standard animal-1, Pgametogenic pattern between the two populations, and most of the females of both populations spawned between August and September. During spawning season, egg mass of oysters determined using enzyme-linked immunosorbant assay (ELISA) in the oil spill area was significantly higher (136.3 mg standard animal-1, P<0.05) than the control population (120.5 mg standard animal-1, P<0.05). The tissue protein level in the oysters at the contaminated area was significantly higher (102.6 mg standard animal-1, P<0.05) than the level measured from the control oysters (81.4 mg standard animal-1, P<0.05). The observed better biological performances of oysters at the contaminated site suggested their recovery of the physiological status to normal level after two years of the oil spill accident.

  18. Concentrations of 108mAg, 137Cs, and 210Pb in oyster (Crassostrea gigas) on the Japanese coast in relation to the distribution and behavior of radionuclides in sea water

    International Nuclear Information System (INIS)

    Ishikawa, Y.; Kikuchi, T.; Sekine, T.; Yoshihara, K.

    1995-01-01

    Concentrations of 108m Ag, 137 Cs, and 210 Pb in oysters (Crassostrea gigas) were measured for about 10 years on the northeast coast of Japan. Silver-108m was detected in oyster samples collected from an open bay, and its concentrations decreased from the initial value of about 30 mBq/kg fresh in the early 1980s to the value of about 10 mBq/kg fresh in the early 1990s. This decrease could be mainly explained by effects of the ocean current in the early 1980s, and the coastal sea water thereafter, as well as by the advection and diffusion in the ocean. In the nearly-closed bays, concentrations of 108m Ag and 210 Pb in oysters were remarkably lower than in the open bays. It suggests that scavenging of silver and lead from the sea water effectively occurred in the nearly-closed bays. In contrast, concentrations of 137 Cs in oysters were similar in the open bays and in the nearly-closed bays. (author). 17 refs., 5 figs., 3 tabs

  19. Ostreid herpesvirus in wild oysters from the Huelva coast (SW Spain).

    Science.gov (United States)

    López-Sanmartín, M; López-Fernández, J R; Cunha, M E; De la Herrán, R; Navas, J I

    2016-08-09

    This is the first report of ostreid herpesvirus 1 microvariant (OsHV-1 µVar) infecting natural oyster beds located in Huelva (SW Spain). The virus was detected in 3 oyster species present in the intertidal zone: Crassostrea gigas (Thunberg, 1793), C. angulata (Lamarck, 1819) and, for the first time, in Ostrea stentina Payraudeau, 1826. Oysters were identified by a specific polymerase chain reaction (PCR) and posterior restriction fragment length polymorphism (RFLP) analysis based on cytochrome oxidase I (COI) mitochondrial DNA. Results confirmed that C. angulata still remains the dominant oyster population in SW Spain despite the introduction of C. gigas for cultivation in the late 1970s, and its subsequent naturalization. C. angulata shows a higher haplotype diversity than C. gigas. OsHV-1 virus was detected by PCR with C2/C6 pair primers. Posterior RFLP analyses with the restriction enzyme MfeI were done in order to reveal the OsHV-1 µVar. Detections were confirmed by DNA sequencing, and infections were evidenced by in situ hybridization in C. gigas, C. angulata and O. stentina samples. The prevalence was similar among the 3 oyster species but varied between sampling locations, being higher in areas with greater harvesting activities. OsHV-1 µVar accounted for 93% of all OsHV-1 detected.

  20. Avances en el estudio del sistema inmunitario de moluscos bivalvos : una aproximación genómica

    OpenAIRE

    Moreira Sanmartín, Rebeca

    2015-01-01

    Identificación y estudio molecular, mediante PCR cuantitativa, pirosecuenciación y microarrays, de genes relacionados con la respuesta inmunitaria frente a patógenos y también frente a diferentes PAMPs (patrones asociados a patógenos): a) Recopilación y análisis de todas las ESTs que existen en la base de datos de almeja fina y almeja japonesa. Estudio de secuencias relacionadas con el sistema inmunológico. Se realizará una recopilación de todas las secuencias que existen en el Genbank...

  1. 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)

    Science.gov (United States)

    Piontkivska, Helen; Chung, J. Sook; Ivanina, Anna V.; Sokolov, Eugene P.; Techa, Sirinart; Sokolova, Inna M.

    2010-01-01

    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 O2- and Fe2+-dependent enzymes prolyl hydroxylases (PHDs). Currently very little is known about the function of this important pathway and the molecular structure of its key players in hypoxia-tolerant intertidal mollusks including oysters, which are among the animal champions of anoxic and hypoxic tolerance and thus can serve as excellent models to study the role of HIF cascade in adaptations to oxygen deficiency. We have isolated transcripts of two key components of the oxygen sensing pathway - the oxygen-regulated HIF-α subunit and PHD - from an intertidal mollusk, the eastern oyster Crassostrea virginica, and determined the transcriptional responses of these two genes to anoxia, hypoxia and cadmium (Cd) stress. HIF-α and PHD homologs from eastern oysters C. virginica show significant sequence similarity and share key functional domains with the earlier described isoforms from vertebrates and invertebrates. Phylogenetic analysis shows that genetic diversification of HIF and PHD isoforms occurred within the vertebrate lineage indicating functional diversification and specialization of the oxygen-sensing pathways in this group, which parallels situation observed for many other important genes. HIF-α and PHD homologs are broadly expressed at the mRNA level in different oyster tissues and show transcriptional responses to prolonged hypoxia in the gills consistent with their putative role in oxygen sensing and the adaptive response to hypoxia. Similarity in amino acid sequence, domain structure and transcriptional

  2. Identification of expressed genes in cDNA library of hemocytes from the RLO-challenged oyster, Crassostrea ariakensis Gould with special functional implication of three complement-related fragments (CaC1q1, CaC1q2 and CaC3).

    Science.gov (United States)

    Xu, Ting; Xie, Jiasong; Li, Jianming; Luo, Ming; Ye, Shigen; Wu, Xinzhong

    2012-06-01

    A SMARTer™ cDNA library of hemocyte from Rickettsia-like organism (RLO) challenged oyster, Crassostrea ariakensis Gould was constructed. Random clones (400) were selected and single-pass sequenced, resulted in 200 unique sequences containing 96 known genes and 104 unknown genes. The 96 known genes were categorized into 11 groups based on their biological process. Furthermore, we identified and characterized three complement-related fragments (CaC1q1, CaC1q2 and CaC3). Tissue distribution analysis revealed that all of three fragments were ubiquitously expressed in all tissues studied including hemocyte, gills, mantle, digestive glands, gonads and adductor muscle, while the highest level was seen in the hemocyte. Temporal expression profile in the hemocyte monolayers reveled that the mRNA expression levels of three fragments presented huge increase after the RLO incubation at 3 h and 6 h in post-challenge, respectively. And the maximal expression levels at 3 h in post-challenge are about 256, 104 and 64 times higher than the values detected in the control of CaC1q1, CaC1q2 and CaC3, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. A integração da pesquisa ao conhecimento ecológico local no subsídio ao manejo: variações no estoque natural da ostra de mangue crassostrea spp. na reserva extrativista do Mandira, Cananéia-SP, Brasil

    Directory of Open Access Journals (Sweden)

    Ingrid Cabral Machado

    2011-06-01

    Full Text Available Este estudo teve o objetivo de descrever uma experiência de integração entre conhecimento científico e comunitário no subsídio ao manejo, a partir das avaliações do estoque da ostra de mangue Crassostrea spp. na Reserva Extrativista do Mandira, baseadas em estudos populacionais e no Conhecimento Ecológico Local (CEL e percepção da comunidade. Os dados dos estudos populacionais apresentaram aspectos concordantes com o Conhecimento Ecológico Local, evidenciando variações no estoque de ostras na Reserva.This study aimed to illustrate the experience of integration between scientific knowledge and Local Ecological Knowledge to subside management from the assessments of the mangrove oyster stock in the Mandira Extractive Reserve, based on population studies and on local ecological knowledge and perception of the community. Data from population studies showed features consistent with the Local Ecological Knowledge, providing evidence of variations in the stock of oysters in the Mandira Extractive Reserve.

  4. Alkylphenols and polycyclic aromatic hydrocarbons in bivalves from Comunidad Valenciana coastal waters; Alquilfenoles e hidrocarburos aromaticos policiclicos en bivalvos de las coastas de la comunidad Valenciana

    Energy Technology Data Exchange (ETDEWEB)

    Marti Ortega, N.; Aguado Garcia, D.; Bouzas Blanco, A.; Segovia Martinez, L.; Albargues Llamas, M.; Sevillano Cabeza, A.; Campins Falco, P.; Seco Torrecillas, A.; Ferrer Polo, J.

    2009-07-01

    This paper reports the results on alkylphenol and polycyclic aromatic hydrocarbons (PAH) pollution in mussels and cleans from Comunidad Valenciana coastal waters, in 2008. The significant presence of nonylphenol observed in both bivalves reflects an exposure to alkyl phenolic surfactants from the discharges of wastewater treatment plants that treat industrial and urban wastewaters, where the presence of alkylphenol polyethoxylated is common due to its extensive use (detergents, solubilizers...). The presence of low levels of PAH was observed in most of the studied areas. However, it must be highlighted that bivalves consumption does not imply any risk for human health. (Author) 21 refs.

  5. Efecto del detergente biodegradable (aquil sulfonato de sodio en el consumo de oxígeno y tasa de filtración del bivalvo Semimytilus algosus

    Directory of Open Access Journals (Sweden)

    Guillermo Alvarez

    2014-06-01

    Full Text Available El consumo de oxigeno específico (COE e individual (COI de Semimytilus algosus (0,0856 a 0,1869 g fue determinado en respirómetros cerrados estáticos (300 ml aprox. en presencia de 3 concentraciones de detergente (CO = 0,00; C1 = 0,02; C2 = 0,04; y C3 = 0,06 mg I-1 de detergente. Para detectar el oxigeno disuelto se usó el método de Winkler. La tasa de Filtración individual (TFI fue calculada en ausencia de detergente por consumo de la diatomea Chaetoceros gracilis con los mismos individuos expuestos al detergente durante los experimentos de respiración. Las condiciones de experimentación fueron 35 % de salinidad y 17 ± 0,5ºC. Los resultados observados indican que el detergente aún siendo biodegradable, a tiempos; cortos de exposición altera la tasa respiratoria e incrementa el consumo de oxigeno y velocidad de la tasa de filtración a medida que la concentración de detergente se incrementa.

  6. The use of multivariate analysis to link sediment contamination and toxicity data to establish sediment quality guidelines: an example in the Gulf of Cadiz (Spain); El uso del analisis multivariante en la union de datos de toxicidad y contaminacion para establecer guias de calidad de sedimento: Un ejemplo en la Bahia de Cadiz (Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Del Valls, T. Angel; Forja, Jesus M [Departamento de Quimica Fisica, Facultad de Ciencias del Mar, Universidad de Cadiz, Cadiz, (Spain); Gomez-Parra, Abelardo [Instituto de Ciencias Marinas de Andalucia, CSIC, Puerto Real, Cadiz, (Spain)

    1998-03-01

    which biological effects have been shown to be minimal (mg kg{sup -}1 dry sediment), are: Hg, 0.25; Ag, 0.78; Pb, 66.80; Cr, 101.2; LAS, 2.6. [Spanish] Para evaluar la calidad de los sedimentos marinos en el Golfo de Cadiz, los datos provenientes de concentraciones quimicas y respuestas de toxicidad en sedimentos fueron unidos usando el analisis ultivariante. Las muestras de sedimentos fueron recogidas sinopticamente en siete estaciones de dos ecosistemas litorales en el Golfo de Cadiz (cinco en la Bahia de Cadiz y dos en las marismas del rio Barbate) y fueron sujetas a seis tests de toxicidad de forma independiente y replicada, asi como a analisis quimicos. Los efectos toxicos en los sedimentos se chequearon utilizando tres fases operativas del sedimento: sedimento bruto, utilizando el anfipodo Microdeutopus gryllotalpa (10 d estatico: supervivencia) y la almeja de estuario Ruditapes philippinarum (48 h estatico: enterramiento); extracto de sedimento, utilizando larvas del bivalvo de estuario Crassostrea angulata (48 h estatico: supervivencia) y del pez marino Sparus aurata (48 h estatico: supervivencia); y agua intersticial, utilizando poblaciones del rotifero de estuario Brachionus plicatilis (7 d estatico: decaimiento de la poblacion) y de la bacteria marina Photobacterium phosphoreum (Microtox ). Para evaluar los niveles de contaminacion se determinaron las concentraciones en los sedimentos de carbono organico, 14 metales traza (Fe, Mn, Cu, Zn, Pb, Cd, Ag, Hg, As, Sn, V, Ni, Co y Cr) y el detergente alquibencenosulfonato lineal (LAS). Los resultados de los ensayos de toxicidad se compararon mediante relaciones de respuesta entre las diferentes estaciones, demostrando una concordancia general entre los valores de toxicidad determinados en todos los tests, excepto en el caso de la toxicidad en el agua intersticial (principalmente debido a mezclas de metales traza toxicas). Los datos obtenidos en los ensayos quimicos y de toxicidad se ensamblaron utilizando tecnicas

  7. Contaminação fecal da ostra Crassostrea rhizophorae e da água de cultivo do estuário do Rio Pacoti (Eusébio, Estado do Ceará: Isolamento e identificação de Escherichia coli e sua susceptibilidade a diferentes antimicrobianos

    Directory of Open Access Journals (Sweden)

    Regine Helena Silva dos Fernandes Vieira

    2008-06-01

    Full Text Available This study has been designed to assess the microbiological quality of oyster Crassostrea rhizophorae and of the water used in farms located at the Pacoti River estuary, Ceará State, by means of the MPN of total coliforms (Ct and thermtolerant coliforms (CT. The database consisted of 15 samples collected from June to November, 2006. The water was kept within the limits set up by the current legislation. MPN values were in the ranges of <1.8 18,000 Ct per 100 ml and <1.8 2,000 CT per 100 ml, for the water, and <1.8 3,500 Ct per gram and <1.8 2,800 CT per gram for the oyster itself. Twenty-five strains isolated from the cultivation water and identified as Escherichia coli were tested for susceptibility to a few antimicrobians and proved resistant to ampicillin, nitrofurantoin, tetracycline, sulfazotrin, nalidixic acid, ciprofloxacin and imipenem. From the oysters, four strains were identified as E. coli and proved resistant to tetracycline and imipenem. From the afore-mentioned results, it can be concluded that: Pacoti River waters have received a clean bill of health according to the national legislation; the majority of water-isolated E.coli strains (59.43% were sensitive to the currently used antimicrobians, except for imipenem to which 80% of the identified E. coli strains proved resistant; sensitivity of the oyster-isolated E. coli strains was found to be high to most of the tested antimicrobians. In all, it is suggested that more clear management measures be made available so as to allow for microbiological quality evaluation of raw-consumed mollusks.

