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

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

Indian marine bivalves: Potential source of antiviral drugs

Digital Repository Service at National Institute of Oceanography (India)

Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Bichurina, M.A.; Sovetova, M.; Boikov, Y.A.

in large quantities by traditional methods and sold live in the market for human consumption. The economically important sp e cies of marine bivalves are green mussel ( Perna viridis ), e s tuarine oyster ( Crassostrea madrasensis ), giant oyster... in developing an effecti ve drug has been the unique characteristics of antigenic variation of virus resulting in the emergence of new variant virus strains 14 . There are a number of antiviral drugs introduced in the market such as tricyclic sy m- metric...

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

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

Science.gov (United States)

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.

Acumulación de cobre y alteraciones histopatológicas en el ostión Crassostrea angulata

Directory of Open Access Journals (Sweden)

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

Parasites of economically important bivalves from the southern coast of Bahia State, Brazil Parasitos de bivalves de interesse econômico no Litoral Sul do Estado da Bahia, Brasil

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Gabriela Calvi Zeidan

2012-12-01

Full Text Available This study investigated the parasites of three commercially important bivalve species (Crassostrea rhizophorae, Mytella guyanensis and Lucina pectinata from the southern coast of Bahia, Brazil. A total of 540 specimens were collected in August 2009 and February 2010, at three localities. The bivalve specimens were measured on their longest axis, opened, and macroscopically examined for the presence of parasites or signs of disease. They were then fixed in Davidson' solution and subjected to routine histological processing, with paraffin embedding and H&E staining; next, the specimens were examined under a light microscope. No parasites were observed associated with L. pectinata. Rickettsia-like organisms (RLOs, Sphenophrya sp. (Ciliophora, Nematopsis sp. (Apicomplexa, Urastoma sp. (Turbellaria and Bucephalus sp. (Digenea were observed in both C. rhizophorae and M. guyanensis, as well as Ancistrocoma sp. (Ciliophora and Tylocephalum sp. (Cestoda in the former. A high prevalence of Nematopsis sp. was seen, but caused no apparent damage to the host. Bucephalus sp. caused the destruction of tissues, with castration, but showed low prevalence. The other parasites occurred in low prevalence and intensity, without causing significant damage.Neste estudo foram investigados os parasitos de três espécies de bivalves de interesse econômico (Crassostrea rhizophorae, Mytella guyanensis e Lucina pectinata da Bahia. Foram analisados 540 exemplares, obtidos em duas coletas (agosto-2009 e fevereiro-2010, em três localidades. Os bivalves foram medidos quanto ao seu maior eixo, abertos e examinados macroscopicamente quanto à presença de parasitos ou sinais de enfermidades. Depois disso, foram fixados em solução de Davidson e processados por rotina de histologia, com inclusão em parafina e coloração com H&E. O material foi examinado ao microscópio de luz. Nenhum parasito esteve associado a L. pectinata. Bactérias do tipo RLOs (organismos assemelhados a

The miRNA biogenesis in marine bivalves

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Umberto Rosani

2016-03-01

Full Text Available Small non-coding RNAs include powerful regulators of gene expression, transposon mobility and virus activity. Among the various categories, mature microRNAs (miRNAs guide the translational repression and decay of several targeted mRNAs. The biogenesis of miRNAs depends on few gene products, essentially conserved from basal to higher metazoans, whose protein domains allow specific interactions with dsRNA. Here, we report the identification of key genes responsible of the miRNA biogenesis in 32 bivalves, with particular attention to the aquaculture species Mytilus galloprovincialis and Crassostrea gigas. In detail, we have identified and phylogenetically compared eight evolutionary conserved proteins: DROSHA, DGCR8, EXP5, RAN, DICER TARBP2, AGO and PIWI. In mussels, we recognized several other proteins participating in the miRNA biogenesis or in the subsequent RNA silencing. According to digital expression analysis, these genes display low and not inducible expression levels in adult mussels and oysters whereas they are considerably expressed during development. As miRNAs play an important role also in the antiviral responses, knowledge on their production and regulative effects can shed light on essential molecular processes and provide new hints for disease prevention in bivalves.

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

Bivalve aquaculture-environment interactions in the context of climate change.

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Filgueira, Ramón; Guyondet, Thomas; Comeau, Luc A; Tremblay, Réjean

2016-12-01

Coastal embayments are at risk of impacts by climate change drivers such as ocean warming, sea level rise and alteration in precipitation regimes. The response of the ecosystem to these drivers is highly dependent on their magnitude of change, but also on physical characteristics such as bay morphology and river discharge, which play key roles in water residence time and hence estuarine functioning. These considerations are especially relevant for bivalve aquaculture sites, where the cultured biomass can alter ecosystem dynamics. The combination of climate change, physical and aquaculture drivers can result in synergistic/antagonistic and nonlinear processes. A spatially explicit model was constructed to explore effects of the physical environment (bay geomorphic type, freshwater inputs), climate change drivers (sea level, temperature, precipitation) and aquaculture (bivalve species, stock) on ecosystem functioning. A factorial design led to 336 scenarios (48 hydrodynamic × 7 management). Model outcomes suggest that the physical environment controls estuarine functioning given its influence on primary productivity (bottom-up control dominated by riverine nutrients) and horizontal advection with the open ocean (dominated by bay geomorphic type). The intensity of bivalve aquaculture ultimately determines the bivalve-phytoplankton trophic interaction, which can range from a bottom-up control triggered by ammonia excretion to a top-down control via feeding. Results also suggest that temperature is the strongest climate change driver due to its influence on the metabolism of poikilothermic organisms (e.g. zooplankton and bivalves), which ultimately causes a concomitant increase of top-down pressure on phytoplankton. Given the different thermal tolerance of cultured species, temperature is also critical to sort winners from losers, benefiting Crassostrea virginica over Mytilus edulis under the specific conditions tested in this numerical exercise. In general, it is

Soundscapes and Larval Settlement: Larval Bivalve Responses to Habitat-Associated Underwater Sounds.

Science.gov (United States)

Eggleston, David B; Lillis, Ashlee; Bohnenstiehl, DelWayne R

2016-01-01

We quantified the effects of habitat-associated sounds on the settlement response of two species of bivalves with contrasting habitat preferences: (1) Crassostrea virginicia (oyster), which prefers to settle on other oysters, and (2) Mercenaria mercenaria (clam), which settles on unstructured habitats. Oyster larval settlement in the laboratory was significantly higher when exposed to oyster reef sound compared with either off-reef or no-sound treatments. Clam larval settlement did not vary according to sound treatments. Similar to laboratory results, field experiments showed that oyster larval settlement in "larval housings" suspended above oyster reefs was significantly higher compared with off-reef sites.

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 ...

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 ...

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

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.

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.

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...

Lower Oligocene bivalves of Ramanian Stage from Kachchh, Gujarat, India

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Kachhara, R. P.; Jodhawat, R. L.; Devi, K. Bigyapati

2012-04-01

Marine Oligocene sequences in India outcrop only in western part of Kachchh. Earlier researchers have recognized the Oligocene strata under the Nari Series (Nagappa 1959; Chatterji and Mathur 1966). The Nari Series has a type area in Pakistan. It has two subdivisions - the Lower Nari (Lower Oligocene) and the Upper Nari (Upper Oligocene). It seems that there is no valid proof about the age of the Lower Nari due to lack of proper fauna (Eames 1975), and according to Pascoe (1962), the Upper Nari slightly transgress into Aquitanian (Lower Miocene), therefore, one has to be very cautious. Biswas and Raju (1971) reclassified the Oligocene strata of Kachchh and lithostratigraphically clubbed them as the Maniyara Fort Formation with type section along the Bermoti stream. This Formation has four members. The lower three members correspond to the Ramanian Stage (Lower Oligocene, Biswas 1971, 1973) while the uppermost to the Waiorian Stage (Upper Oligocene, Biswas 1965, 1971, 1973). The Ramanian Stage is characterized by large forams especially Nummulites fichteli, Nummulites fichteli intermedius, Lepidocyclina ( Eulepidina) dialata and Operculina sp. Several ostracods are also known to occur. Megafauna include bivalves, gastropods, echinoids, corals, mammals and reptiles. Concerning bivalves earlier researchers have recorded a few taxa namely Trisidos semitorta (Lamarck), Cubitostrea angulata (J de C Sowerby), Pecten ( Amussiopecten) labadyei d'Archiac and Haime, Periglypta puerpera (Linne') var. aglaurae Brongniart, Ostrea fraasi Mayer Eymer and listed Pecten laevicostatus J de C Sowerby, Callista pseudoumbonella Vredenburg and Clementia papyracea (Gray) from Kachchh as against overall 42 forms from the Nari Series as a whole (Vredenburg 1928). This tempted us to make an attempt to collect bivalve fauna systematically which are occurring prolifically in the Ramanian Stage. In the present work, for this purpose, sections are worked out around Lakhpat (23°50'N; 68°47'E

Microplastics in bivalves cultured for human consumption.

Science.gov (United States)

Van Cauwenberghe, Lisbeth; Janssen, Colin R

2014-10-01

Microplastics are present throughout the marine environment and ingestion of these plastic particles (microplastics in two species of commercially grown bivalves: Mytilus edulis and Crassostrea gigas. Microplastics were recovered from the soft tissues of both species. At time of human consumption, M. edulis contains on average 0.36 ± 0.07 particles g(-1) (wet weight), while a plastic load of 0.47 ± 0.16 particles g(-1) ww was detected in C. gigas. As a result, the annual dietary exposure for European shellfish consumers can amount to 11,000 microplastics per year. The presence of marine microplastics in seafood could pose a threat to food safety, however, due to the complexity of estimating microplastic toxicity, estimations of the potential risks for human health posed by microplastics in food stuffs is not (yet) possible. Copyright © 2014 Elsevier Ltd. All rights reserved.

Field clearance of an intertidal bivalve bed: relative significance of the co-occurring blue mussel Mytilus edulis and Pacific oyster Crassostrea gigas

DEFF Research Database (Denmark)

Vismann, Bent; Holm, Mark Wejlemann; Davids, Jens

2016-01-01

was estimated by combining field measurements of clearance rates and modelling of the bivalve bed (topography, biomass distribution, temporal and spatial water coverage and depth). The average density of C. gigas and M. edulis was 35 ± 36 and 1001 ± 685 ind. m−2, respectively. The water volume cleared during...... a tidal cycle was estimated at 45 838 m3, of which C. gigas and M. edulis contributed 9169 and 36 669 m3, respectively. Therefore, M. edulis contributed 4 times as much as C. gigas to the bivalve bed’s clearance, and the 2 bivalves were estimated to clear the water volume 1.9 times during each tidal cycle....... However, the estimated water column cleared during low tide is overestimated due to phytoplankton depletion. Hence, it is concluded that the bivalve bed clears the water close to 1 time each tidal cycle. This, together with a low dry weight of soft parts, indicates that the bivalve bed, in general...

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.

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.

Accumulation of butyl- and phenyltin compounds in starfish and bivalves from the coastal environment of Korea

Energy Technology Data Exchange (ETDEWEB)

Shim, Won Joon [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of)]. E-mail: wjshim@kordi.re.kr; Yim, Un Hyuk [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Kim, Nam Sook [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Hong, Sang Hee [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Oh, Jae Ryoung [Southern Coastal Environment Research Division, Korea Ocean Research and Development Institute, Jangmok-myon 391, Geoje 656-830 (Korea, Republic of); Jeon, Joong Kyun [Department of Marine Bioscience and Technology, Kangnung National University, Kangnung 210-702 (Korea, Republic of); Okamura, Hideo [Laboratory of Marine Environment Management, Kobe University Mercantile Marine, Fukaeminami 5-1-1, Highshinada, Kobe 658-0022 (Japan)

2005-02-01

Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteria pectinifera and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from <2 to 797 ng/g as Sn on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT. - Starfish are effective organisms for monitoring phenyltin contamination in the marine environment.

Accumulation of butyl- and phenyltin compounds in starfish and bivalves from the coastal environment of Korea

International Nuclear Information System (INIS)

Shim, Won Joon; Yim, Un Hyuk; Kim, Nam Sook; Hong, Sang Hee; Oh, Jae Ryoung; Jeon, Joong Kyun; Okamura, Hideo

2005-01-01

Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteria pectinifera and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from <2 to 797 ng/g as Sn on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT. - Starfish are effective organisms for monitoring phenyltin contamination in the marine environment

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.

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

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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.

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

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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.

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.

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

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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

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

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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.

A critical examination of the possible application of zinc stable isotope ratios in bivalve mollusks and suspended particulate matter to trace zinc pollution in a tropical estuary.

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Araújo, Daniel; Machado, Wilson; Weiss, Dominik; Mulholland, Daniel S; Boaventura, Geraldo R; Viers, Jerome; Garnier, Jeremie; Dantas, Elton L; Babinski, Marly

2017-07-01

The application of zinc (Zn) isotopes in bivalve tissues to identify zinc sources in estuaries was critically assessed. We determined the zinc isotope composition of mollusks (Crassostrea brasiliana and Perna perna) and suspended particulate matter (SPM) in a tropical estuary (Sepetiba Bay, Brazil) historically impacted by metallurgical activities. The zinc isotope systematics of the SPM was in line with mixing of zinc derived from fluvial material and from metallurgical activities. In contrast, source mixing alone cannot account for the isotope ratios observed in the bivalves, which are significantly lighter in the contaminated metallurgical zone (δ 66 Zn JMC  = +0.49 ± 0.06‰, 2σ, n = 3) compared to sampling locations outside (δ 66 Zn JMC  = +0.83 ± 0.10‰, 2σ, n = 22). This observation suggests that additional factors such as speciation, bioavailability and bioaccumulation pathways (via solution or particulate matter) influence the zinc isotope composition of bivalves. Copyright © 2017 Elsevier Ltd. All rights reserved.

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 P_CO₂ enhanced accumulation of Cu and Cd in the gills of mollusks. • The proteasome activities were affected by metals but robust to elevated P_CO₂. • Exposure to Cd and Cu had opposite effects on the proteasome activity. • Combined exposure to Cu and elevated P_CO₂ 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 P_CO₂ ~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_CO₂ 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_CO₂, but P_CO₂ modulated the proteasome response to metals. Cd exposure stimulated the chymotrypsin-like activity of the oyster proteasome

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...

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

Near infra-red spectroscopy quantitative modelling of bivalve protein, lipid and glycogen composition using single-species versus multi-species calibration and validation sets

Science.gov (United States)

Bartlett, Jill K.; Maher, William A.; Purss, Matthew B. J.

2018-03-01

Near infrared spectroscopy (NIRS) quantitative modelling was used to measure the protein, lipid and glycogen composition of five marine bivalve species (Saccostrea glomerata, Ostrea angasi, Crassostrea gigas, Mytilus galloprovincialis and Anadara trapezia) from multiple locations and seasons. Predictive models were produced for each component using individual species and aggregated sample populations for the three oyster species (S. glomerata, O. angasi and C. gigas) and for all five bivalve species. Whole animal tissues were freeze dried, ground to > 20 μm and scanned by NIRS. Protein, lipid and glycogen composition were determined by traditional chemical analyses and calibration models developed to allow rapid NIRS-measurement of these components in the five bivalve species. Calibration modelling was performed using wavelet selection, genetic algorithms and partial least squares analysis. Model quality was assessed using RPIQ and RMESP. For protein composition, single species model results had RPIQ values between 2.4 and 3.5 and RMSEP between 8.6 and 18%, the three oyster model had an RPIQ of 2.6 and an RMSEP of 10.8% and the five bivalve species had an RPIQ of 3.6 and RMSEP of 8.7% respectively. For lipid composition, single species models achieved RPIQ values between 2.9 and 5.3 with RMSEP between 9.1 and 11.2%, the oyster model had an RPIQ of 3.6 and RMSEP of 6.8 and the five bivalve model had an RPIQ of 5.2 and RMSEP of 6.8% respectively. For glycogen composition, the single species models had RPIQs between 3.8 and 18.9 with RMSEP between 3.5 and 9.2%, the oyster model had an RPIQ of 5.5 and RMSEP of 7.1% and the five bivalve model had an RPIQ of 4 and RMSEP of 7.6% respectively. Comparison between individual species models and aggregated models for three oyster species and five bivalve species for each component indicate that aggregating data from like species produces high quality models with robust and reliable quantitative application. The benefit of

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.

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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.

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

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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

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

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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.

Marine Bacteria with antimicrobials capacity isolated from cultures of bivalve mollusks

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Fabiola Pellon

2014-06-01

Full Text Available Microorganisms have commonly been studied as producers of antibacterial substances; yet they are also considered producers of antifungic, antiviral, antiparasitic, citotoxics and inhibitory of other forms of cellular growth substances. This paper describes the isolation, inhibitory potential and phenotipic characterization of native bacterial strains associated to bivalve mollusks such as Argopecten purpuratus “concha de abanico” and Crassostrea gigas “ostra” in cultivation systems. From 345 marine strains collected, 20 strains were recovered that had the ability of inhibiting a wide spectrum of fish, mollusks and shellfish pathogenic bacteria; being the most sensitive pathogens Aeromonas sobria P-281, Aeromonas hydrophila ATCC 7966, Vibrio vulnificus ATCC 27562 and Vibrio parahaemolyticus ATCC 17803. The phenotipic characterization of this strains with inhibitory capacity allowed the identification of the following genera: Vibrio (40%, Aeromonas (15%, Flavobacterium (10%, Pseudomonas (5%, Moraxella (5%, Flexibacter (5%. A 20% could not be identified. The results suggest that the isolated bacteria could be used as probiotics agents for the biological control of pathogens from marine organisms of interest in mariculture.

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.

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.

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.

Hemocyte parameters of the Pacific oyster Crassostrea gigas a year after the Hebei Spirit oil spill off the west coast of Korea

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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.

Occurrence of potentially pathogenic Vibrio in oysters (Crassostrea gigas) and waters from bivalve mollusk cultivations in the South Bay of Santa Catarina.

Science.gov (United States)

Ramos, Roberta Juliano; Miotto, Letícia Adélia; Miotto, Marília; Silveira Junior, Nelson; Cirolini, Andréia; Silva, Helen Silvestre da; Rodrigues, Dália dos Prazeres; Vieira, Cleide Rosana Werneck

2014-01-01

This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Twenty-nine (48.3%) oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from oyster and from oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3%) showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL(-1) to 1.7 log10MPN·100mL(-1) seawater and from < 0.3 log10 MPN·100mL(-1) to 2.0 log10 MPN·100mL(-1) seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish.

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

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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.

Metals and pesticides in commercial bivalve mollusc production areas in the North and South Bays, Santa Catarina (Brazil).

Science.gov (United States)

de Souza, R V; Garbossa, L H P; Campos, C J A; Vianna, L F de N; Vanz, A; Rupp, G S

2016-04-15

Concentrations of heavy metals were quantified in mussels Perna perna and Pacific oysters Crassostrea gigas in 28 cultivation sites in the North and South Bays, SC (Brazil). Concentrations of pesticides were also quantified in these bivalve, water and sediment samples collected in 14 cultivation sites on four occasions in the period October 2012-October 2013. Pesticides were not detected in any of the mussel, oyster, water or sediment samples. The South Bay was found to be generally more contaminated with As while the North Bay showed higher concentrations of Ni. Concentrations of Pb and Cd were below the limit of detection of the method (0.5mg/kg) in all samples. Mussels accumulated more As and Ni than oysters, while the opposite was observed for Cu. Metal concentrations were below the maximum levels for foodstuffs specified in the Brazilian legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microplastics in commercial bivalves from China

International Nuclear Information System (INIS)

Li, Jiana; Yang, Dongqi; Li, Lan; Jabeen, Khalida; Shi, Huahong

2015-01-01

We investigated microplastic pollution in 9 commercial bivalves from a fishery market in China. Multiple types of microplastics, including fibers, fragments and pellets, occurred in the tissue of all bivalves. The number of total microplastics varied from 2.1 to 10.5 items/g and from 4.3 to 57.2 items/individual for bivalves. Scapharca subcrenata contained on average 10.5 items/g and exhibited the highest levels of microplastics by weight. Fibers were the most common microplastics and consisted of more than half of the total microplastics in each of the 8 species. In Alectryonella plicatula, pellets accounted for 60% of the total microplastics. The most common size class was less than 250 μm and accounted for 33–84% of the total microplastics calculated by species. Our results suggest that microplastic pollution was widespread and exhibited a relatively high level in commercial bivalves from China. More intensive investigations on microplastics should be conducted in seafood. - Highlights: • Fiber, fragment and pellet microplastics were found in 9 bivalves. • The abundance of microplastics was 2.1–10.5 items/g. • Fibers were the most common microplastics. • The most common size class of microplastics was less than 250 μm. • Microplastic pollution was widespread and serious in commercial bivalves. - Fiber, fragment and pellet microplastics in the range of 2.1–10.5 items/g were observed in 9 species of commercially popular bivalves from China.

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

Recirculation nursery systems for bivalves

NARCIS (Netherlands)

Kamermans, P.; Blanco Garcia, A.; Joaquim, Sandra; Matias, Domitilia; Magnesen, Thorolf; Nicolas, J.; Petten, Bruno; Robert, Rene

2016-01-01

n order to increase production of bivalves in hatcheries and nurseries, the development of new technology and its integration into commercial bivalve hatcheries is important. Recirculation aquaculture systems (RASs) have several advantages: high densities of the species can be cultured resulting in

Occurrence of potentially pathogenic Vibrio in oysters (Crassostrea gigas and waters from bivalve mollusk cultivations in the South Bay of Santa Catarina

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Roberta Juliano Ramos

2014-06-01

Full Text Available Introduction This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Methods Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Results Twenty-nine (48.3% oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from < 0.5 log10 Most Probable Number (MPN g–1 to 2.3 log10 MPN g–1 oyster and from < 0.5 log10 MPN g–1 to 2.1 log10 MPN g–1 oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3% showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL–1 to 1.7 log10MPN·100mL–1 seawater and from < 0.3 log10 MPN·100mL–1 to 2.0 log10 MPN·100mL–1 seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. Conclusions The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish.

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

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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.

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

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

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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.

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

Factors influencing the microplastic contamination of bivalves from the French Atlantic coast: Location, season and/or mode of life?

Science.gov (United States)

Phuong, Nam Ngoc; Poirier, Laurence; Pham, Quoc Tuan; Lagarde, Fabienne; Zalouk-Vergnoux, Aurore

2018-04-01

Monitoring the presence of microplastics (MP) in marine organisms is currently of high importance. This paper presents the qualitative and quantitative MP contamination of two bivalves from the French Atlantic coasts: the blue mussel (Mytilus edulis) and the Pacific oyster (Crassostrea gigas). Three factors potentially influencing the contamination were investigated by collecting at different sampling sites and different seasons, organisms both wild and cultivated. Inter- and intra-species comparisons were also achieved. MP quantity in organisms was evaluated at 0.61±0.56 and 2.1±1.7MP per individual respectively for mussels and oysters. Eight different polymers were identified. Most of the MPs were fragments; about a half of MPs were grey colored and a half with a size ranging from 50 to 100μm for both studied species. Some inter-specific differences were found but no evidence for sampling site, season or mode of life effect was highlighted. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Ecological drivers and habitat associations of estuarine bivalves

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C. Seabird McKeon

2015-11-01

Full Text Available Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess the community composition, distribution, and ecological drivers of the infaunal bivalves of this estuary system. Salinity had the strongest influence on bivalve assemblage across the 15 sites, superseding the influences of sediment type, water turbidity, temperature and other environmental parameters. The greatest diversity was found in higher salinity euhaline sites, while the greatest abundance of individual bivalves was found in medium salinity mixohaline sites, the lowest diversity and abundances were found in the low salinity oligohaline sites, demonstrating a strong positive association between salinity and diversity/abundance. Water management decisions for the estuary should incorporate understanding of the role of salinity on bivalve diversity, abundance, and ecosystem function.

Ecological drivers and habitat associations of estuarine bivalves.

Science.gov (United States)

McKeon, C Seabird; Tunberg, Björn G; Johnston, Cora A; Barshis, Daniel J

2015-01-01

Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess the community composition, distribution, and ecological drivers of the infaunal bivalves of this estuary system. Salinity had the strongest influence on bivalve assemblage across the 15 sites, superseding the influences of sediment type, water turbidity, temperature and other environmental parameters. The greatest diversity was found in higher salinity euhaline sites, while the greatest abundance of individual bivalves was found in medium salinity mixohaline sites, the lowest diversity and abundances were found in the low salinity oligohaline sites, demonstrating a strong positive association between salinity and diversity/abundance. Water management decisions for the estuary should incorporate understanding of the role of salinity on bivalve diversity, abundance, and ecosystem function.

Microplastics in commercial bivalves from China.

Science.gov (United States)

Li, Jiana; Yang, Dongqi; Li, Lan; Jabeen, Khalida; Shi, Huahong

2015-12-01

We investigated microplastic pollution in 9 commercial bivalves from a fishery market in China. Multiple types of microplastics, including fibers, fragments and pellets, occurred in the tissue of all bivalves. The number of total microplastics varied from 2.1 to 10.5 items/g and from 4.3 to 57.2 items/individual for bivalves. Scapharca subcrenata contained on average 10.5 items/g and exhibited the highest levels of microplastics by weight. Fibers were the most common microplastics and consisted of more than half of the total microplastics in each of the 8 species. In Alectryonella plicatula, pellets accounted for 60% of the total microplastics. The most common size class was less than 250 μm and accounted for 33-84% of the total microplastics calculated by species. Our results suggest that microplastic pollution was widespread and exhibited a relatively high level in commercial bivalves from China. More intensive investigations on microplastics should be conducted in seafood. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

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

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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.

Assessing the presence of marine toxins in bivalve molluscs from southwest India.

Science.gov (United States)

Turner, Andrew D; Dhanji-Rapkova, Monika; Rowland-Pilgrim, Stephanie; Turner, Lucy M; Rai, Ashwin; Venugopal, Moleyur N; Karunasagar, Indrani; Godhe, Anna

2017-12-15

The south west coast of India has been showing a steady increase in shellfish cultivation both for local consumption and fishery export, over recent years. Perna viridis and Crassostrea madrasensis are two species of bivalve molluscs which grow in some selected regions of southern Karnataka, close to the city of Mangalore. In the early 1980s, shellfish consumers in the region were affected by intoxication from Paralytic Shellfish Poison present in local bivalves (clams and oysters) resulting in hospitalisation of many, including one fatality. Since then, there have been no further reports of serious shellfish intoxication and there is little awareness of the risks from natural toxins and no routine monitoring programme in place to protect shellfish consumers. This study presents the findings from the first ever systematic assessment of the presence of marine toxins in mussels and oysters grown in four different shellfish harvesting areas in the region. Shellfish were collected and subjected to analysis for ASP, PSP and lipophilic toxins, as well as a suite of non-EU regulated toxins such as tetrodotoxin and selected cyclic imines. Results revealed the presence of low levels of PSP toxins in oysters throughout the study period. Overall, total toxicities reached a maximum of 10% of the EU regulatory limit of 800 μg STX eq/kg. Toxin profiles were similar to those reported from the 1980 outbreak. No evidence was found for significant levels of ASP and lipophilic toxins, although some cyclic imines were detected, including gymnodimine. The results indicated that the risk to shellfish consumers during this specific study period would have been low. However, with historical evidence for extremely high levels of PSP toxins in molluscs, there is a strong need for routine surveillance of shellfish production areas for marine toxins, in order to mitigate against human health impacts resulting from unexpected harmful algal blooms, with potentially devastating socio

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

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.

Ecological drivers and habitat associations of estuarine bivalves

OpenAIRE

McKeon, C. Seabird; Tunberg, Bj?rn G.; Johnston, Cora A.; Barshis, Daniel J.

2015-01-01

Community composition of the infaunal bivalve fauna of the St. Lucie Estuary and southern Indian River Lagoon, eastern Florida was sampled quarterly for 10 years as part of a long-term benthic monitoring program. A total of 38,514 bivalves of 137 taxa were collected and identified. We utilized this data, along with sediment samples and environmental measurements gathered concurrently, to assess the community composition, distribution, and ecological drivers of the infaunal bivalves of this es...

Bivalve grazing can shape phytoplankton communities

Science.gov (United States)

Lucas, Lisa; Cloern, James E.; Thompson, Janet K.; Stacey, Mark T.; Koseff, Jeffrey K.

2016-01-01

The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.

Immunotoxicological effects of environmental contaminants on marine bivalves.

Science.gov (United States)

Renault, T

2015-09-01

Coastal areas are complex environments frequently contaminated by numerous pollutants that represent a potential threat to marine organisms, especially bivalves. These pollutants may have major ecological consequences. Although effects of different environmental contaminants on the immune system in marine bivalves have been already reported, a few of reviews summarizes these effects. The main purpose of this chapter relies on summarizing recent body of data on immunotoxicity in bivalves subjected to contaminants. Immune effects of heavy metals, pesticides, HAP, PCB and pharmaceuticals are presented and discussed and a particular section is devoted to nanoparticle effects. A large body of literature is now available on this topic. Finally, the urgent need of a better understanding of complex interactions between contaminants, marine bivalves and infectious diseases is noticed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Laboratory investigations of the effects of predator sex and size on prey selection by the Asian crab, Hemigrapsus sanguineus.

Science.gov (United States)

Brousseau, D J.; Filipowicz, A; Baglivo, J A.

2001-07-30

Laboratory studies have shown that the nonindigenous Asian shore crab, Hemigrapsus sanguineus, readily consumes three species of commercial bivalves: blue mussels, Mytilus edulis, soft-shell clams, Mya arenaria, and oysters, Crassostrea virginica. Although crabs can eat bivalves of a wide size range, they preferred the smaller prey (Hemigrapsus that occur in the wild, their effectiveness as predators of juvenile bivalves and their large appetites suggest an important role for these predators in restructuring the prey communities in habitats into which they have been introduced.

Artificially evolved functional shell morphology of burrowing bivalves

DEFF Research Database (Denmark)

Germann, D. P.; Schatz, W.; Hotz, Peter Eggenberger

2014-01-01

The morphological evolution of bivalves is documented by a rich fossil record. It is believed that the shell shape and surface sculpture play an important role for the burrowing performance of endobenthic species. While detailed morphometric studies of bivalve shells have been done...... dimensional (3D) objects, the first ever artificial evolution of a physical bivalve shell was performed. The result was a vertically flattened shell occupying only the top sediment layers. Insufficient control of the sediment was the major limitation of the setup and restricted the significance of the results...

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.

Persistent organic pollutants in four bivalve species from Svalbard waters

International Nuclear Information System (INIS)

Vieweg, Ireen; Hop, Haakon; Brey, Thomas; Huber, Sandra; Ambrose, William G.; Locke V, William L.; Gabrielsen, Geir W.

2012-01-01

Organochlorine compounds (OC) were determined in Arctic bivalves (Mya truncata, Serripes groenlandicus, Hiatella arctica and Chlamys islandica) from Svalbard with regard to differences in geographic location, species and variations related to their size and age. Higher chlorinated polychlorinated biphenyls (PCB 101–PCB 194), chlordanes and α-hexachlorocyclohexane (α-HCH) were consistently detected in the bivalves and PCBs dominated the OC load in the organisms. OC concentrations were highest in Mya truncata and the lowest in Serripes groenlandicus. Species-specific OC levels were likely related to differences in the species’ food source, as indicated by the δ 13 C results, rather than size and age. Higher OC concentrations were observed in bivalves from Kongsfjorden compared to the northern sampling locations Liefdefjorden and Sjuøyane. The spatial differences might be related to different water masses influencing Kongsfjorden (Atlantic) and the northern locations (Arctic), with differing phytoplankton bloom situations. - Highlights: ► Organochlorine compounds (OC) were analyzed in 4 bivalve species from Svalbard. ► Polychlorinated biphenyls dominated the OC load observed in the bivalves. ► Atlantic water influenced bivalves had higher OC levels than those from Arctic water. ► Location and species, rather than size and age, determined the OC pattern found. - New findings of organochlorines in Arctic bivalves that are central for evaluating the importance of geographical location and species for the organochlorine pattern in benthic organisms.

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

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.

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.

Metabolites of saxitoxin analogues in bivalves contaminated by Gymnodinium catenatum.

Science.gov (United States)

Vale, Paulo

2010-01-01

Bivalve metabolites of saxitoxin analogues, not present in microalgae, were recently described as an important toxin fraction in mussels contaminated by Alexandrium tamarense. These possess very low fluorescence, and require mass spectrometry detection. HILIC-MS was implemented to look for these metabolites in bivalves contaminated during Gymnodinium catenatum blooms at the Portuguese coast. The presence of M1 was tentatively identified in several bivalves, ranging from estuarine (Mytilus galloprovinciallis, Cerastoderma edule and Ruditapes decussatus) to oceanic habitat (Donax trunculus and Ensis spp.). It was hypothesized that M1 could contribute to an important fraction of the profile of STX analogues. M1 was more abundant in estuarine bivalves that retain longer PSP toxins, in the following order: mussels>cockles>clams. These data highlight that the study by fluorimetry alone of the carbamoyl, N-sulfocarbamoyl, and decarbamoyl families is manifestly insufficient to fully understand toxin dynamics in bivalves feeding on G. catenatum without a proper study of hydroxybenzoate and hydroxylated M-toxins.

Microbial Diseases of Bivalve Mollusks: Infections, Immunology and Antimicrobial Defense.

Science.gov (United States)

Zannella, Carla; Mosca, Francesco; Mariani, Francesca; Franci, Gianluigi; Folliero, Veronica; Galdiero, Marilena; Tiscar, Pietro Giorgio; Galdiero, Massimiliano

2017-06-17

A variety of bivalve mollusks (phylum Mollusca, class Bivalvia) constitute a prominent commodity in fisheries and aquacultures, but are also crucial in order to preserve our ecosystem's complexity and function. Bivalve mollusks, such as clams, mussels, oysters and scallops, are relevant bred species, and their global farming maintains a high incremental annual growth rate, representing a considerable proportion of the overall fishery activities. Bivalve mollusks are filter feeders; therefore by filtering a great quantity of water, they may bioaccumulate in their tissues a high number of microorganisms that can be considered infectious for humans and higher vertebrates. Moreover, since some pathogens are also able to infect bivalve mollusks, they are a threat for the entire mollusk farming industry. In consideration of the leading role in aquaculture and the growing financial importance of bivalve farming, much interest has been recently devoted to investigate the pathogenesis of infectious diseases of these mollusks in order to be prepared for public health emergencies and to avoid dreadful income losses. Several bacterial and viral pathogens will be described herein. Despite the minor complexity of the organization of the immune system of bivalves, compared to mammalian immune systems, a precise description of the different mechanisms that induce its activation and functioning is still missing. In the present review, a substantial consideration will be devoted in outlining the immune responses of bivalves and their repertoire of immune cells. Finally, we will focus on the description of antimicrobial peptides that have been identified and characterized in bivalve mollusks. Their structural and antimicrobial features are also of great interest for the biotechnology sector as antimicrobial templates to combat the increasing antibiotic-resistance of different pathogenic bacteria that plague the human population all over the world.

A novel filtering mutualism between a sponge host and its endosymbiotic bivalves.

Science.gov (United States)

Tsubaki, Remi; Kato, Makoto

2014-01-01

Sponges, porous filter-feeding organisms consisting of vast canal systems, provide unique substrates for diverse symbiotic organisms. The Spongia (Spongia) sp. massive sponge is obligately inhabited by the host-specific endosymbiotic bivalve Vulsella vulsella, which benefits from this symbiosis by receiving protection from predators. However, whether the host sponge gains any benefit from this association is unclear. Considering that the bivalves exhale filtered water into the sponge body rather than the ambient environment, the sponge is hypothesized to utilize water exhaled by the bivalves to circulate water around its body more efficiently. We tested this hypothesis by observing the sponge aquiferous structure and comparing the pumping rates of sponges and bivalves. Observations of water currents and the sponge aquiferous structure revealed that the sponge had a unique canal system enabling it to inhale water exhaled from bivalves, indicating that the host sponge adapted morphologically to receive water from the bivalves. In addition, the volume of water circulating in the sponge body was dramatically increased by the water exhaled from bivalves. Therefore, this sponge-bivalve association can be regarded as a novel mutualism in which two filter-feeding symbionts promote mutual filtering rates. This symbiotic association should be called a "filtering mutualism".

Ecology and culturing of edible bivalves in Goa

Digital Repository Service at National Institute of Oceanography (India)

Parulekar, A.H.; Nair, S.A.; Ansari, Z.A.; Harkantra, S.N.; Chatterji, A.; Ingole, B.S.; Roy, J.M.

Environmental characteristics, growth rate, total production and technically feasible methods for the mass cultivation of Meretrix casta, Paphia malabarica, Villorita cyprinoides, Donax incarnatus, Perna viridis, Modiolus metcalfei and Crassostrea...

Mercury accumulation in marine bivalves: Influences of biodynamics and feeding niche

Energy Technology Data Exchange (ETDEWEB)

Pan Ke [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

2011-10-15

Differences in the accumulation of mercury (Hg) in five species of marine bivalves, including scallops Chlamys nobilis, clams Ruditapes philippinarum, oysters Saccostrea cucullata, green mussels Perna viridis, and black mussels Septifer virgatus, were investigated. The bivalves displayed different patterns of Hg accumulation in terms of the body concentrations of methylmercury (MeHg) and total Hg (THg), as well as the ratio of MeHg to THg. Parameters of the biodynamics of the accumulation of Hg(II) and MeHg could reflect the species-dependent Hg concentrations in the bivalves. With the exception of black mussels, we found a significant relationship between the efflux rates of Hg(II) and the THg concentrations in the bivalves. The interspecific variations in the MeHg to THg ratio were largely controlled by the relative difference between the elimination rates of Hg(II) and MeHg. Stable isotope ({delta}{sup 13}C) analysis indicated that the five bivalve species had contrasting feeding niches, which may also affect the Hg accumulation. - Highlights: > Significant difference in Hg accumulation and MeHg:THg ratio in different bivalves. > THg concentrations in the bivalves were generally related to the efflux rates of Hg(II). > Elimination of Hg(II) and MeHg controlled the interspecific variation in MeHg:THg ratio. > MeHg and THg concentrations reflect the interaction of Hg biodynamics and food. - The species-specific body concentrations of MeHg and THg in bivalves reflect the complicated interaction between the biodynamics of Hg(II) and MeHg and the different food sources.

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

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

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

Bio-accumulation kinetics of radioruthenium in marine bivalves. Laboratory study

International Nuclear Information System (INIS)

Mu, D.H.; Yan, S.P.; Gu, Y.J.; Li, D.J.; Du, J.Z.

2007-01-01

Three kinds of marine bivalves (wild Saccostrea cucullata, aquacultured Perna viridis and aquacultured Pinctada martens), collected from Daya Bay, the South China Sea, were used to investigate the bio-accumulation of radioruthenium in the glass aquarium with natural seawater (pH 8.20, 35 per mille salinity, filtered by 0.45 μm) at ambient temperature under laboratory feeding conditions. The experimental results show that the stead-state of biology concentration factor (BCF, ml/g) of radioruthenium was approached around 6 days for most species of bivalves. The values of BCF in shells are the highest in organs all the three bivalves. The orders of BCF values (ml x g -1 ) are as: Perna viridis (33.2) < Saccostrea cucullata (47.0) < Pinctada martensi (208.4) for shells and Saccostrea cucullata (1.5) < Pinctada martensi (2.2) ∼ Perma viridis (2.4) for soft tissues, respectively, after exposed for 14 days. The rate constants of uptake and elimination of radioruthenium on marine bivalves were also discussed by first-order kinetics model. The Pinctada martensi may be applicable to be an indictor for monitoring radioruthenium among the three bivalves. (author)

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.

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...

Galeommatid bivalves from Phuket, Thailand

DEFF Research Database (Denmark)

Lützen, Jørgen; Nielsen, Claus

2005-01-01

Twenty-seven species of galeommatid bivalves from six genera have been collected at intertidal reef flats near Phuket Marine Biological Center, Thailand (Andaman Sea, Indian Ocean). Fourteen of the species are new to science and a new genus (Nudiscintilla gen. nov.) has been established. The spec......Twenty-seven species of galeommatid bivalves from six genera have been collected at intertidal reef flats near Phuket Marine Biological Center, Thailand (Andaman Sea, Indian Ocean). Fourteen of the species are new to science and a new genus (Nudiscintilla gen. nov.) has been established...... crustacean, the remainder hide under shale, rocks and coral blocks, often in small intra- or interspecific family flocks. The behaviour was also noted for some of the species. It is presumed that galeommatid species go through a lengthy planktonic phase....

Modeling the carbon isotope composition of bivalve shells (Invited)

Science.gov (United States)

Romanek, C.

2010-12-01

The stable carbon isotope composition of bivalve shells is a valuable archive of paleobiological and paleoenvironmental information. Previous work has shown that the carbon isotope composition of the shell is related to the carbon isotope composition of dissolved inorganic carbon (DIC) in the ambient water in which a bivalve lives, as well as metabolic carbon derived from bivalve respiration. The contribution of metabolic carbon varies among organisms, but it is generally thought to be relatively low (e.g., 90%) in the shells from terrestrial organisms. Because metabolic carbon contains significantly more C-12 than DIC, negative excursions from the expected environmental (DIC) signal are interpreted to reflect an increased contribution of metabolic carbon in the shell. This observation contrasts sharply with modeled carbon isotope compositions for shell layers deposited from the inner extrapallial fluid (EPF). Previous studies have shown that growth lines within the inner shell layer of bivalves are produced during periods of anaerobiosis when acidic metabolic byproducts (e.g., succinic acid) are neutralized (or buffered) by shell dissolution. This requires the pH of EPF to decrease below ambient levels (~7.5) until a state of undersaturation is achieved that promotes shell dissolution. This condition may occur when aquatic bivalves are subjected to external stressors originating from ecological (predation) or environmental (exposure to atm; low dissolved oxygen; contaminant release) pressures; normal physiological processes will restore the pH of EPF when the pressure is removed. As a consequence of this process, a temporal window should also exist in EPF at relatively low pH where shell carbonate is deposited at a reduced saturation state and precipitation rate. For example, EPF chemistry should remain slightly supersaturated with respect to aragonite given a drop of one pH unit (6.5), but under closed conditions, equilibrium carbon isotope fractionation

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.

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

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.

Prospecção de moluscos bivalves no estudo da poluição dos rios Cachoeira e Santana em Ilhéus, Bahia, Brasil

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Denise Sande

2010-06-01

Full Text Available A survey about the pollution level of the Cachoeira and Santana Rivers (Ilheus, Bahia, Brazil was performed for a quarter, through the assessment of the microbiological quality of water and seafood (Crassostrea rhizophorae - oyster and Tagelus plebeius - razor clam extracted from these rivers. Traditional indicators of pollution such as total coliforms (Ct and thermtolerant coliforms (CT, and total count of micro-organisms, with isolation and identification of Enterobacteriaceae were determined in rivers samples, which exhibited different levels of faecal pollution. An amount of 68 micro-organisms was isolated, distributed in ten species, among them, Salmonella typhi, Escherichia coli and Shigella sp., warning about the risk of consuming these shellfish in nature, even when there is accordance with the laws established for CT. The bivalve prospection to monitor pollution levels was not effective considering CT detection in oysters and moapens. There was also the highest contamination degree in the Cachoeira River, which is used for water distribution in the region and as livelihood source through extractive activities for the riverside population.

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

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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

Accumulation of diarrhetic shellfish poisoning toxins in the oyster ...

African Journals Online (AJOL)

Diarrhetic shellfish poisoning (DSP) poses a significant threat to the safe consumption of shellfish in the southern Benguela ecosystem. The accumulation of DSP toxins was investigated in two cultivated bivalve species, the Pacific oyster Crassostrea gigas and the mussel Choromytilus meridionalis, suspended from a ...

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...

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) ...

Artificially evolved functional shell morphology of burrowing bivalves

DEFF Research Database (Denmark)

Germann, D. P.; Schatz, W.; Hotz, Peter Eggenberger

2014-01-01

dimensional (3D) objects, the first ever artificial evolution of a physical bivalve shell was performed. The result was a vertically flattened shell occupying only the top sediment layers. Insufficient control of the sediment was the major limitation of the setup and restricted the significance of the results......, there are almost no studies experimentally testing their dynamic properties. To investigate the functional morphology of the bivalve shell, we employed a synthetic methodology and built an experimental setup to simulate the burrowing process. Using an evolutionary algorithm and a printer that prints three...

Veda-scope: More comfortable than the bivalve speculum and cytologically equivalent.

Science.gov (United States)

Longmore, Peter G

2004-04-01

The aim of the present study was to confirm that the Veda-scope is equivalent to the bivalve speculum in the collection of endocervical cells, as confirmation of adequate cervical sampling for Pap smear testing. The study also aimed to assess the comfort level of the Veda-scope compared to the traditional bivalve speculum and the patient preference of the Veda-scope compared to the bivalve speculum. Multicentre, randomised, controlled crossover, cytologist blinded study. The total number of subjects enrolled in the study were 250. The number of evaluable subjects were 210. In primary efficacy analysis, no significant difference was seen between the presence or absence of endocervical cells in the smears using either the Veda-scope or the bivalve speculum. There was a high concordance level between the diagnosis assigned to each specimen of a paired sample, the diagnosis agreeing in 97.6% cases. The primary reason given by many women for avoidance of regular Pap smear examinations is the discomfort or pain experienced with sample collection with the bivalve speculum. In the present study, 92% of subjects indicated a preference for the Veda-scope for Pap smear collection, while only 8.4% preferred the bivalve speculum. Subject preference was also assessed with respect to how the subject rated the comfort level of her previous Pap smear. In subjects who rated their previous Pap smear as very comfortable or comfortable, 86% expressed a preference for the Veda-scope. This rose to 93% in subjects who rated their previous Pap smear as only tolerable. The results of the present study show that Pap smear collections with the Veda-scope are of equal quality to those collected with the bivalve speculum, with an equivalent diagnostic outcome. A very strong preference for the Veda-scope was shown by the women enrolled in the present study based on the comfort levels experienced with the two devices.

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.

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

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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

First evidence of immunomodulation in bivalves under seawater acidification and increased temperature.

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Valerio Matozzo

Full Text Available Water acidification, temperature increases and changes in seawater salinity are predicted to occur in the near future. In such a global climate change (GCC scenario, there is growing concern for the health status of both wild and farmed organisms. Bivalve molluscs, an important component of coastal marine ecosystems, are at risk. At the immunological level, the ability of an organism to maintain its immunosurveillance unaltered under adverse environmental conditions may enhance its survival capability. To our knowledge, only a few studies have investigated the effects of changing environmental parameters (as predicted in a GCC scenario on the immune responses of bivalves. In the present study, the effects of both decreased pH values and increased temperature on the important immune parameters of two bivalve species were evaluated for the first time. The clam Chamelea gallina and the mussel Mytilus galloprovincialis, widespread along the coast of the Northwestern Adriatic Sea, were chosen as model organisms. Bivalves were exposed for 7 days to three pH values (8.1, 7.7 and 7.4 at two temperatures (22 and 28°C. Three independent experiments were carried out at salinities of 28, 34 and 40 PSU. The total haemocyte count, Neutral Red uptake, haemolymph lysozyme activity and total protein levels were measured. The results obtained demonstrated that tested experimental conditions affected significantly most of the immune parameters measured in bivalves, even if the variation pattern of haemocyte responses was not always linear. Between the two species, C. gallina appeared more vulnerable to changing pH and temperature than M. galloprovincialis. Overall, this study demonstrated that climate changes can strongly affect haemocyte functionality in bivalves. However, further studies are needed to clarify better the mechanisms of action of changing environmental parameters, both individually and in combination, on bivalve haemocytes.

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

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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

The isotopic biosignatures of photo- vs. thiotrophic bivalves: are they preserved in fossil shells?

Science.gov (United States)

Dreier, A; Loh, W; Blumenberg, M; Thiel, V; Hause-Reitner, D; Hoppert, M

2014-09-01

Symbiont-bearing and non-symbiotic marine bivalves were used as model organisms to establish biosignatures for the detection of distinctive symbioses in ancient bivalves. For this purpose, the isotopic composition of lipids (δ13C) and bulk organic shell matrix (δ13C, δ34S, δ15N) from shells of several thiotrophic, phototrophic, or non-symbiotic bivalves were compared (phototrophic: Fragum fragum, Fragum unedo, Tridacna maxima; thiotrophic: Codakia tigerina, Fimbria fimbriata, Anodontia sp.; non-symbiotic: Tapes dorsatus, Vasticardium vertebratum, Scutarcopagia sp.). ∆13C values of bulk organic shell matrices, most likely representing mainly original shell protein/chitin biomass, were depleted in thio- and phototrophic bivalves compared to non-symbiotic bivalves. As the bulk organic shell matrix also showed a major depletion of δ15N (down to -2.2 ‰) for thiotrophic bivalves, combined δ13C and δ15N values are useful to differentiate between thio-, phototrophic, and non-symbiotic lifestyles. However, the use of these isotopic signatures for the study of ancient bivalves is limited by the preservation of the bulk organic shell matrix in fossils. Substantial alteration was clearly shown by detailed microscopic analyses of fossil (late Pleistocene) T. maxima and Trachycardium lacunosum shell, demonstrating a severe loss of quantity and quality of bulk organic shell matrix with time. Likewise, the composition and δ13C-values of lipids from empty shells indicated that a large part of these compounds derived from prokaryotic decomposers. The use of lipids from ancient shells for the reconstruction of the bivalve's life style therefore appears to be restricted. © 2014 John Wiley & Sons Ltd.

Bioconcentration of trace metals by Saccostrea cucullata (von Born 1778) from Andaman waters

Digital Repository Service at National Institute of Oceanography (India)

Abhilash, K.R.; Gireeshkumar, T.R.; Venu, S.; Raveendran, T.V.

glomerata 97 - 900 4.4 - 380 x x x 5. Bhat et al., 1968 27 Crassostrea gryphoides 171 - 403 x x x x 6. Coombs, 1972 28 Ostrea edulis 1050 - 395 42 - 67 x x x 7. Pringle et al., 1968 29 Crassostrea virginica 180 - 1420 7 - 517 x x x 8. Mc Farren et... Oyster, Mar Poll Bull, 6 (1975) 72–73. 27 Bhat Y M, Sastry H, Shah S M & Krishnamurthy T M, Manganese and cobalt content of some marine bivalves from Bombay. Indian National Science Academy Proceeding, Biology, 34 (1968) 283–287. 28 Coombs T L...

Trace Fossil Evidence of Trematode-Bivalve Parasite-Host Interactions in Deep Time.

Science.gov (United States)

Huntley, John Warren; De Baets, Kenneth

2015-01-01

Parasitism is one of the most pervasive phenomena amongst modern eukaryotic life and yet, relative to other biotic interactions, almost nothing is known about its history in deep time. Digenean trematodes (Platyhelminthes) are complex life cycle parasites, which have practically no body fossil record, but induce the growth of characteristic malformations in the shells of their bivalve hosts. These malformations are readily preserved in the fossil record, but, until recently, have largely been overlooked by students of the fossil record. In this review, we present the various malformations induced by trematodes in bivalves, evaluate their distribution through deep time in the phylogenetic and ecological contexts of their bivalve hosts and explore how various taphonomic processes have likely biased our understanding of trematodes in deep time. Trematodes are known to negatively affect their bivalve hosts in a number of ways including castration, modifying growth rates, causing immobilization and, in some cases, altering host behaviour making the host more susceptible to their own predators. Digeneans are expected to be significant agents of natural selection. To that end, we discuss how bivalves may have adapted to their parasites via heterochrony and suggest a practical methodology for testing such hypotheses in deep time. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Bivalve Production Chain in Santa Catarina, Brazil, and its Management and Operational Limitations

OpenAIRE

Gallon, Alessandra Vasconcelos; Universidade Federal do Ceará (UFC); Nascimento, Cristiano; Universidade Federal do Paraná - UFPR; Pfitscher, Elisete Dahmer; Universidade Federal de Santa Catarina

2011-01-01

Bivalve farming (mussels and oysters), a major component in the socio-economic development of the state of Santa Catarina, Brazil, combines the activities of public and private agencies in fish farming. Current analysis deals with the management and the operational limitations of the local bivalve production chain. Current exploratory research, undertaken by direct observations and the literature on the subject, employs data quality. Results show that the bivalve production chain, comprising ...

Predation and habitat modification synergistically interact to control bivalve recruitment on intertidal mudflats

NARCIS (Netherlands)

van der Heide, T.; Tielens, E.; van der Zee, E.M.; Weerman, E.J.; Holthuijsen, S.; Eriksson, B.K.; Piersma, T.; van de Koppel, J.; Olff, H.

2014-01-01

Bivalves are key components of coastal ecosystems because they link pelagic and benthic food webs, and shape the landscape through habitat modification. Nevertheless, many bivalve stocks have dramatically declined, and recruitment failure due to (anthropogenically-) increased predation by

Predation and habitat modification synergistically interact to control bivalve recruitment on intertidal mudflats

NARCIS (Netherlands)

van der Heide, Tjisse; Tielens, Elske; van der Zee, Els; Weerman, Ellen J.; Holthuijsen, Sander; Eriksson, Britas Klemens; Piersma, Theun; van de Koppel, Johan; Olff, Han

Bivalves are key components of coastal ecosystems because they link pelagic and benthic food webs, and shape the landscape through habitat modification. Nevertheless, many bivalve stocks have dramatically declined, and recruitment failure due to (anthropogenically-) increased predation by

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.

Short-term fluctuations in bivalve larvae compared with some environmental factors in a coastal lagoon (South Portugal

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Luis M.Z. Chícaro

2000-12-01

Full Text Available In this study, short-term fluctuations in bivalve larvae were compared with some triggering factors for a period of sixteen months. Data on the abundance of planktonic larvae, collected two to three times a week were related to water temperature, salinity, wind velocity, tidal amplitude and chlorophyll a. Higher densities of planktonic bivalve larvae were caught between May and August, but intense fluctuations in abundance were observed. Planktonic bivalve larvae of eighteen taxa were identified. Larvae of Mytilus galloprovincialis, Cerastoderma edule, Ruditapes decussates and Venerupis spp. were the most abundant. The seasonal fluctuations of bivalve abundance seem to be controlled by temperature, the major factor in the timing of the reproduction of bivalves. Nevertheless, advection may be also a key factor during the planktonic life of bivalve species in coastal systems, such as the Ria Formosa.

Genomics study of the exposure effect of Gymnodinium catenatum, a paralyzing toxin producer, on Crassostrea gigas' defense system and detoxification genes.

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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

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.

Bivalves: From individual to population modelling

NARCIS (Netherlands)

Saraiva, S.; van der Meer, J.; Kooijman, S.A.L.M.

2014-01-01

An individual based population model for bivalves was designed, built and tested in a 0D approach, to simulate the population dynamics of a mussel bed located in an intertidal area. The processes at the individual level were simulated following the dynamic energy budget theory, whereas initial egg

Development of human impact on suspension-feeding bivalves in coastal soft-bottom ecosystems

NARCIS (Netherlands)

Wolff, Wim J.; Dame, RF; Olenin, S

2005-01-01

Suspension-feeding bivalves often may occur in large concentrations ('beds') on tidal flats. This makes them attractive for human consumers and the archaeological record shows collection of bivalves by coastal populations already tens of thousands of years ago. In modem time human interference with

Histological techniques for marine bivalve mollusks and crustaceans, 2nd edition

OpenAIRE

Howard, Dorothy W.; Lewis, Earl J.; Keller, B. Jane; Smith, Cecelia S.

2004-01-01

Investigators at the Cooperative Oxford Laboratory (COL) diagnose and study crustaceans, mollusks, finfish, and a variety of other marine and estuarine invertebrates to assess animal health. This edition updates the Histological Techniques for Marine Bivalve Mollusks manual by Howard and Smith (1983) with additional chapters on molluscan and crustacean techniques. The new edition is intended to serve as a guide for histological processing of shellfish, principally bivalve mollusks and crustac...

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...