  8. Antibacterial activity of the fruit extract of Physalis angulata and its

    African Journals Online (AJOL)

    User

    includes about 120 species with herbal characteris- tics and perennial habits. It is distributed through- out tropical and subtropical regions of the world ... Zinc oxide has been shown to have therapeutic applica- tion in treating a variety of skin conditions in prod- ucts such as baby powder, barrier creams to treat diaper rashes ...

  9. Nutritional quality in terms of lipid content and fatty acid composition of neutral and polar lipids in the adductor muscle of the oyster Crassostrea gigas (Thunberg, 1794 farmed in the Bizert lagoon (Tunisia in relation with sexual cycle and environmental settings

    Directory of Open Access Journals (Sweden)

    Salwa Dridi

    2017-12-01

    Full Text Available Monthly variations of fatty acid composition of the two fractions polar lipids (PL and neutral lipids (NL in the adductor muscle of cupped oyster Crassostrea gigas, were studied from May 2005 until June 2006 in the Bizert lagoon, related to environmental parameters and reproductive events. C. gigas showed a clear cycle of energy storage and utilization in the site of study. Total PL and NL content varied significantly during the year and showed a negative and significant correlation with the gametogenic condition index which can be explained by transfer of fatty acids from the adductor muscle to gonads to support the gametogenic cycle. Nevertheless, PL and NL have no significant correlations either with temperature or chlorophyll a registered in the site of study. The adductor muscle proved to be less influenced by chlorophyll a richness of the farming environment. The dominance of total polyunsaturated fatty acids (PUFAs over the saturated fatty acids (SFAs and monounsaturated fatty acids (MUFAs in both PL and NL fractions was established throughout the period of study. Oysters analyzed were characterized by high levels of PUFAs n−3 and high n−3/n−6 PUFAs ratio in both PL and NL fractions. PUFAs n−3 and SFAs of PL and PUFAs and SFAs of NL, showed a negative and significant correlation between them. In fact, low temperature values produce generally an increase in the PUFAs percentages in order to maintain the fluidity of cell membranes. We deduce that annual variations of fatty acids content in PL and NL fractions of the adductor muscle of C. gigas seem to be in relation with the reproductive events. According to our results, the adductor muscle tissues were relatively poor in fatty acids (maximum values (% of dry weight of PL and NL respectively were 2.04 ± 0.33 and 1.75 ± 0.9. Lipids fluctuations were not pronounced all over the period of study in the site of sampling due to low effects of the environment richness and phases of

  10. Composição de esteróis e ácidos graxos de ostras (Crassostrea gigas cultivadas em Florianópolis - SC, em duas estações do ano Fatty acids and sterols composition of oyster cultivated in two seasons of the year in Florianópolis - SC city-Brazil

    Directory of Open Access Journals (Sweden)

    Jane Parisenti

    2010-05-01

    Full Text Available O objetivo deste trabalho foi determinar os ácidos graxos e esteróis das ostras (Crassostrea gigas cultivadas em Florianópolis em duas estações do ano. As ostras foram secas em estufa a 60 °C por 48 horas e trituradas. A fração lipídica foi determinada pelo método de Soxhlet e os ácidos graxos identificados por cromatografia gasosa. As ostras apresentaram um teor de lipídios considerado baixo nas duas estações, sendo maior na primavera (2,7 g.100 g-1 que no verão (1,5 g.100 g-1. As ostras coletadas na primavera apresentaram maior proporção de ácidos graxos poli-insaturados que as do verão, sendo que ambas apresentaram boas quantidades de ácidos graxos da série ômega-3, 550 mg.100 g-1 (verão e 892 mg.100 g-1 (primavera. Quanto aos esteróis totais, as ostras da primavera (27,1 mg.100 g-1 apresentaram maior proporção de que as do verão (8,4 mg.100 g-1, sendo a proporção de colesterol somente 42% no verão e 45% na primavera. As ostras de cultivo da região de Florianópolis, localizada no sul do Brasil, contêm lipídios benéficos à saúde incluindo ácidos graxos da série ômega-3 e baixo teor de colesterol. Pela sua composição lipídica, as ostras em quantidade e forma de preparo adequada, podem fazer parte de uma dieta saudável.The aim of this study was to determine the concentration of sterols and fatty acids of oysters cultivated in Florianopolis-SC in two seasons of the year. Oysters were dried in oven at 60 °C for 48 hours and ground. Lipids were determined by Soxhlet method and fatty acids were identified by gas chromatography. Oysters collected during the spring showed a higher content of polyunsaturated fatty acids than oysters collected during summer. Even so, both samples showed good quantities of n-3: 550 mg.100 g-1 (summer and 892 mg.100 g-1 (spring. Oysters collected during the spring showed a higher content of total steroids; however, only 42% (summer and 45% (spring of these steroids were

  11. Thallium in the marine environment: first ecotoxicological assessments in the Guadalquivir estuary and its potential adverse effect on the donana european natural reserve after the Aznalcollar mining spill (SW Spain); Talio en el medio marino: primera valoracion ecotoxicologica en el estuario del Guadalquivir y su efecto potencial adverso en la reserva natural de donana despues del vertido minero de Aznalcollar (SW de Espana).

    Energy Technology Data Exchange (ETDEWEB)

    DelValls, T.A [Departamento de Quimica Fisica, Facultad de Ciencias del Mar, Universidad de Cadiz, Puerto Real, Cadiz (Spain); Saenz, V; Arias, A.M; Blasco, J [Instituto de Ciencias Marinas de Andalucia, CSIC, Puerto Real, Cadiz (Spain)

    1999-06-01

    Thallium (Tl) is an extremely toxic but little-studied element in the marine environment and practically no information has been reported on the levels of Tl in marine organisms. After the Aznalcollar mining Spill (April 1998), high levels of metals were put into the environment. This acud-contaminated medium was responsible for the initial pollution effects measured in the Guadiamar River, which is an affluent of the Guadalquivir River and very close to the biggest natural reserve in Europe (Donana). Four different species were used in the monitoring from April to September 1998 and a sediment field bioassay to check bioacumulation was performed. We present the first ecotoxicological evaluation of the mining spill in the Guadalquivir River, with reference to Tl, a little-known metal. Also, Pb and Cd data were compared to Tl during field sediment testing. Results show low levels of this metal in all of the organisms studied and they do not show any increase in the level of this metal, ranging from 40 to 90 ng g{sup -}1, 80 to 210 ng g{sup -}1, 15 to 98 ng g{sup -}1 and 75 to 125 whole body dry weight for Scrobicularia plana, Liza ramada (muscle), Crassostrea angulata and Uca Tangeri, respectively. These are the first field data of Tl concentration measured using estuarine organisms. Field sediment toxicity test results confirm those obtained during the monitoring: Tl is not bioaccumulated by the organisms (C. angulata) used in the test. The sequence in bioaccumulation of metals was Cd > Pb > Tl. Both studies, bioaccumulation and sediment toxicity, should be maintained during the next few years to really evaluate the potential effect of the mining spill on the ecosystem and society. [Spanish] El talio (Tl) es un elemento extremadamente toxico aunque poco estudiado en el medio marino y la informacion sobre niveles de Tl en organismos marinos con anterioridad al presente trabajo es practicamente nula. Despues del vertido minero de Aznalcollar (abril de 1998) se

  12. Copper and zinc contamination in oysters: subcellular distribution and detoxification.

    Science.gov (United States)

    Wang, Wen-Xiong; Yang, Yubo; Guo, Xiaoyu; He, Mei; Guo, Feng; Ke, Caihuan

    2011-08-01

    Metal pollution levels in estuarine and coastal environments have been widely reported, but few documented reports exist of severe contamination in specific environments. Here, we report on a metal-contaminated estuary in Fujian Province, China, in which blue oysters (Crassostrea hongkongensis) and green oysters (Crassostrea angulata) were discovered to be contaminated with Cu and other metals. Extraordinarily high metal concentrations were found in the oysters collected from the estuary. Comparison with historical data suggests that the estuary has recently been contaminated with Cr, Cu, Ni, and Zn. Metal concentrations in blue oysters were as high as 1.4 and 2.4% of whole-body tissue dry wt for Cu and Zn, respectively. Cellular debris was the main subcellular fraction binding the metals, but metal-rich granules were important for Cr, Ni, and Pb. With increasing Cu accumulation, its partitioning into the cytosolic proteins decreased. In contrast, metallothionein-like proteins increased their importance in binding with Zn as tissue concentrations of Zn increased. In the most severely contaminated oysters, only a negligible fraction of their Cu and Zn was bound with the metal-sensitive fraction, which may explain the survival of oysters in such contaminated environments. Copyright © 2011 SETAC.

  13. Persistence of enteric viruses within oysters (Crassostrea virginica)

    Science.gov (United States)

    It is well known that water-borne enteric viruses are concentrated by bivalves. Why these viruses are selectively retained and remain infectious within shellfish tissues for extended periods is unknown. Our current hypothesis is that phagocytic hemocytes (blood cells) are a site of virus persiste...

  14. Development of twenty-six microsatellite loci from Crassostrea ...

    Indian Academy of Sciences (India)

    food oyster species primarily inhabiting the coastal waters of the South China Sea (Li et al. 1988; Lam and ... with 20 U Sau3AI (Takara, Dalian, China) in a volume of ..... Bassam B. J., Caetanoanolles G. and Gresshoff P. M. 1991 Fast and.

  15. Evaluation of buffering potency of oyster ( Crassostrea gasar ) shells ...

    African Journals Online (AJOL)

    ) shells on acidic borehole water for fish farming. Eighteen (18), 100-litre shaded plastic tanks (3/4- filled, pH 4.0) of three replicates per treatment of 270 g buffer agent were used. There were four trials of six treatments (T) namely control (C) ...

  16. The extracts of pacific oyster ( Crassostrea gigas ) alleviate Ovarian ...

    African Journals Online (AJOL)

    Background: Bisphenol-A (BPA) is one of the widespread industrial compounds, which ... functional disorders of female rats with exposure to BPA and the underlying possible mechanism. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  17. Responses of wild husk tomato, Physalis angulata L. to growth regulators and gamma rays on chlorophyll content and fruit yield

    International Nuclear Information System (INIS)

    Raghava, R.P.; Raghava, Nisha

    1994-01-01

    Effect of different growth regulators and gamma rays on the total chlorophyll content and fruit yield were studied in wild species of husk tomato and concluded that indole-3-acetic acid (IAA) 200 and kinetin (KIN) 10 ppm showed remarkable enhancement in both total chlorophyll content and fruit yield, while maleic hydrazide (MH) 100, 200 ppm and coumarin (COU) in all the treatments enhanced total chlorophyll content. Gamma ray treatments significantly enhanced both the parameters. Amongst all the treatments maximum fruit yield was in 20 kR of gamma rays. (author). 31 refs., 1 tab

  18. Effects of Ethanolic Ferolagu angulata Extract on Pathogenic Gastrointestinal Bacteria and Probiotic Bacteria in Skimmed Milk Medium

    Directory of Open Access Journals (Sweden)

    Reza Naghiha

    2016-12-01

    Full Text Available Background:    Due to excessive consumption of synthetic drugs, drug resistance rate of pathogenic bacteria is increasing and there is an ever-increasing need to find new safe compounds to tackle this problem. This study was conducted to investigate the consequences of chavill extract on the growth and viability of gastrointestinal pathogenic bacterium and probiotics bacteria. Methods:    The experiment contained three levels of the chavill extract concentrations (0, 1 and 3% which were added to the milk free fat in accompany with three probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei and lactobacillus plantaram and a pathogenic gastrointestinal bacterium (Salmonella typhimurium. Bacterial inoculums (1×107 CFU/ml with different concentrations of chavill extract were added to skimmed milk medium and bacteria growth were enumerated. Results:  The concentration of 1% chavill extract significantly increased the total count of probiotic bacteria compared to the control group, while the number of pathogenic bacteria was decreased. At 3% chavill extract the growth of Lactobacillus acidophilus and Lactobacillus plantaram were increased. On the other hand, it prevented the growth of Salmonella typhimurium Conclusion:   Chavill extracts would play as an alternative to antibiotics in pharmacological studies to decreases harmful bacteria and increase probiotic bacteria.

  19. Ausencia de detección de enterovirus en bivalvos Anadara tuberculosa (Bivalvia: Arcidae) por contaminación química en el Pacífico de Costa Rica

    OpenAIRE

    Herrero U., Libia; Palacios F., Alejandro; Hun O., Laya; Vega A., Francisco

    1999-01-01

    Anadara tuberculosa es uno de los moluscos más abundantes de importancia comercial en Costa Rica. Su hábitat acuático es una fuente potencial de contaminación fecal y química para el ser humano. El objetivo de este trabajo fue determinar enterovirus, especialmente poliovirus y el virus de la hepatitis A y contaminación química como nitratos y sulfatos en las carnes y los líquidos internos. Se recogieron trece muestras de cuatro sitios del golfo de Nicoya, de tres sitios del manglar Sierpe-Tér...

  20. Ausencia de detección de enterovirus en bivalvos Anadara tuberculosa (Bivalvia: Arcidae por contaminación química en el Pacífico de Costa Rica

    Directory of Open Access Journals (Sweden)

    Libia Herrero U.

    1999-09-01

    Full Text Available Anadara tuberculosa es uno de los moluscos más abundantes de importancia comercial en Costa Rica. Su hábitat acuático es una fuente potencial de contaminación fecal y química para el ser humano. El objetivo de este trabajo fue determinar enterovirus, especialmente poliovirus y el virus de la hepatitis A y contaminación química como nitratos y sulfatos en las carnes y los líquidos internos. Se recogieron trece muestras de cuatro sitios del golfo de Nicoya, de tres sitios del manglar Sierpe-Térraba (pacífico de Costa Rica y de cinco pescaderías de San José, la capital de Costa Rica. Las muestras fueron ensayadas por 1 coliformes fecales (Número Más Probable/100 ml, 2 aislamiento de enterovirus en cultivos celulares (Hep-2 y FrhK-4, 3 citotoxicidad en células Vero y 4 la habilidad de las muestras de inactivar 10 DI50% de poliovirus en cultivos celulares. El Número Más Probable/100 ml de las aguas fue más alto de lo que se considera adecuado para el uso recreacional, aunque los coliformes en los líquidos y las carnes fue en general mucho más bajo. No se logró el aislamiento de ningún agente citopatogénico, pero encontramos que la concentración de nitratos y sulfatos de las muestras fue mayor a lo aceptable para consumo humano. La toxicidad intrínseca de las muestras en cultivos celulares fue de una dilución de 1/8 aunque algunas muestras mostraron toxicidad a una dilución de 1/128. Los líquidos fueron más tóxicos que las carnes pero no se encontró una correlación entre la toxicidad en cultivos celulares y la toxicidad química: aparentemente otros contaminantes no identificados en este trabajo fueron los responsables. Se analizó la habilidad de los líquidos y las carnes de inactivar 10 DI50% de poliovirus demostrando que los líquidos y las carnes con más toxicidad en cultivos celulares fueron los que mostraron un porcentaje mayor de inactivación del poliovirus. Se recomienda la vigilancia de la contaminación química de estas aguas.Anadara tuberculosa is one of the most abundant mollusks of commercial importance in Costa Rica. Its habitat water is a potential source of fecal and chemical contamination to humans. We wanted to asses enterovirus, mainly poliovirus and hepatitis A virus and chemicals such as sulphates and nitrates in meat and body fluids. Thirteen samples were taken from four sites in Nicoya Gulf, three sites in the Sierpe-Térraba mangrove (Pacific of Costa Rica and from five fish markets in San José, the capital of Costa Rica. Samples were tested for 1 fecal coliforms (Most Probable Number/100 ml, 2 isolation of enterovirus in cell culture (Hep-2, FrhK-4, 3 cell cytotoxicity in Vero cells and 4 the ability to inactivate 10 ID50% of poliovirus in cell culture. The Most Probable Number/100 ml in surrounding water was higher than the accepted standard for recreational waters, although the number of fecal coliforms in meats and body fluids was lower than in the external water. No cytopathogenic agents were isolated, but we found nitrate and sulphate concentrations that exceeded maxima for human consumption and recreation. The intrinsic cytotoxicity of the samples was at a 1/8 dilution, but some samples were cytotoxic at dilutions of 1/128. Body fluids were more cytotoxic than meats, but a positive correlation between cytotoxicity and chemical contamination was not determined: apparently other pollutants not identified in this study were responsible. Fluid and meat capacity to inactivate 10 ID50% of poliovirus in cell culture was demonstrated. Samples that were toxic for cell cultures also showed a higher percentage of poliovirus inactivation. Monitoring chemical pollution in these waters is highly recommended.

  1. Ecotoxicidad de metales en el bivalvo dulceacuícola Anodontites trapesialis y su potencial uso en el biomonitoreo de ambientes acuáticos en la Amazonía peruana

    NARCIS (Netherlands)

    Loayza-Muro, R.; Elías-Letts, R.; Herkovits, J.

    2009-01-01

    The effects of Cd, Cu and Zn on the filtration rate of Anodontites trapesialis were tested in order to evaluate the suitability of this freshwater mussel for ecotoxicity bioassays. This sublethal endpoint is very relevant due to the ecological role of this mussel in Amazonian environments. The

  2. La contaminación por metales pesados en la Ciénaga Grande de Santa Marta, Caribe colombiano La contaminación por metales pesados en la Ciénaga Grande de Santa Marta, Caribe colombiano

    Directory of Open Access Journals (Sweden)

    Campos C. Néstor Hernando

    1990-09-01

    Full Text Available Se dan los resultados de los estudios sobre la contaminación por metales pesados en la Ciénaga Grande de Santa Marta. Las determinaciones se realizaron en el material en suspensión, en los bivalvos Crassostrea rhizophorae e Isognomon alatus y en los peces Gathorops spixii y Ariopsis bonillai. Los análisis de los metales Cd, Zn y Cu en el material en suspensión permitieron determinar que las mayores descargas de estos metales se suceden principalmente desde el Río Magdalena a través del Canal del Clarín y de los ríos que fluyen del piedemonte de la Sierra Nevada de Santa Marta. La comparación de los contenidos en bivalvas permiten determinar la importancia de estos organismos como bioindicadores. Los análisis en las dos especies de peces mostraron una diferenciación en la capacidad de acumulación entre una y otra.  Al comparar los contenidos de metales entre los diferentes tipos de muestras con los cambios en los contenidos en el material en suspensión y la salinidad, se observó que estos dos parámetros son principalmente los que controlan la biodisponibilidad de los metales y además afectan los procesos fisiológicos de los organismos, aumentando o disminuyendo la capacidad de bioacumulación. Results of the studies of heavy metals pollution in the Ciénaga Grande de Santa Marta are provided. The determinations have been done on the suspended matter, on the bivalves Crassostrea rhizophorae and Isognomon alatus, and in the fishes Gathorops spixii and Ariopsis bonillai. The analysis of Cd, Zn and Cu in the suspended matter led to determine that the discharges come principally from the Río Magdalena through the Canal del Clarín and the rivers coming from the Sierra Nevada de Santa Marta. Comparisons of the concentration in bivalves show the importance of this organisms as bioindicators. The analysis in both fish species show a difference in their capacity of accumulation. Comparison of the metals contents between different types

  3. Moluscos asociados a las raíces sumergidas del mangle rojo Rhizophora mangle, en el Golfo de Santa Fe, Estado Sucre, Venezuela

    Directory of Open Access Journals (Sweden)

    B. Márquez

    2002-12-01

    Full Text Available Se realizó un estudio mensual cualitativo y cuantitativo de la comunidad de moluscos asociados a las raíces sumergidas del mangle rojo, Rhizophora mangle, entre octubre de 1998 y septiembre de 1999, en seis estaciones del Golfo de Santa Fe (Estado Sucre, Venezuela. Se colectaron e identificaron un total de 4 704 individuos pertenecientes a 45 especies de moluscos (22 gasterópodos, 15 bivalvos y 8 polyplacóforos. Las especies más abundantes fueron: Crassostrea rhizophorae, Isognomon bicolor L alatus y Brachidontes exustus. Los valores más altos de diversidad y equitabilidad, y los menores valores de dominancia, se encontraron en las estaciones tres y cuatro, mientras que lo opuesto ocurrió en las estaciones uno y dos. El análisis de afinidad mostró que en las cinco primeras estaciones las variaciones espaciales en la composición de la comunidad son mayores que las variaciones temporales, mientras que en la estación seis priman las diferencias temporales. Se encontraron factores que podrían ser importantes para determinar la estructura de la comunidad, como vecindad a otros ecosistemas y/6 aspectos biológicos específicos de las especies como adaptaciones a condiciones fluctuantes, hábitos alimenticios y migración en busca de ambientes sombreados y protegidos.A qualitative and quantitative monthly study of the mollusks community associated to the submered roots of the red mangrove, Rhizophora mangle (L., between October of 1998 and September of 1999, in six stations of the Gulf of Santa Fe. (Suere State, Venezuela. Were collected 4 704 specimens, 45 species of mollusks were identified (22 gastropods, 15 bivalves and 8 chitons. The most abundant species were: Crassostrea rhizophorae, Isognomon bicolor, L alatus and Brachidontes exustus. The highest values in diversity and evenness, and the smallest dominant values, were in the stations three and four, while the opposed happened in the stations one and two. The analysis of likeness

  4. Bioavailability of cadmium, copper, mercury, lead, and zinc in subtropical coastal lagoons from the southeast Gulf of California using mangrove oysters (Crassostrea corteziensis and Crassostrea palmula).

    Science.gov (United States)

    Páez-Osuna, Federico; Osuna-Martínez, Carmen C

    2015-02-01

    Cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn) were assessed in the edible tissues of Crassrotrea corteziensis oysters collected during the rainy and dry seasons in 27 sites from 8 coastal lagoons of the southeast Gulf of California. In addition, C. palmula oysters were sampled at 9 sites from the same mangrove roots where C. corteziensis oysters were collected. Metal analyses were performed by flame atomic absorption spectrophotometry (Cd, Cu, and Zn), graphite furnace (Pb), and cold vapor detection (Hg). The obtained mean levels were (µg g(-1) dry weight) as follows: Cd 6.05 ± 2.77, Cu 60.0 ± 33.4, Hg 0.38 ± 0.17, Pb 1.11 ± 0.63, and Zn 777 ± 528 µg g(-1). For all metals except Hg, the concentrations were greater during dry season than during rainy seasons. The high levels, particularly that for Cd, were related to upwelling along the eastern Gulf of California. High Hg levels in the rainy season were associated with the transport of materials from the watershed to the lagoon. Shrimp farming, agriculture, and other sources were considered as potential sources to explain the differences in metal bioavailability in the 8 lagoons. The mean concentrations of Cd (Santa María-La Reforma lagoon), Cu [San Ignacio-Navachiste-El Macapule (SINM), Urías (URI), and Altata-Ensenada del Pabellón lagoons], and zinc (Zn) (URI, Santa María-Ohuira-Topolobampo, El Colorado, and SINM lagoons) during the dry season were greater than the maximum permissible limits. C. palmula collected in 8 sites where they were present simultaneously with C. corteziensis had consistently greater metal levels than C. corteziensis, but correlation analyses showed a high and significant (P < 0.05) correlation between metal concentrations in both species. The correlation equations obtained are useful where the same species is not distributed and is necessary to compare results from distinct regions.

  5. Some aspects of growth and condition index of Saccostrea cuculata (Born), Cerithium rubus (Desh) and Tellina angulata Gmlen from Bombay coast

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L; Nair, V.R.; Govindan, K.

    stream_size 9 stream_content_type text/plain stream_name J_Indian_Fish_Assoc_20_21.pdf.txt stream_source_info J_Indian_Fish_Assoc_20_21.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  6. Source and impact of lead contamination on δ-aminolevulinic acid dehydratase activity in several marine bivalve species along the Gulf of Cadiz

    International Nuclear Information System (INIS)

    Company, R.; Serafim, A.; Lopes, B.; Cravo, A.; Kalman, J.; Riba, I.; DelValls, T.A.; Blasco, J.; Delgado, J.; Sarmiento, A.M.; Nieto, J.M.; Shepherd, T.J.; Nowell, G.; Bebianno, M.J.