Nursery function of coastal temperate benthic habitats: New insight from the bivalve recruitment perspective

Science.gov (United States)

Barbier, Pierrick; Meziane, Tarik; Forêt, Martin; Tremblay, Réjean; Robert, René; Olivier, Frédéric

2017-03-01

Marine habitat function has been typically investigated in terms of biogeochemical regulation but rarely in terms of population renewal, which is mainly controlled by recruitment dynamics. The recruitment phase is crucial for organisms with a bentho-pelagic life cycle, such as bivalves, and it regulates the population renewal success. This study provides new insight on the role of temperate benthic habitats on bivalve recruitment, as a function of nursery areas. Six dominant benthic habitats of the Chausey archipelago (Normandy, France) were studied. In each habitat, bivalve recruit assemblages were described at the end of two reproductive seasons. Furthermore, Ostrea edulis juveniles were immerged on each habitat during two months to compare growth performances and feeding status, estimated by fatty acid composition. Recruit assemblages differ from each habitat according to sediment grain-size composition and bathymetrical levels. Subtidal habitats, and especially Crepidula fornicata banks and Glycymeris glycymeris coarse sands, supported the highest species abundance and richness of recruits. All O. edulis juveniles fed on the same trophic resources but digestive glands of juveniles from C. fornicata banks were more concentrated in total fatty acids than those from subtidal G. glycymeris coarse sands and maerl banks. Our results depict the key role of subtidal and structured habitats, composed of ecosystem engineers, in enhancing bivalve recruitment and extending the bivalve population renewal. This study suggests that the crucial role of these habitats as bivalve nurseries must be integrated in management perspectives. 2-column fitting image. 1-column fitting image.

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.

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

A Darriwilian (Middle Ordovician bivalve-dominated molluscan fauna from the Stairway Sandstone, Amadeus Basin, central Australia

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Kristian G. Jakobsen

2016-12-01

Full Text Available A bivalve-dominated molluscan fauna is described from the Darriwilian (Middle Ordovician Stairway Sandstone, Amadeus Basin, central Australia. The fauna comprises 16 species of bivalves and rostroconchs plus six gastropod species which are treated under open nomenclature. Two new bivalves, Sthenodonta paenesymmetrica sp. nov. and Modiolopsis pojetai sp. nov., are described. The relatively low-diverse molluscan fauna constitutes around 62% of the total benthic macrofauna. Approximately 75% of the molluscs comprise bivalves, especially nuculoids, which were biogeographically restricted to low latitudes during the Ordovician. The molluscan assemblage displays a very high degree of endemism at species level, though the bivalve Sthenodonta eastii also occurs in the Georgina Basin farther to the northeast. This indicates a possible marine connective seaway between the Georgina and Amadeus basins during the Darriwilian. Nuculites, Cyrtodonta, and Modiolopsis are cosmopolitan and previously reported from North China, Avalonia, and Southern Gondwana.

Infectious diseases in oyster aquaculture require a new integrated approach.

Science.gov (United States)

Pernet, Fabrice; Lupo, Coralie; Bacher, Cédric; Whittington, Richard J

2016-03-05

Emerging diseases pose a recurrent threat to bivalve aquaculture. Recently, massive mortality events in the Pacific oyster Crassostrea gigas associated with the detection of a microvariant of the ostreid herpesvirus 1 (OsHV-1µVar) have been reported in Europe, Australia and New Zealand. Although the spread of disease is often viewed as a governance failure, we suggest that the development of protective measures for bivalve farming is presently held back by the lack of key scientific knowledge. In this paper, we explore the case for an integrated approach to study the management of bivalve disease, using OsHV-1 as a case study. Reconsidering the key issues by incorporating multidisciplinary science could provide a holistic understanding of OsHV-1 and increase the benefit of research to policymakers. © 2016 The Author(s).

Dioxin-like chemicals in bivalves and sediment collected from around Australia

Energy Technology Data Exchange (ETDEWEB)

Mueller, J.F.; Muller, R.; Goudkamp, K. [EnTox, The University of Queensland, Brisbane (AU)] (and others)

2004-09-15

The aquatic environment is a significant sink for persistent organic pollutants including dioxin-like chemicals. Besides continuous investigations into sources of higher chlorinated PCDD that have initially been found in soils, and later in dugong and sediments little is known about the levels of dioxin-like chemicals in Australia's aquatic environment. In 2002 the National Dioxin Program (NDP) was commissioned by the Department of Environment and Heritage, Australia. One focus of the NDP was to evaluate background levels of dioxin-like chemicals in Australia's environment. One component of the 'Environmental Levels' project aimed to identify dioxinlike chemicals in the aquatic environment including bivalves collected in both marine, estuarine and freshwater systems. Here we report results from the NDP aquatic study with a particular emphasis on the levels of dioxin-like chemicals in bivalves and sediments respectively in areas from where the bivalves were collected.

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.

Bioaccumulation of 210Po in common gastropod and bivalve species from the northern Gulf.

Science.gov (United States)

Uddin, S; Bebhehani, M

2014-06-01

This study sets the baseline for the concentration of the natural-series radionuclide polonium-210 in two species of gastropods and four species of bivalves that are common to the Northern Arabian/Persian Gulf. (210)Po is primarily absorbed from water and via ingestion of detrital material by gastropoda and bivalves. This concentrated (210)Po can then be passed along to the next trophic level of the marine food web. The lowest (210)Po concentration was measured in the gastropod Stomatella auricular (10.36-12.39Bq kg(-1)dry) and the highest in the bivalve Marica marmorata (193.51-215.60Bq kg(-1)dry). The measured concentration factor for these molluscs in the northern Gulf varied between 4.8 and 115×10(3), values very similar to the IAEA recommended value for bivalves and gastropods of 2×10(4). Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of dietary polyunsaturated fatty acids on reproductive output and larval growth of bivalves

NARCIS (Netherlands)

Hendriks, I.E.; Van Duren, L.A.; Herman, P.M.J.

2003-01-01

The pre-spawning condition of adult bivalves is influenced by quantity and quality of available food. For bivalves, the essential polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) 20:5(n-3) and docosahexaenoic acid (DHA) 22:6(n-3) are presumed to determine the nutritional value of

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.

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.

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.

Prevalence of Perkinsus marinus (dermo), Haplosporidium nelsoni (MSX), and QPX in bivalves of Delaware's inland bays and quantitative, high-throughput diagnosis of dermo by QPCR.

Science.gov (United States)

Ulrich, Paul N; Ewart, John W; Marsh, Adam G

2007-01-01

Restoration of oyster reef habitat in the Inland Bays of Delaware was accompanied by an effort to detect and determine relative abundance of the bivalve pathogens Perkinsus marinus, Haplosporidium nelsoni, and QPX. Both the oyster Crassostrea virginica and the clam Mercenaria mercenaria were sampled from the bays. In addition, oysters were deployed at eight sites around the bays as sentinels for the three parasites. Perkinsus marinus prevalence was measured with a real-time, quantitative polymerase chain reaction (PCR) methodology that enabled high-throughput detection of as few as 31 copies of the ribosomal non-transcribed spacer region in 500 ng oyster DNA. The other pathogens were assayed using PCR with species-specific primers. Perkinsus marinus was identified in Indian River Bay at moderate prevalence ( approximately 40%) in both an artificial reef and a wild oyster population whereas sentinel oysters were PCR-negative after 3-months exposure during summer and early fall. Haplosporidium nelsoni was restricted to one oyster deployed in Little Assawoman Bay. QPX and P. marinus were not detected among wild clams. While oysters in these bays have historically been under the greatest threat by MSX, it is apparent that P. marinus currently poses a greater threat to recovery of oyster aquaculture in Delaware's Inland Bays.

Travel report Mauritania bivalve Molluscs october 2008

NARCIS (Netherlands)

Poelman, M.

2008-01-01

During the last four years Mauritania has been working on the completion of a Food Safety Program of Bivalve Mollusks, in order to obtain an export approval by the Europe Union. During the preparations for an inspection by the FVO (Food and Veterinary Office) no fisheries or production activities

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...

Linking changes in subcellular cadmium distribution to growth and mortality rates in transplanted freshwater bivalves (Pyganodon grandis)

International Nuclear Information System (INIS)

Perceval, Olivier; Couillard, Yves; Pinel-Alloul, Bernadette; Campbell, Peter G.C.

2006-01-01

Relationships between Cd accumulation and subcellular distribution, and growth and mortality rates were examined in the freshwater bivalve Pyganodon grandis in a transplant experiment. Organisms were transferred from a clean lacustrine site to four lakes situated along a Cd concentration gradient in the mining region of Rouyn-Noranda. The bivalves were maintained in open enclosures placed in the bottom sediments of the littoral zone of all five lakes for 400 days. At the end of the experiment, metallothionein (MT) was measured in the bivalve gills with a Hg-saturation assay and Cd partitioning among the various cytosolic protein pools was determined by size-exclusion chromatography. Marked differences were observed among the five sites: the range in calculated free-cadmium ion concentrations in water overlying the sediments was 35-fold whereas Cd concentrations in the gill cytosol of the transplanted bivalves varied three-fold. In the transplanted bivalves, the distribution of gill Cd among the various cytosolic complexes also varied significantly among sites. For bivalves transplanted to the three most contaminated sites, Cd concentrations in the high molecular weight pool (HMW > 25 kDa) were significantly higher than the baseline levels determined from bivalves caged at the reference site; a similar trend was seen for Cd concentrations in the metallothionein pool (Cd-MT). For bivalves transferred to two of the high contamination sites, proportionately less of the gill cytosolic Cd was sequestered (i.e. detoxified) by MT-like proteins. Reductions in survival were also observed at these two sites, and these elevated mortalities, in turn, were consistent with the absence of indigenous bivalve populations at these sites. This result is compatible with our recent work on P. grandis populations living in lakes of the Rouyn-Noranda area, in which we demonstrated that excessive accumulation of Cd in the HMW pool of the gill cytosol of the individual mollusks could be

Bivalve aquaculture transfers in Atlantic Europe. Part A: Transfer activities and legal framework

DEFF Research Database (Denmark)

Muehlbauer, F.; Fraser, D.; Brenner, M.

2014-01-01

environment and address economic considerations remains unanswered. This study provides the first overview of bivalve transfer activities for aquaculture purposes along the European Atlantic coast. Existing international and EU legislation is described, and potential weaknesses in the existing legislative......Intentional transfers of numerous bivalve species have had a long tradition and are commonly conducted along the European Atlantic coast. However numerous studies have concluded that intentional transfer of species for aquaculture purposes is one of the most principal vectors for the introduction...... frameworks are discussed. Recommendations for the development of integrated risk assessment methods are given. These may help to minimize the intrinsic threats of transfer activities in marine environments. The resulting impacts and effects of transfer activities of bivalves for aquaculture purpose...

Morphometric Studies on Anodonta Anatine Bivalve Population from the Dognecea Lake

Directory of Open Access Journals (Sweden)

Marian Bura

2011-10-01

Full Text Available In the Dognecea Lake, near town Bocsa in Caras-Severin county a strong bivalve population has been discovered from the duck mussel specie (Anodonta anatina. Harvested individuals were transported to the Aquaculture laboratory where measurements and correct identification was made. This specie is considered endangered but in Banat area, especially in the Dognecea Lake it is well represented, having an ecological importance, but the bivalve can have an economical importance too, due to the high percentage of edible part of 56.5%.

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...

Proteomic Profiling of Cytosolic Glutathione Transferases from Three Bivalve Species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea

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José Carlos Martins

2014-01-01

Full Text Available Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs, in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST were surveyed in three bivalves with different habitats and life strategies: Corbicula fluminea, Anodonta cygnea and Mytilus galloprovincialis. GSTs were purified by glutathione-agarose affinity chromatography, and the collection of expressed cGST classes of each bivalve were identified using a proteomic approach. All the purified extracts were also characterized kinetically. Results reveal variations in cGST subunits collection (diversity and properties between the three tested bivalves. Using proteomics, four pi-class and two sigma-class GST subunits were identified in M. galloprovincialis. C. fluminea also yielded four pi-class and one sigma-class GST subunits. For A. cygnea, two mu-class and one pi-class GST subunits were identified, these being the first record of GSTs from these freshwater mussels. The affinity purified extracts also show differences regarding enzymatic behavior among species. The variations found in cGST collection and kinetics might justify diverse selective advantages for each bivalve organism.

The use of bivalves as rapid, real-time indicators of aquatic pollution

International Nuclear Information System (INIS)

Markich, S.J.

1995-01-01

The ability of bivalves to filter large volumes of water on a daily basis, combined with the relatively high permeability of their cell membranes, make them valuable organisms to use in the contemporary detection of pollution. Bivalves are well known to respond to chemical contaminants by isolating their soft tissues from the aquatic medium by valve closure. The sensory acuity (via specialized sensory regions including the osphradium) and associated repertoire of this behavioral response can be employed to assess subtle effects exerted by chemical contaminants, such as complex effluents, that may ultimately influence the survival of these organisms. As hazard assessment tools, behavioral studies reflect sublethal toxicity and often yield a highly sensitive estimate of the lowest observable effect concentration (LOEC). Moreover, valve movement behavior has been identified as one of the more sensitive biological early warning measures to a variety of aquatic contaminants, in comparison with those used in other aquatic animal phyla. Therefore, the valve movement behavior of both freshwater (Hyridella depressa, Velesunio angasi and V. ambiguus) and marine (Mytilus edulis) bivalves was continuously monitored, using an on-line computer based data acquisition system, during exposure to either trace metals (e.g. Cu, Cd, Mn and U) or complex effluents (ie treated sewage effluent and acid leachate derived from contaminated Sydney Harbour sediments), in the context of using the valve movement behavior of the bivalve species to indicate the biological significance of exposure to the above-mentioned pollutants. The results indicate that several components of the valve movement behavior of each bivalve provide quantifiable and ecologically interpretable sub-lethal endpoints for the rapid and sensitive evaluation of waters containing either complex effluents or elevated levels of trace metals

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

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

An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

DEFF Research Database (Denmark)

Filgueira, Ramón; Byron, C.J.; Comeau, L.A.

2015-01-01

, is needed to provide a rigorous assessment of the role of bivalve mariculture in the CO2 cycle. On the other hand, the discussion about the inclusion of shells of cultured bivalves into the carbon trading system should be framed in the context of ecosystem goods and services. Humans culture bivalves......The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities...... with the aim of producing food, not sequestering CO2 in their shells, therefore the main ecosystem good provided by bivalve aquaculture is meat production, and shells should be considered as by-products of this human activity. This reasoning is key to split the CO2 released due to respiration between meat...

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

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).

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...

Lower Oligocene bivalves of Ramanian Stage from Kachchh ...

Indian Academy of Sciences (India)

Sehe area of western Kachchh considered their. Bed Nos. 4 and 5 as .... with very thin population. The Bermoti stream ...... Recent; Indo–Pacific. Subgenus: .... Type species: Cardium discors Lamarck' 1805; T. Eocene–Miocene; Europe–Asia ..... Shuto Tsugio 1971 Neogene Bivalves from Panay Island, the. Philippines.

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

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

76 FR 65200 - Risk Assessment on Norovirus in Bivalve Molluscan Shellfish: Request for Comments and for...

Science.gov (United States)

2011-10-20

... transmission of norovirus from infected or ill food workers in food manufacturing or retail establishments to... Molluscan Shellfish Contamination Levels During Food Preparation and Bivalve Molluscan Shellfish Consumption... and other factors influencing bivalve molluscan shellfish contamination levels during food preparation...

Trophic Dynamics of Filter Feeding Bivalves in the Yangtze Estuarine Intertidal Marsh: Stable Isotope and Fatty Acid Analyses

Science.gov (United States)

Wang, Sikai; Jin, Binsong; Qin, Haiming; Sheng, Qiang; Wu, Jihua

2015-01-01

Benthic bivalves are important links between primary production and consumers, and are essential intermediates in the flow of energy through estuarine systems. However, information on the diet of filter feeding bivalves in estuarine ecosystems is uncertain, as estuarine waters contain particulate matter from a range of sources and as bivalves are opportunistic feeders. We surveyed bivalves at different distances from the creek mouth at the Yangtze estuarine marsh in winter and summer, and analyzed trophic dynamics using stable isotope (SI) and fatty acid (FA) techniques. Different bivalve species had different spatial distributions in the estuary. Glauconome chinensis mainly occurred in marshes near the creek mouth, while Sinonovacula constricta preferred the creek. Differences were found in the diets of different species. S. constricta consumed more diatoms and bacteria than G. chinensis, while G. chinensis assimilated more macrophyte material. FA markers showed that plants contributed the most (38.86 ± 4.25%) to particular organic matter (POM) in summer, while diatoms contributed the most (12.68 ± 1.17%) during winter. Diatoms made the largest contribution to the diet of S. constricta in both summer (24.73 ± 0.44%) and winter (25.51 ± 0.59%), and plants contributed no more than 4%. This inconsistency indicates seasonal changes in food availability and the active feeding habits of the bivalve. Similar FA profiles for S. constricta indicated that the bivalve had a similar diet composition at different sites, while different δ13C results suggested the diet was derived from different carbon sources (C4 plant Spartina alterniflora and C3 plant Phragmites australis and Scirpus mariqueter) at different sites. Species-specific and temporal and/or spatial variability in bivalve feeding may affect their ecological functions in intertidal marshes, which should be considered in the study of food webs and material flows in estuarine ecosystems. PMID:26261984

Environmentally applications of invasive bivalves for water and wastewater decontamination.

Science.gov (United States)

Gomes, João; Matos, Ana; Quinta-Ferreira, Rosa M; Martins, Rui C

2018-07-15

The environmental and economic impact of invasive bivalve species implies the development of suitable pest management strategies. Chemical control is the most usual approach. However, the production of toxic intermediates as well as the unavoidable impact over non target biota is of special concern. Another approach consists on the physical removal of the animals from the invaded sites. The high biofiltration and bioaccumulation capacity of such animals make them interesting for the removal of contaminants from water and wastewater. In this context, environmental applications can be given for these pests encompassing nutrients removal for the recovery of eutrophic sites, water disinfection, organic and metal contaminants abatement. These approaches may be integrated with pest management where the physical removed animals from the invaded spots could be used for assembling biofilter for water and wastewater decontamination. However, some drawbacks must be addressed before proposing such alternative. In fact, the further spreading of the bivalves into non-invaded sites must be avoided. Moreover, some operational questions must be addressed such as the fate of contaminated animals after biofiltration. Bearing in mind the interesting results already available in this subject, this paper aims to critically overview literature regarding the environmental applications of invasive bivalves. Copyright © 2018 Elsevier B.V. All rights reserved.

Spermatozoan ultrastructure in the trigonioid bivalve Neotrigonia margaritacea Lamarck (Mollusca): Comparison with other bivalves, especially Trigonioida and Unionoida

Science.gov (United States)

Healy, J. M.

1996-06-01

Spermatozoa of the trigonioid bivalve Neotrigonia margaritacea (Lamarck) (Trigoniidae, Trigonioida) are examined ultrastructurally. A cluster of discoidal, proacrosomal vesicles (between 9 to 15 in number) constitutes the acrosomal complex at the nuclear apex. The nucleus is short (2.4 2.6 μm long, maximum diameter 2.2 μm), blunt-conical in shape, and exhibits irregular lacunae within its contents. Five or sometimes four round mitochondria are impressed into shallow depressions in the base of the nucleus as is a discrete centriolar fossa. The mitochondria surround two orthogonally arranged centrioles to form, collectively, the midpiece region. The distal centriole, anchored by nine satellite fibres to the plasma membrane, acts as a basal body to the sperm flagellum. The presence of numerous proacrosomal vesicles instead of a single, conical acrosomal vesicle sets Neotrigonia (and the Trigonioida) apart from other bivalves, with the exception of the Unionoida which are also known to exhibit this multivesicular condition. Spermatozoa of N. margaritacea are very similar to those of the related species Neotrigonia bednalli (Verco) with the exception that the proacrosomal vesicles of N. margaritacea are noticeably larger than those of N. bednalli.

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.

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.

First records of Freshwater Bivalves of Ilha Grande National Park, Paraná, Brazil

Directory of Open Access Journals (Sweden)

Flávio Henrique Ragonha

2014-03-01

Full Text Available The Ilha Grande National Park, Paraná, Brazil, is located in the Upper Paraná River and has characteristics typical of a floodplains. This protected area includes lagoons connected and disconnected to the Paraná River, although the latter also connect during periods of high water level, thus composing a heterogeneous group of lacustrine environments. The enormous potential the flora and fauna diversities are still little known to the region, as can be seen through benthic invertebrates, inclunding bivalves mollusks. The granulometric composition of these floodplain lagoons was formed mainly by mud and very fine sand. Furthermore, organic matter composition was predominantly of fine particulate. The other abiotic factors differed from lagoons located within the island of the park to those located in the left margin of Paraná River. The results demonstrated the importance of abiotic factors such as the physical composition of granulometric texture, organic matter and macrophyte banks, to the establishment of bivalves in these floodplain lagoons. We recorded bivalves of Pisidium (native, Diplodon (native, and Corbicula (invasive. The highest values of Diplodon sp. density were observed at São João/C lake, for Pisidium sterkianum (Pilsbry, 1897 at São João/M lake, and to Jatobá/C lagoon with high density of invasive species Corbicula fluminea (Müller, 1774. This study to obtain conduct the first records of freshwater bivalves in floodplains lagoon in the Ilha Grande National Park, and provides contributions to better understanding the ecology of these mollusks. The recording of native species in the region of Upper Paraná River floodplain after a lomg period without new records, demonstrated the importance of protecting the lagoons of the Ilha Grande National Park as they can be a possible refuge to some species of native freshwater bivalves.

Geochemical aspects of Meretrix casta (bivalve) shells of Vellar ...

African Journals Online (AJOL)

SAM

2014-05-14

May 14, 2014 ... The bivalve mollusk, Meretrix casta shells are abundant in the Vellar estuary along the East .... the Shervarayan hills of Salem District in Tamil Nadu, India. .... coast of Peninsular Malaysia and its potential as biomaterial for use.

Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

International Nuclear Information System (INIS)

Praveen Kumar, M.K.; Shyama, S.K.; Sonaye, B.S.; Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A.; Chaubey, R.C.

2014-01-01

Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

Energy Technology Data Exchange (ETDEWEB)

Praveen Kumar, M.K., E-mail: here.praveen@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Shyama, S.K., E-mail: skshyama@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Sonaye, B.S. [Department of Radiation Oncology, Goa Medical College, Goa (India); Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A. [Department of Zoology, Goa University, Goa 403206 (India); Chaubey, R.C. [Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Mumbai (India)

2014-05-01

Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

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...

An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

Science.gov (United States)

Duperron, S.; Gaudron, S. M.; Rodrigues, C. F.; Cunha, M. R.; Decker, C.; Olu, K.

2013-05-01

Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria that ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, eastern Americas, the Gulf of Mexico, and from hydrothermal vents on the Mid-Atlantic Ridge. In parallel, numerous, more easily accessible shallow marine species have been studied. Herein we provide a summary of the current knowledge available on chemosymbiotic bivalves in the area ranging west-to-east from the Gulf of Mexico to the Sea of Marmara, and north-to-south from the Arctic to the Gulf of Guinea. Characteristics of symbioses in 53 species from the area are summarized for each of the five bivalve families documented to harbor chemosynthetic symbionts (Mytilidae, Vesicomyidae, Solemyidae, Thyasiridae and Lucinidae). Comparisons are made between the families, with special emphasis on ecology, life cycle, and connectivity. Chemosynthetic symbioses are a major adaptation to ecosystems and habitats exposed to reducing conditions. However, relatively little is known regarding their diversity and functioning, apart from a few "model species" on which effort has focused over the last 30 yr. In the context of increasing concern about biodiversity and ecosystems, and increasing anthropogenic pressure on oceans, we advocate a better assessment of the diversity of bivalve symbioses in order to evaluate the capacities of these remarkable ecological and evolutionary units to withstand environmental change.

An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

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S. Duperron

2013-05-01

Full Text Available Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria that ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, eastern Americas, the Gulf of Mexico, and from hydrothermal vents on the Mid-Atlantic Ridge. In parallel, numerous, more easily accessible shallow marine species have been studied. Herein we provide a summary of the current knowledge available on chemosymbiotic bivalves in the area ranging west-to-east from the Gulf of Mexico to the Sea of Marmara, and north-to-south from the Arctic to the Gulf of Guinea. Characteristics of symbioses in 53 species from the area are summarized for each of the five bivalve families documented to harbor chemosynthetic symbionts (Mytilidae, Vesicomyidae, Solemyidae, Thyasiridae and Lucinidae. Comparisons are made between the families, with special emphasis on ecology, life cycle, and connectivity. Chemosynthetic symbioses are a major adaptation to ecosystems and habitats exposed to reducing conditions. However, relatively little is known regarding their diversity and functioning, apart from a few "model species" on which effort has focused over the last 30 yr. In the context of increasing concern about biodiversity and ecosystems, and increasing anthropogenic pressure on oceans, we advocate a better assessment of the diversity of bivalve symbioses in order to evaluate the capacities of these remarkable ecological and evolutionary units to withstand environmental change.

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...

Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay.

Science.gov (United States)

Praveen Kumar, M K; Shyama, S K; Sonaye, B S; Naik, U Roshini; Kadam, S B; Bipin, P D; D'costa, A; Chaubey, R C

2014-05-01

Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of 'Comet assay' for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in both bivalve species. This showed a dose-dependent increase of genetic damage induced in bivalves by EMS as well as gamma radiation. Further, the highest DNA damage was observed at 24h. The damage gradually decreased with time, i.e. was smaller at 48 and 72 h than at 24h post irradiation in both species of bivalves. This may indicate repair of the damaged DNA and/or loss of heavily damaged cells as the post irradiation time advanced. The present study

Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

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George G Waldbusser

Full Text Available Ocean acidification (OA is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4 with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material

Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

Science.gov (United States)

Waldbusser, George G; Hales, Burke; Langdon, Chris J; Haley, Brian A; Schrader, Paul; Brunner, Elizabeth L; Gray, Matthew W; Miller, Cale A; Gimenez, Iria; Hutchinson, Greg

2015-01-01

Ocean acidification (OA) is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4) with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material affected only by

Anodontites trapesialis (LAMARCK, 1819: a bivalve parasite of freshwater fishes / Anodontites trapesialis (LAMARCK, 1819: um bivalve parasito de peixes de água doce

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Ângela Teresa Silva-Souza

2008-08-01

Full Text Available The bivalve mollusk Anodontites trapesialis has been indicated as an alternative source for aquaculture because it is considered a food of good nutritional value with a protein content close to that of fish. Its shells can be utilized as fertilizer and mixed to the food of domestic animals, and the nacre can be used to manufacture buttons and crafts. However, the larvae of A. trapesialis, which are the lasidium type, are obligatory parasites of freshwater fishes, and the introduction of this bivalve in fish farm tanks have caused trouble and losses for producers. Nothing is known, however, about their development in these environments. On the other hand, it should be pointed out that A. trapesialis is on Brazil’s list of species threatened with extinction. This article provides a compilation of information present in the literature, offering a detailed review, with the aim of presenting a general panorama of what is known about Anodontites trapesialis and its larval parasitism of fishes.O molusco bivalve, Anodontites trapesialis, tem sido indicado como fonte alternativa para a aqüicultura, por ser considerado um alimento de bom valor nutricional com um conteúdo protéico próximo ao do pescado. Suas conchas podem ser utilizadas como fertilizantes calcáreos e ser agregadas a alimentos de animais domésticos e o nácar pode ser utilizado para fabricar botões e artesanatos. No entanto, as larvas de A. trapesialis, que são do tipo lasidium, são parasitas obrigatórias de peixes de água doce e a introdução desse bivalve em tanques de piscicultura tem causado transtornos e prejuízos aos produtores. Nada se conhece, porém, sobre o seu desenvolvimento nesses ambientes. Por outro lado, ressalta-se que A. trapesialis consta da lista brasileira de espécies ameaçadas de extinção. No presente artigo são compiladas as informações presentes na literatura, em uma revisão detalhada, com o objetivo de apresentar o panorama geral do

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.

Modiolarca lateralis (Pteryomorphia: Mytilidae: bivalve associated to six species of ascidians from Bocas del Toro, Panama

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Juan I Cañete

2013-11-01

Full Text Available We describe the presence of the bivalve Modiolarca lateralis (Say, 1822 in six tropical ascidians Ascidia curvata, A. sydneiensis, A. panamensis, A. interrupta, Herdmania pallida and Polycarpa spongiabilis collected at depths of 1-3 m on coral reefs, mangrove roots and dock supports in Almirante Bay, Bocas del Toro, Panama (9°18'N, 82°13'W during June-July 2011. Bivalve prevalence varied between 9-30% across species, but was mainly associated with A. panamensis, P. spongiabilis and A. interrupta. Prevalence seems to be influenced by tunic thickness rather than by the ascidian size. Bivalves varied in size (0.6-11 mm shell length, with the smallest individual found in A. sydneiensis. There were only one or two bivalves per ascidians, although a maximum of 18 was found in one A. panamensis. M. lateralis seems to behave similarly to its temperate counterparts: it has a variety of hosts, occurs mainly in the anterior region of the ascidians, and has a variable abundance per host.

Shell growth and environmental control of methanophyllic Thyasirid bivalves from Svalbard cold seeps

Science.gov (United States)

Carroll, Michael; Åström, Emmelie; Ambrose, William; Locke, William; Oliver, Graham; Hong, Wei-Li; Carroll, JoLynn

2016-04-01

The analysis of molluscan shell material (sclerochronology) can provide information about an organism's age, growth history, and environmental conditions during its lifetime. Bivalve molluscs are common members of hydrothermal vents and methane cold seeps communities where, supported by chemosynthetic symbionts, they can reach high density and biomass. But little is known about methane-associated bivalve populations inhabiting high-Arctic cold seeps, and sclerochronological analysis of methane-influenced bivalves is rare. We measured growth rates and elemental and isotopic shell signatures in a newly discovered species of bivalve (Thyasiridae) from cold seeps at 350-390m depth southwest of Svalbard. First discovered in 2014, recently described shells of Thyasira capitanea sp.nov. were found at 2 independent seep systems in Storfjordrenna. Mean shell carbon isotopic ratios from inorganic δ13C (mean = -4.8‰) and organic δ13C (mean = -26.9‰) fractions clearly indicate a methane influenced habitat and food source for these organisms. Shell mineral ratios (Li/Ca, Mg/Ca, Mn/Ca, Fe/Ca, Sr/Ca, Ba/Ca, Pb/Ca) sampled along the axis of growth with laser-ablated ICP-MS exhibit variability through time and between sites, suggesting that concentrations of these elements that may be affected by methane emissions. The mineralogical data also elucidates the internal pattern of shell deposition and growth checks, and combined with the isotopic and growth rate data, enables us to interpret the temporal history of methane release from these locations.

Influence of food on the assimilation of selected metals in tropical bivalves from the New Caledonia lagoon: Qualitative and quantitative aspects

International Nuclear Information System (INIS)

Hedouin, Laetitia; Metian, Marc; Lacoue-Labarthe, Thomas; Fichez, Renaud; Teyssie, Jean-Louis; Bustamante, Paco; Warnau, Michel

2010-01-01

The present study aimed at examining the influence of food quality and quantity on the assimilation efficiency (AE) of metals in two abundant bivalves in the New Caledonia lagoon, the oyster Isognomon isognomon and the clam Gafrarium tumidum. Bivalves were exposed via their food to the radiotracers of three metals of concern in New Caledonia ( 54 Mn, 57 Co and 65 Zn) under different feeding conditions (phytoplankton species, cell density, and cell-associated metal concentration). When bivalves were fed Heterocapsa triquetra, Emiliania huxleyi and Isochrysis galbana, AE of Mn, Co and Zn was strongly influenced by the phytoplankton species and by the metal considered. In contrast, when fed one given phytoplankton species previously exposed to different concentrations of Co, phytoplankton-associated Co load had no influence on the AE and on the retention time of the metal in both bivalves. Metals ingested with I. galbana displayed generally the highest AE in both bivalve species, except for Mn in clams for which the highest AE was observed for H. triquetra. Influence of food quantity was investigated by exposing bivalves to different cell densities of I. galbana (5 x 10 3 , 10 4 or 5 x 10 4 cell ml -1 ). As for food quality, food quantity was found to influence AE of Mn, Co and Zn, the highest AE being observed when bivalves were fed the lowest cell density. Overall, results indicate that the two bivalve species are able to adjust their feeding strategies according to the food conditions prevailing in their environment.

Congener-specific distribution and bioaccumulation of short-chain chlorinated paraffins in sediments and bivalves of the Bohai Sea, China.

Science.gov (United States)

Ma, Xindong; Chen, Chen; Zhang, Haijun; Gao, Yuan; Wang, Zhen; Yao, Ziwei; Chen, Jiping; Chen, Jingwen

2014-02-15

Short-chain chlorinated paraffins (SCCPs) are a new type of persistent organic pollutants that are of great environmental concern because of their wide distribution. In this study, surface sediments and bivalve samples were collected from the coastal area of the Bohai Sea in China. Total SCCP (ΣSCCP) concentrations in surface sediments and bivalves ranged from 97.4 ng g(-1) dry weight (dw) to 1756.7 ng g(-1) dw and 476.4-3269.5 ng g(-1) dw, respectively. C10-CPs and C11-CPs were the predominant homologue groups in all sediments and bivalves. Specific congener composition analysis and correspondence analysis indicated that the local SCCP source mainly came from CP-42 and CP-52 products, and riverine input had an important function. The biota-sediment accumulation factors of ΣSCCPs for bivalves ranged from 1.08 to 1.61, and a significant correlation indicated that the SCCP congener with higher chlorination degree was more likely to be accumulated in bivalves. Copyright © 2014. Published by Elsevier Ltd.

The reproductive cycle of the oyster Crassostrea gasar

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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.

Uncharted waters: Bivalves of midway atoll and integrating mathematics into biology education

Science.gov (United States)

McCully, Kristin M.

To protect and conserve the Earth's biodiversity and ecosystem services, it is important not only to understand and conserve species and ecosystems, but also to instill an understanding and appreciation for biodiversity and ecosystem services in the next generations of both scientists and citizens. Thus, this dissertation combines research into the ecology and identity of large bivalves at Midway Atoll in the Northwestern Hawaiian Islands (NWHI) with research on pedagogical strategies for integrating mathematics into undergraduate biology education. The NWHI is one of the few remaining large, mainly intact, predator-dominated coral reef ecosystems and one of the world's largest marine protected areas. Previous bivalve studies focused on the black-lipped pearl oyster, Pinctada margaritifera, which was heavily harvested in the late 1920s, has not recovered, and is now a candidate species for restoration. First, I combined remote sensing, geographic information systems, SCUBA, and mathematical modeling to quantify the abundance, spatial distributions, and filtration capacity of large epifaunal bivalves at Midway Atoll. These bivalves are most abundant on the forereef outside the atoll, but densities are much lower than reported on other reefs, and Midway's bivalves are unlikely to affect plankton abundance and productivity inside the lagoon. Second, I used molecular techniques and phylogenetic reconstructions to identify pearl oysters (Pinctada) from Midway Atoll as P. maculata , a species not previously reported in Hawaii. As a small morphologically cryptic species, P. maculata may be a native species that has not been collected previously, a native species that has been identified incorrectly as the morphologically similar P. radiata, or it may be a recent introduction or natural range extension from the western Pacific. Finally, I review science education literature integrating mathematics into undergraduate biology curricula, and then present and evaluate a

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...

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.

EU Regulatory Risk Management of Marine Biotoxins in the Marine Bivalve Mollusc Food-Chain.

Science.gov (United States)

O'Mahony, Micheál

2018-03-10

Food safety risk assessment in the European Union (EU) recognises consumer illness that arises from marine biotoxins as a risk associated with bivalve mollusc consumption. EU food regulations contain various general food safety obligations, which should contribute significantly to managing this risk. EU food regulations additionally impose various specific obligations on both Food Business Operators and Competent Authorities in order to manage the marine biotoxin food safety risk in the bivalve mollusc food-chain. These have a particular focus on the pre-harvest component of the food-chain. A central component of these specific systems is the requirement for ongoing monitoring of phytoplankton and biotoxin concentrations in water and molluscs, respectively. This monitoring explicitly brings a potential outcome of closing production areas delineated by classification to prohibit the harvest of bivalve molluscs as food from those areas when acceptable biotoxin concentrations are exceeded. This review considers the utility of these systems, at conceptual and practical levels, and explores their contribution to an effective regulatory risk management approach.

SHRIMP (CRANGON-CRANGON L) BROWSING UPON SIPHON TIPS INHIBITS FEEDING AND GROWTH IN THE BIVALVE MACOMA-BALTHICA (L)

NARCIS (Netherlands)

KAMERMANS, P; HUITEMA, HJ

1994-01-01

The influence of siphon browsing on the feeding behaviour and growth of Macoma balthica, a deposit-feeding bivalve, was studied in three manipulative experiments. Browsing was simulated by removing part of the inhalant siphon with scissors, or studied by exposing the bivalves to shrimps (Crangon

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...

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.

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

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....

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....

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...

Seasonal variability in somatic and reproductive investment of the bivalve

NARCIS (Netherlands)

Santos, S.; Cardoso, J.F.M.F.; Carvalho, C.; Luttikhuizen, P.C.; van der Veer, H.W.

2011-01-01

Monthly investment in soma and gonads in the bivalve Scrobicularia plana is described for three populations along its distributional range: Minho estuary, Portugal; Westerschelde estuary, The Netherlands and Buvika estuary, Norway. Seasonal cycles in body mass (BMI), somatic mass (SMI) and

Organisms associated with the sandy-beach bivalve Donax serra ...

African Journals Online (AJOL)

57: 134-136. BROWN, AC. & WEBB, S.c. 1994. Organisms associated \\.,.,ith burrowing whelks of the genus Bullia. S Afr. 1. Zool. 29: 144-151. BROWN, A.C., STENTON-DOZEY, J.~.E. & TRUEMAN, E.R.. 1989. Sandy-beach bivalves and gastropods; a comparison between Donax serra and Ruilia digitalis. Adv. mar. Bioi. 25:.

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.

Otimização do processo de depuração de moluscos bivalves

OpenAIRE

Correia, Maria Helena Oliveira Casimiro

2016-01-01

A contaminação microbiológica de moluscos bivalves constitui uma das principais preocupações inerentes à segurança alimentar desta importante fonte de receitas para a economia portuguesa. Os bivalves capturados ou produzidos em zonas estuarinas ou lagunares devem passar por um processo de depuração, para redução dos níveis de contaminação microbiológica, antes da sua comercialização. Este trabalho teve como principal objetivo o desenvolvimento de sistemas modulares de dep...

Phenology of abundance of bivalve spat and of their epibenthic predators: limited evidence for mismatches after cold winters

NARCIS (Netherlands)

Dekker, R.; Beukema, J.J.

2014-01-01

Annual recruitment of bivalves in the Wadden Sea is usually more successful in summers after cold than after mild winters. The new generation (0-group) of the main predators (shrimps and shore crabs) of early benthic stages of bivalves appear later in spring on tidal flats after colder winters. If

EU Regulatory Risk Management of Marine Biotoxins in the Marine Bivalve Mollusc Food-Chain

Directory of Open Access Journals (Sweden)

Micheál O’Mahony

2018-03-01

Full Text Available Food safety risk assessment in the European Union (EU recognises consumer illness that arises from marine biotoxins as a risk associated with bivalve mollusc consumption. EU food regulations contain various general food safety obligations, which should contribute significantly to managing this risk. EU food regulations additionally impose various specific obligations on both Food Business Operators and Competent Authorities in order to manage the marine biotoxin food safety risk in the bivalve mollusc food-chain. These have a particular focus on the pre-harvest component of the food-chain. A central component of these specific systems is the requirement for ongoing monitoring of phytoplankton and biotoxin concentrations in water and molluscs, respectively. This monitoring explicitly brings a potential outcome of closing production areas delineated by classification to prohibit the harvest of bivalve molluscs as food from those areas when acceptable biotoxin concentrations are exceeded. This review considers the utility of these systems, at conceptual and practical levels, and explores their contribution to an effective regulatory risk management approach.

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...

In situ method for measurements of community clearance rate on shallow water bivalve populations

DEFF Research Database (Denmark)

Hansen, Benni W.; Dolmer, Per; Vismann, Bent

2011-01-01

An open-top chamber was designed for measuring ambient community clearance rate on undisturbed bivalve populations in the field. The chamber was pressed 5-10 cm down in the sediment on the mussel bed. It holds approximately 30-40 cm water column equal to a volume of 43-77 L. It was provided...... with an air lift connected to a SCUBA diver pressure tank generating a continuous and gentle water circulation. This ensures a complete mixture of suspended particles, and thereby, a maximum filtration by the bivalves. An in situ fluorometer was mounted to record plant pigment reduction due to mussel...

Deciphering the link between doubly uniparental inheritance of mtDNA and sex determination in bivalves: Clues from comparative transcriptomics

Science.gov (United States)

Capt, Charlotte; Renaut, Sébastien; Ghiselli, Fabrizio; Milani, Liliana; Johnson, Nathan A.; Sietman, Bernard E.; Stewart, Donald; Breton, Sophie

2018-01-01

Bivalves exhibit an astonishing diversity of sexual systems and sex-determining mechanisms. They can be gonochoric, hermaphroditic or androgenetic, with both genetic and environmental factors known to determine or influence sex. One unique sex-determining system involving the mitochondrial genome has also been hypothesized to exist in bivalves with doubly uniparental inheritance (DUI) of mtDNA. However, the link between DUI and sex determination remains obscure. In this study, we performed a comparative gonad transcriptomics analysis for two DUI-possessing freshwater mussel species to better understand the mechanisms underlying sex determination and DUI in these bivalves. We used a BLAST reciprocal analysis to identify orthologs between Venustaconcha ellipsiformis and Utterbackia peninsularis and compared our results with previously published sex-specific bivalve transcriptomes to identify conserved sex-determining genes. We also compared our data with other DUI species to identify candidate genes possibly involved in the regulation of DUI. A total of ∼12,000 orthologous relationships were found, with 2,583 genes differentially expressed in both species. Among these genes, key sex-determining factors previously reported in vertebrates and in bivalves (e.g., Sry, Dmrt1, Foxl2) were identified, suggesting that some steps of the sex-determination pathway may be deeply conserved in metazoans. Our results also support the hypothesis that a modified ubiquitination mechanism could be responsible for the retention of the paternal mtDNA in male bivalves, and revealed that DNA methylation could also be involved in the regulation of DUI. Globally, our results suggest that sets of genes associated with sex determination and DUI are similar in distantly-related DUI species.

Thyasirid bivalves from Cretaceous and Paleogene cold seeps

Directory of Open Access Journals (Sweden)

Krzysztof Hryniewicz

2017-11-01

Full Text Available We present a systematic study of thyasirid bivalves from Cretaceous to Oligocene seep carbonates worldwide. Eleven species of thyasirid bivalves are identified belonging to three genera: Conchocele, Maorithyas, and Thyasira. Two species are new: Maorithyas humptulipsensis sp. nov. from middle Eocene seep carbonates in the Humptulips Formation, Washington State, USA, and Conchocele kiritachiensis sp. nov. from the late Eocene seep deposit at Kiritachi, Hokkaido, Japan. Two new combinations are provided: Conchocele townsendi (White, 1890 from Maastrichtian strata of the James Ross Basin, Antarctica, and Maorithyas folgeri (Wagner and Schilling, 1923 from Oligocene rocks from California, USA. Three species are left in open nomenclature. We show that thyasirids have Mesozoic origins and appear at seeps before appearing in “normal” marine environments. These data are interpreted as a record of seep origination of thyasirids, and their subsequent dispersal to non-seep environments. We discuss the age of origination of thyasirids in the context of the origin of the modern deep sea fauna and conclude that thyasirids could have deep sea origins. This hypothesis is supported by the observed lack of influence of the Cretaceous and Paleogene Oceanic Anoxic Events on the main evolutionary lineages of the thyasirids, as seen in several other members of the deep sea fauna.

Bivalve grazing, nutrient cycling and phytoplankton dynamics in an estuarine ecosystem

NARCIS (Netherlands)

Prins, T.C.

1996-01-01

This thesis has considered the impact of the suspension feeding bivalve Mytilusedulis on nutrient cycling and phytoplankton in an estuarine ecosystem. The research was started within the framework of an extensive research project with the

An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

NARCIS (Netherlands)

Filgueira, R.; Byron, C.J.; Comeau, L.A.; Jansen, H.M.; Smaal, A.C.

2015-01-01

The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities,

Labelling and Marketing of Bivalve and Gastropod Molluscs Retailed in Sardinia, Italy Between 2009 and 2013.

Science.gov (United States)

Meloni, Domenico

2015-05-28

The aim of the present survey was to investigate the correct enforcement of the Community rules on the labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013. A total of 1500 packages and labels for live bivalve and gastropod molluscs were considered. A total of 375 labels (25%) presented non-compliance concerning the wrong trade name and additional wrong or missing information. The highest percentage of anomalous labels has been detected in small-scale retail shops (35%) and open-air markets (25%) compared with the big retailing chains (20%). The 5% of packages were not in compliance with the European Community rules on packaging of bivalve and gastropod molluscs. The high percentage of non-compliance with the European regulations on labelling results is a strong limitation for the consumers and highlights the need to improve the control system about labelling of seafood products.

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.

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...

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)

Growth rates and geochemical proxies in Late Campanian bivalves - New insights from micro-X-ray Fluorescence mapping and numerical growth modelling

Science.gov (United States)

de Winter, Niels; Goderis, Steven; van Malderen, Stijn; Vanhaecke, Frank; Claeys, Philippe

2017-04-01

Understanding the Late Cretaceous greenhouse climate is of vital importance for understanding present and future climate change. While a lot of good work has been done to reconstruct climate in this interesting period, most paleoclimatic studies have focused on long-term climate change[1]. Alternatively, multi-proxy records from marine bivalves provide us with a unique opportunity to study past climate on a seasonal scale. However, previous fossil bivalve studies have reported ambiguous results with regard to the interpretation of trace element and stable isotope proxies in marine bivalve shells[2]. One major problem in the interpretation of such records is the bivalve's vital effect and the occurrence of disequilibrium fractionation during bivalve growth. Both these problems are linked to the annual growth cycle of marine bivalves, which introduces internal effects on the incorporation of isotopes and trace elements into the shell[3]. Understanding this growth cycle in extinct bivalves is therefore of great importance for the interpretation of seasonal proxy records in their shells. In this study, three different species of extinct Late Campanian bivalves (two rudist species and one oyster species) that were found in the same stratigraphic interval are studied. Micro-X-Ray Fluorescence line scanning and mapping of trace elements such as Mg, Sr, S and Zn, calibrated by LA-ICP-MS measurements, is combined with microdrilled stable carbon and oxygen isotope analysis on the well-preserved part of the shells. Data of this multi-proxy study is compared with results from a numerical growth model written in the open-source statistics package R[4] and based on annual growth increments observed in the shells and shell thickness. This growth model is used together with proxy data to reconstruct rates of trace element incorporation into the shell and to calculate the mass balance of stable oxygen and carbon isotopes. In order to achieve this goal, 2D mapping of bivalve shell

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.

The potential accumulation of polycyclic aromatic hydrocarbons in phytoplankton and bivalves in Can Gio coastal wetland, Vietnam.

Science.gov (United States)

Thuy, Hoang Thi Thanh; Loan, Tu Thi Cam; Phuong, Trinh Hong

2018-05-12

Polycyclic aromatic hydrocarbons (PAHs) are one of the most important classes of anthropogenic persistent organic contaminants in the marine environment. This review discusses a whole range of findings that address various aspects of the bioaccumulation of PAHs in two common marine biota (phytoplankton and bivalves) globally and especially for Can Gio coastal wetland, Vietnam. The published information and collected data on the bioconcentration and accumulation mechanisms of PAHs as well as implications for Can Gio coastal wetland are compiled for phytoplankton and bivalves. PAHs are still released to Can Gio coastal environments from various sources and then transported to coastal environments through various physical processes; they may enter marine food chains and be highly accumulated in phytoplankton and bivalves. Thus, PAHs' bioaccumulation should be considered as one important criterion to assess the water's quality, directly linked to human health due to seafood consumption. Ecologically, Can Gio coastal wetland plays an important role to the South Vietnam key economic zone. However, it is also an area of potential PAHs inputs. With the abundant phytoplankton and bivalves in Can Gio coastal wetland, the PAHs bioaccumulation in these biota is inevitably detected. Thus, further study on the bioavailability of these contaminants is urgently needed in order to mitigate their negative effects and protect the ecosystems.

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.

Wood-Boring Bivalves (Mollusca: Teredinidae, Pholadidae) of Pacific coast of Colombia

International Nuclear Information System (INIS)

Cantera K, Jaime R

2010-01-01

Twelve species of wood-boring bivalves, ten of the family Teredinidae and two of family Pholadidae were collected in mangroves at 6 locations of the Pacific coast of Colombia. This paper presents a brief escription of these species, including size, ecological notes and geographical distribution.

Labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013

Directory of Open Access Journals (Sweden)

Domenico Meloni

2015-06-01

Full Text Available The aim of the present survey was to investigate the correct enforcement of the Community rules on the labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013. A total of 1500 packages and labels for live bivalve and gastropod molluscs were considered. A total of 375 labels (25% presented non-compliance concerning the wrong trade name and additional wrong or missing information. The highest percentage of anomalous labels has been detected in small-scale retail shops (35% and open-air markets (25% compared with the big retailing chains (20%. The 5% of packages were not in compliance with the European Community rules on packaging of bivalve and gastropod molluscs. The high percentage of non-compliance with the European regulations on labelling results is a strong limitation for the consumers and highlights the need to improve the control system about labelling of seafood products.

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

Semi-automatic surface sediment sampling system - A prototype to be implemented in bivalve fishing surveys

Science.gov (United States)

Rufino, Marta M.; Baptista, Paulo; Pereira, Fábio; Gaspar, Miguel B.

2018-01-01

In the current work we propose a new method to sample surface sediment during bivalve fishing surveys. Fishing institutes all around the word carry out regular surveys with the aim of monitoring the stocks of commercial species. These surveys comprise often more than one hundred of sampling stations and cover large geographical areas. Although superficial sediment grain sizes are among the main drivers of benthic communities and provide crucial information for studies on coastal dynamics, overall there is a strong lack of this type of data, possibly, because traditional surface sediment sampling methods use grabs, that require considerable time and effort to be carried out on regular basis or on large areas. In face of these aspects, we developed an easy and un-expensive method to sample superficial sediments, during bivalve fisheries monitoring surveys, without increasing survey time or human resources. The method was successfully evaluated and validated during a typical bivalve survey carried out on the Northwest coast of Portugal, confirming that it had any interference with the survey objectives. Furthermore, the method was validated by collecting samples using a traditional Van Veen grabs (traditional method), which showed a similar grain size composition to the ones collected by the new method, on the same localities. We recommend that the procedure is implemented on regular bivalve fishing surveys, together with an image analysis system to analyse the collected samples. The new method will provide substantial quantity of data on surface sediment in coastal areas, using a non-expensive and efficient manner, with a high potential application in different fields of research.

Marine Bivalve Cellular Responses to Beta Blocker Exposures ...

Science.gov (United States)

β blockers are prescription drugs used for medical treatment of hypertension and arrhythmias. They prevent binding of agonists such as catecholamines to β adrenoceptors. In the absence of agonist induced activation of the receptor, adenylate cyclase is not activated which in turn limits cAMP production and protein kinase A activation, preventing increases in blood pressure and arrhythmias. After being taken therapeutically, commonly prescribed β blockers may make their way to coastal habitats via discharge from waste water treatment plants (WWTP) posing a potential risk to aquatic organisms. The aim of our research is to evaluate cellular responses of three commercially important marine bivalves - Eastern oysters, blue mussels and hard clams - upon exposure to two β blocker drugs, propranolol and metoprolol, and to find molecular initiating events (MIEs) indicative of the exposure. Bivalves were obtained from Narragansett Bay (Rhode Island, USA) and acclimated in the laboratory. Following acclimation, gills and hepatopancreas (HP) tissues were harvested and separately exposed to 0, 1, 10, 100 and 1000 ng/l of each drug. Tissues were bathed in 30 parts per thousand (ppt) filtered seawater, antibiotic mix, Leibovitz nutrient media, and the test drug. Exposures were conducted for 24 hours and samples were saved for cellular biomarker assays. A lysosomal destabilization assay, which is a marker of membrane damage, was also performed at the end of each exposure.

Distribution of organotin compounds in the bivalves of the Aegean Sea, Greece

NARCIS (Netherlands)

Chandrinou, S.; Pappas, K.; Nikolaou, A.; Stasinakis, A.S.; Wegener, J.W.M.; Alexandropoulos, Th.; Thomaidis, N.S.

2007-01-01

Five bivalve species - Mytilus galloprovinciallis (Mediterranean mussels), Venus gallina (stripped venus), Modiola barbatus L. (bearded horse mussels), Pecten jacobeus (scallops) and Callista chione (hard clams) - were collected from seven areas in Aegean Sea, Greece, between August 2001 and January

Adaptive morphologies and guild structure in a high-diversity bivalve fauna from an early Campanian rocky shore, Ivö Klack (Sweden)

DEFF Research Database (Denmark)

Sørensen, Anne Mehlin; Surlyk, Finn; Jagt, John W. M.

2012-01-01

habitats. Study of the functional morphology of bivalve shells and comparison with extant relatives has resulted in a subdivision of the fauna into seven guilds and five habitats. The bivalve fauna represents a withinhabitat, time-averaged assemblage to which none of the species was introduced from...

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...

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

Chemosynthetic bacteria found in bivalve species from mud volcanoes of the Gulf of Cadiz.

Science.gov (United States)

Rodrigues, Clara F; Webster, Gordon; Cunha, Marina R; Duperron, Sébastien; Weightman, Andrew J

2010-09-01

As in other cold seeps, the dominant bivalves in mud volcanoes (MV) from the Gulf of Cadiz are macrofauna belonging to the families Solemyidae (Acharax sp., Petrasma sp.), Lucinidae (Lucinoma sp.), Thyasiridae (Thyasira vulcolutre) and Mytilidae (Bathymodiolus mauritanicus). The delta(13)C values measured in solemyid, lucinid and thyasirid specimens support the hypothesis of thiotrophic nutrition, whereas isotopic signatures of B. mauritanicus suggest methanotrophic nutrition. The indication by stable isotope analysis that chemosynthetic bacteria make a substantial contribution to the nutrition of the bivalves led us to investigate their associated bacteria and their phylogenetic relationships based on comparative 16S rRNA gene sequence analysis. PCR-denaturing gradient gel electrophoresis analysis and cloning of bacterial 16S rRNA-encoding genes confirmed the presence of sulfide-oxidizing symbionts within gill tissues of many of the studied specimens. Phylogenetic analysis of bacterial 16S rRNA gene sequences demonstrated that most bacteria were related to known sulfide-oxidizing endosymbionts found in other deep-sea chemosynthetic environments, with the co-occurrence of methane-oxidizing symbionts in Bathymodiolus specimens. This study confirms the presence of several chemosynthetic bivalves in the Gulf of Cadiz and further highlights the importance of sulfide- and methane-oxidizing symbionts in the trophic ecology of macrobenthic communities in MV.

Distribution of DTHS3 satellite DNA across 12 bivalve species Eva ...

Indian Academy of Sciences (India)

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In this work, characterization of DTHS3 satellite DNA was further expanded within the Class. Bivalvia. Monomer variants of DTHS3 satDNA were compared in 12 bivalve species belonging to two different Subclasses, Heterodonta and Pteriomorphia. This satDNA, whose age is estimated to a minimum of 516 Ma, ...

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.

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.

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.

Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

Energy Technology Data Exchange (ETDEWEB)

Negri, Andrew [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia)]. E-mail: a.negri@aims.gov.au; Burns, Kathryn [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Boyle, Steve [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Brinkman, Diane [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Webster, Nicole [Australian Institute of Marine Science, PMB 3, Townsville, Qld (Australia); Biological Sciences, University of Canterbury, Christchurch (New Zealand)

2006-10-15

This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent. - Analyses of Antarctic marine sediments, bivalves and sponges revealed strong PAH, PCB and trace metal gradients in McMurdo Sound.

Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

International Nuclear Information System (INIS)

Negri, Andrew; Burns, Kathryn; Boyle, Steve; Brinkman, Diane; Webster, Nicole

2006-01-01

This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent. - Analyses of Antarctic marine sediments, bivalves and sponges revealed strong PAH, PCB and trace metal gradients in McMurdo Sound

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...