    2011-01-01

    Coastal areas and estuaries are particularly sensitive to metal contamination from anthropogenic sources and in the last few decades the study of space-time distribution and variation of metals has been extensively researched. The Gulf of Cadiz is no exception, with several rivers draining one of the largest concentrations of sulphide deposits in the world, the Iberian Pyrite Belt (IPB). Of these rivers, the Guadiana, one of the most important in the Iberian Peninsula, together with smaller rivers like the Tinto and Odiel, delivers a very high metal load to the adjacent coastal areas. The purpose of this work was to study the source and impact of lead (Pb) drained from historical or active mining areas in the IPB on the activity of a Pb inhibited enzyme (δ-aminolevulinic acid dehydratase, ALAD) in several bivalve species along the Gulf of Cadiz. Seven marine species (Chamelea gallina, Mactra corallina, Donax trunculus, Cerastoderma edule, Mytilus galloprovincialis, Scrobicularia plana and Crassostrea angulata) were collected at 12 sites from Mazagon, near the mouth of the rivers Tinto and Odiel (Spain), to Cacela Velha (Ria Formosa lagoon system, Portugal). Lead concentrations, ALAD activity and lead isotope ratios ( 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb) were determined in the whole soft tissues. The highest Pb concentrations were determined in S. plana (3.50 ± 1.09 μg g -1 Pb d.w.) and D. trunculus (1.95 ± 0.10 μg g -1 Pb d.w.), while M. galloprovincialis and C. angulata showed the lowest Pb levels ( -1 Pb d.w.). In general, ALAD activity is negatively correlated with total Pb concentration. However this relationship is species dependent (e.g. linear for C. gallina ALAD = -0.36[Pb] + 0.79; r = 0.837; or exponential for M. galloprovincialis ALAD = 2.48e -8.3[Pb] ; r = 0.911). This indicates that ALAD activity has considerable potential as a biomarker of Pb and moreover, in marine bivalve species with different feeding habits. Lead isotope data

  7. Sub-chronic exposure to fluoxetine in juvenile oysters (Crassostrea gigas): uptake and biological effects.

    Science.gov (United States)

    Di Poi, Carole; Evariste, Lauris; Séguin, Alexis; Mottier, Antoine; Pedelucq, Julie; Lebel, Jean-Marc; Serpentini, Antoine; Budzinski, Hélène; Costil, Katherine

    2016-03-01

    The bioconcentration potential of fluoxetine (FLX) and its biological effects were investigated in juvenile Pacific oyster exposed for 28 days to environmentally relevant concentrations of FLX (1 ng L(-1), 100 ng L(-1) and up to 10 μg L(-1)). FLX bioaccumulated in oyster flesh resulting in 28-day bioconcentration factors greater than 2,000 and 10,000 by referring to wet and dry weights, respectively. Nevertheless, FLX did not induce oyster mortality, delayed gametogenesis, or lead to adverse histopathological alterations. At the two highest concentrations, despite non-optimal trophic conditions, FLX stimulated shell growth but only in a transient manner, suggesting a role of serotonin in the regulation of feeding and metabolism in bivalves. Those high concentrations seemed to drive bell-shaped responses of catalase and glutathione S-transferase activities throughout the exposure period, which may indicate the activation of antioxidant enzyme synthesis and then an enhanced catabolic rate or direct inhibition of those enzymes. However, no clear oxidative stress was detected because no strong differences in thiobarbituric acid-reactive substance (TBARS) content (i.e. lipid peroxidation) were observed between oyster groups, suggesting that cellular defence mechanisms were effective. These results demonstrate the importance of considering additional biomarkers of oxidative stress to obtain a comprehensive overview of the FLX-induced changes in marine bivalves exposed under realistic conditions. Considering the battery of biomarkers used, FLX appears to induce little or no effects on oyster physiology even at a concentration of 10 μg L(-1). These results do not confirm the lowest observed effect concentration (LOEC) values reported by some authors in other mollusc species.

  8. Application of chitosan microparticles for reduction of vibrio species in seawater and live oysters (Crassostrea virginica).

    Science.gov (United States)

    Fang, Lei; Wolmarans, Bernhard; Kang, Minyoung; Jeong, Kwang C; Wright, Anita C

    2015-01-01

    Human Vibrio infections associated with consumption of raw shellfish greatly impact the seafood industry. Vibrio cholerae-related disease is occasionally attributed to seafood, but V. vulnificus and V. parahaemolyticus are the primary targets of postharvest processing (PHP) efforts in the United States, as they pose the greatest threat to the industry. Most successful PHP treatments for Vibrio reduction also kill the molluscs and are not suitable for the lucrative half-shell market, while nonlethal practices are generally less effective. Therefore, novel intervention strategies for Vibrio reduction are needed for live oyster products. Chitosan is a bioactive derivative of chitin that is generally recognized as safe as a food additive by the FDA, and chitosan microparticles (CMs) were investigated in the present study as a potential PHP treatment for live oyster applications. Treatment of broth cultures with 0.5% (wt/vol) CMs resulted in growth cessation of V. cholerae, V. vulnificus, and V. parahaemolyticus, reducing culturable levels to nondetectable amounts after 3 h in three independent experiments. Furthermore, a similar treatment in artificial seawater at 4, 25, and 37°C reduced V. vulnificus levels by ca. 7 log CFU/ml after 24 h of exposure, but 48 h of exposure and elevated temperature were required to achieve similar results for V. parahaemolyticus and V. cholerae. Live oysters that either were artificially inoculated or contained natural populations of V. vulnificus and V. parahaemolyticus showed significant and consistent reductions following CM treatment (5%) compared to the amounts in the untreated controls. Thus, the results strongly support the promising potential for the application of CMs as a PHP treatment to reduce Vibrio spp. in intact live oysters. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Absence of surface-associated microorganisms in adult oysters (Crassostrea gigas).

    OpenAIRE

    Garland, C D; Nash, G V; McMeekin, T A

    1982-01-01

    Healthy, actively feeding intertidal oysters were removed from an estuarine environment (Pipeclay Lagoon, Tasmania). The epithelial surfaces of various organs of the mantle cavity and alimentary tract were explored by scanning and transmission electron microscopy. All epithelial tissues examined were ciliated, and nearly all were partly covered with secreted mucus. However, microorganisms were seen rarely in the adhesive mucus and never attached to the epithelium. Electron microscopy also fai...

  10. A habitat suitability model for Pacific oysters (Crassostrea gigas) in the Oosterschelde

    NARCIS (Netherlands)

    Schellekens, T.; Wijsman, J.W.M.; Brink, van den A.M.

    2012-01-01

    The modelled habitat suitability maps show a reasonable estimation of the suitability for oysters throughout the Delta and can be used to broadly indicate the consequences of the effect of climate change and infrastructural changes on the habitat suitability for oysters. The largest effect on the

  11. The depuration dynamics of oysters (Crassostrea gigas artificially contaminated with hepatitis A virus and human adenovirus

    Directory of Open Access Journals (Sweden)

    Adriana de Abreu Corrêa

    2012-02-01

    Full Text Available Within the country of Brazil, Santa Catarina is a major shellfish producer. Detection of viral contamination is an important step to ensure production quality and consumer safety during this process. In this study, we used a depuration system and ultraviolet (UV disinfection to eliminate viral pathogens from artificially infected oysters and analysed the results. Specifically, the oysters were contaminated with hepatitis A virus (HAV or human adenovirus type 5 (HAdV5. After viral infection, the oysters were placed into a depuration tank and harvested after 48, 72 and 96 h. After sampling, various oyster tissues were dissected and homogenised and the viruses were eluted with alkaline conditions and precipitated with polyethylene glycol. The oyster samples were evaluated by cell culture methods, as well as polymerase chain reaction (PCR and quantitative-PCR. Moreover, at the end of the depuration period, the disinfected seawater was collected and analysed by PCR. The molecular assays showed that the HAdV5 genome was present in all of the depuration time samples, while the HAV genome was undetectable after 72 h of depuration. However, viral viability tests (integrated cell culture-PCR and immunofluorescence assay indicated that both viruses were inactivated with 96 h of seawater recirculation. In conclusion, after 96 h of UV treatment, the depuration system studied in this work purified oysters that were artificially contaminated with HAdV5 and HAV.

  12. The potential of aerial photography for estimating surface areas of intertidal Pacific oyster beds (Crassostrea gigas)

    NARCIS (Netherlands)

    Kater, B.J.; Baars, J.M.D.D.

    2004-01-01

    Pacific oysters were introduced into the Eastern Scheldt in 1964 for breeding purposes. The first spatfall of wild Pacific oysters was recorded in 1976, and a second larval outburst in 1982 definitely settled wild Pacific oysters in the Eastern Scheldt waters. Oyster beds on intertidal and subtidal

  13. Survival, growth and reproduction of cryopreserved larvae from a marine invertebrate, the Pacific oyster (Crassostrea gigas.

    Directory of Open Access Journals (Sweden)

    Marc Suquet

    Full Text Available This study is the first demonstration of successful post-thawing development to reproduction stage of diploid cryopreserved larvae in an aquatic invertebrate. Survival, growth and reproductive performances were studied in juvenile and adult Pacific oysters grown from cryopreserved embryos. Cryopreservation was performed at three early stages: trochophore (13±2 hours post fertilization: hpf, early D-larvae (24±2 hpf and late D-larvae (43±2 hpf. From the beginning (88 days at the end of the ongrowing phase (195 days, no mortality was recorded and mean body weights did not differ between the thawed oysters and the control. At the end of the growing-out phase (982 days, survival of the oysters cryopreserved at 13±2 hpf and at 43±2 hpf was significantly higher (P<0.001 than those of the control (non cryopreserved larvae. Only the batches cryopreserved at 24±2 hpf showed lower survival than the control. Reproductive integrity of the mature oysters, formely cryopreserved at 13±2 hpf and 24±2 hpf, was estimated by the sperm movement and the larval development of their offspring in 13 crosses gamete pools (five males and five females in each pool. In all but two crosses out of 13 tested (P<0.001, development rates of the offspring were not significantly different between frozen and unfrozen parents. In all, the growth and reproductive performances of oysters formerly cryopreserved at larval stages are close to those of controls. Furthermore, these performances did not differ between the three initial larval stages of cryopreservation. The utility of larvae cryopreservation is discussed and compared with the cryopreservation of gametes as a technique for selection programs and shellfish cryobanking.

  14. Thermal inactivation of enteric viruses and bioaccumulation of enteric foodborne viruses in live oysters (Crassostrea virginica)

    Science.gov (United States)

    Human enteric viruses are one of the main causative agents of shellfish associated outbreaks. In this study, the kinetics of viral bioaccumulation in live oysters and the heat stability of the most predominant enteric viruses were determined in both tissue culture and in oyster tissues. A human nor...

  15. Growth, morphometrics and nutrient content of farmed eastern oysters, Crassostrea virginica (Gmelin), in New Hampshire, USA

    Science.gov (United States)

    When harvested, oysters represent a removal from the ecosystem of nutrients such as nitrogen (N)and carbon (C). A number of factors potentially affect nutrient content, but a quantitative understanding across the geographical range of the eastern oysters is lacking. This study wa...

  16. EFFECTS OF FRESHWATER RELEASES AND SEASON ON OYSTERS (CRASSOSTREA VIRGINICA) IN CALOOSAHATCHEE ESTUARY, FLORIDA

    Science.gov (United States)

    The influence of freshwater releases and season on disease prevalence and intensity of Perkinsus marinus, condition index, gonadal condition, recruitment potential, and growth of oysters was examined monthly at five locations along the Caloosahatchee estuary, Florida. Temperature...

  17. Evaluating the Ability of Oysters (Crassostrea virginica) to Mitigate Coastal Nitrogen Over-Enrichment

    Science.gov (United States)

    Human actions have resulted in a doubling of the rate of bio-available nitrogen production in the biosphere, leading to over-fertilization of coastal ecosystems worldwide. Such over-fertilization has numerous negative consequences for coastal ecosystems, such as excessive algal g...

  18. Effect of carbonate chemistry alteration on the early embryonic development of the Pacific oyster (Crassostrea gigas)

    NARCIS (Netherlands)

    Gazeau, F.; Gattuso, J.-P.; Greaves, M.; Elderfield, H.; Peene, J.; Heip, C.H.R.; Middelburg, J.J.

    2011-01-01

    Ocean acidification, due to anthropogenic CO2 absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on

  19. Effect of carbonate chemistry alteration on the early embryonic development of the Pacific oyster (Crassostrea gigas)

    OpenAIRE

    Gazeau Frédéric; Gattuso Jean-Pierre; Greaves Mervyn; Elderfield Henry; Peene J; Heip Carlo H R; Middelburg Jack J

    2011-01-01

    Ocean acidification, due to anthropogenic CO(2) absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportion...

  20. Effect of carbonate chemistry alteration on the early embryonic development of the pacific pyster (Crassostrea gigas)

    NARCIS (Netherlands)

    Gazeau, F.P.H.; Gattuso, J.P.; Greaves, M.; Elderfield, H.; Peene, J.; Heip, C.H.R.; Middelburg, J.J.

    2011-01-01

    Ocean acidification, due to anthropogenic CO(2) absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on

  1. Antioxidant responses in gills and digestive gland of oyster Crassostrea madrasensis (Preston) under lead exposure

    Digital Repository Service at National Institute of Oceanography (India)

    Shenai-Tirodkar, P.S.; Gauns, M.; Mujawar, M.W.A.; Ansari, Z.A.

    madrasensis against lead (Pb) exposure under laboratory conditions. Antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione-s-transferase (GST) and oxidative damage parameter lipid peroxidation (LPO) were measured in the gills...

  2. Dimensional Relationships in Crassostrea madrasensis (Preston) and C. gryphoides (Schlotheim) in Mangrove Ecosystem

    Digital Repository Service at National Institute of Oceanography (India)

    Nagi, H.M.; Shenai-Tirodkar, P.S.; Jagtap, T.G.

    of the relationship between shell and soft body characteristics are essential in understanding ecological variations and productivity of oyster population. A total number of 627 oyster specimens were collected from different locations in Goa as a case study...

  3. Cloning, characterization and chromosomal location of a satellite DNA from the Pacific oyster, Crassostrea gigas

    Digital Repository Service at National Institute of Oceanography (India)

    Clabby, C.; Goswami, U.; Flavin, F.; Wilkins, N.P.; Houghton, J.A.; Powell, R.