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

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

Availability of pearl producing marine bivalves in south-eastern coast of Bangladesh and culture potentialities

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Md Ataur Rahman

2015-12-01

Full Text Available The present study was conducted during September 2014 to July 2015 to identify the pearl bearing bivalves in south-eastern coast of Bangladesh and culture potentialities of marine oyster in captivity based on field investigation. A total of 7 pearl bearing bivalve species were identified in the coast with a salinity of 18-34 ppt, pH 8.1-8.3 and water depth ranged 0.2-2.0 meter in their habitat. From the collected bivalves, most abundant oyster species windowpane oyster, Placuna placenta (Linnaeus, 1758 was reared in fiber glass tanks with seawater for a period of 6 months. During rearing highest survival rate of 88% was observed in T1 with sandy and gravel substratum and lowest survival rate of 78% was found in T2 with muddy substratum. Average temperature and salinity were varied between 24 °C-25 °C and 21-26 ppt respectively. From the reared oyster, highest 54 nos. small pearls in the month of April and lowest 7 pearls in December from a single P. placenta were obtained. The study proved that pearls can be obtained from the marine oysters in captivity in Bangladesh, and this offers large scale culture potentialities in our coast.

Climate change and body size shift in Mediterranean bivalve assemblages: unexpected role of biological invasions.

Science.gov (United States)

Nawrot, Rafał; Albano, Paolo G; Chattopadhyay, Devapriya; Zuschin, Martin

2017-08-16

Body size is a synthetic functional trait determining many key ecosystem properties. Reduction in average body size has been suggested as one of the universal responses to global warming in aquatic ecosystems. Climate change, however, coincides with human-enhanced dispersal of alien species and can facilitate their establishment. We address effects of species introductions on the size structure of recipient communities using data on Red Sea bivalves entering the Mediterranean Sea through the Suez Canal. We show that the invasion leads to increase in median body size of the Mediterranean assemblage. Alien species are significantly larger than native Mediterranean bivalves, even though they represent a random subset of the Red Sea species with respect to body size. The observed patterns result primarily from the differences in the taxonomic composition and body-size distributions of the source and recipient species pools. In contrast to the expectations based on the general temperature-size relationships in marine ectotherms, continued warming of the Mediterranean Sea indirectly leads to an increase in the proportion of large-bodied species in bivalve assemblages by accelerating the entry and spread of tropical aliens. These results underscore complex interactions between changing climate and species invasions in driving functional shifts in marine ecosystems. © 2017 The Author(s).

Comparative sensitivity of European native (Anodonta anatina) and exotic (Corbicula fluminea) bivalves to mercury

Science.gov (United States)

Oliveira, Patrícia; Lopes-Lima, Manuel; Machado, Jorge; Guilhermino, Lúcia

2015-12-01

Pollution is believed to be an important factor modulating the competition between exotic invasive bivalves and their native competitors. Thus, the objective of the present study was to compare the sensitivity of the European native Anodonta anatina and the exotic invasive species Corbicula fluminea to mercury, a ubiquitous environmental contaminant of high concern. In laboratory acute bioassays, adult organisms of both species were exposed independently to mercury for 96 h (31-500 μg/L). The criteria indicative of toxicity were mortality and biomarkers of oxidative stress and damage, neurotoxicity, and energy production changes. Mercury induced mortality in A. anatina (72 h-LC10 and 72 h-LC50 of 14.0 μg/L and 49.6 μg/L, respectively) but not in C. fluminea. The ability of C. fluminea to maintaining the shell closed for considerable periods of time when exposed to high concentrations of mercury and the effective activation (up to 63 μg/L) of mechanisms against the oxidative stress caused by mercury may have contributed to its relatively low sensitivity. In the range of concentrations tested, mercury had no significant effects on the other parameters analysed in C. fluminea. Overall, the findings of the present study, suggest that in real scenarios of competition between C. fluminea and A. anatina populations, the presence of mercury may modulate the process, acting in favour of the exotic species because it is less sensitive to this environmental contaminant than the native bivalve. The results of the present study highlight the need of further investigation on the effects of mercury on the competition between exotic invasive species and their native competitors, especially the effects potentially induced by long-term exposure to low concentrations of this metal, the mechanisms involved in the tolerance to mercury-induced stress, and the potential post-exposure recovery of both exotic invasive and native bivalves. This knowledge is most important for

Ecology of megabenthic bivalve communities from sandy beaches on the south coast of Portugal

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Marta M. Rufino

2010-03-01

Full Text Available Ecological aspects of 75 megabenthic bivalve species found on the south coast of Portugal (from Vila Real to Sagres were studied based on the information provided by seasonal bivalve surveys from 2000 to 2007 (8600 hauls, simultaneously using a razor shell dredge and a clam dredge. Of the 75 species identified, 36 occurred less than 30 times, and thus were considered rare in the area. The remaining 39 bivalves were analysed according to their occurrence, bathymetric distribution, geographic preferences, seasonal preferences, burying-depth, beach exposure and river mouth proximity. All species belonging to the Pharidae and Solenidae families (razor shells and most Tellinidae were significantly more frequent in the razor shell dredge (indicating deeper burying in the sediment, whilst the families Cardiidae and Donacidae were significantly more frequent in the clam dredge (indicating that these species are probably closer to the sediment surface. As for the season, most bivalve species occurred similarly in both seasons (19 sp; 49%, but a large proportion were more abundant during the autumn surveys (17 sp., 44%, whereas only three species were commoner during the spring surveys. Most species belonging to the families Cardiidae and Mactridae were commoner in the autumn surveys. The spatial distribution differed between species and cluster analysis identified four communities with greater geographic affinity. Species belonging to the family Cardiidae were preferably found in the western part (WB and the eastern part (S of the study area, whereas the families Donacidae, Mactridae and Tellinidae occurred mainly in the central area (EB and the eastern (S coastal sectors. Overall, shallower species (modal depth at 3-6 m showed greater occurrences and abundances than the deeper ones, and the depth pattern observed did not change between seasons. Donacidae and Mactridae (except Mactra glauca were represented essentially by shallow species, whereas

Molecular and Biochemical Methods Useful for the Epigenetic Characterization of Chromatin-Associated Proteins in Bivalve Molluscs

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Ciro Rivera-Casas

2017-08-01

Full Text Available Bivalve molluscs constitute a ubiquitous taxonomic group playing key functions in virtually all ecosystems, and encompassing critical commercial relevance. Along with a sessile and filter-feeding lifestyle in most cases, these characteristics make bivalves model sentinel organisms routinely used for environmental monitoring studies in aquatic habitats. The study of epigenetic mechanisms linking environmental exposure and specific physiological responses (i.e., environmental epigenetics stands out as a very innovative monitoring strategy, given the role of epigenetic modifications in acclimatization and adaptation. Furthermore, the heritable nature of many of those modifications constitutes a very promising avenue to explore the applicability of epigenetic conditioning and selection in management and restoration strategies. Chromatin provides a framework for the study of environmental epigenetic responses. Unfortunately, chromatin and epigenetic information are very limited in most non-traditional model organisms and even completely lacking in most environmentally and ecologically relevant organisms. The present work aims to provide a comprehensive and reproducible experimental workflow for the study of bivalve chromatin. First, a series of guidelines for the molecular isolation of genes encoding chromatin-associated proteins is provided, including information on primers suitable for conventional PCR, Rapid Amplification of cDNA Ends (RACE, genome walking and quantitative PCR (qPCR experiments. This section is followed by the description of methods specifically developed for the analysis of histone and SNBP proteins in different bivalve tissues, including protein extraction, purification, separation and immunodetection. Lastly, information about available antibodies, their specificity and performance is also provided. The tools and protocols described here complement current epigenetic analyses (usually limited to DNA methylation by incorporating

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

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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.

Light indirectly mediates bivalve habitat modification and impacts on seagrass

DEFF Research Database (Denmark)

Castorani, Max C. N.; Glud, Ronnie; Hasler-Sheetal, Harald

2015-01-01

Environmental context may influence the sign, strength, andmechanisms of species interactions but few studies have experimentally tested the potential for abiotic conditions to mediate interactions through multiple cooccurring stress pathways. Abiotic conditionsmay mediate species interactions...... by directly or indirectly influencing the effects of habitat-modifying organisms that are capable of simultaneously ameliorating and exacerbating multiple stressors. Itwas hypothesized that light availability changes seagrassmetabolismand thereby indirectly regulates bivalve habitat modification...

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...

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

A checklist of malacofauna of the Vellar Estuarine Mangroves, India

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K. Kesavan

2009-07-01

Full Text Available A survey conducted to know the diversity of malacofauna in Vellar estuarine mangroves (southeast coast of India. In this study, 13 species of molluscs (10 species of gastropods - Melampus ceylonicus, Cerithidea cingulata, Cassidula nucleus, Pythia plicata, Neritina (Dostia violacea, Littorina scabra, Littorina melanostoma, Ellobium aurisjudae, C. obtusa T. telescopium and Assiminea nitida and 3 species of bivalves - Perna viridis, Crassostrea madrasensis and Modiolus metcalfei were recorded. M. pulchella, C. obtusa, L. scabra and N. violacea were found arboreal. T. telescopium, C. cingulata and E. aurisjudae were found crawling on the intertidal mud.

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.

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...

An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

DEFF Research Database (Denmark)

Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche

2012-01-01

for bivalve aquaculture be based on a tiered indicator monitoring system that is structured on the principle that increased environmental risk requires increased monitoring effort. More than 1 threshold for each indicator would permit implementation of predetermined impact prevention and mitigation measures......An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social...... and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture–environment interactions and policy-related developments and decisions. The Drivers-Pressures-State Change-Impact-Response...

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...

Cellular Responses to Beta Blocker Exposures in Marine ...

Science.gov (United States)

β blockers are prescription drugs used for medical treatment of hypertension and arrhythmias. They prevent activation of adenylate cyclase and increases in blood pressure by limiting cAMP production and protein kinase A activation. After being taken therapeutically, β blockers may make their way to coastal habitats via discharge from waste water treatment plants, posing a potential risk to aquatic organisms. The aim of our research is to evaluate cellular biomarkers of β blocker exposure using two drugs, propranolol and metoprolol, in three commercially important marine bivalves -Crassostrea virginica, Mytilus edulis and Mercenaria mercenaria. Bivalves were obtained from Narragansett Bay (Rhode Island, USA) and acclimated in the laboratory. Following acclimation, gills and hepatopancreas tissues were harvested and separately exposed to 0, 1, 10, 100 and 1000 ng/l of each drug for 24 hours. Samples were preserved for cellular biomarker assays. Elevated cellular damage and changes in enzymatic activities were noted at environmentally relevant concentrations, and M. mercenaria was found to be the most sensitive bivalve out of the three species tested. These studies enhance our understanding of the potential impacts of commonly used prescription medication on organisms in coastal ecosystems, and demonstrate that filter feeders such as marine bivalves may serve as good model organisms to examine the effects of water soluble drugs. Evaluating a suite of biomarkers

Ocean acidification increases cadmium accumulation in marine bivalves: a potential threat to seafood safety.

Science.gov (United States)

Shi, Wei; Zhao, Xinguo; Han, Yu; Che, Zhumei; Chai, Xueliang; Liu, Guangxu

2016-01-21

To date, the effects of ocean acidification on toxic metals accumulation and the underlying molecular mechanism remains unknown in marine bivalve species. In the present study, the effects of the realistic future ocean pCO2 levels on the cadmium (Cd) accumulation in the gills, mantle and adductor muscles of three bivalve species, Mytilus edulis, Tegillarca granosa, and Meretrix meretrix, were investigated. The results obtained suggested that all species tested accumulated significantly higher Cd (p ocean acidification-induced increase in Cd accumulation may have occurred due to (i) the ocean acidification increased the concentration of Cd and the Cd(2+)/Ca(2+) in the seawater, which in turn increased the Cd influx through Ca channel; (ii) the acidified seawater may have brought about epithelia damage, resulting in easier Cd penetration; and (iii) ocean acidification hampered Cd exclusion.

Characterizing Photosymbiosis Between Fraginae Bivalves and Symbiodinium Using Phylogenetics and Stable Isotopes

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Jingchun Li

2018-04-01

Full Text Available Photosymbiotic associations between heterotrophic hosts and photosynthetic algae play crucial roles in maintaining the trophic and structural integrity of coral reef ecosystems. The marine bivalve subfamily Fraginae contains both non-symbiotic and photosymbiotic lineages, making it an ideal comparative system to study the origin and evolutionary adaptations of photosymbiosis. The symbiotic species exhibit unique morphological adaptations to photosymbiosis. However, the basic biology of these photosymbiotic relationships, such as symbiont diversity and nutritional benefits, has not been thoroughly characterized. In this study, we examined the general morphology of four Fraginae species occupying different depths (0–10 m: Corculum cardissa, Fragum fragum, Fragum scruposum, and Fragum sueziense. Abundant symbionts were found in the mantle, gill, and part of the foot, contained in tubular networks within host tissues. We used molecular phylogenetics to investigate the algal symbiont community of these Fraginae species. Results showed that symbionts from all four species are dinoflagellates belonging to the Symbiodinium clade C and we did not detect any host-specific or geographic-specific genetic structures within the symbionts. We also used stable carbon isotope analyses to examine whether the cockles are directly utilizing photosynthetically derived carbon sources. All species show less depleted 13C compared to filter-feeding bivalves, suggesting at least part of their organic carbon is derived directly from the symbionts. However, 13C depletion of Fragum sueziense collected from deeper habitats are less distinguishable from filter-feeding bivalves. This indicates that species in deeper habitats may rely less on photosymbiosis due to the reduced light availability. Given that the symbiotic fragines exhibit varying morphologies, habitats, and utilization of symbiont photosynthesis, the subfamily represents an ideal model system to study

High pressure processing of bivalve shellfish and HPP's potential use as a virus intervention

Science.gov (United States)

Bivalve shellfish readily bioconcentrate pathogenic microbes and substance, such as algal and dinoflagulate toxins, fecal viruses and bacteria, and naturally present vibrio bacteria. High pressure processing (HPP) is currently used as an intervention for Vibrio vulnificus bacteria within molluscan ...

Dinophysis caudata generated lipophilic shellfish toxins in bivalves from the Nanji Islands, East China Sea

Science.gov (United States)

Jiang, Tao; Xu, Yixiao; Li, Yang; Qi, Yuzao; Jiang, Tianjiu; Wu, Feng; Zhang, Fan

2014-01-01

A 12-month program of monitoring potentially toxic microalgae (that produce lipophilic shellfish toxins; LSTs) and their toxins in bivalves was conducted from April 2006 to March 2007 in the Nanji Islands, East China Sea. Two Dinophysis species, D. caudata and D. acuminata, were identified, and D. caudata was found to be the dominant species. D. caudata was detected in water samples between April and June 2006, and between February and March 2007. It reached its highest abundances in May, with a mean abundance of 1.38×102 cells/L in surface water and 1.25×102 cells/L in bottom water (cultured bivalves sampled between April and June were contaminated with LSTs, with an average toxicity of 85 μg okadaic acid (OA) eq./100 g meat, which was four times higher than the Chinese regulatory limit (20 μg OA eq./100 g meat). Ten out of fifteen wild samples (66.7%) collected during the same period were positive for LSTs, and contained an average LST toxicity of 45 μg OA eq./100 g meat (more than twice the regulatory value). Cultured Patinopecten yessoensis collected on 15 May 2006 had the highest toxicity, 320 μg OA eq./100 g meat, and relatively high toxicities (80 to 160 μg OA eq./100 g meat) were found in bivalves until the end of July.

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...

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...

Biochemical and behavioural responses of the endobenthic bivalve Scrobicularia plana to silver nanoparticles in seawater and microalgal food.

Science.gov (United States)

Buffet, Pierre-Emmanuel; Pan, Jin-Fen; Poirier, Laurence; Amiard-Triquet, Claude; Amiard, Jean-Claude; Gaudin, Pierre; Risso-de Faverney, Christine; Guibbolini, Marielle; Gilliland, Douglas; Valsami-Jones, Eugenia; Mouneyrac, Catherine

2013-03-01

Because of their bactericidal effects, Ag nanoparticles (Ag NPs) have promising industrial development but could lead to potential ecological risks. The aim of this study was to examine the uptake and effect of silver (soluble or as lactate Ag NPs of 40 nm) at low concentrations (10 μg L(-1)) in the endobenthic bivalve Scrobicularia plana exposed, for 14 days, directly (water) or via the diet (microalgae). The stability of Ag NPs in seawater was examined using dynamic light scattering. Release of soluble Ag from Ag NPs in the experimental media was quantified by using diffusive gradient in thin film. Bioaccumulation of Ag in bivalves was measured by electrothermal atomic absorption spectrometry. Behavioural and biochemical biomarkers were determined in bivalves. Aggregation of Ag NPs and the release of soluble Ag from Ag NPs were observed in the experimental media. For both forms of Ag, bioaccumulation was much more important for waterborne than for dietary exposure. The response of oxidative stress biomarkers (catalase, glutathion S-transferase, superoxide dismutase) was more important after dietary than waterborne exposure to Ag (soluble and NPs). These defences were relatively efficient since they led to a lack of response of damage biomarkers. Burrowing was not affected for bivalves exposed directly or through the diet to both Ag forms but feeding behaviour was impaired after 10 days of dietary exposure. Since no differences of responses to Ag either soluble or nanoparticulate were observed, it seems that labile Ag released from Ag NPs was mainly responsible for toxicity. Copyright © 2012 Elsevier Inc. All rights reserved.

Assessment of Heavy Metals in Bivalves Molluscs of Apulian Region: a 3-years control activity of a EU Laboratory

Directory of Open Access Journals (Sweden)

Miedico O.

2013-04-01

Full Text Available The bivalve molluscs represent an important matrix to be studied for several reasons. Their nutritional properties make them valuable to the consumers, so that their consumption and commercial value has risen worldwide. Simultaneously, their significant water-filtering capability and their persistence in the same place make them good bio-indicators of marine ecosystems. The presence of the heavy metal contaminants, as Cd, Pb and Hg, was investigated in bivalve molluscs such as mussels (Mytilus galloprovincialis, clams (Venus gallina and oysters (Ostrea edulis. In the present study, a survey was carried out on 334 samples addressed to the Istituto Zooprofilattico Sperimentale – Puglia e Basilicata, Foggia (ITALY between 2009-2011, and collected by official authorities along the coasts of Apulia Region. The conformity of heavy metal content in bivalve molluscs was verified, in according to EC Reg. 1881/2006. The compliance was found for the total amount of samples. The obtained data on heavy metals concentration in bivalve molluscs were compared with data found in monitoring studies on the incidence of heavy metals in 1981 in North-Western Mediterranean Sea, in 2003 in Tyrrhenian Sea and in 2010 in Pacific Ocean (Chile, reported in literature. The information obtained from this work offer an essential database, not only for the authorities involved in food control, but also for the official institutions responsible of a constant control of the marine ecosystem pollution.

[Nutrition and biological value of food parts of a trade bivalve mollusk Anadara broughtoni].

Science.gov (United States)

Tabakaeva, O V; Tabakaev, A V

2015-01-01

Currently, the human diet includes different new products of seafishing, including non-fish--bivalves and gastropods, holothurias, echinoderms, jellyfishes that demands careful studying of their chemical composition. The purpose of the study was to determine the nutritional and biological value of all soft parts of the burrowing bivalve MOLLUSK Anadara broughtoni from the Far East region. It was established thatfood parts of a bivalve were significantly flooded (water content--73.5-84.2%), with the minimum water content in the adductor and maximum in the mantle. Dry solids are presented by organic (89-93%) and mineral (7-11%) components. Organic components consist of protein (14.6-20.7%), lipids (1.8-2.3%), carbohydrates (2.1-2.6%). The analysis of amino-acid composition of proteins of food parts of the mollusk of Anadara broughtonishowed the presence of all essential amino acids with slight differences in their content depending on the localization of the protein. All edible parts have tryptophan as the limiting amino acid. Muscle proteins have maximum level of lysine, methionine, cysteine, phenylalanine and tyrosine; mantle proteins--leucine, isoleucine and threonine; adductor proteins--valine, phenylalanine, tyrosine, methionine and cysteine. Predominant nonessential amino acids forproteins of all food pieces are glycine, aspartic acid, glutamic acid, arginine. The coefficient of amino-acid score differences of adductor protein (31.7%) is less than the same of cloak by 3.7%. The indicator "biological value" is maximal for adductor (68.3%), but the differenceformuscle is only 0.83%. Mantle proteins are characterized by minimum biological value (64.6%). The coefficient of utility of amino acid composition of protein is maximalfor muscle (57.83%), and values for a cloak and an adductor differ slightly (55.81 and 55.96%). Taurine content in food parts of a mollusk Anadara broughtoni is rather high compared to with other bivalve mollusks of the Far East region

Evaluation of the threat of marine CO2 leakage-associated acidification on the toxicity of sediment metals to juvenile bivalves

International Nuclear Information System (INIS)

Basallote, M. Dolores; Rodríguez-Romero, Araceli; De Orte, Manoela R.; Del Valls, T. Ángel; Riba, Inmaculada

2015-01-01

Highlights: • Short-term tests using juveniles of bivalves to study the effects of CO 2 dissolved. • CO 2 causes effects if the threshold concentration of the organism is overlapped. • Flows of escaped CO 2 would affect the geochemical composition of sediment–seawater. • CO 2 -induced acidification would affect differently to marine sediment toxicity. - Abstract: The effects of the acidification associated with CO 2 leakage from sub-seabed geological storage was studied by the evaluation of the short-term effects of CO 2 -induced acidification on juveniles of the bivalve Ruditapes philippinarum. Laboratory scale experiments were performed using a CO 2 -bubbling system designed to conduct ecotoxicological assays. The organisms were exposed for 10 days to elutriates of sediments collected in different littoral areas that were subjected to various pH treatments (pH 7.1, 6.6, 6.1). The acute pH-associated effects on the bivalves were observed, and the dissolved metals in the elutriates were measured. The median toxic effect pH was calculated, which ranged from 6.33 to 6.45. The amount of dissolved Zn in the sediment elutriates increased in parallel with the pH reductions and was correlated with the proton concentrations. The pH, the pCO 2 and the dissolved metal concentrations (Zn and Fe) were linked with the mortality of the exposed bivalves

Burrowing Behavior of a Deposit Feeding Bivalve Predicts Change in Intertidal Ecosystem State

NARCIS (Netherlands)

Compton, T.J.; Bodnar, W.; Koolhaas, A.; Dekinga, A.; Holthuijsen, S.; Ten Horn, J.; McSweeney, N.; van Gils, J.A.; Piersma, T.

2016-01-01

Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is

Burrowing behavior of a deposit feeding bivalve predicts change in intertidal ecosystem state

NARCIS (Netherlands)

Compton, Tanya J.; Bodnar, Wanda; Koolhaas, Anita; Dekinga, Anne; Holthuijsen, Sander; ten Horn, Job; McSweeney, Niamh; van Gils, Jan; Piersma, Theunis

2016-01-01

Behavior has a predictive power that is often underutilized as a tool for signaling ecological change. The burrowing behavior of the deposit feeding bivalve Macoma balthica reflects a typical food-safety trade-off. The choice to live close to the sediment surface comes at a risk of predation and is

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...

Chemosymbiotic bivalves from the mud volcanoes of the Gulf of Cadiz, NE Atlantic, with descriptions of new species of Solemyidae, Lucinidae and Vesicomyidae.

Science.gov (United States)

Olive, Graham; Rodrigues, Clara F; Cunha, Marina R

2011-01-01

The chemosymbiotic bivalves collected from the mud volcanoes of the Gulf of Cadiz are reviewed. Of the thirteen species closely associated with chemosynthetic settings two Solemyidae, Solemya (Petrasma) elarraichensissp. n. and Acharax gadiraesp. n., one Lucinidae, Lucinoma asapheussp. n., and one Vesicomyidae, Isorropodon megadesmussp. n. are described and compared to close relatives of their respective families. The biodiversity and distribution of the chemosymbiotic bivalves in the Gulf of Cadiz are discussed and compared to the available information from other cold seeps in the Eastern Atlantic and Mediterranean. Although there is considerable similarity at the genus level between seep/mud volcano fields in the Eastern Atlantic and Mediterranean, there is little overlap at the species level. This indicates a high degree of endemism within chemosymbiotic bivalve assemblages.

Zoochorous dispersal of freshwater bivalves: an overlooked vector in biological invasions?

Directory of Open Access Journals (Sweden)

Coughlan Neil E.

2017-01-01

Full Text Available Vectors that underpin the natural dispersal of invasive alien species are frequently unknown. In particular, the passive dispersal (zoochory of one organism (or propagule by another, usually more mobile animal, remains poorly understood. Field observations of the adherence of invasive freshwater bivalves to other organisms have prompted us to assess the importance of zoochory in the spread of three prolific invaders: zebra mussel Dreissena polymorpha; quagga mussel Dreissena bugensis; and Asian clam Corbicula fluminea. An extensive, systematic search of the literature was conducted across multiple on-line scientific databases using various search terms and associated synonyms. In total, only five publications fully satisfied the search criteria. It appears that some fish species can internally transport viable adult D. polymorpha and C. fluminea specimens. Additionally, literature indicates that veligers and juvenile D. polymorpha can adhere to the external surfaces of waterbirds. Overall, literature suggests that zoochorous dispersal of invasive bivalves is possible, but likely a rare occurrence. However, even the establishment of a few individuals (or a single self-fertilising C. fluminea specimen can, over-time, result in a substantial population. Here, we highlight knowledge gaps, identify realistic opportunities for data collection, and suggest management protocols to mitigate the spread of invasive alien species.

Subcellular partitioning of cadmium in the freshwater bivalve, Pyganodon grandis, after separate short-term exposures to waterborne or diet-borne metal

Energy Technology Data Exchange (ETDEWEB)

Cooper, Sophie; Hare, Landis [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada)

2010-11-15

The dynamics of cadmium uptake and subcellular partitioning were studied in laboratory experiments conducted on Pyganodon grandis, a freshwater unionid bivalve that shows promise as a biomonitor for metal pollution. Bivalves were collected from an uncontaminated lake, allowed to acclimate to laboratory conditions ({>=}25 days), and then either exposed to a low, environmentally relevant, concentration of dissolved Cd (5 nM; 6, 12 and 24 h), or fed Cd-contaminated algae ({approx}70 nmol Cd g{sup -1} dry weight; 4 x 4 h). In this latter case, the bivalves were allowed to depurate for up to 8 days after the end of the feeding phase. As anticipated, the gills were the main target organ during the aqueous Cd exposure whereas the intestine was the initial site of Cd accumulation during the dietary exposure; during the subsequent depuration period, the dietary Cd accumulated in both the digestive gland and in the gills. For the gills, the distribution of Cd among the subcellular fractions (i.e., granules > heat-denatured proteins (HDP) {approx} heat-stable proteins (HSP) > mitochondria {approx} lysosomes + microsomes) was insensitive to the exposure route; both waterborne and diet-borne Cd ended up largely bound to the granule fraction. The subcellular distribution of Cd in the digestive gland differed markedly from that in the gills (HDP > HSP {approx} granules {approx} mitochondria > lysosomes + microsomes), but as in the case of the gills, this distribution was relatively insensitive to the exposure route. For both the gills and the digestive gland, the subcellular distributions of Cd differed from those observed in native bivalves that are chronically exposed to Cd in the field - in the short-term experimental exposures of P. grandis, metal detoxification was less effective than in chronically exposed native bivalves.

Impact of seawater carbonate chemistry on the calcification of marine bivalves

OpenAIRE

Thomsen Jörn; Haynert Kristin; Wegner K Mathias; Melzner Frank

2015-01-01

Bivalve calcification, particular of the early larval stages is highly sensitive to the change of ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32−] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the e...

Reproductive investment in the intertidal bivalve Macoma balthica

Science.gov (United States)

Honkoop, P. J. C.; Van der Meer, J.; Beukema, J. J.; Kwast, D.