    F2.18 (includ- ing pBGS8 vector) was labelled with fluor-12-dUTP and hybridized to the chromosome slides. The fluorescence signals were directly observed without additional immu- nological enhancement. No fluorescence signals were obtained when...-it-Fluor, Stratagene, La Jolla, CA, USA). Chromosomes were denatured at 72°C in 70% formamide/2 × SSC and the denatured labelled Cgl70 probe was added and hybridization performed at 37°C overnight. Post-hybridization washes were according to manufacturer...

  4. Incorporation of metabolites into glycogen and lipids of the oyster, crassostrea virginica

    International Nuclear Information System (INIS)

    Swift, M.L.; Humphrey, C.L.

    1987-01-01

    Groups of oysters, either fed or unfed, were exposed to U- 14 C labelled D-glucose, L-asp, L-leu, L-ala or acetate for 6 hrs. Except for the glucose trials, the disappearance of radioactivity from the saline of the unfed oysters was greater (83%) than for the fed animals (65%). With glucose, 88% of the radioactivity disappeared in each trial. The specific radioactivity of glycogen isolated from oysters exposed to labelled glucose, asp and ala was 1283, 468 and 8.22 dpm/mg glycogen respectively. Radioactivity was found primarily in the triacylglycerols and phospholipids (PL) in fed oysters and in PL only in unfed oysters. Phosphatidyl choline, phosphatidyl ethanolamine, and a fraction containing phosphatidyl serine and phosphatidyl inositol, had 32%, 25% and 35-40% of the radioactivity respectively. Incorporation of total radioactivity into PL was 70% lower in unfed vs. fed trials, but the distribution of counts among the phospholipids classes was unchanged. Glycogenesis does not appear to be a significant pathway in the oyster. Apparently well-fed oysters are able to store excess dietary calories as lipid. During periods of starvation exogenous small metabolites along with glucose from glycogen are catabolized

  5. Oyster condition index in Crassostrea rhizophorae (Guilding, 1828 from a heavy-metal polluted coastal lagoon

    Directory of Open Access Journals (Sweden)

    M. F. Rebelo

    Full Text Available The condition index (CI of oysters represents an ecophysiological approach to estimate meat quality and yield in cultured bivalve mollusks. In the present study, the CI of oysters from a heavy-metal polluted bay was analyzed with respect to Zn and Cd contamination in soft tissues, spawning, and polychaete infestation. The CI was calculated through a new technique based on molds made to measure the volume of oyster-shell internal cavities. The higher CI values (over 9 in the dry season were probably related availability of suspended particles rich in organic matter in the bay, while the rapid reduction in the CI from one season to the next at some stations suggests the effect of spawning. Polychaete infestation was considered low (18.7% and produced no clear CI effects. The Cd in the oyster tissue collected during the rainy season was weak, although still significantly correlated with the CI (r = -0.36; p < 0.05. All other comparisons of CI and metal concentrations demonstrated a non-significant correlation. The CI variations observed on the temporal and spatial scale were likely to have been caused by availability of organic matter and spawning, rather than spionid infestation or metal body burdens.

  6. Uptake of cadmium from Pacific oysters (Crassostrea gigas) in British Columbia oyster growers

    International Nuclear Information System (INIS)

    Copes, Ray; Clark, Nina Annika; Rideout, Karen; Palaty, Jan; Teschke, Kay

    2008-01-01

    Background: Pacific oysters along the North American coast from Washington to Alaska contain concentrations of cadmium (Cd) that are high by comparison with Atlantic oysters, frequently exceeding 2 μg/g wet weight, but it is unclear whether this Cd is absorbed by consumers. Objectives: To determine the effect of oyster consumption on Cd in blood and urine among a group with high oyster consumption. Methods: Sixty-one non-smoking oyster growers and family members with a mean age of 47.3±7.6 years (range 33-64) were interviewed by telephone to assess their oyster consumption and other sources of Cd exposure at present and 5 years prior to the start of oyster farming. Their blood and urine Cd concentrations were measured. Results: The geometric mean Cd concentration in blood was 0.83 μg/L and in urine was 0.76 μg/g creatinine. Thirty-six percent of participants had urinary Cd levels above 1 μg/g creatinine and 5% were above 2 μg/g creatinine. Recent (last 12 months) and long-term oyster consumptions were positive predictors of blood Cd but did not directly predict urinary Cd. The optimal model for predicting the variance in blood Cd included recent intake of oyster-derived Cd, serum iron concentration and recent ketchup consumption (R 2 =0.34, p=0.00004), with the latter two variables showing a protective effect. The factors found to predict urinary Cd were blood Cd concentration and duration of oyster farming. A rise in blood Cd was observed after 12 years of farming oysters, likely caused by higher consumption of oysters during this period. Conclusions: Oyster-derived Cd is bioavailable and affects body stores of the metal

  7. A semiquantitative PCR assay for assessing Perkinsus marinus infections in the eastern oyster, Crassostrea virginica.

    Science.gov (United States)

    Marsh, A G; Gauthier, J D; Vasta, G R

    1995-08-01

    A 3.2-kb fragment of Perkinsus marinus DNA was cloned and sequenced. A noncoding domain was identified and targeted for the development of a semiquantitative polymerase chain reaction (PCR) assay for the presence of P. marinus in eastern oyster tissues. The assay involves extracting total DNA from oyster hemolymph and using 1 microgram of that DNA as template in a stringent PCR amplification with oligonucleotide primers that are specific for the P. marinus 3.2-kb fragment. With this assay, we can detect 10 pg of total P. marinus DNA per 1 microgram of oyster hemocyte DNA with ethidium bromide (EtBr) staining of agarose gels, 100 fg total P. marinus DNA with Southern blot autoradiography, and 10 fg of total P. marinus DNA with dot-blot hybridizations. We have used the sensitivity of the PCR assay to develop a method for estimating the level of P. marinus DNA in oyster hemolymph and have successfully applied this technique to gill tissues. Our semiquantitative assay uses a dilution series to essentially titrate the point at which a P. marinus DNA target is no longer amplified in a sample. We refer to this technique as "dilution endpoint" PCR. Using hemocytes obtained by withdrawing a 1-ml sample of hemolymph, this assay provides a nondestructive methodology for rapidly screening large numbers of adult oysters for the presence and quantification of P. marinus infection levels. This technique is applicable to other tissues (gills) and could potentially be applied to DNA extracts of whole larvae or spat.

  8. Effectiveness of standard UV depuration at inactivating Cryptosporidium parvum recovered from spiked Pacific oysters (Crassostrea gigas).

    Science.gov (United States)

    Sunnotel, O; Snelling, W J; McDonough, N; Browne, L; Moore, J E; Dooley, J S G; Lowery, C J

    2007-08-01

    When filter-feeding shellfish are consumed raw, because of their ability to concentrate and store waterborne pathogens, they are being increasingly associated with human gastroenteritis and have become recognized as important pathogen vectors. In the shellfish industry, UV depuration procedures are mandatory to reduce pathogen levels prior to human consumption. However, these guidelines are based around more susceptible fecal coliforms and Salmonella spp. and do not consider Cryptosporidium spp., which have significant resistance to environmental stresses. Thus, there is an urgent need to evaluate the efficiency of standard UV depuration against the survival of Cryptosporidium recovered from shellfish. Our study found that in industrial-scale shellfish depuration treatment tanks, standard UV treatment resulted in a 13-fold inactivation of recovered, viable C. parvum oocysts from spiked (1 x 10(6) oocysts liter (-1)) Pacific oysters. Depuration at half power also significantly reduced (P oysters. While UV treatment resulted in significant reductions of recovered viable oocysts, low numbers of viable oocysts were still recovered from oysters after depuration, making their consumption when raw a public health risk. Our study highlights the need for increased periodic monitoring programs for shellfish harvesting sites, improved depuration procedures, and revised microbial quality control parameters, including Cryptosporidium assessment, to minimize the risk of cryptosporidiosis.

  9. Pathogenic bacteria associated with oysters (Crassostrea brasiliana) and estuarine water along the south coast of Brazil.

    Science.gov (United States)

    Ristori, Christiane A; Iaria, Sebastião T; Gelli, Dilma S; Rivera, Irma N G

    2007-08-01

    Oysters and estuarine water samples were collected monthly, from June 1998 to March 1999, in the Cananéia estuary, on the south coast of São Paulo, Brazil, and analyzed for bacterial hazards with and without depuration in filtered estuarine water. Aeromonas spp., Plesiomonas shigelloides, Vibrio cholerae O1, Vibrio parahaemolyticus, and Vibrio vulnificus were counted in oyster samples using the most probable number (MPN) and their presence verified in the surrounding estuarine water samples. The presence of Salmonella, Shigella, Escherichia coli O157:H7, and fecal coliforms counts were determined in oysters and in water samples too. Sixty percent of water samples contained fecal coliforms ranging from 200 CFU/100 ml and 100%, 30%, 20% and 10% were positive for V. parahaemolyticus, Salmonella, Aeromonas, and V. vulnificus in 5 l of water samples, respectively. In oyster samples, the fecal coliforms concentration ranged from or =2.4 x 10(3) MPN/g in 40% of untreated and from oyster samples and their concentration varied from 3.6 to > or =2.4 x 10(3) MPN/g. For the untreated oyster samples 80%, 70%, and 10% were positive for V. vulnificus (oyster samples 60%, 30%, and 0% of them contained the same bacteria, respectively. Escherichia coli O157:H7, Shigella spp., P. shigelloides, and V. cholerae O1 were not detected in any of the samples. Fecal indicators did not correlate with Vibrio presence (p>0.05), although the isolation of Aeromonas species had a positive correlation (p = 0.017). The results showed no correlation between temperature, salinity, and bacteria (p > 0.05). The comparison between bacterial concentration in treated and untreated oyster samples, showed that only Aeromonas was higher in untreated oyster samples (p = 0.039). This study contributes toward creating a more global understanding of food-borne bacterial pathogens. The presence and concentration of viable bacterial hazards in oysters and water surrounding areas was determined for the first time on the south coast of São Paulo and it helps to define better the true microbial hazard in the aquatic environment and oysters.

  10. Pesticides and Ostreid Herpesvirus 1 Infection in the Pacific Oyster, Crassostrea gigas.

    Science.gov (United States)

    Moreau, Pierrick; Faury, Nicole; Burgeot, Thierry; Renault, Tristan

    2015-01-01

    Since 2008, mass mortality outbreaks have been reported in all French regions producing Pacific oysters, and in several Member States of the European Union. These mass mortality events of Pacific oysters are related to OsHV-1 infection. They occur during spring and summer periods leaving suspect the quality of the marine environment and the role of seasonal use of pesticides associated with the arrival of freshwater in oyster rearing areas. Pesticides have been also detected in French coastal waters, especially in areas of oyster production. Using PMA real-time PCR we showed that a mixture of 14 pesticides has no effect on the integrity of virus capsids from viral suspension in the conditions tested. A contact of oysters with this pesticide mixture was related to higher mortality rates among experimentally infected animals in comparison with control ones (no previous pesticide exposure before experimental infection). We therefore suggest that pesticides at realistic concentration can exert adverse effects on Pacific oysters and causes an increased susceptibility to the viral infection in experimental conditions.

  11. Environmental studies on mangrove cover changes in Goa and its resident Crassostrea population

    Digital Repository Service at National Institute of Oceanography (India)

    Nagi, H.M.H.

    and height were found in the ranges of 17-41 mm and 12-35 mm, respectively. The total weight of the animal ranged between 3.37-37.18 g, and the fresh weight of meat ranged between 1.81-0.32 g. Following are the relationships obtained from the statistical... regression equation between them was Log y = -0.8008 + 1.4188 log x Its corresponding parabolic equation may be represented as y = 0.1582 x 1.4188 Where, y is the total weight and x is the shell height. 133 5.2.3.1.1.4. Shell length : Meat wet weight...

  12. Karyotype details of Crassostrea gryphoides (Rivalvia: Ostreidae) from central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.

    stream_size 4 stream_content_type text/plain stream_name Chromosome_Inf_Ser_50_7.pdf.txt stream_source_info Chromosome_Inf_Ser_50_7.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  13. Improvement of remote setting of the Pacific oyster (Crassostrea gigas) on French platic pipes

    OpenAIRE

    Baud, Jean-pierre; Jolly, C.; Bodoy, Alain

    1991-01-01

    L'ostréiculture française est basée traditionnellement sur le captage de naissains de gisements naturels. Les collecteurs sont ensuite transférés sur l'estran pour une durée d'élevage de 1,5 à 3 ans. La croissance finale s'effectue généralement après avoir séparé les huîtres de leur support dans des poches posées sur des tables ou à plat sur le sol. Pour améliorer la rotation des cheptels et les conditions d'élevage des juvéniles, des expérimentations ont été réalisées afin de définir les con...

  14. THE EFFECT OF PCBS ON GLYCOGEN RESERVES IN THE EASTERN OYSTER CRASSOSTREA VIRGINICA. (R825349)

    Science.gov (United States)

    Recent declines in Chesapeake Bay oyster populations have been attributed to disease, and reduced water quality from pollution. The stress associated with pollutant exposure may reduce energy available for growth and reproduction. Polychlorinated biphenyls (PCBs) are lipophilic c...

  15. High pressure processing with hot sauce flavoring enhances sensory quality for raw oysters (Crassostrea virginica)

    Science.gov (United States)

    This study evaluated the feasibility of flavoring raw oysters by placing them under pressure in the presence of selected flavorings. Hand-shucked raw oysters were processed at high pressure (600 MPa), in the presence or absence of (Sriracha®) flavoring, and evaluated by a trained sensory panel 3 an...

  16. Review of the histopathological effects of ionizing radiation on the Pacific oyster, Crassostrea gigas

    International Nuclear Information System (INIS)

    Mix, M.C.

    1976-01-01

    Oysters were exposed to various doses of gamma radiation up to 400 k rads and maintained in a flow-through seawater system. They were sampled at intervals and histological analyses were made. Chronic degeneration was observed in all tissues dependent on a cell renewal system for their integrity. Results indicated that mortality was related to the failure of the cell renewal system to restore depleted cell populations and that the LD 50 concept has little practical value in studies on invertebrates

  17. Selection of reference genes for expression analysis of Kumamoto and Portuguese oysters and their hybrid

    Science.gov (United States)

    Yan, Lulu; Su, Jiaqi; Wang, Zhaoping; Yan, Xiwu; Yu, Ruihai

    2017-12-01

    Quantitative real-time polymerase chain reaction (qRT-PCR) is a rapid and reliable technique which has been widely used to quantifying gene transcripts (expression analysis). It is also employed for studying heterosis, hybridization breeding and hybrid tolerability of oysters, an ecologically and economically important taxonomic group. For these studies, selection of a suitable set of housekeeping genes as references is crucial for correct interpretation of qRT-PCR data. To identify suitable reference genes for oysters during low temperature and low salinity stresses, we analyzed twelve genes from the gill tissue of Crassostrea sikamea (SS), Crassostrea angulata (AA) and their hybrid (SA), which included three ribosomal genes, 28S ribosomal protein S5 ( RPS5), ribosomal protein L35 ( RPL35), and 60S ribosomal protein L29 ( RPL29); three structural genes, tubulin gamma ( TUBγ), annexin A6 and A7 ( AA6 and AA7); three metabolic pathway genes, ornithine decarboxylase ( OD), glyceraldehyde-3-phosphate dehydrogenase ( GAPDH) and glutathione S-transferase P1 ( GSP); two transcription factors, elongation factor 1 alpha and beta ( EF1α and EF1β); and one protein synthesis gene (ubiquitin ( UBQ). Primers specific for these genes were successfully developed for the three groups of oysters. Three different algorithms, geNorm, NormFinder and BestKeeper, were used to evaluate the expression stability of these candidate genes. BestKeeper program was found to be the most reliable. Based on our analysis, we found that the expression of RPL35 and EF1α was stable under low salinity stress, and the expression of OD, GAPDH and EF1α was stable under low temperature stress in hybrid (SA) oyster; the expression of RPS5 and GAPDH was stable under low salinity stress, and the expression of RPS5, UBQ, GAPDH was stable under low temperature stress in SS oyster; the expression of RPS5, GAPDH, EF1β and AA7 was stable under low salinity stress, and the expression of RPL35, EF1α, GAPDH

  18. Comunidad de moluscos asociados al mejillón verde Perna viridis (Mollusca: Bivalvia y sus relaciones tróficas en la costa norte de la Península de Araya, Estado Sucre, Venezuela

    Directory of Open Access Journals (Sweden)

    Sioliz Villafranca

    2006-12-01

    Full Text Available Perna viridis es un bivalvo procedente del Indo-Pacífico que habita en la zona intermareal y ha invadido varios ecosistemas de la costa norte del estado Sucre, Venezuela. Con la finalidad de realizar un estudio sobre las comunidades de moluscos asociadas a esta especie y sus relaciones tróficas, se llevaron a cabo muestreos bimensuales entre octubre/97 y agosto/98, en un banco natural de mejillones a dos metros de profundidad en la costa norte de la península de Araya (10°40’N -48°63’W. Los organismos fueron recolectados delimitando el área con una cuadrícula de 0.25 m². Se identificaron los organismos hasta la categoría de especies utilizando claves específicas para moluscos y bibliográficamente se les determinó categoría trófica.Se capturó un total de 1 235 individuos de P. viridis y asociados a la especie 3 163 especímenes pertenecientes al phylum Mollusca, contenidos en tres clases: Bivalvia,Gastropoda y Polyplacophora. Éstas estuvieron representadas por 50 especies correspondientes a 10 órdenes, 24 familias; para los gasterópodos se contabilizaron 25 especies, para los bivalvos 22 y tres para los poliplacóforos. Del total de las especies, 40% fueron filtradoras, 26% carnívoras, 24% herbívoras y el 10% restante presentó dos categorías.De las filtradoras las más representativas fueron: Perna perna, Musculus lateralis, Crassostrea rhizophorae y Ostrea equestris; en el grupo de los carnívoros dominaron tres especies de la familia Columbellidae:Mitrella lunata, Anachis obesa y Nitidella ocellata y para el grupo de los herbívoros destacaron dos especies de la familia Fisurellidae: Diodora cayenensis y D. minuta. Se registraron dos especies filtradoras-detritívoras, y tres especies herbívoras-filtradoras representantes del género C repidula. El alto porcentaje de filtradores sería un indicativo de que dentro de este sistema probablemente hay una mayor disponibilidad de fracciones alimenticias para este grupo

  19. Heating and cooling rates and their effects upon heart rate in the ...

    African Journals Online (AJOL)

    The heating and cooling rates of adult Chersina angulata were investigated to ascertain whether these tortoises can physiologically alter their rates of heat exchange. In addition, heart rates were recorded to provide an insight into the control of heat exchange. C. angulata heats significantly faster than it cools. Heart rates ...

  20. Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae

    Directory of Open Access Journals (Sweden)

    Cynthia Annes Rubião

    2017-08-01

    Full Text Available ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN of Total Coliforms (TC, Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several antimicrobial resistance genes to pathogenic bacteria, including those from Gram-negative group. The oysters were bought from local fishermen and a total of 123 individuals were analyzed. The TC, E. coli and Enterococcus spp. MPN mean were 26,300/100 g, 3,260/100 g and 2,820/100 g, respectively. The only correlation found was between TC and E. coli. Two strains of Enterococcus spp. were resistant to three different antimicrobial categories, including a high level resistance to streptomycin. One strain presented intermediate resistance to vancomycin. The E. coli levels exceeded the limits established by international legislation. This microbiological contamination in oysters reflects the water pollution and indicates a probable contamination of other seafood species from this mangrove, which can represent a risk for consumers and a threat to the environment and public health.

  1. Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae)

    OpenAIRE

    Rubião, Cynthia Annes; Franco, Robson Maia; Mesquita, Eliana de Fátima Marques de; Miguel, Marco Antonio Lemos; Cabral, Claudius Couto; Fonseca, Ana Beatriz Monteiro

    2017-01-01

    ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN) of Total Coliforms (TC), Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several ...

  2. A Restoration Suitability Index Model for the Eastern Oyster (Crassostrea virginica) in the Mission-Aransas Estuary, TX, USA

    Science.gov (United States)

    Beseres Pollack, Jennifer; Cleveland, Andrew; Palmer, Terence A.; Reisinger, Anthony S.; Montagna, Paul A.

    2012-01-01

    Oyster reefs are one of the most threatened marine habitats on earth, with habitat loss resulting from water quality degradation, coastal development, destructive fishing practices, overfishing, and storm impacts. For successful and sustainable oyster reef restoration efforts, it is necessary to choose sites that support long-term growth and survival of oysters. Selection of suitable sites is critically important as it can greatly influence mortality factors and may largely determine the ultimate success of the restoration project. The application of Geographic Information Systems (GIS) provides an effective methodology for identifying suitable sites for oyster reef restoration and removes much of the uncertainty involved in the sometimes trial and error selection process. This approach also provides an objective and quantitative tool for planning future oyster reef restoration efforts. The aim of this study was to develop a restoration suitability index model and reef quality index model to characterize locations based on their potential for successful reef restoration within the Mission-Aransas Estuary, Texas, USA. The restoration suitability index model focuses on salinity, temperature, turbidity, dissolved oxygen, and depth, while the reef quality index model focuses on abundance of live oysters, dead shell, and spat. Size-specific Perkinsus marinus infection levels were mapped to illustrate general disease trends. This application was effective in identifying suitable sites for oyster reef restoration, is flexible in its use, and provides a mechanism for considering alternative approaches. The end product is a practical decision-support tool that can be used by coastal resource managers to improve oyster restoration efforts. As oyster reef restoration activities continue at small and large-scales, site selection criteria are critical for assisting stakeholders and managers and for maximizing long-term sustainability of oyster resources. PMID:22792410

  3. SURVEY OF OYSTERS CRASSOSTREA VIRGINICA FROM TAMPA BAY, FLORIDA: ASSOCIATIONS OF INTERNAL DEFENSE MEASUREMENTS WITH CONTAMINANT BURDENS

    Science.gov (United States)

    Oysters from 16 sites in Tampa Bay, Florida, were collected during a 6-week period in winter 1993 and analyzed for both biological characteristics and tissue chemical concentrations. Using previous sediment contamination and toxicity data, oyster tissues from the selected sites w...

  4. Effects of Desiccation Practices of Cultured Atlantic Oysters (Crassostrea virginica) on Vibrio spp. in Portersville Bay, Alabama, USA.

    Science.gov (United States)

    Grodeska, Stephanie M; Jones, Jessica L; Arias, Covadonga R; Walton, William C

    2017-08-01

    The expansion of off-bottom aquaculture to the Gulf of Mexico has raised public health concerns for human health officials. High temperatures in the Gulf of Mexico are associated with high levels of Vibrio parahaemolyticus and Vibrio vulnificus. Routine desiccation practices associated with off-bottom aquaculture expose oysters to ambient air, allowing Vibrio spp. to proliferate in the closed oyster. Currently, there is limited research on the length of time needed for Vibrio spp. levels in desiccated oysters to return to background levels, defined as the levels found in oysters that remain continually submersed and not exposed to ambient air. This study determined the time needed to return V. parahaemolyticus, V. vulnificus, and Vibrio cholerae levels to background levels in oysters exposed to the following desiccation practices: 3-h freshwater dip followed by 24-h ambient air exposure, 27-h ambient air exposure, and control. All oysters were submerged at least 2 weeks prior to the beginning of each trial, with the control samples remaining submerged for the duration of each trial. Vibrio spp. levels were enumerated from samples collected on days 0, 1, 2, 3, 7, 10, and 14 after resubmersion using a three-tube most-probable-number enrichment followed by BAX PCR. V. cholerae levels were frequently (92%) below the limit of detection at all times, so they were not statistically analyzed. V. parahaemolyticus and V. vulnificus levels in the 27-h ambient air exposure and the 3-h freshwater dip followed by 24-h ambient air exposure samples were significantly elevated compared with background samples. In most cases, the Vibrio spp. levels in oysters in both desiccation treatments remained elevated compared with background levels until 2 or 3 days post-resubmersion. However, there was one trial in which the Vibrio spp. levels did not return to background levels until day 7. The results of this study provide scientific support that oyster farmers should be required to implement a minimum 7-day resubmersion regimen. This length of time allowed the Vibrio spp. levels to become not significantly different across all treatments.

  5. Interactions between the introduced Pacific oyster Crassostrea gigas and the indigenous blue mussel Mytilus edulis. Local-scale food competition

    NARCIS (Netherlands)

    Hans, I.W.

    2004-01-01

    The aim of this study was to determine if food competition between mussels and oysters occurs, and how mussel and oyster growth is affected by this interaction. This was done by relating mussel growth to oyster density relating oyster growth to oyster biomass and perform a field control, by

  6. A microbial spoilage profile of half shell Pacific oysters (Crassostrea gigas) and Sydney rock oysters (Saccostrea glomerata).

    Science.gov (United States)

    Madigan, Thomas L; Bott, Nathan J; Torok, Valeria A; Percy, Nigel J; Carragher, John F; de Barros Lopes, Miguel A; Kiermeier, Andreas

    2014-04-01

    This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Impact of prolonged storm activity on the Ecological Status of intertidal benthic habitats within oyster (Crassostrea gigas) trestle cultivation sites.

    Science.gov (United States)

    O'Carroll, Jack P J; Quinn, Christina; Forde, James; Patterson, Adrian; O'Beirn, Francis X; Kennedy, Robert

    2016-09-15

    The Ecological Status (ES; sensu the Water Framework Directive) of intertidal benthic communities within six oyster trestle cultivation sites was found to be negatively impacted along the access routes to trestles in a 2013 study. All cultivation sites occur within Natura 2000 sites. The current study revisited four of the 2013 cultivation sites in February 2014 one month after the storm activity of winter 2013/14 to test if the compaction effect along access routes persisted after the storms. Three levels of the fixed factor treatment were sampled; immediately below the trestles, along the access route and 300m away from any anthropogenic activity. The compaction effect at the Access treatment persisted in spite of the major storm activity. The current study showed the IQI to be effective for assessing the impacts of aquaculture and highlights the IQI as a tool for monitoring Conservation Status of intertidal communities under the Habitats Directive. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. De novo arachidonic acid synthesis in Perkinsus marinus, a protozoan parasite of the eastern oyster Crassostrea virginica.