1999-05-01

Bivalve eggs generally contain large amounts of lipids which, in comparison with proteins and carbohydrates, have high energy contents and are thus costly in energetic terms. As lipid contents vary between species, comparisons of reproductive investments should not only include numbers and sizes of eggs, but also their energy content. We estimated the investment in egg material of mature females of the Baltic tellin Macoma balthica (L.) in terms of both mass and energy content. All mass below a minimum body mass (below which no eggs are produced) was defined as structural mass. This threshold amounts to a body mass index (BMI) of 5.6 (ash-free dry mass per cubic shell length in mg cm -3). More than half (55%) of the mass above the structural mass was invested in egg material and 45% in extra somatic tissue and tissue for production and storage of gametes. This means that the amount of eggs spawned ranged from 0 (at BMI = 5.6 mg cm -3) to 33% of the total ash-free dry mass (at a high BMI value of 14 mg cm -3). Eggs contained a relatively large amount of lipids, about 30% of their ash-free dry mass, whereas non-egg material contained only about 7% lipids. Eggs of two other bivalves in the Wadden Sea, the cockle Cerastoderma edule and the mussel Mytilus edulis, were smaller and contained only about 11% and 20% lipids, respectively. Energy content of M. balthica eggs amounted to ˜0.006 J, in the other two species to ˜0.002 J. The function of the more expensive eggs in M. balthica may be related to its early spawning in spring, causing slower larval development until first feeding.

Predation on intertidal mussels: Influence of biotic factors on the survival of epibenthic bivalve beds

NARCIS (Netherlands)

Waser, A.M.

2018-01-01

Coastal areas are amongst the most productive ecosystems in the world. Important components of these coastal areas are reef-forming bivalves such as mussels and oysters, as they have important facilitating effects on many associated organisms through the provision of substratum,

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.

Sodium provides unique insights into transgenerational effects of ocean acidification on bivalve shell formation.

Science.gov (United States)

Zhao, Liqiang; Schöne, Bernd R; Mertz-Kraus, Regina; Yang, Feng

2017-01-15

Ocean acidification is likely to have profound impacts on marine bivalves, especially on their early life stages. Therefore, it is imperative to know whether and to what extent bivalves will be able to acclimate or adapt to an acidifying ocean over multiple generations. Here, we show that reduced seawater pH projected for the end of this century (i.e., pH7.7) led to a significant decrease of shell production of newly settled juvenile Manila clams, Ruditapes philippinarum. However, juveniles from parents exposed to low pH grew significantly faster than those from parents grown at ambient pH, exhibiting a rapid transgenerational acclimation to an acidic environment. The sodium composition of the shells may shed new light on the mechanisms responsible for beneficial transgenerational acclimation. Irrespective of parental exposure, the amount of Na incorporated into shells increased with decreasing pH, implying active removal of excessive protons through the Na + /H + exchanger which is known to depend on the Na + gradient actively built up by the Na + /K + -ATPase as a driving force. However, the shells with a prior history of transgenerational exposure to low pH recorded significantly lower amounts of Na than those with no history of acidic exposure. It therefore seems very likely that the clams may implement less costly and more ATP-efficient ion regulatory mechanisms to maintain pH homeostasis in the calcifying fluid following transgenerational acclimation. Our results suggest that marine bivalves may have a greater capacity to acclimate or adapt to ocean acidification by the end of this century than currently understood. Copyright © 2016 Elsevier B.V. All rights reserved.

An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

NARCIS (Netherlands)

Cranford, P.J.; Kamermans, P.; Krause, G.H.M.; Mazurie, J.

2012-01-01

An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social and

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...

Evaluation of the threat of marine CO{sub 2} leakage-associated acidification on the toxicity of sediment metals to juvenile bivalves

Energy Technology Data Exchange (ETDEWEB)

Basallote, M. Dolores, E-mail: dolores.basallote@uca.es [Cátedra UNESCO/UNITWIN WiCop, Departamento de Química-Física, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz (Spain); Rodríguez-Romero, Araceli [Departamento de Ecología y Gestión Costera, Instituto de Ciencias Marinas de Andalucía (CSIC), Campus Río San Pedro, 11510 Puerto Real, Cádiz (Spain); De Orte, Manoela R.; Del Valls, T. Ángel; Riba, Inmaculada [Cátedra UNESCO/UNITWIN WiCop, Departamento de Química-Física, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Polígono Río San Pedro s/n, 11510 Puerto Real, Cádiz (Spain)

2015-09-15

Highlights: • Short-term tests using juveniles of bivalves to study the effects of CO{sub 2} dissolved. • CO{sub 2} causes effects if the threshold concentration of the organism is overlapped. • Flows of escaped CO{sub 2} would affect the geochemical composition of sediment–seawater. • CO{sub 2}-induced acidification would affect differently to marine sediment toxicity. - Abstract: The effects of the acidification associated with CO{sub 2} leakage from sub-seabed geological storage was studied by the evaluation of the short-term effects of CO{sub 2}-induced acidification on juveniles of the bivalve Ruditapes philippinarum. Laboratory scale experiments were performed using a CO{sub 2}-bubbling system designed to conduct ecotoxicological assays. The organisms were exposed for 10 days to elutriates of sediments collected in different littoral areas that were subjected to various pH treatments (pH 7.1, 6.6, 6.1). The acute pH-associated effects on the bivalves were observed, and the dissolved metals in the elutriates were measured. The median toxic effect pH was calculated, which ranged from 6.33 to 6.45. The amount of dissolved Zn in the sediment elutriates increased in parallel with the pH reductions and was correlated with the proton concentrations. The pH, the pCO{sub 2} and the dissolved metal concentrations (Zn and Fe) were linked with the mortality of the exposed bivalves.

Element availability of bivalve with symbiotic zooxanthellae in coral sea area as studied by multielement profiling analysis

Science.gov (United States)

Itoh, A.; Kabe, N.

2008-12-01

In coral sea, a characteristic ecosystem is formed by many kinds of marine animals and plants, although seawater is uneutrophic. This may be explained by the fact that various chemical species with bioessentiality are effectively taken and used by lower animals and plants in coral sea area. A symbiotic relationship often found among different animals and plants in this area is considered to be working as one of such processes. However, the specific bioavailability of the elements for the marine animals and plants in coral reef area has not been studied from the viewpoints of trace and ultratrace elements. It is found by the present authors that bivalve with symbiotic zooxanthellae (Tridacna crocea) living on coral reef had relatively higher bio- accumulation factors for many bio-essential elements than other kinds of bivalves, although they live in the uneutrophic sea area. The present authors focused on Tridacna crocea as one of the symbiotic animals. Thus, in the present study, at first, multielement determination of major-to-ultratrace elements (about 20 elements) in each organ of Tridacna crocea with symbiotic zooxanthellae, were carried out by ICP-AES, ICP- MS, and CHN coder. At Second, the specific bioavailability of trace and ultratrace elements in Tridacna crocea was discussed on the multielement data for seawater, seaweeds, and other bivalves in coral sea area.

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.

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

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.

Abundance, biomass and caloric content of Chukchi Sea bivalves and association with Pacific walrus (Odobenus rosmarus divergens) relative density and distribution in the northeastern Chukchi Sea

Science.gov (United States)

Young, Jordann K.; Black, Bryan A.; Clarke, Janet T.; Schonberg, Susan V.; Dunton, Kenneth H.

2017-10-01

The northeastern Chukchi Sea is a shallow subarctic shelf ecosystem that supports a substantial benthic infaunal community of which bivalves are a major component. We assessed the patterns in population abundance, biomass, and caloric content of ten dominant bivalve taxa in relation to the distribution of the upper trophic level consumer Pacific walrus (Odobenus rosmarus divergens). Bivalves were collected over four cruises in the northeastern Chukchi Sea (2009, 2010, 2012, 2013). Our samples were largely dominated by calorie-dense, deposit-feeding species, including Macoma spp., Ennucula tenuis, Nuculana spp. and Yoldia spp. Weight-frequency distributions were strongly right-skewed for most taxa, though some showed evidence of a bimodal distribution. Caloric densities as measured through bomb calorimetry significantly differed among taxa (ANOVA F = 32.57, df = 9, p-valueanimal wet weight was found to be a reliable predictor of whole animal caloric content. Bivalve populations and peak caloric densities were centered on and to the southeast of Hanna Shoal, which coincided with peak Pacific walrus relative density (walruses per km surveyed) from July through October. Significant differences in mean caloric values were found between areas with and without walruses present (student's t-test, t=-2.9088, df = 252.24, p-value = 0.003952), as well as between areas with low and high walrus relative densities in the pooled annual dataset and in each individual month except October (ANOVA, p-value<0.05). The high-calorie deposit feeders that dominate these bivalve communities preferentially consume food sources, such as sea ice algae, that are likely to be affected by shifting sea ice dynamics. As such, continued warming has the potential to alter bivalve communities in the northeastern Chukchi Sea, which may have profound implications for upper trophic levels.

Contamination of raw bivalve molluscs available in Poland between 2009 and 2013 with marine biotoxins

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Michalski Mirosław

2016-12-01

Full Text Available Introduction: Growing consumption of shellfish is associated with an increased risk of food poisoning. The study was carried out on live bivalve molluscs available on the Polish market between 2009 and 2013. Material and Methods: ELISA was used for the determination of the following marine biotoxins: paralytic shellfish poison (PSP, amnaesic shellfish poison (ASP, and diarrhoeic shellfish poison (DSP. The molluscs, of which seven species were examined, were obtained from wholesale companies and markets. Results: Marine biotoxins were detected below the permitted levels in 67.6% of the samples. The maximum amounts of PSP and ASP biotoxins were found in great scallops (532.6 μg/kg and 1.0 mg/kg respectively and the peak for DSP was in blue mussels (107 μg/kg. Conclusion: The analysis of toxicological status of raw bivalve molluscs available on the market in Poland indicates that they are safe for consumers.

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...

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

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

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

Efeitos do caranguejo Pinnotheres ostreum em ostras Crassostrea rhizophorae

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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.

Plio-Pleistocene extinctions and immigration credit reflected in the size-frequency distribution of Mediterranean marine bivalves

Science.gov (United States)

Nawrot, Rafal; Zuschin, Martin; Chattopadhyay, Devapriya

2015-04-01

Following the opening of the Suez Canal hundreds of Red Sea species have entered the Mediterranean Sea making it a global hot spot of marine bioinvasion. With the ongoing influx of the subtropical and tropical alien species and increasing sea surface temperatures, the Mediterranean biota is currently gaining a more tropical character and increasingly becoming a mixture of faunal stocks with different evolutionary histories. This susceptibility to invasion was suggested to reflect the presence of an empty ecological space left after decimation of incumbent warm-water fauna during Plio-Pleistocene climate fluctuations. As molluscs are among the most prolific immigrants, we test this hypothesis using data on taxonomic composition and body size of Pliocene Mediterranean bivalves derived from the literature sources and museum collections. The Pliocene inter-specific size-frequency distribution (SFD) is strikingly similar to the SFDs of the Recent Red Sea bivalve fauna, in spite of different biogeographic provenance and the absence of true reef ecosystems in the Pliocene of the Mediterranean region. In contrast, body-size patterns in both assemblages are significantly different from the present-day Mediterranean fauna characterized by smaller median and modal size. Our preliminary results suggest that the distinct shape of the modern Mediterranean SFD may reflect the selective nature of the late Piacenzian - Galesian (Late Pliocene - Early Pleistocene) extinctions pulses related to the onset of the Northern Hemisphere glaciations. These extinctions affected almost 40% of Pliocene species and were biased towards large-bodied taxa. They were not followed by re-immigration of warm-water species owing to the isolation from the tropical Atlantic biota by the cold upwelling along the NW coasts of Africa. The resulting invasion credit (sensu Jackson & Sax, 2010) is currently being paid by the Red Sea bivalves colonizing the Mediterranean Sea through the Suez Canal. Successful

Light and scanning electron microscopic studies of Unionicola tetrafurcatus (Acari: Unionicolidae) infecting four freshwater bivalve species with referring to histopathological effect on its hosts.

Science.gov (United States)

Abdel-Gaber, Rewaida; Fol, Mona; Al Quraishy, Saleh

2018-05-08

Water mites of the genus Unionicola are the most common symbionts of freshwater bivalves. During the current investigation, a total of 120 live freshwater mussels [Corbicula fluminea (Veneroida), Coelatura aegyptiaca (Unionoidea) Mutela rostrata and Chambardia rubens (Mutelidae)], were collected from 2 localities in Tura (Helwan Governorate) and El Kanater (Qaluobiya Governorate), Egypt. Only 3 of the 4 bivalve species listed are considered freshwater bivalves (members of Unionoidea). While, C. fluminea belong to the family Cyrenidae within Veneroida. The collected mussels were dissected and examined for the presence of unionicolid mites. It was found that 30.83% (37/120) were infected with a single mite species Unionicola tetrafurcatus (Unionicolidae). The highest prevalence was observed during the summer with 83.33% (25/30), whereas the least was observed in autumn, i.e. 33.33% (10/30). Mites were recovered from the gills, gonads, and visceral mass of mussel hosts. gills of host mussels were the primary site of oviposition for unionicola mites. Smaller bivalves in size had significantly greater numbers of mites than larger ones in size. Numbers of mites per host species was variable and the highest prevalence level of 83.33% (25/30) was recorded in C. fluminea, while, the lowest one of 16.66% (5/30) was found in C. rubens. Morphological and morphometric characterizations of mites revealed some differences between the present species and other related Unionicola. Histopathological responses of host mussels to the eggs, larvae, and cuticular remnants of U. tetrafurcatus were also studied. Therefore, the present study demonstrated that freshwater bivalves have a new host and locality records for infection with U. tetrafurcatus. Future studies are recommended to include advanced molecular characteristics for these mites.

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...

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...

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.

HMGB in mollusk Crassostrea ariakensis Gould: structure, pro-inflammatory cytokine function characterization and anti-infection role of its antibody.

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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

Comparative susceptibility of veliger larvae of four bivalve mollusks to a Vibrio alginolyticus strain.

Science.gov (United States)

Luna-González, A; Maeda-Martínez, A N; Sainz, J C; Ascencio-Valle, F

2002-06-03

The susceptibility of 7 d old veliger larvae of the scallops Argopecten ventricosus and Nodipecten subnodosus, the penshell Atrina maura, and the Pacific oyster Crassostrea gigas to a pathogenic strain of Vibrio alginolyticus was investigated by challenging the larvae with different bacterial concentrations in a semi-static assay. The results indicate that the larvae of the 2 scallop species are more susceptible to the V. alginolyticus strain than those of the oyster and the penshell. Signs of the disease were similar to bacillary necrosis described in previous work. Interspecies differences in susceptibility to pathogens are discussed.

Uniform Variation in Genetic-Traits of a Marine Bivalve Related to Starvation, Pollution and Geographic Clines

NARCIS (Netherlands)

Hummel, H.; Bogaards, R.H.; Amiard-Triquet, C.; Bachelet, G.; Desprez, M.; Marchand, J.; Rybarczyk, H.; Sylvand, B.; De Wit, Y.; De Wolf, L.

1995-01-01

Consistent patterns of genetic variation in the marine bivalve Macoma balthica (L.) were found after exposure to low levels of copper, starvation, and along geographic dines. The geographic dines were related to temperature and salinity. Genetic differences were primarily found in the LAP (Leucine

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)

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)

Mobile Element Evolution Playing Jigsaw - SINEs in Gastropod and Bivalve Mollusks.

Science.gov (United States)

Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

2016-01-06

SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc-snail and SCoica-mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain-Snail-is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5' end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves-extending the distribution range of this superfamily. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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.

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.

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

Biomonitoring of Heavy metals using the bivalve molluscs in sunderban mangrove wetland, Northeast Coast of Bay of bengal (india): possible risks to Human health

Energy Technology Data Exchange (ETDEWEB)

Cabral, Henrique; Cardoso, Ines [Departamento de Biologia Animal/Instituto de Oceanografia, Campo Grande, Lisboa (Portugal); Chatterjee, Mousumi; Kumar Bhattacharya, Asok; Aftab Alam, Mohammad [Department of Marine Science, University of Calcutta, Calcutta (India); Kanta Satpathy, Kamala [Indira Gandhi Centre for Atomic Research, Environmental and Industrial Safety Section, Safety Group, Kalpakkam, Tamil Nadu (India); Kumar Sarkar, Santosh

2008-02-15

The suitability of using four bivalve molluscs (Sanguinolaria acuminata, Anadara granosa, Meretrix meretrix, and Pelecyora trigona) in biomonitoring of heavy metals (Cu, Pb, Cd, Zn, and Hg) collected from intertidal regions of the Sunderban mangrove wetland, northeastern part of the Bay of Bengal, were evaluated. Both speciesdependent variability and temporal variations were pronounced. A high degree of organ specificity was evident in the bivalves where gill and mantle exhibited higher metal accumulation due to ion exchange property of the mucous layer covering these organs while shells represent very poor accumulation. Elevated values of Zn and Cu reflect high potential for biomagnification through marine food chain. Metal concentrations in different body size groups of the bivalves do not follow uniform trend. Correlation coefficient between different metal couplings as tested statistically revealed significant coupling for Pb-Zn, Pb-Cu, Zn-Cu, and Hg-Cu. Concentrations of all the metals in specific organs (visceral mass, mantle and gill) of the bivalves exceeded the safe levels according to the international standards for metals compiled by Food and Agricultural Organization of the United Nations and would be of great risk for human consumption. It is concluded that the mussel and clam are suitable biomonitors to employ in programs designed to assess changes in metal pollution in the Sunderban mangrove wetland. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

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

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...

Boreholes on three bivalve species found on the sand beach at Sagot Cape, Baengnyeongdo, Korea

Directory of Open Access Journals (Sweden)

Dal-Yong Kong

2017-12-01

Full Text Available Circular to subcircular boreholes were found on the surfaces of three different bivalve shells (Mactra chinensis, Felaniella usta, and Nuttallia japonica that were pushed onto the sand beach at Sagot Cape, Baengnyeongdo, Korea. The boreholes are characterized by beveled holes that are parabolic in cross section. The boreholes are classified into the ichnospecies Oichnus paraboloides, probably drilled by a naticid gastropod Glossaulax didyma didyma living in the Baengnyeong tidal flat. In the case of Mactrashells, boreholes are observed more or less evenly on left and right valves, and 96% of boreholes are located on the umbo. This may suggest that the life position of the Baengnyeong bivalves did not dictate the preference of G. didyma didyma in the Baengnyeong tidal flat ecosystem. The clustered distribution of the boreholes in the umbo area indicates a strong site selectivity for boreholes that is quite a common phenomenon in many naticid gastropods. Keywords: Baengnyeongdo, Mactra chinensis, Naticid gastropods, Oichnus paraboloides, Prey–predator interactions

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

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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.

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.

Metals and organotins in multiple bivalve species in a one-off global survey

DEFF Research Database (Denmark)

Larsen, Martin Mørk; Strand, Jakob; Christensen, Jan H.

2011-01-01

contamination levels on a global scale. Metal concentrations in nine bivalve species were normalised to the Mytilidae family using conversion factors based on cosampled species and literature bioconcentration factors. The lowest metal and tributyltin concentrations were below background assessment...... were low, but not always lower than expected impacted areas. The most contaminated areas were harbours, where especially Copenhagen, St Croix and Sydney, can be considered hotspots of tributyltin as well as a number of metals....

Some effects of temperature and starvation on the bivalve @iDonax vittatus@@ (da Costa) in experimental laboratory populations

Digital Repository Service at National Institute of Oceanography (India)

Ansell, A.D.; Sivadas, P.

The effect of temperature on the body weight and composition, and on respiration, filtration and NH, excretion of the bivalve Donax uittatus (da Costa) has been investigated in laboratory-maintained populations under conditions of starvation In all...

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...

Uptake and metabolism of 14C-chloropyrifos by marine bivalves

International Nuclear Information System (INIS)

Zhong, C.G.; Chen, S.; Zhao, X.; Shi, J.; Carvalho, F.P.

1999-01-01

The uptake and metabolism of 14 C-chlorpyrifos by two marine bivalves, Paphia undulata and Sinonovacula constricta, were studied in a simulated ecosystem. The experiments were carried out in two 30 L glass tanks containing each 20 L of filtered sea water, contaminated with 14 C-chlorpyrifos 1.85x10 4 Bq.L -1 (16.7 μg.L -1 ) at the beginning of the exposure period. At different time intervals, three specimens of each species were sampled for analysis of the pesticide in the molluscs tissues. The 14 C-chlorpyrifos residues were extracted from the digestive gland of the molluscs and analyzed by co-chromatography with pesticide standards by TLC methods described before

Trace element determination in soft tissues of marine bivalves by activation analysis

International Nuclear Information System (INIS)

Fukushima, M.; Tamate, H.; Nakano, Y.

2003-01-01

Trace elements in soft tissues of marine bivalves were determined by neutron activation analysis (NAA) and photon activation analysis (PAA). Elemental levels of Ag, As, Br, Co, Cu, Fe, I, Mn, Ni, Rb, Se, and Zn in the organs of giant ezoscallos, rock oysters, and giant crams were obtained. The metal-bound proteins were extracted from the mantles and hepatopancreases of rock oysters. By irradiating the fraction obtained by HPLC gel chromatography, the possibility for the existence of an Ag bound protein in the mantles was found. (author)

Cephalic and limb anatomy of a new Isoxyid from the Burgess Shale and the role of "stem bivalved arthropods" in the disparity of the frontalmost appendage.

Directory of Open Access Journals (Sweden)

Cédric Aria

Full Text Available We herein describe Surusicaris elegans gen. et sp. nov. (in Isoxyidae, amended, a middle (Series 3, Stage 5 Cambrian bivalved arthropod from the new Burgess Shale deposit of Marble Canyon (Kootenay National Park, British Columbia. Surusicaris exhibits 12 simple, partly undivided biramous trunk limbs with long tripartite caeca, which may illustrate a plesiomorphic "fused" condition of exopod and endopod. We construe also that the head is made of five somites (= four segments, including two eyes, one pair of anomalocaridid-like frontalmost appendages, and three pairs of poorly sclerotized uniramous limbs. This fossil may therefore be a candidate for illustrating the origin of the plesiomorphic head condition in euarthropods, and questions the significance of the "two-segmented head" in, e.g., fuxianhuiids. The frontalmost appendage in isoxyids is intriguingly disparate, bearing similarities with both dinocaridids and euarthropods. In order to evaluate the relative importance of bivalved arthropods, such as Surusicaris, in the hypothetical structuro-functional transition between the dinocaridid frontal appendage and the pre-oral-arguably deutocerebral-appendage of euarthropods, we chose a phenetic approach and computed morphospace occupancy for the frontalmost appendages of 36 stem and crown taxa. Results show different levels of evolutionary decoupling between frontalmost appendage disparity and body plans. Variance is greatest in dinocaridids and "stem bivalved" arthropods, but these groups do not occupy the morphospace homogeneously. Rather, the diversity of frontalmost appendages in "stem bivalved" arthropods, distinct in its absence of clear clustering, is found to link the morphologies of "short great appendages," chelicerae and antennules. This find fits the hypothesis of an increase in disparity of the deutocerebral appendage prior to its diversification in euarthropods, and possibly corresponds to its original time of development. The

Cephalic and limb anatomy of a new Isoxyid from the Burgess Shale and the role of "stem bivalved arthropods" in the disparity of the frontalmost appendage.

Science.gov (United States)

Aria, Cédric; Caron, Jean-Bernard

2015-01-01

We herein describe Surusicaris elegans gen. et sp. nov. (in Isoxyidae, amended), a middle (Series 3, Stage 5) Cambrian bivalved arthropod from the new Burgess Shale deposit of Marble Canyon (Kootenay National Park, British Columbia). Surusicaris exhibits 12 simple, partly undivided biramous trunk limbs with long tripartite caeca, which may illustrate a plesiomorphic "fused" condition of exopod and endopod. We construe also that the head is made of five somites (= four segments), including two eyes, one pair of anomalocaridid-like frontalmost appendages, and three pairs of poorly sclerotized uniramous limbs. This fossil may therefore be a candidate for illustrating the origin of the plesiomorphic head condition in euarthropods, and questions the significance of the "two-segmented head" in, e.g., fuxianhuiids. The frontalmost appendage in isoxyids is intriguingly disparate, bearing similarities with both dinocaridids and euarthropods. In order to evaluate the relative importance of bivalved arthropods, such as Surusicaris, in the hypothetical structuro-functional transition between the dinocaridid frontal appendage and the pre-oral-arguably deutocerebral-appendage of euarthropods, we chose a phenetic approach and computed morphospace occupancy for the frontalmost appendages of 36 stem and crown taxa. Results show different levels of evolutionary decoupling between frontalmost appendage disparity and body plans. Variance is greatest in dinocaridids and "stem bivalved" arthropods, but these groups do not occupy the morphospace homogeneously. Rather, the diversity of frontalmost appendages in "stem bivalved" arthropods, distinct in its absence of clear clustering, is found to link the morphologies of "short great appendages," chelicerae and antennules. This find fits the hypothesis of an increase in disparity of the deutocerebral appendage prior to its diversification in euarthropods, and possibly corresponds to its original time of development. The analysis of this

Optimal designs of mollusk shells from bivalves to snails.

Science.gov (United States)

Okabe, Takuya; Yoshimura, Jin

2017-02-10

Bivalve, ammonite and snail shells are described by a small number of geometrical parameters. Raup noted that the vast majority of theoretically possible shell forms do not occur in nature. The constraint factors that regulate the biased distribution of natural form have long since been an open problem in evolution. The problem of whether natural shell form is a result of optimization remains unsolved despite previous attempts. Here we solve this problem by considering the scaling exponent of shell thickness as a morphological parameter. The scaling exponent has a drastic effect on the optimal design of shell shapes. The observed characteristic shapes of natural shells are explained in a unified manner as a result of optimal utilization of shell material resources, while isometric growth in thickness leads to impossibly tight coiling.

Assessing phototoxicity of petroleum using the bivalve Mulinia lateralis and the mysid Mysidopsis bahia

International Nuclear Information System (INIS)

Pelletier, M.; Champlin, D.; Burgess, R.; Ho, K.; Kuhn-Hines, A.

1995-01-01

One of the major inputs of PAHs in the marine environment is petroleum products. A large and often catastrophic source of petroleum is an oil spill, which releases concentrated quantities of PAHs into the water column. Intermediate molecular weight compounds remain in the water column for a relatively extended length of time. These compounds include phototoxic PAHs such as anthracene, fluoranthene, pyrene, and their substituted derivatives. Assessments of the environmental impact of marine oil spills have not included phototoxicity tests using pelagic larvae of benthic invertebrates. In this study, the photoreactive toxicity of individual PAHs, including anthracene, pyrene, and fluoranthene, were determined using the bivalve, Mulinia lateralis and the mysid, Mysidopsis bahia. Ultraviolet light exposures increased toxicity relative to fluorescent light for both species but a particularly dramatic response was seen using M. lateralis embryos. This species was relatively insensitive when exposed under fluorescent lights, but exhibited up to a 4,000 fold increase in toxicity under ultraviolet lights. Exposures with different types of petroleum (e.g., fuel oil number-sign 2 and crude oil) under fluorescent and ultraviolet light will demonstrate the utility of this bivalve and mysid for assessing oil spill-related acute and sublethal toxicity in the marine environment

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.

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.

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...

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 ...

The quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897) – another Ponto-Caspian dreissenid bivalve in the southern Baltic catchment: the first record from the Szczecin Lagoon

OpenAIRE

Adam Woźniczka; Brygida Wawrzyniak-Wydrowska; Teresa Radziejewska; Anna Skrzypacz

2016-01-01

In 2014, a non-indigenous dreissenid bivalve, the quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897) was for the first time recorded in the Szczecin Lagoon. This was also the first record of the species in the Baltic Sea catchment. The quagga mussel was found to accompany the zebra mussel (Dreissena polymorpha), a non-indigenous bivalve already firmly established in the Lagoon. As indicated by the new immigrant's estimated abundance (4000.0 ± 355.44 ind. m−2) and the zebra mussel ...

Metal accumulation in marine bivalves under various tributyltin burdens.

Science.gov (United States)

Tang, Chuan-Ho; Lin, Chan-Shing; Wang, Wei-Hsien

2009-11-01

In the present study, a field survey was conducted to measure the accumulation of butyltin, Cu, Zn, and Cd in green mussels (Perna viridis) and Pacific oysters (Crassostrea gigas) at the regions along a tributyltin pollution gradient. A negative correlation was found between the tributyltin/total butyltin ratio (0.87-0.31) and tributyltin content (114-5,817 ng/g as tin dry wt) in oysters, while the Cu content (44.2-381 mg/kg dry wt) was positively correlated with the logarithm of tributyltin content during the summer and winter. This suggests that as the tributyltin burden increases, the rates of tributyltin metabolism may be elevated, leading to enhanced Cu accumulation. A similar accumulation pattern for Zn was also found in oysters. In mussels, however, the tributyltin/total butyltin ratio and the Cu and Zn contents remained relatively constant (~ 0.7, 12, and 100 mg/kg dry wt, respectively) regardless of the tributyltin burden. Clearly, the butyltin and Cu/Zn accumulation processes in oysters differ from those in mussels under tributyltin pollution. These observations provide valuable information for those who evaluate or compare tributyltin and/or Cu/Zn pollution using oysters and mussels as bioindicators.