    Science.gov (United States)

    Chu, Fu-Lin E; Lund, Eric; Soudant, Philippe; Harvey, Ellen

    2002-02-01

    The capability of synthesizing fatty acids de novo in the meront stage of the oyster protozoan parasite, Perkinsus marinus, was investigated employing stable-isotope-labeled precursors (1,2 13C-acetate and palmitic-d(31) acid). Fatty acid methyl esters derived from 1,2 13C-acetate and palmitic-d(31) acid were analyzed using gas chromatography/mass spectrometry and gas chromatography/flame ionization detection. Results revealed that in vitro cultured P. marinus meronts utilized 13C-acetate to synthesize a range of saturated and unsaturated fatty acids. The saturated fatty acids 14:0, 16:0, 18:0, 20:0, 22:0, 24:0 and the unsaturated fatty acids, 18:1(n-9), 18:2(n-6), 20:1(n-9), 20:2(n-6), 20:2(n-9), 20:3(n-6), 20:4(n-6) were found to contain 13C, after 7, 14, and 21 days incubation with the precursor. This indicates that meronts can synthesize fatty acid de novo using acetate as a substrate. Meronts efficiently elongated 16:0-d(31) to 18:0, 20:0, 22:0, 24:0, but desaturation activity was limited, after 7 and 14 days cultivation. Only a small quantity of 18:1-d(29) was detected. This suggests that meronts cannot directly convert exogenous palmitic acid or its products of elongation to unsaturated counterparts. The ability to synthesize 20:4(n-6) from acetate is particularly interesting. No parasitic protozoan has been reported to be capable of synthesizing long chain essential fatty acids, such as 20:4(n-6) de novo. Future study will be directed to determine whether the observed in vitro activities indeed reflect the in vivo activities, when meronts are associated with the host.

  9. Determination of the optimum commercial size for the mangrove oyster (Crassostrea rhizophorae) in Todos os Santos Bay, Brazil

    OpenAIRE

    Nascimento, Iracema Andrade; Pereira, Solange Andrade; Souza, Raymundo Costa e

    1980-01-01

    Texto completo. Acesso restrito. p. 1 – 8 Pilot studies were conducted in 1977-1978 on the cultivation of mangrove oysters in the Jacuruna River estuary at Todos OS Santos Bay, Salvador, Brazil. Growth characteristics were studied by comparing the relationships between total live weight, volume of the shell cavity fluid and yield of meat, and dry body weight to size (height). The most economically feasible proposition was production of approximately 7 cm high oysters for the sh...

  10. Effect of Carbonate Chemistry Alteration on the Early Embryonic Development of the Pacific Oyster (Crassostrea gigas)

    OpenAIRE

    Gazeau, F.; Gattuso, J.P.; Greaves, M.; Elderfield, H.; Peene, J.; Heip, C.H.R.; Middelburg, J.J.

    2011-01-01

    Ocean acidification, due to anthropogenic CO(2) absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportion...

  11. Preliminary stochastic model for managing Vibrio parahaemolyticus and total viable bacterial counts in a Pacific oyster (Crassostrea gigas) supply chain.

    Science.gov (United States)

    Fernandez-Piquer, Judith; Bowman, John P; Ross, Tom; Estrada-Flores, Silvia; Tamplin, Mark L

    2013-07-01

    Vibrio parahaemolyticus can accumulate and grow in oysters stored without refrigeration, representing a potential food safety risk. High temperatures during oyster storage can lead to an increase in total viable bacteria counts, decreasing product shelf life. Therefore, a predictive tool that allows the estimation of both V. parahaemolyticus populations and total viable bacteria counts in parallel is needed. A stochastic model was developed to quantitatively assess the populations of V. parahaemolyticus and total viable bacteria in Pacific oysters for six different supply chain scenarios. The stochastic model encompassed operations from oyster farms through consumers and was built using risk analysis software. Probabilistic distributions and predictions for the percentage of Pacific oysters containing V. parahaemolyticus and high levels of viable bacteria at the point of consumption were generated for each simulated scenario. This tool can provide valuable information about V. parahaemolyticus exposure and potential control measures and can help oyster companies and regulatory agencies evaluate the impact of product quality and safety during cold chain management. If coupled with suitable monitoring systems, such models could enable preemptive action to be taken to counteract unfavorable supply chain conditions.

  12. Effects of Florida Red Tides on histone variant expression and DNA methylation in the Eastern oyster Crassostrea virginica.

    Science.gov (United States)

    Gonzalez-Romero, Rodrigo; Suarez-Ulloa, Victoria; Rodriguez-Casariego, Javier; Garcia-Souto, Daniel; Diaz, Gabriel; Smith, Abraham; Pasantes, Juan Jose; Rand, Gary; Eirin-Lopez, Jose M

    2017-05-01

    Massive algal proliferations known as Harmful Algal Blooms (HABs) represent one of the most important threats to coastal areas. Among them, the so-called Florida Red Tides (FRTs, caused by blooms of the dinoflagellate Karenia brevis and associated brevetoxins) are particularly detrimental in the southeastern U.S., causing high mortality rates and annual losses in excess of $40 million. The ability of marine organisms to cope with environmental stressors (including those produced during HABs) is influenced by genetic and epigenetic mechanisms, the latter resulting in phenotypic changes caused by heritable modifications in gene expression, without involving changes in the genetic (DNA) sequence. Yet, studies examining cause-effect relationships between environmental stressors, specific epigenetic mechanisms and subsequent responses are still lacking. The present work contributes to increase this knowledge by investigating the effects of Florida Red Tides on two types of mechanisms participating in the epigenetic memory of Eastern oysters: histone variants and DNA methylation. For that purpose, a HAB simulation was conducted in laboratory conditions, exposing oysters to increasing concentrations of K. brevis. The obtained results revealed, for the first time, the existence of H2A.X, H2A.Z and macroH2A genes in this organism, encoding histone variants potentially involved in the maintenance of genome integrity during responses to the genotoxic effect of brevetoxins. Additionally, an increase in H2A.X phosphorylation (γH2A.X, a marker of DNA damage) and a decrease in global DNA methylation were observed as the HAB simulation progressed. Overall, the present work provides a basis to better understand how epigenetic mechanisms participate in responses to environmental stress in marine invertebrates, opening new avenues to incorporate environmental epigenetics approaches into management and conservation programs. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. DECREASED RESISTANCE OF EASTERN OYSTERS (CRASSOSTREA VIRGINICA) TO A PROTOZOAN PATHOGEN (PERKINSUS MARINUS) AFTER SUBLETHAL EXPOSURE TO TRIBUTYLTIN OXIDE

    Science.gov (United States)

    Anthropogenic environmental stress is a likely contributor to outbreaks of disease due to immunosuppression or increased host vulnerability. Estuarine organisms are exposed to variable concentrations of marine antifouling agents, such as tributyltin (TBT), with higher exposures e...

  14. Effects of Florida Red Tides on histone variant expression and DNA methylation in the Eastern oyster Crassostrea virginica

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Romero, Rodrigo; Suarez-Ulloa, Victoria [Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181 (United States); Rodriguez-Casariego, Javier [Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181 (United States); Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181 (United States); Garcia-Souto, Daniel [Departamento de Bioquimica, Xenetica e Inmunoloxia, Universidade de Vigo, E-36310 Vigo (Spain); Diaz, Gabriel [Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181 (United States); Smith, Abraham [Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181 (United States); Pasantes, Juan Jose [Departamento de Bioquimica, Xenetica e Inmunoloxia, Universidade de Vigo, E-36310 Vigo (Spain); Rand, Gary [Ecotoxicology and Risk Assessment Laboratory, Southeast Environmental Research Center, Florida International University, North Miami, FL 33181 (United States); Eirin-Lopez, Jose M., E-mail: jeirinlo@fiu.edu [Environmental Epigenetics Group, Department of Biological Sciences, Florida International University, North Miami, FL 33181 (United States)

    2017-05-15

    Massive algal proliferations known as Harmful Algal Blooms (HABs) represent one of the most important threats to coastal areas. Among them, the so-called Florida Red Tides (FRTs, caused by blooms of the dinoflagellate Karenia brevis and associated brevetoxins) are particularly detrimental in the southeastern U.S., causing high mortality rates and annual losses in excess of $40 million. The ability of marine organisms to cope with environmental stressors (including those produced during HABs) is influenced by genetic and epigenetic mechanisms, the latter resulting in phenotypic changes caused by heritable modifications in gene expression, without involving changes in the genetic (DNA) sequence. Yet, studies examining cause-effect relationships between environmental stressors, specific epigenetic mechanisms and subsequent responses are still lacking. The present work contributes to increase this knowledge by investigating the effects of Florida Red Tides on two types of mechanisms participating in the epigenetic memory of Eastern oysters: histone variants and DNA methylation. For that purpose, a HAB simulation was conducted in laboratory conditions, exposing oysters to increasing concentrations of K. brevis. The obtained results revealed, for the first time, the existence of H2A.X, H2A.Z and macroH2A genes in this organism, encoding histone variants potentially involved in the maintenance of genome integrity during responses to the genotoxic effect of brevetoxins. Additionally, an increase in H2A.X phosphorylation (γH2A.X, a marker of DNA damage) and a decrease in global DNA methylation were observed as the HAB simulation progressed. Overall, the present work provides a basis to better understand how epigenetic mechanisms participate in responses to environmental stress in marine invertebrates, opening new avenues to incorporate environmental epigenetics approaches into management and conservation programs.

  15. Effectiveness of Standard UV Depuration at Inactivating Cryptosporidium parvum Recovered from Spiked Pacific Oysters (Crassostrea gigas)▿

    Science.gov (United States)

    Sunnotel, O.; Snelling, W. J.; McDonough, N.; Browne, L.; Moore, J. E.; Dooley, J. S. G.; Lowery, C. J.

    2007-01-01

    When filter-feeding shellfish are consumed raw, because of their ability to concentrate and store waterborne pathogens, they are being increasingly associated with human gastroenteritis and have become recognized as important pathogen vectors. In the shellfish industry, UV depuration procedures are mandatory to reduce pathogen levels prior to human consumption. However, these guidelines are based around more susceptible fecal coliforms and Salmonella spp. and do not consider Cryptosporidium spp., which have significant resistance to environmental stresses. Thus, there is an urgent need to evaluate the efficiency of standard UV depuration against the survival of Cryptosporidium recovered from shellfish. Our study found that in industrial-scale shellfish depuration treatment tanks, standard UV treatment resulted in a 13-fold inactivation of recovered, viable C. parvum oocysts from spiked (1 × 106 oocysts liter −1) Pacific oysters. Depuration at half power also significantly reduced (P oysters. While UV treatment resulted in significant reductions of recovered viable oocysts, low numbers of viable oocysts were still recovered from oysters after depuration, making their consumption when raw a public health risk. Our study highlights the need for increased periodic monitoring programs for shellfish harvesting sites, improved depuration procedures, and revised microbial quality control parameters, including Cryptosporidium assessment, to minimize the risk of cryptosporidiosis. PMID:17574996

  16. Limitations of the A-1M method for fecal coliform enumeration in the Pacific oyster (Crassostrea gigas).

    Science.gov (United States)

    Kaysner, C A; Weagant, S D

    1987-01-01

    Use of the A-1M method, which was originally devised for testing water samples, has recently been extended for enumeration of fecal coliforms and Escherichia coli in shellfish and other food products. Results of our study indicate that while this method is reliable for analysis of growing waters, the use of the A-1M method for testing Pacific oysters may be less reliable because bacteria not belonging to the coliform group but which are sometimes present in these animals also give a positive reaction.

  17. Comparative study of methods for the enumeration of total and fecal coliforms in the eastern oyster, Crassostrea virginica.

    Science.gov (United States)

    Richards, G P

    1978-12-01

    Violet red bile agar and Coli-Count Sampler (Millipore Corp.) procedures were shown to be acceptable alternatives to the standard most-probable-number method for monitoring relative coliform levels in oysters.

  18. Ecological studies on the seasonal production of the edible oyster, Crassostrea madrasensis (Preston) in Cochin Backwater, Kerala

    Digital Repository Service at National Institute of Oceanography (India)

    Purushan, K.S.; Gopalan, U.K.; Rao, T.S.S.

    the intertidal ones, but as regards percentage meat weight the latter out-weighed the former. Among environmental variables, salinity seemed to be the foremost factor in influencing the production of oysters. A large majority (90-98%) of the intertidal oysters...

  19. Effects of Florida Red Tides on histone variant expression and DNA methylation in the Eastern oyster Crassostrea virginica

    International Nuclear Information System (INIS)

    Gonzalez-Romero, Rodrigo; Suarez-Ulloa, Victoria; Rodriguez-Casariego, Javier; Garcia-Souto, Daniel; Diaz, Gabriel; Smith, Abraham; Pasantes, Juan Jose; Rand, Gary; Eirin-Lopez, Jose M.

    2017-01-01

    Massive algal proliferations known as Harmful Algal Blooms (HABs) represent one of the most important threats to coastal areas. Among them, the so-called Florida Red Tides (FRTs, caused by blooms of the dinoflagellate Karenia brevis and associated brevetoxins) are particularly detrimental in the southeastern U.S., causing high mortality rates and annual losses in excess of $40 million. The ability of marine organisms to cope with environmental stressors (including those produced during HABs) is influenced by genetic and epigenetic mechanisms, the latter resulting in phenotypic changes caused by heritable modifications in gene expression, without involving changes in the genetic (DNA) sequence. Yet, studies examining cause-effect relationships between environmental stressors, specific epigenetic mechanisms and subsequent responses are still lacking. The present work contributes to increase this knowledge by investigating the effects of Florida Red Tides on two types of mechanisms participating in the epigenetic memory of Eastern oysters: histone variants and DNA methylation. For that purpose, a HAB simulation was conducted in laboratory conditions, exposing oysters to increasing concentrations of K. brevis. The obtained results revealed, for the first time, the existence of H2A.X, H2A.Z and macroH2A genes in this organism, encoding histone variants potentially involved in the maintenance of genome integrity during responses to the genotoxic effect of brevetoxins. Additionally, an increase in H2A.X phosphorylation (γH2A.X, a marker of DNA damage) and a decrease in global DNA methylation were observed as the HAB simulation progressed. Overall, the present work provides a basis to better understand how epigenetic mechanisms participate in responses to environmental stress in marine invertebrates, opening new avenues to incorporate environmental epigenetics approaches into management and conservation programs.

  20. The Giant Pacific Oyster (Crassostrea gigas) as a modern analogue for fossil ostreoids

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz; Böhm, Florian; Rickaby, Rosalind E.M.

    2013-01-01

    carbon isotope values of different oysters agree within 0.1 ‰, but ontogenic variability is complicated by shell growth patterns and potential small vital effects. The calcium isotope ratios are found to be constant throughout ontogeny within analytical precision at a value of δ44/40Ca = 0.68 ± 0.16 ‰ (2...... sd) SRM 915a which is consistent with other bivalve species. Calcium isotope ratios in oyster shell material might thus be a possible proxy for palaeo seawater calcium isotope ratios. Element/Ca ratios are significantly higher in the chalky substance than in the foliate layers and especially high Sr...

  1. Water quality parameters and total aerobic bacterial and vibrionaceae loads in eastern oysters (Crassostrea virginica) from oyster gardening sites

    Science.gov (United States)

    Oyster gardening is a practice designed to restore habitat for marine life and to improve water quality. This study determined physical and chemical water quality parameters at two oyster gardening sites in the Delaware Inland Bays and compared them with total aerobic bacteria and Vibrionaceae conc...

  2. Identificación de genes implicados en la eliminación de biotoxinas en el mejillón Mytilus galloprovincialis Lmk.: clonación y expresión de los cDNA que codifican para tres proteínas transportadoras ABC pertenecientes a las subfamilias C (proteínas MRP) y G.

    OpenAIRE

    Lozano Paredes, Vanesa

    2013-01-01

    Los mejillones del género Mytilus viven en hábitats fluctuantes en los que su capacidad para adaptarse a los cambios del entorno es esencial para su supervivencia. Como organismos filtradores se alimentan sobre todo de fitoplancton y también de la materia orgánica en suspensión. En ocasiones el fitoplancton contiene especies tóxicas para el hombre o que producen efectos nocivos en los bivalvos. Una vez que las toxinas son ingeridas por los bivalvos pueden acumularse, transformarse y eliminars...

  3. Programa de Cooperacion sur - sur Convenio de Cooperacion Tecnica y Cientifica a Mexico-Panama. Proyecto: Producción de Semilla de Moluscos y Cultivos en el Mar

    OpenAIRE

    Mazón Suástegui, J.M.,; Guerra-Lima, Z.I.,

    2012-01-01

    Este documento presenta 4 aspectos importantes 1. Generación de nuevo conocimiento: Estudios básicos sobre crecimiento, supervivencia, reproducción, nutrición, cultivo larvario de moluscos bivalvos y evaluación de dietas para juveniles. 2. Aplicación del conocimiento: Diseño de instalaciones y equipos para el cultivo de moluscos bivalvos. Asesoría internacional para el cultivo de moluscos nativos, financiados por PNUD, SENACYT-CCP (Ciencia Contra Pobreza), GEF-PNUD. Participan producto...

  4. Source and impact of lead contamination on {delta}-aminolevulinic acid dehydratase activity in several marine bivalve species along the Gulf of Cadiz

    Energy Technology Data Exchange (ETDEWEB)

    Company, R.; Serafim, A.; Lopes, B.; Cravo, A. [CIMA, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Kalman, J.; Riba, I.; DelValls, T.A. [Catedra UNESCO/UNITWIN/WiCop, Department of Physical-Chemistry, Faculty Marine and Environmental Sciences, University of Cadiz, 11510 Puerto Real, Cadiz (Spain); Blasco, J. [Instituto Ciencias Marinas Andalucia (CSIC), Campus Rio San Pedro, 11510 Puerto Real, Cadiz (Spain); Delgado, J. [Department of Geology, University of Huelva, Avda Fuerzas Armadas s/n, 21071 Huelva (Spain); Sarmiento, A.M. [Catedra UNESCO/UNITWIN/WiCop, Department of Physical-Chemistry, Faculty Marine and Environmental Sciences, University of Cadiz, 11510 Puerto Real, Cadiz (Spain); Department of Geology, University of Huelva, Avda Fuerzas Armadas s/n, 21071 Huelva (Spain); Nieto, J.M. [Department of Geology, University of Huelva, Avda Fuerzas Armadas s/n, 21071 Huelva (Spain); Shepherd, T.J.; Nowell, G. [Department of Earth Sciences, University of Durham, Science Laboratories, Durham DH1 3LE (United Kingdom); Bebianno, M.J., E-mail: mbebian@ualg.pt [CIMA, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2011-01-17

    Coastal areas and estuaries are particularly sensitive to metal contamination from anthropogenic sources and in the last few decades the study of space-time distribution and variation of metals has been extensively researched. The Gulf of Cadiz is no exception, with several rivers draining one of the largest concentrations of sulphide deposits in the world, the Iberian Pyrite Belt (IPB). Of these rivers, the Guadiana, one of the most important in the Iberian Peninsula, together with smaller rivers like the Tinto and Odiel, delivers a very high metal load to the adjacent coastal areas. The purpose of this work was to study the source and impact of lead (Pb) drained from historical or active mining areas in the IPB on the activity of a Pb inhibited enzyme ({delta}-aminolevulinic acid dehydratase, ALAD) in several bivalve species along the Gulf of Cadiz. Seven marine species (Chamelea gallina, Mactra corallina, Donax trunculus, Cerastoderma edule, Mytilus galloprovincialis, Scrobicularia plana and Crassostrea angulata) were collected at 12 sites from Mazagon, near the mouth of the rivers Tinto and Odiel (Spain), to Cacela Velha (Ria Formosa lagoon system, Portugal). Lead concentrations, ALAD activity and lead isotope ratios ({sup 206}Pb/{sup 204}Pb, {sup 207}Pb/{sup 204}Pb and {sup 208}Pb/{sup 204}Pb) were determined in the whole soft tissues. The highest Pb concentrations were determined in S. plana (3.50 {+-} 1.09 {mu}g g{sup -1} Pb d.w.) and D. trunculus (1.95 {+-} 0.10 {mu}g g{sup -1} Pb d.w.), while M. galloprovincialis and C. angulata showed the lowest Pb levels (<0.38 {mu}g g{sup -1} Pb d.w.). In general, ALAD activity is negatively correlated with total Pb concentration. However this relationship is species dependent (e.g. linear for C. gallina ALAD = -0.36[Pb] + 0.79; r = 0.837; or exponential for M. galloprovincialis ALAD = 2.48e{sup -8.3[Pb]}; r = 0.911). This indicates that ALAD activity has considerable potential as a biomarker of Pb and moreover, in

  5. Comparative feeding on chlorophyll - rich versus remaining organic matter in bivalve shellfish

    NARCIS (Netherlands)

    Hawkins, A.; Pascoe, P.L.; Parry, H.; Brinsley, M.; Cacciatore, F.; Black, K.; Fang, J.; Smaal, A.C.

    2013-01-01

    Filter feeding was compared in the blue mussel Mytilus edulis, Mediterranean mussel Mytilus galloprovincialis, Pacific oyster Crassostrea gigas, Chinese pleated oyster Crassostrea plicatula, Chinese scallop Chlamys farreri,Manila clam Tapes phillipinarum, razor clam Sinonvacula constricta, and blood

  6. Phytochemical constituents of some Nigerian medicinal plants ...

    African Journals Online (AJOL)

    Alkaloids, tannins, saponins, steroid, terpenoid, flavonoids, phlobatannin and cardic glycoside distribution in ten medicinal plants belonging to different families were assessed and compared. The medicinal plants investigated were Cleome nutidosperma, Emilia coccinea, Euphorbia heterophylla, Physalis angulata, ...

  7. Differences in extreme low salinity timing and duration differentially affect eastern oyster (Crassostrea virginica) size class growth and mortality in Breton Sound, LA

    Science.gov (United States)

    LaPeyre, Megan K.; Eberline, Benjamin S.; Soniat, Thomas M.; La Peyre, Jerome F.

    2013-01-01

    Understanding how different life history stages are impacted by extreme or stochastic environmental variation is critical for predicting and modeling organism population dynamics. This project examined recruitment, growth, and mortality of seed (25–75 mm) and market (>75 mm) sized oysters along a salinity gradient over two years in Breton Sound, LA. In April 2010, management responses to the Deepwater Horizon oil spill resulted in extreme low salinity (25 °C) significantly and negatively impacted oyster recruitment, survival and growth in 2010, while low salinity (25 °C). With increasing management of our freshwater inputs to estuaries combined with predicted climate changes, how extreme events affect different life history stages is key to understanding variation in population demographics of commercially important species and predicting future populations.

  8. An in situ study using caged Nucella lapillus and Crassostrea gigas to monitor TBT induced bio-effects in Irish coastal waters

    DEFF Research Database (Denmark)

    Giltrap, M.; Macken, A.; Minchin, D.

    Tributyltin (TBT) is recognised as an effective antifouling agent for use in marine paints for shipping and on aquaculture fish cages and in other marine applications. It has however been found to be toxic to many species of gastropods and can affect these species at concentrations as low as 2ng/...

  9. Role of solubles and particulates in radionuclide accumulation in the oyster Crassostrea Gigas in the discharge canal of a nuclear power plant

    International Nuclear Information System (INIS)

    Harrison, F.L.; Wong, K.M.; Heft, R.E.

    1972-01-01

    Changes in 54 Mn, 60 Co, 65 Zn, and 137 Cs concentrations were followed in oysters introduced into a discharge canal receiving low-level radioactive waste from a boiling water reactor. Groups of animals were maintained either in filtered or nonfiltered discharge-canal water. They were sampled immediately before and after single radioactive releases and at one-day intervals thereafter. Radionuclide concentrations were determined also in the water and in suspended and settled particulates. In the canal water, concentrations changed rapidly during a release, reaching peak values within 30 minutes. The partition between soluble and particulate (filterable) phases in the water differed with the radionuclide. Continuous sampling of suspended particulates after single releases showed considerable variation in concentrations per liter of water for each radionuclide. Comparisons of animals held in filtered water to those in nonfiltered water showed similar concentrations only for 137 Cs. Results indicate that suspended particulates play an important role in the accumulation of some radionuclides and that resuspension of particulates is an important source between periods of releases. (U.S.)

  10. A shell-formation related carbonic anhydrase in Crassostrea gigas modulates intracellular calcium against CO2 exposure: Implication for impacts of ocean acidification on mollusk calcification.

    Science.gov (United States)

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Song, Xiaorui; Wang, Lingling; Song, Linsheng

    2017-08-01

    Ocean acidification (OA) could decrease the shells and skeletons formation of mollusk by reducing the availability of carbonate ions at calcification sites. Carbonic anhydrases (CAs) convert CO 2 to HCO 3 - and play important roles in biomineralization process from invertebrate to vertebrate. In the present study, a CA (designated as CgCA) was identified and characterized in Pacific oyster C. gigas. The cDNA of CgCA was of 927bp encoding a predicted polypeptide of 308 amino acids with a signal peptide and a CA catalytic function domain. The mRNA transcripts of CgCA were constitutively expressed in all tested tissues with the highest levels in mantle and hemocytes. During the early development period, the mRNA transcripts of CgCA could be detected in all the stages with the highest level in D-veliger larvae. Elevated CO 2 increased the mRNA transcripts of CgCA in muscle, mantle, hepatopancreas, gill and hemocytes significantly (p<0.05) and induced the translocation of CgCA in hemocytes and mantle. Moreover, elevated CO 2 also caused the decrease of intracellular Ca 2+ in hemocytes (p<0.05). The inhibition of CA by acetazolamide and suppression of CgCA gene via RNA interference could increase the intracellular Ca 2+ in hemocytes (p<0.05). Besides, the decrease of intracellular Ca 2+ content caused by Ca 2+ reagent ionomycin could affect localization of CgCA in mantle tissue. The results indicated CgCA played essential roles in calcification and elevated CO 2 accelerated the mutual modulation between calcium and CgCA, implying reduced calcification rate and dissolved shells under OA. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. An evaluation of the use of remotely sensed parameters for prediction of incidence and risk associated with Vibrio parahaemolyticus in Gulf Coast oysters (Crassostrea virginica).

    Science.gov (United States)

    Phillips, A M B; Depaola, A; Bowers, J; Ladner, S; Grimes, D J

    2007-04-01

    The U.S. Food and Drug Administration recently published a Vibrio parahaemolyticus risk assessment for consumption of raw oysters that predicts V. parahaemolyticus densities at harvest based on water temperature. We retrospectively compared archived remotely sensed measurements (sea surface temperature, chlorophyll, and turbidity) with previously published data from an environmental study of V. parahaemolyticus in Alabama oysters to assess the utility of the former data for predicting V. parahaemolyticus densities in oysters. Remotely sensed sea surface temperature correlated well with previous in situ measurements (R(2) = 0.86) of bottom water temperature, supporting the