An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

OpenAIRE

Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche; Mazurie, Joseph; Buck, Bela H.; Dolmer, Per; Fraser, David; Van Nieuwenhove, Kris; O'Beirn, Francis X.; Sanchez-mata, Adoracion; Thorarinsdottir, Gudrun G.; Strand, Oivind

2012-01-01

An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture–en...

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.

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.

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

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...

Sensitivity of Mediterranean bivalve mollusc aquaculture to climate change, ocean acidification, and other environmental pressures: findings from a producers’ survey

NARCIS (Netherlands)

Rodrigues, L.; van den Bergh, J.C.J.M.; Mass, F.; Theodorou, J.A.; Ziveri, P.; Gazeau, F.

2015-01-01

Human-induced climate change and ocean acidification are global environmental phenomena with a common driver: anthropogenic emissions of carbon dioxide. Both processes potentially threaten the Mediterranean bivalve mollusc aquaculture sector, which is economically relevant to several regions and

Carbon and nitrogen elemental and isotopic ratios of filter-feeding bivalves along the French coasts: An assessment of specific, geographic, seasonal and multi-decadal variations.

Science.gov (United States)

Briant, Nicolas; Savoye, Nicolas; Chouvelon, Tiphaine; David, Valérie; Rodriguez, Samuel; Charlier, Karine; Sonke, Jeroen E; Chiffoleau, Jean François; Brach-Papa, Christophe; Knoery, Joël

2018-02-01

Primary consumers play a key role in coastal ecosystems by transferring organic matter from primary producers to predators. Among them, suspension-feeders, like bivalve molluscs are widely used in trophic web studies. The main goal of this study was to investigate variations of C and N elemental and isotopic ratios in common bivalves (M. edulis, M. galloprovincialis, and C. gigas) at large spatial (i.e. among three coastal regions) and different temporal (i.e. from seasonal to multi-decadal) scales in France, in order to identify potential general or specific patterns and speculate on their drivers. The observed spatial variability was related to the trophic status of the coastal regions (oligotrophic Mediterranean Sea versus meso- to eutrophic English Channel and Atlantic ocean), but not to ecosystem typology (estuaries, versus lagoons versus bays versus littoral systems). Furthermore, it highlighted local specificities in terms of the origin of the POM assimilated by bivalves (e.g., mainly continental POM vs. marine phytoplankton vs. microphytobenthic algae). Likewise, seasonal variability was related both to the reproduction cycle for C/N ratios of Mytilus spp. and to changes in trophic resources for δ 13 C of species located close to river mouth. Multi-decadal evolution exhibited shifts and trends for part of the 30-year series with decreases in δ 13 C and δ 15 N. Specifically, shifts appeared in the early 2000's, likely linking bivalve isotopic ratios to a cascade of processes affected by local drivers. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of a step-change in metal exposure (Cd, Cu, Zn) on metal accumulation and subcellular partitioning in a freshwater bivalve, Pyganodon grandis: A long-term transplantation experiment between lakes with contrasting ambient metal levels

Energy Technology Data Exchange (ETDEWEB)

Cooper, Sophie [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada); Bonneris, Emmanuelle [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada) and Bayer S.A.S., Bayer CropScience, 16 Rue Jean-Marie Leclair, CP 90106, F 69266 Lyon Cedex 09 (France); Michaud, Annick [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada) and Direction des Évaluations environnementales, Ministère du Développement durable, de l’Environnement et des Parcs, 675, boul. René-Lévesque Est, 6e étage, Québec, QC G1R 5V7 (Canada); Pinel-Alloul, Bernadette [Groupe de Recherche Interuniversitaire en Limnologie et Environnement Aquatique (GRIL), Département de Sciences Biologiques, Université de Montréal, C.P. 6128, Montréal, QC H3C 3J7 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [INRS-Eau, Terre et Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9 (Canada)

2013-05-15

Highlights: ? We transferred freshwater bivalves from a reference lake to a Cd and Zn contaminated lake. ? Changes in metal accumulation and subcellular partitioning were followed over time (up to 860 d). ? Metal detoxification strategies differed between target organs (gills vs. digestive gland). ? The ability to handle Cd is inherent in P. grandis, not a trait acquired after long-term adaptation. -- Abstract: The objective of the present field experiment was to identify detoxification responses in the gills and digestive gland of a freshwater unionid bivalve, Pyganodon grandis, subjected to a step-change in metal exposure. Adult bivalves were transferred from a reference site (Lake Opasatica) and a metal-contaminated lake (Lake Héva) to a second contaminated lake (Lake Vaudray) in northwestern Quebec, Canada. Changes in organ metal concentrations, in the subcellular distribution of metals and in metallothionein concentrations were followed over time (t = 0, 132, (400) and 860 days). At each collection time and for each bivalve, the gills and digestive gland were excised and gently homogenized; six sub-cellular fractions were separated by differential centrifugation and analyzed for their Cd, Cu and Zn content, and metallothionein was quantified independently. Metal detoxification strategies were shown to differ between target organs: in the gills, incoming metals were sequestered largely in the granules, whereas in the digestive gland the same metals primarily accumulated in the cytosol, in the metallothionein-like protein fraction. These metal-handling strategies, as employed by the metal-naïve bivalves originating in the reference lake, closely resemble those identified in free-living P. grandis chronically exposed in the metal-contaminated lake, suggesting that the ability to handle incoming metals (Cd in particular) is inherent in P. grandis and is not a trait acquired after long-term adaptation of the bivalve to metal-contaminated environments. The

Subcellular compartmentalization of Cd and Zn in two bivalves. II. Significance of trophically available metal (TAM)

Science.gov (United States)

Wallace, W.G.; Luoma, S.N.

2003-01-01

This paper examines how the subcellular partitioning of Cd and Zn in the bivalves Macoma balthica and Potamocorbula amurensis may affect the trophic transfer of metal to predators. Results show that the partitioning of metals to organelles, 'enzymes' and metallothioneins (MT) comprise a subcellular compartment containing trophically available metal (TAM; i.e. metal trophically available to predators), and that because this partitioning varies with species, animal size and metal, TAM is similarly influenced. Clams from San Francisco Bay, California, were exposed for 14 d to 3.5 ??g 1-1 Cd and 20.5 ??g 1-1 Zn, including 109Cd and 65Zn as radiotracers, and were used in feeding experiments with grass shrimp Palaemon macrodatylus, or used to investigate the subcellular partitioning of metal. Grass shrimp fed Cd-contaminated P. amurensis absorbed ???60% of ingested Cd, which was in accordance with the partitioning of Cd to the bivalve's TAM compartment (i.e. Cd associated with organelles, 'enzymes' and MT); a similar relationship was found in previous studies with grass shrimp fed Cd-contaminated oligochaetes. Thus, TAM may be used as a tool to predict the trophic transfer of at least Cd. Subcellular fractionation revealed that ???34% of both the Cd and Zn accumulated by M. balthica was associated with TAM, while partitioning to TAM in P. amurensis was metal-dependent (???60% for TAM-Cd%, ???73% for TAM-Zn%). The greater TAM-Cd% of P. amurensis than M. balthica is due to preferential binding of Cd to MT and 'enzymes', while enhanced TAM-Zn% of P. amurensis results from a greater binding of Zn to organelles. TAM for most species-metal combinations was size-dependent, decreasing with increased clam size. Based on field data, it is estimated that of the 2 bivalves, P. amurensis poses the greater threat of Cd exposure to predators because of higher tissue concentrations and greater partitioning as TAM; exposure of Zn to predators would be similar between these species.

Immunomodulation by different types of N-oxides in the hemocytes of the marine bivalve Mytilus galloprovincialis.

Directory of Open Access Journals (Sweden)

Caterina Ciacci

Full Text Available The potential toxicity of engineered nanoparticles (NPs for humans and the environment represents an emerging issue. Since the aquatic environment represents the ultimate sink for NP deposition, the development of suitable assays is needed to evaluate the potential impact of NPs on aquatic biota. The immune system is a sensitive target for NPs, and conservation of innate immunity represents an useful basis for studying common biological responses to NPs. Suspension-feeding invertebrates, such as bivalves, are particularly at risk to NP exposure, since they have extremely developed systems for uptake of nano and microscale particles integral to intracellular digestion and cellular immunity. Evaluation of the effects of NPs on functional parameters of bivalve immunocytes, the hemocytes, may help understanding the major toxic mechanisms and modes of actions that could be relevant for different NP types in aquatic organisms.In this work, a battery of assays was applied to the hemocytes of the marine bivalve Mytilus galloprovincialis to compare the in vitro effects of different n-oxides (n-TiO(2, n-SiO(2, n-ZnO, n-CeO(2 chosen on the basis of their commercial and environmental relevance. Physico-chemical characterization of both primary particles and NP suspensions in artificial sea water-ASW was performed. Hemocyte lysosomal and mitochondrial parameters, oxyradical and nitric oxide production, phagocytic activity, as well as NP uptake, were evaluated. The results show that different n-oxides rapidly elicited differential responses hemocytes in relation to their chemical properties, concentration, behavior in sea water, and interactions with subcellular compartments. These represent the most extensive data so far available on the effects of NPs in the cells of aquatic organisms. The results indicate that Mytilus hemocytes can be utilized as a suitable model for screening the potential effects of NPs in the cells of aquatic invertebrates, and may

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

Systematics, functional morphology and distribution of a bivalve (Apachecorbula muriatica gen. et sp. nov.) from the rim of the 'Valdivia Deep' brine pool in the Red Sea

KAUST Repository

Oliver, Pere Graham

2014-11-11

The deep brine pools of the Red Sea comprise extreme, inhospitable habitats yet house microbial communities that potentially may fuel adjacent fauna. We here describe a novel bivalve from a deep-sea (1525 m) brine pool in the Red Sea, where conditions of high salinity, lowered pH, partial anoxia and high temperatures are prevalent. Remotely operated vehicle (ROV) footage showed that the bivalves were present in a narrow (20 cm) band along the rim of the brine pool, suggesting that it is not only tolerant of such extreme conditions but is also limited to them. The bivalve is a member of the Corbulidae and named Apachecorbula muriatica gen. et sp. nov. The shell is atypical of the family in being modioliform and thin. The semi-infaunal habit is seen in ROV images and reflected in the anatomy by the lack of siphons. The ctenidia are large and typical of a suspension feeding bivalve, but the absence of \\'guard cilia\\' and the greatly reduced labial palps suggest that it is non-selective as a response to low food availability. It is proposed that the low body mass observed is a consequence of the extreme habitat and low food availability. It is postulated that the observed morphology of Apachecorbula is a result of paedomorphosis driven by the effects of the extreme environment on growth but is in part mitigated by the absence of high predation pressures. © Marine Biological Association of the United Kingdom, 2014.

Using transplanted bivalves to assess oil exposure and effects in Delaware Bay

International Nuclear Information System (INIS)

Salazar, M.; Salazar, S.; Mearns, A.; Venosa, A.; Eberhart, B.

1995-01-01

To evaluate the effectiveness of bioremediation, the US EPA oiled intertidal plots in Delaware Bay and monitored oil degradation rates. This controlled release of oil was also used to test the utility of transplanted bivalves in assessing oil spills and to evaluate the extent and potential effects of the release. Measuring the accumulation of oil in bivalve tissues was used to estimate exposure and the extent of contamination. Growth was used to estimate potential bioeffects. Approximately 1,800 mussels and 1,200 oysters were transplanted to 11 intertidal sites. Five treatment sites were within 1 meter of the lower end of the oiled plots. A total of six sites were used as controls, three on either side of the oiled plots at 5, 10, and 100 m. Samples were taken on Day 0, 2, 15, and 28 to estimate the rate of bioaccumulation. All of the mussels died within the first week of exposure; oysters exhibited over 95% survival but growth was minimal. The authors found a statistically significant difference in tissue weights when comparing treatment sites with control sites. The total concentration of polynuclear aromatic hydrocarbons (PAHs) in tissues of oysters nearest the oiled plots increased by a factor of four after an exposure period of two days. PAH concentrations in control oysters nearest the mouth of the bay increased slightly but the differences were not statistically significant. The control oysters nearest the head of the bay received an intermediate dose which was depurated by the end of the 28-day experiment. PAHs in the oysters nearest the oiled plots approached but did not return to background levels by the end of the test

ICP-MS: suitable method to study the metals distribution in estuarine regions

International Nuclear Information System (INIS)

Vasconcelos, Danilo C.; Oliveira, Arno H.; Santos, Silvio J. dos; Brito, Veronica F.O.; Severo, Maria Isabel G.

2005-01-01

Anthropogenic inputs of pollutants such as heavy metals into the marine environment have increased their levels to large extents within past a few decades. These pollutants tend to accumulate in the bottom sediments. As a result, ecosystems such as seaports or other industrialized coastal areas that have chronic inputs of metals have highly contaminated sediments. This characteristic has led to concerns over the ecological effects that may be associated with sediment quality. Of particular concern are toxic effects and the potential for bioaccumulation of metals in biota exposed to the sediments. The bivalves Crassostrea rhizophorae, Lucina pectinata and Mytella falcata have been used as biomonitors of trace metal contamination in two estuaries from Ilheus city, Bahia state, in Brazil. Bivalves, sediment and water samples were collected in March 2004 in Acuipe and Rio do Engenho mangroves. The proposed technique to analyze the studied matrices was the inductively coupled plasma mass spectrometry (ICP-MS). The results suggested that the studied molluscs are bioaccumulators of metals and showed the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) as an adequate technique to determine a large range of inorganic elements, because its high sensibility and low detection limits. (author)

ICP-MS: suitable method to study the metals distribution in estuarine regions; ICP-MS metodo adequado para o estudo da distribuicao de metais em regioes estuarinas

Energy Technology Data Exchange (ETDEWEB)

Vasconcelos, Danilo C.; Oliveira, Arno H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear]. E-mail: danilochagas@yahoo.com.br; heeren@nuclear.ufmg.br; Santos, Silvio J. dos; Brito, Veronica F.O.; Severo, Maria Isabel G. [Universidade Estadual de Santa Cruz, Ilheus, BA (Brazil). Dept. de Ciencias Biologicas

2005-07-01

Anthropogenic inputs of pollutants such as heavy metals into the marine environment have increased their levels to large extents within past a few decades. These pollutants tend to accumulate in the bottom sediments. As a result, ecosystems such as seaports or other industrialized coastal areas that have chronic inputs of metals have highly contaminated sediments. This characteristic has led to concerns over the ecological effects that may be associated with sediment quality. Of particular concern are toxic effects and the potential for bioaccumulation of metals in biota exposed to the sediments. The bivalves Crassostrea rhizophorae, Lucina pectinata and Mytella falcata have been used as biomonitors of trace metal contamination in two estuaries from Ilheus city, Bahia state, in Brazil. Bivalves, sediment and water samples were collected in March 2004 in Acuipe and Rio do Engenho mangroves. The proposed technique to analyze the studied matrices was the inductively coupled plasma mass spectrometry (ICP-MS). The results suggested that the studied molluscs are bioaccumulators of metals and showed the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) as an adequate technique to determine a large range of inorganic elements, because its high sensibility and low detection limits. (author)

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

Respiration of bivalves from three different deep-sea areas: Cold seeps, hydrothermal vents and organic carbon-rich sediments

Science.gov (United States)

Khripounoff, A.; Caprais, J. C.; Decker, C.; Le Bruchec, J.; Noel, P.; Husson, B.

2017-08-01

We studied bivalves (vesicomyids and mytilids) inhabiting four different areas of high sulfide and methane production: (1) in the Gulf of Guinea, two pockmarks (650 m and 3150 m depth) and one site rich in organic sediments in the deepest zone (4950 m average depth), (2) at the Azores Triple Junction on the Mid-Atlantic Ridge, one hydrothermal site (Lucky Strike vent field, 1700 m depth). Two types of Calmar benthic chambers were deployed, either directly set into the sediment (standard Calmar chamber) or fitted with a tank to isolate organisms from the sediment (modified Calmar chamber), to assess gas and solute exchanges in relation to bivalve bed metabolism. Fluxes of oxygen, total carbon dioxide, ammonium and methane were measured. At the site with organic-rich sediments, oxygen consumption by clams measured in situ with the standard benthic chamber was variable (1.3-6.7 mmol m-2 h-1) as was total carbon dioxide production (1-9.6 mmol m-2 h-1). The observed gas and solute fluxes were attributed primarily to bivalve respiration (vesicomyids or mytilids), but microbial and geochemical processes in the sediment may be also responsible for some of variations in the deepest stations. The respiration rate of isolated vesicomyids (16.1-0.25.7 μmol g-1 dry weight h-1) was always lower than that of mytilids (33 μmol g-1 dry weight h-1). This difference was attributed to the presence of a commensal scaleworm in the mytilids. The respiratory coefficient (QR) ≥1 indicated high levels of anaerobic metabolism. The O:N index ranged from 5 to 25, confirming that vesicomyids and mytilids, living in symbiosis with bacteria, have a protein-based food diet.

Estimation of food limitation of bivalve larvae in coastal waters of north-western Europe

DEFF Research Database (Denmark)

Bos, O.G.; Hendriks, I.E.; Strasser, M.

2006-01-01

Marine invertebrate recruitment may be affected by food limitation during the pelagic larval life stages. In the present study, field data on abundance of bivalve larvae along with their prey (small phytoplankton) were examined to see whether they were consistent with predictions made...... assimilation rate averaged 7-26% of the maximum assimilation rate. Under the assumptions made for the present study, it is suggested that growth of larvae in north-west European waters is often food-limited. (c) 2005 Elsevier B.V. All rights reserved...

PAH assessment in the main Brazilian offshore oil and gas production area using semi-permeable membrane devices (SPMD) and transplanted bivalves

Science.gov (United States)

André Lourenço, Rafael; Francisco de Oliveira, Fábio; Haddad Nudi, Adriana; Rebello Wagener, Ângela de Luca; Guadalupe Meniconi, Maria de Fátima; Francioni, Eleine

2015-06-01

The Campos Basin is Brazil's main oil and gas production area. In 2013, more than 50 million cubic meters of produced water (PW) was discharged into these offshore waters. Despite the large volumes of PW that are discharged in the Campos Basin each day, the ecological concern of the chemicals in the PW are not completely understood. Polycyclic aromatic hydrocarbons (PAH) are the most important contributors to the ecological hazards that are posed by discharged PW. This study aimed to evaluate the potential bioaccumulation of PAH using transplanted bivalves (Nodipecten nodosus) and semi-permeable membrane devices (SPMD). The study was conducted in two platforms that discharge PW (P19 and P40). Another platform that does not discharge PW (P25) was investigated for comparison with the obtained results. Time-integrated hydrocarbon concentrations using SPMD and transplanted bivalves were estimated from the seawater near the three platforms. The bioaccumulation of the PAH in the transplanted bivalves at platforms P19 and P40 were up to fivefold greater than the bioaccumulation of the PAH at platform P25. The lowest PAH concentrations were estimated for platform P25 (4.3-6.2 ng L-1), and the highest PAH concentrations were estimated for platform P19 (9.2-37.3 ng L-1). Both techniques were effective for determining the bioavailability of the PAH and for providing time-integrated hydrocarbon concentrations regarding oil and gas production activities.

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.

Bioaccumulation of selected metals in bivalves (Unionidae) and Phragmites australis inhabiting a municipal water reservoir

OpenAIRE

Rzymski, Piotr; Niedzielski, Przemysław; Klimaszyk, Piotr; Poniedziałek, Barbara

2014-01-01

Urbanization can considerably affect water reservoirs by, inter alia, input, and accumulation of contaminants including metals. Located in the course of River Cybina, Maltański Reservoir (Western Poland) is an artificial shallow water body built for recreation and sport purposes which undergoes restoration treatment (drainage) every 4 years. In the present study, we demonstrate an accumulation of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in water, sediment, three bivalve species (Anodo...

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.

Preliminary Results on the Evaluation of the Occurrence of Tetrodotoxin Associated to Marine Vibrio spp. in Bivalves from the Galician Rias (Northwest of Spain

Directory of Open Access Journals (Sweden)

Jose Manuel Leão

2018-03-01

Full Text Available Tetrodotoxins (TTX are a potent group of natural neurotoxins putatively produced by symbiotic microorganisms and affecting the aquatic environment. These neurotoxins have been recently found in some species of bivalves and gastropods along the European Coasts (Greece, UK, and The Netherlands linked to the presence of high concentrations of Vibrio, in particular Vibrio parahaemolyticus. This study is focused on the evaluation of the presence of Vibrio species and TTX in bivalves (mussels, oysters, cockles, clams, scallops, and razor clams from Galician Rias (northwest of Spain. The detection and isolation of the major Vibrio spp. and other enterobacterial populations have been carried out with the aim of screening for the presence of the pathways genes, poliketide synthase (PKS and non-ribosomal peptide synthetase (NRPS possibly involved in the biosynthesis of these toxins. Samples containing Vibrio spp. were analyzed by biochemical (API20E-galery and genetic tests (PCR-RT. These samples were then screened for TTX toxicity by a neuroblastoma cell-based assay (N2a and the presence of TTX was further confirmed by LC-MS/MS. TTX was detected in two infaunal samples. This is the first confirmation of the presence of TTX in bivalve molluscs from the Galician Rias.

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.

Traces (ichnospecies Oichnus paraboloides of predatory gastropods on bivalve shells from the Seogwipo Formation, Jejudo, Korea

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Dal-Yong Kong

2015-12-01

Full Text Available Circular to subcircular drill holes were identified on the bivalve shells collected from the Seogwipo Formation, Jejudo, Korea. A great majority of the drill holes (>70% were found on the surfaces of a bivalve species Glycymeris rotunda. They are characterized by a beveled sharp edge and paraboloid in cross section with larger outer borehole diameter (OBD; mean 4.21 mm and smaller inner borehole diameter (mean 2.94 mm. Walls of the drill holes are generally smooth, and walls ornamented with etched relief-like structures were also recognized. A slightly raised central boss observed in an incomplete specimen may indicate a failure of predator’s attack. All drill holes collected are classified as a single ichnospecies Oichnus paraboloides Bromley, 1981. They are interpreted as boring traces produced by predatory gastropods, particularly naticid gastropods. Most O. paraboloides boreholes are observed in the central area of shell surfaces; a few boreholes lie marginally, which may reflect a borehole-site selectivity. No correlation between size of prey (shell height and size of predator (OBD is recognized. It is likely, however, that drilled shells of about 30 mm in height represent optimal prey size for naticid predators that lived in a benthic Seogwipo community.

Immunotoxicity of nanoparticle nTiO2 to a commercial marine bivalve species, Tegillarca granosa.

Science.gov (United States)

Shi, Wei; Han, Yu; Guo, Cheng; Zhao, Xinguo; Liu, Saixi; Su, Wenhao; Zha, Shanjie; Wang, Yichen; Liu, Guangxu

2017-07-01

The increasing production and extensive application of nanoparticles (NPs) inevitably leads to increased release of NPs into the marine environment and therefore poses a potential threat to marine organisms, especially the sessile benthic bivalves. However, the impacts of NPs on the immunity of commercial and ecological important bivalve species, Tegillarca granosa, still remain unknown to date. In addition, the molecular mechanism of the immunotoxicity of NPs still remains unclear in marine invertebrates. Therefore, the immunotoxicity of nTiO 2 exposure to T. granosa at environmental realistic concentrations was investigated in the present study. Results obtained showed that the total number, phagocytic activity, and red granulocytes ratio of the haemocytes were significantly reduced after 30 days nTiO 2 exposures at the concentrations of 10 and 100 μg/L. Furthermore, the expressions of genes encoding Pattern Recognition Receptors (PPRs) and downstream immune-related molecules were significantly down-regulated by nTiO 2 exposures, indicating a reduced sensitivity to pathogen challenges. In conclusion, evident immunotoxicity of nTiO 2 to T. granosa at environmental realistic concentrations was detected by the present study. In addition, the gene expression analysis suggests that the PRRs (both TLRs and RIG1 investigated) may be the molecules for NPs recognition in marine invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Abnormalities in bivalve larvae from the Puck Bay (Gulf of Gdansk, southern Baltic Sea) as an indicator of environmental pollution.

Science.gov (United States)

Lasota, Rafal; Gierszewska, Katarzyna; Viard, Frédérique; Wolowicz, Maciej; Dobrzyn, Katarzyna; Comtet, Thierry

2018-01-01

This study described the occurrence of abnormalities in bivalve larvae from the Puck Bay. Analyses of plankton samples collected in 2012-2013 showed that larval Mytilus trossulus, Mya arenaria, and Cerastoderma glaucum exhibited abnormalities that could indicate adverse environmental impacts. The deformities were mainly in shells, but missing soft tissue fragments and protruding vela were also noted. In addition to larval studies, we analyzed benthic postlarvae of Mytilus trossulus. Interestingly, grooves and notches at different locations of the prodissoconch, dissoconch, and shell margin were observed. Some of these deformations were reminiscent of the indentations found on the shell edge of larvae. Comparing the proportion of abnormal postlarvae to larvae with shell abnormalities suggested that the survival of larvae with shell abnormalities was low. Overall, our results suggested that the ratio of abnormal bivalve larvae could be used as an indicator of the biological effects of hazardous substances in the pelagic environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transgenerational exposure of North Atlantic bivalves to ocean acidification renders offspring more vulnerable to low pH and additional stressors.

Science.gov (United States)

Griffith, Andrew W; Gobler, Christopher J

2017-09-12

While early life-stage marine bivalves are vulnerable to ocean acidification, effects over successive generations are poorly characterized. The objective of this work was to assess the transgenerational effects of ocean acidification on two species of North Atlantic bivalve shellfish, Mercenaria mercenaria and Argopecten irradians. Adults of both species were subjected to high and low pCO 2 conditions during gametogenesis. Resultant larvae were exposed to low and ambient pH conditions in addition to multiple, additional stressors including thermal stress, food-limitation, and exposure to a harmful alga. There were no indications of transgenerational acclimation to ocean acidification during experiments. Offspring of elevated pCO 2 -treatment adults were significantly more vulnerable to acidification as well as the additional stressors. Our results suggest that clams and scallops are unlikely to acclimate to ocean acidification over short time scales and that as coastal oceans continue to acidify, negative effects on these populations may become compounded and more severe.

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

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

Impact of seawater carbonate chemistry on the calcification of marine bivalves

Science.gov (United States)

Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

2015-07-01

Bivalve calcification, particularly of the early larval stages, is highly sensitive to the change in ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no effects and [HCO3-] and pH had only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. An equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the mechanisms that limit or facilitate adaptation to future ocean acidification, it is necessary to better

Bivalves: From individual to population modelling

Science.gov (United States)

Saraiva, S.; van der Meer, J.; Kooijman, S. A. L. M.; Ruardij, P.

2014-11-01

An individual based population model for bivalves was designed, built and tested in a 0D approach, to simulate the population dynamics of a mussel bed located in an intertidal area. The processes at the individual level were simulated following the dynamic energy budget theory, whereas initial egg mortality, background mortality, food competition, and predation (including cannibalism) were additional population processes. Model properties were studied through the analysis of theoretical scenarios and by simulation of different mortality parameter combinations in a realistic setup, imposing environmental measurements. Realistic criteria were applied to narrow down the possible combination of parameter values. Field observations obtained in the long-term and multi-station monitoring program were compared with the model scenarios. The realistically selected modeling scenarios were able to reproduce reasonably the timing of some peaks in the individual abundances in the mussel bed and its size distribution but the number of individuals was not well predicted. The results suggest that the mortality in the early life stages (egg and larvae) plays an important role in population dynamics, either by initial egg mortality, larvae dispersion, settlement failure or shrimp predation. Future steps include the coupling of the population model with a hydrodynamic and biogeochemical model to improve the simulation of egg/larvae dispersion, settlement probability, food transport and also to simulate the feedback of the organisms' activity on the water column properties, which will result in an improvement of the food quantity and quality characterization.

Polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons in a one-off global survey of bivalves

DEFF Research Database (Denmark)

Vorkamp, Katrin; Strand, Jakob; Christensen, Jan H.

2010-01-01

During the Danish Galathea 3 expedition, bivalve samples were collected at the Faroe Islands, Greenland, Ghana, South Africa, Australia, Solomon Islands, New Zealand, Chile, US Virgin Islands, Boston, Newfoundland and Shetland Islands and analysed for organochlorines and PAHs. Concentration...... in terms of PCB and PAH levels, while other Greenland samples came closest to representing PAH background levels. Several locations had undetectable organochlorine levels, including Hobart and Chile, which had the lowest Sigma PAH concentrations (group the stations...

Uptake and loss of 134Cs and 60Co by the Baltic bivalve Macoma Baltica under laboratory conditions

International Nuclear Information System (INIS)

Evans, S.

1982-01-01

In order to predict the radiological impact on man via harvestable sea food products, it is essential to make a critical evaluation of the transfer routes and the rates on which radionuclides are transferred through the aquatic food chains. In the Baltic, the bivalve Macoma Baltica comprises a main food item for fish species of commercial interest, such as flounder. The accumulation and release of Cs-134 and Co-60 by Macoma was experimentally investigated. The nuclides were added to the water and the activity content of the bivalves was determined at regular intervals. The uptake was quite rapid, 40 per cent (Cs) and 55 per cent (Co) respectively of the final steady state was obtained after 24 hours. The subsequent release was rapid as well, 50 per cent (Cs) and 40 per cent (Co) respectively of the accumulated activity was lost within 6 days. The experiments demonstrated that the major intake route following short-term releases of activity will be from the water column. The close connection between activity in water and organism can thus be used for predictive purposes without the complication of radionuclide uptake from contaminated sediments. (Author)

Late Devonian (Frasnian) bivalves from the Nocedo Formation: the results of Wilhelm Kegel’s 1927 field trip to northern Spain

NARCIS (Netherlands)

Amler, M.R.W.

2010-01-01

During a field trip to the Peña-Corada Unit of the southernmost Esla region of the Cantabrian Mountains in 1927, the German stratigrapher Wilhelm Kegel sampled brachiopods and bivalves from a section in the Laoz valley near La Ercina. The stratigraphic position is believed to be part of the Nocedo

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

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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

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.

Physiological effects of hypercapnia in the deep-sea bivalve Acesta excavata (Fabricius, 1779) (Bivalvia; Limidae)

DEFF Research Database (Denmark)

Hammer, Karen M.; Kristiansen, Erlend; Zachariassen, Karl Erik

2011-01-01

The option of storing CO(2) in subsea rock formations to mitigate future increases in atmospheric CO(2) may induce problems for animals in the deep sea. In the present study the deep-sea bivalve Acesta excavata was subjected to environmental hypercapnia (pHSW 6.35, P(CO2), =33,000 mu atm...... extracellular pH remained significantly lower during recovery. Intracellular non-bicarbonate buffering capacity of the posterior adductor muscle of hypercapnic animals was significantly lower than control values, but this was not the case for the remaining tissues analyzed. Oxygen consumption initially dropped...

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.)

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.

Phenoloxidase activity in larval and juvenile homogenates and adult plasma and haemocytes of bivalve molluscs.

Science.gov (United States)

Luna-González, Antonio; Maeda-Martínez, Alfonso N; Vargas-Albores, Francisco; Ascencio-Valle, Felipe; Robles-Mungaray, Miguel

2003-10-01

Phenoloxidase (PO) activity was studied in larval and juvenile homogenates and in the plasma and haemocytes of adult Crassostrea gigas, Argopecten ventricosus, Nodipecten subnodosus, and Atrina maura. Samples were tested for the presence of PO activity by incubation with the substrate L-3, 4-dihydroxyphenylalanine using trypsin, alpha-chymotrypsin, laminarin, lipopolysaccharides (LPS), and sodium dodecyl sulphate (SDS) to elicit activation of prophenoloxidase (proPO) system. PO activity was not detected in larval homogenate. In juvenile homogenate, PO activity was found only in C. gigas and N. subnodosus. PO activity was present in adult samples and was enhanced by elicitors in the plasma of all species tested, but in haemocyte lysate supernatant (HLS) of only N. subnodosus. Activation of proPO by laminarin was suppressed by a protease inhibitor cocktail (P-2714) in plasma and HLS of all species tested.

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

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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.

Study on the bioaccumulation of Polonium-210 on bivalve indicator organisms of Tamilnadu and Pondicherry coast (East Coast of India)

International Nuclear Information System (INIS)

Syed Mohamed, H.E.; Sadiq Bukhari, A.; Meeramaideen, M.; Masilamani, V.; Shamsudin, Mohamed; Shahul Hameed, P.

2012-01-01

210 Po is a major contributor (90%) of the natural radiation dose from alpha-emitting radionuclides, received by most marine organisms. Among marine organisms, benthic fauna are superior to many other biological groups, since they could be monitored due to their sedentary habits and then must either adapt to environmental stress or perish. They also reflect the water conditions not only at the time of sampling but also for some past time as well. The affinity of 210 Po for protein enables it to pass through the food chain, and increased body burdens of 210 Po have been found where diets include protein-rich meat and seafood. The present study was launched to evaluate the rate of accumulation of 210 Po in the benthic bivalve molluscs such as Perna indica, P.viridis, Meretrix casta, Cardium coronatum, Gafrarium tumidum, Paphia textrix, Vellorita cyprinodea and Pinctada sp., of Tamilnadu and Pondicherry coast. Water samples, sediments and bivalves were collected from Gulf of Mannar (6 sampling stations), Palk Strait (8 sampling stations) of Tamilnadu and Pondicherry (6 sampling stations). 210 Po determination as made was as per standard protocols. The results showed that 210 Po concentration in coastal waters of Gulf of Mannar, Palk Strait and Pondicherry ranged 0.5 - 2.83 mBq/l (mean 1.33 mBq/I), 2.14 - 32.14 mBq/l (mean 15.3 mBq/l) and 1.36 - 2.0 mBq/1 (mean 1.59 mBq/1) respectively. The sediments maintained higher level of 210 Po (mean value of 3.62 Bq/kg in Gulf of Mannar, 107.9 Bq/kg in Palk Strait and 3.0 Bq/kg in Pondicherry) than water. The 210 Po rich sediment therefore serves as a vital link in the transfer of Polonium from water to the marine organisms. The concentration of 210 Po in eight species of bivalves collected from the study area, recorded a maximum level ranging from 65.2 to 2668.9 Bq/kg in soft tissues and from 1.19 to 15.3 Bq/kg in shells. The bioaccumulation ability in bivalve species with reference to 210 Po was observed to be highly variable

Inducing the Alternative Oxidase Forms Part of the Molecular Strategy of Anoxic Survival in Freshwater Bivalves

Science.gov (United States)

Yusseppone, Maria S.; Rocchetta, Iara; Sabatini, Sebastian E.; Luquet, Carlos M.; Ríos de Molina, Maria del Carmen; Held, Christoph; Abele, Doris

2018-01-01

Hypoxia in freshwater ecosystems is spreading as a consequence of global change, including pollution and eutrophication. In the Patagonian Andes, a decline in precipitation causes reduced lake water volumes and stagnant conditions that limit oxygen transport and exacerbate hypoxia below the upper mixed layer. We analyzed the molecular and biochemical response of the North Patagonian bivalve Diplodon chilensis after 10 days of experimental anoxia (<0.2 mg O2/L), hypoxia (2 mg O2/L), and normoxia (9 mg O2/L). Specifically, we investigated the expression of an alternative oxidase (AOX) pathway assumed to shortcut the regular mitochondrial electron transport system (ETS) during metabolic rate depression (MRD) in hypoxia-tolerant invertebrates. Whereas, the AOX system was strongly upregulated during anoxia in gills, ETS activities and energy mobilization decreased [less transcription of glycogen phosphorylase (GlyP) and succinate dehydrogenase (SDH) in gills and mantle]. Accumulation of succinate and induction of malate dehydrogenase (MDH) activity could indicate activation of anaerobic mitochondrial pathways to support anoxic survival in D. chilensis. Oxidative stress [protein carbonylation, glutathione peroxidase (GPx) expression] and apoptotic intensity (caspase 3/7 activity) decreased, whereas an unfolded protein response (HSP90) was induced under anoxia. This is the first clear evidence of the concerted regulation of the AOX and ETS genes in a hypoxia-tolerant freshwater bivalve and yet another example that exposure to hypoxia and anoxia is not necessarily accompanied by oxidative stress in hypoxia-tolerant mollusks. PMID:29527172

Inducing the Alternative Oxidase Forms Part of the Molecular Strategy of Anoxic Survival in Freshwater Bivalves

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Maria S. Yusseppone

2018-02-01

Full Text Available Hypoxia in freshwater ecosystems is spreading as a consequence of global change, including pollution and eutrophication. In the Patagonian Andes, a decline in precipitation causes reduced lake water volumes and stagnant conditions that limit oxygen transport and exacerbate hypoxia below the upper mixed layer. We analyzed the molecular and biochemical response of the North Patagonian bivalve Diplodon chilensis after 10 days of experimental anoxia (<0.2 mg O2/L, hypoxia (2 mg O2/L, and normoxia (9 mg O2/L. Specifically, we investigated the expression of an alternative oxidase (AOX pathway assumed to shortcut the regular mitochondrial electron transport system (ETS during metabolic rate depression (MRD in hypoxia-tolerant invertebrates. Whereas, the AOX system was strongly upregulated during anoxia in gills, ETS activities and energy mobilization decreased [less transcription of glycogen phosphorylase (GlyP and succinate dehydrogenase (SDH in gills and mantle]. Accumulation of succinate and induction of malate dehydrogenase (MDH activity could indicate activation of anaerobic mitochondrial pathways to support anoxic survival in D. chilensis. Oxidative stress [protein carbonylation, glutathione peroxidase (GPx expression] and apoptotic intensity (caspase 3/7 activity decreased, whereas an unfolded protein response (HSP90 was induced under anoxia. This is the first clear evidence of the concerted regulation of the AOX and ETS genes in a hypoxia-tolerant freshwater bivalve and yet another example that exposure to hypoxia and anoxia is not necessarily accompanied by oxidative stress in hypoxia-tolerant mollusks.

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

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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

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.

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 ...

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.

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...

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)

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.

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

Scientific opinion on the risks for public health related to the presence of tetrodotoxin (TTX) and TTX analogues in marine bivalves and gastropods

DEFF Research Database (Denmark)

Petersen, Annette

Tetrodotoxin (TTX) and its analogues are produced by marine bacteria and have been detected in marine bivalves and gastropods from European waters. The European Commission asked EFSA for a scientific opinion on the risks to public health related to the presence of TTX and TTX analogues in marine...... bivalves and gastropods. The Panel on Contaminants in the Food Chain reviewed the available literature but did not find support for the minimum lethal dose for humans of 2 mg, mentioned in various reviews. Some human case reports describe serious effects at a dose of 0.2 mg, corresponding to 4 μg/kg body...... weight (bw). However, the uncertainties on the actual exposure in the studies preclude their use for derivation of an acute reference dose (ARfD). Instead, a group ARfD of 0.25 μg/kg bw, applying to TTX and its analogues, was derived based on a TTX dose of 25 μg/kg bw at which no apathy was observed...

The quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 – another Ponto-Caspian dreissenid bivalve in the southern Baltic catchment: the first record from the Szczecin Lagoon

Directory of Open Access Journals (Sweden)

Adam Woźniczka

2016-04-01

Full Text Available In 2014, a non-indigenous dreissenid bivalve, the quagga mussel (Dreissena rostriformis bugensis Andrusov, 1897 was for the first time recorded in the Szczecin Lagoon. This was also the first record of the species in the Baltic Sea catchment. The quagga mussel was found to accompany the zebra mussel (Dreissena polymorpha, a non-indigenous bivalve already firmly established in the Lagoon. As indicated by the new immigrant's estimated abundance (4000.0 ± 355.44 ind. m−2 and the zebra mussel to quagga mussel abundance ratio (about 60:40, the immigration of D. rostriformis bugensis to the Lagoon can be regarded as successful. The quagga mussel has already formed a strong and reproducing population which co-occurs with that of the zebra mussel in the area.

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.

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.

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...

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...

Preliminary Evaluation of Microbial Communities Isolated from the Calcifying Fluid of Oysters

Science.gov (United States)

Banker, R.

2016-02-01

The process of biomineralization is defined as the selective uptake of elements that are incorporated into a defined mineral structure under strict biological control. For bivalve molluscs, such as clams, oysters, and mussels, the mantle is the primary organ in control of shell deposition. Alternatively, remote calcification takes place when carbonate-precipitating microbes (e.g. sulfate reducers) colonize a shell-secreting organism and enhance the ability of the host to build shell material. The oyster syndrome is a term that describes bivalves that possess an unusual shell morphology characterized by exceptionally thick valves containing numerous chambers filled with chalky calcite. Although remote calcification via microbial metabolism has been proposed as a mechanism of chalky deposit formation in oysters, this hypothesis has not yet been rigorously investigated. Here I present data on the microbial communities found in the calcifying fluid of two oyster species; Crassostrea gigas and Ostrea lurida are examples of oysters that do and do not exhibit the oyster syndrome, respectively. Comparison of the microbiomes of these two morphological end members may provide insight into the role of microbes in the formation of chalky deposits. Results indicate that the microbial community in the surrounding water is the dominant source for bacterial taxa found in the calcifying fluid of both oyster species. Also, it appears as though C. gigas maintains a microbial community that is more similar to its ambient environment than O. lurida. These results demonstrate that the ambient aquatic environment has a guiding influence on the microbiome found in the calcifying fluid of bivalve molluscs. However, the magnitude of this effect varies among organisms, even those that are closely related.

Hepatitis A and E Viruses in Wastewaters, in River Waters, and in Bivalve Molluscs in Italy.

Science.gov (United States)

Iaconelli, M; Purpari, G; Della Libera, S; Petricca, S; Guercio, A; Ciccaglione, A R; Bruni, R; Taffon, S; Equestre, M; Fratini, M; Muscillo, M; La Rosa, Giuseppina

2015-12-01

Several studies have reported the detection of hepatitis A (HAV) and E (HEV) virus in sewage waters, indicating a possibility of contamination of aquatic environments. The objective of the present study was to assess the occurrence of HAV and HEV in different water environments, following the route of contamination from raw sewage through treated effluent to the surface waters receiving wastewater discharges . Bivalve molluscan shellfish samples were also analyzed, as sentinel of marine pollution. Samples were tested by RT-PCR nested type in the VP1/2A junction for HAV, and in the ORF1 and ORF2 regions for HEV. Hepatitis A RNA was detected in 12 water samples: 7/21 (33.3%) raw sewage samples, 3/21 (14.3%) treated sewage samples, and 2/27 (7.4%) river water samples. Five sequences were classified as genotype IA, while the remaining 7 sequences belonged to genotype IB. In bivalves, HAV was detected in 13/56 samples (23.2%), 12 genotype IB and one genotype IA. Whether the presence of HAV in the matrices tested indicates the potential for waterborne and foodborne transmission is unknown, since infectivity of the virus was not demonstrated. HEV was detected in one raw sewage sample and in one river sample, both belonging to genotype 3. Sequences were similar to sequences detected previously in Italy in patients with autochthonous HEV (no travel history) and in animals (swine). To our knowledge, this is the first detection of HEV in river waters in Italy, suggesting that surface water can be a potential source for exposure .

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)

Biomarkers of metabolism disturbance in bivalve molluscs induced by environmental pollution with processed by-products of oil

Directory of Open Access Journals (Sweden)

E. V. Sukharenko

2017-05-01

Full Text Available Processed by-products of oil are the most common pollutants in all river and sea water. The increase in oxidative stress in bivalve molluscs was studied in both tissues of the hepatopancreas and the gill. The model for artificial treatment with processed by-products of oil was performed in a laboratory experiment with the river mollusc Dreissena polymorpha Pallas, 1771. The exposure of the molluscs over 28 days to mazut 50 mg/l induced significant increase of both final product of lipid peroxidation (LPO and antioxidant enzime activity. A significant increase in LPO was observed in the hepatopancreas and gill of D. polymorpha treated with mazut compared to the control group. Antioxidant enzyme activity of cartalase, supeoxide dismutase, glutathione reductase and glutathione-S-transferase showed a greater increase (by almost 1.5 times in the hepatopancreas than in the gill of D. polymorpha. A similar LPO growth and modulation of antioxidant enzyme activity were determined in the hepatopancreas and gill of the mussel Mytilus galloprovincialis Lamarck, 1879 collected in an area polluted with resins, hydrocarbons and asphaltenes, Donuzlav lake in the Kerch gulf. Varied cellular reactivation of the antioxidant enzyme system in the hepatopancreas rather than the gill was observed in both kinds of mollusc Dreissena and Mytilus. The obtained results are evidence of the higher sensitivity of the hepatopancreas cells of bivalve molluscs to organic pollutants compared to the gill cells.

RAW TROPICAL OYSTERS AS VEHICLES FOR MULTIDRUG-RESISTANT Vibrio parahaemolyticus

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Renata Albuquerque COSTA

2015-06-01

Full Text Available The following study aimed to determine the antimicrobial susceptibility profile of Vibrio parahaemolyticus strains from fresh and frozen oysters Crassostrea rhizophorae sold in Fortaleza-Brazil. An antibiogram was performed on 87 isolates using nine antibiotics: gentamicin (Gen 10 µg, ampicillin (Amp 10 µg, penicillin G (Pen 10U, ciprofloxacin (Cip 5 µg, chloramphenicol (Chl 30 µg, nalidixic acid (Nal 30 µg, tetracycline (Tet 30 µg, vancomycin (Van 30 µg and erythromycin (Ery 15 µg. All strains were resistant to at least one antibiotic, and 85 (97.7% were multi-resistant, with predominance of the Van+ Pen+Amp resistance profile (n = 46. Plasmid resistance to Pen, Amp and Ery was detected. Thus, the risk that raw oyster consumption poses to the health of consumers is highlighted, due to the fact that these bivalves may host antibacterial-resistant microorganisms.

pH controls spermatozoa motility in the Pacific oyster (Crassostrea gigas

Directory of Open Access Journals (Sweden)

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.

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....

The mismatch between bioaccumulation in field and laboratory environments: Interpreting the differences for metals in benthic bivalves

International Nuclear Information System (INIS)

Belzunce-Segarra, Maria J.; Simpson, Stuart L.; Amato, Elvio D.; Spadaro, David A.; Hamilton, Ian L.; Jarolimek, Chad V.; Jolley, Dianne F.

2015-01-01

Laboratory-based bioaccumulation and toxicity bioassays are frequently used to predict the ecological risk of contaminated sediments in the field. This study investigates the bioassay conditions most relevant to achieving environmentally relevant field exposures. An identical series of metal-contaminated marine sediments were deployed in the field and laboratory over 31 days. Changes in metal concentrations and partitioning in both sediments and waters were used to interpret differences in metal exposure and bioaccumulation to the benthic bivalve Tellina deltoidalis. Loss of resuspended sediments and deposition of suspended particulate matter from the overlying water resulted in the concentrations of Cu, Pb and Zn (major contaminants) becoming lower in the 1-cm surface layer of field-deployed sediments. Lower exchange rates of overlying waters in the laboratory resulted in higher dissolved metal exposures. The prediction of metal bioaccumulation by the bivalves in field and laboratory was improved by considering the metal partitioning within the surface sediments. - Highlights: • Particulate metals are the dominant metal exposure route in laboratory and field tests (87). • There is an over-representation of the dissolved metal exposure in the laboratory (81). • Laboratory bioassays result in higher bioaccumulation of major metals, Cu, Pb, Zn (82). • Differences in exposure must be considered for a proper sediment quality evaluation (83). • Traditional measurements are not sufficient to explain bioaccumulation results (79). - To improve the value of field- and laboratory-based sediment bioassays in ecological risk assessments, it is necessary to create exposure conditions that resemble those in the field

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.

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.

Monitoring of polycyclic aromatic hydrocarbons in a produced water disposal area in the Potiguar Basin, Brazilian equatorial margin.

Science.gov (United States)

Lourenço, Rafael André; de Oliveira, Fábio Francisco; de Souza, João Maximino; Nudi, Adriana Haddad; de Luca Rebello Wagener, Ângela; de Fátima Guadalupe Meniconi, Maria; Francioni, Eleine

2016-09-01

The Potiguar Basin has oil and gas production fields offshore and onshore. All treated produced water (PW) from these fields is discharged through submarine outfalls. Although polycyclic aromatic hydrocarbons (PAHs) are minor constituents of PW, their input into the marine ecosystem is environmentally critical due to potential ecological hazards. A 2-year monitoring program was conducted in the vicinity of the outfalls to evaluate PAH bioaccumulation in marine life from PW discharges. The study was performed using transplanted bivalves Crassostrea brasiliana and semipermeable membrane devices (SPMDs) to measure PAH concentrations via bioaccumulation and in seawater. The bioaccumulation of PAH in transplanted bivalves reached up to 1105 ng g(-1) in the vicinity of the monitored outfall. Significantly lower PAH concentrations were found in the reference area in comparison to the studied area around the outfalls. Time-integrated PAH concentrations in seawater ranged from 38 to 0.3 ng L(-1) near the outfalls and from 10 ng L(-1) to not detected in the reference area. Both measurement techniques were found to be effective for determining a gradient of descending PAH concentrations from the outfalls. In addition, this study also evaluated the bioavailability of PAH for local marine biota and provided information about the influence of PW discharges on the water quality of marine ecosystems.

δ15N as a proxy for historic anthropogenic nitrogen loading in Charleston Harbor, SC, USA

Science.gov (United States)

Payne, T. N.; Andrus, C. F. T.

2015-12-01

Bivalve shell geochemistry can serve as a useful indicator of changes in coastal environments. There is increasing interest in developing paleoenvironmental proxies from mollusk shell organic components. Numerous studies have focused on how the δ15N obtained from bivalve tissues can be used to trace present-day wastewater input into estuaries. However, comparatively little attention has been paid to tracing the impact of anthropogenic nitrogen loading into estuaries over time. By measuring historic levels of δ15N in the organic fraction of oyster shells (Crassostrea virginica) from archaeological sites around Charleston Harbor and comparing those levels to the δ15N content of modern shells, it is possible to assess how nitrogen has fluctuated historically in the area. Whole-shell samples from the Late Archaic Period (~3000-4000 BP, Late Woodland Period (~1400-800 BP), 18th and 19th centuries, and modern controls were measured for %N and d15N. Evidence of increased anthropogenic input of N is expected to begin in the early historic period based on similar analysis in Chesapeake Bay. More ancient samples may give insight into baseline conditions prior to recent population growth and industrialization. This information could help understand how large-scale anthropogenic nitrogen loading has affected coastal ecosystems over time and guide future remediation. Furthermore, this project will help refine and improve this novel proxy of past environmental conditions.

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

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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.

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

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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.

Processes of physical change to the seabed and bivalve recruitment over a 10-year period following experimental hydraulic clam dredging on Banquereau, Scotian Shelf

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Gilkinson, K.; King, E. L.; Li, M. Z.; Roddick, D.; Kenchington, E.; Han, G.

2015-01-01

A previous study on the effects of experimental hydraulic clam dredging on seabed habitat and commercial bivalve populations revealed a lack of recovery after a 3-year post-dredging period (1998-2001) on a deep (65-75 m) offshore sandy bank on the Scotian Shelf, Canada. Follow-up sidescan sonar surveys were carried out 5 and 10 years after dredging (2003, 2008) in order to identify long-term processes of seabed recovery. Grab sampling was carried out 10 years after dredging to identify post-dredging commercial bivalve recruitment. Changes in the seafloor, including dredge tracks, were documented with a series of 7 sidescan sonar surveys between 1998 and 2008. A sediment mobility model was constructed based on modeled tidal current and hindcast wave data over this time period to quantify natural seabed disturbance and interpret changes to the dredge tracks mapped by sidescan sonar surveys. The model indicated that tidal currents had minimal effect on sediment mobilization. The main driving force associated with re-working of surficial sediments as evidenced by deterioration of dredge tracks in sonograms was annual fall/winter storms. While the annual frequency of storms and associated wave heights was variable, the observations and sediment mobility calculations suggest that the most influential variable is the magnitude of individual large storms, specifically storms with a significant wave height of ∼11 m. These storms are capable of generating mobile sediment layers of 20-30 cm thickness, equivalent to the dredge blade cutting depth. It appears that, with minor exceptions, sediment properties have returned to pre-dredging conditions 10 years after dredging in this habitat. Based on known age-length relationships, the four commercial bivalve species showed very low recruitment at the experimental site over the 10-year post-dredging period. However, this is unlikely due to a dredging effect since a similar pattern was observed in non-dredged areas.

DICKINSARTELLA FAUNA FROM THE SAIWAN FORMATION (OMAN: A BIVALVE FAUNA TESTIFYING TO THE LATE SAKMARIAN (EARLY PERMIAN CLIMATIC AMELIORATION ALONG THE NORTH-EASTERN GONDWANAN FRINGE.

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CRISTIANO LARGHI

2005-11-01

Full Text Available The transitional faunas of the Permian Huqf succession of Oman make it one of the key-sections for the intercalibration of Early to Middle Permian biostratigraphical scales. The abundance of fossils improved the knowledge of some marine faunas which populated the North-Eastern Gondwanan fringe during times of climatic changes in the Permian. A Sterlitamakian (upper Sakmarian, Lower Permian bivalve fauna from the Saiwan Formation in the Huqf area, informally named "Dickinsartella Fauna", is described in the present paper. The specimens examined were collected from the "Pachycyrtella Bed" (Auctorum, the basal bed of the Formation in its type locality. The Dickinsartella Fauna can be identified for the presence of the new genus Dickinsartella, which dominates the bivalve thanatocoenosis with D. pistacina sp. n. (type species. The bivalve fauna from the Pachycyrtella Bed includes the new species Stutchburia sangallii and Promytilus  mazzolenii, and also Astartella obliqua Dickins, 1963, Nuculopsis cf. bangarraensis Dickins, 1963, ?Oriocrassatella sp., and indeterminable aviculopectinids. This fauna shows a low taxonomic diversity. Nevertheless, some species are represented by a high number of generally well-preserved specimens, i.e. some specimens of S. sangallii sp. n. and A. obliqua show part of the ligament.  The good preservation of the shells permitted the microstructural analysis of D. pistacina sp. n. and S. sangallii sp. n. The microstructure of S. sangallii sp. n. supports the close phylogenetical link between modiomorphids and crassatelloids recognized by some previous authors.The new genus Dickinsartella includes the more recent species belonging to the important Paleozoic Order Cyrtodontida Scarlato & Starobogatov, 1971. The discovery of Dickinsartella gen. n. and other taxa of the Pachycyrtella Bed, present also in the Sakmarian levels of the Carnarvon and Perth Basins in Western Australia,  indicates a wider distribution of the

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.

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.

Biochemical profile of oyster Crassostrea madrasensis and its nutritional attributes

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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.

Ultrasound assisted enzymatic hydrolysis for isolating titanium dioxide nanoparticles from bivalve mollusk before sp-ICP-MS.

Science.gov (United States)

Taboada-López, María Vanesa; Iglesias-López, Sara; Herbello-Hermelo, Paloma; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

2018-08-14

Applicability of single-particle inductively coupled plasma mass spectrometry (sp-ICP-MS) using dwell times equal to or shorter than 100 μs has been tested for assessing titanium dioxide nanoparticles (TiO 2 NPs) in bivalve mollusks. TiO 2 NPs isolation from fresh mollusk tissues was achieved by ultrasound assisted enzymatic hydrolysis procedure using a pancreatin/lipase mixture. Optimum extraction conditions imply ultrasonication (60% amplitude) for 10 min, and 7.5 mL of a solution containing 3.0 g L -1 of pancreatin and lipase (pH 7.4). The developed method was found to be repeatable (repeatability of 17% for the over-all procedure, TiO 2 NPs concentration of 5.33 × 10 7  ± 8.89 × 10 6 , n = 11), showing a limit of detection of 5.28 × 10 6 NPs g -1 , and a limit of detection in size of 24.4-30.4 nm, based on the 3σ criteria, and on the 3σ/5 σ criteria, respectively. The analytical recovery within the 90-99% range (use of TiO 2 NPs standards of 50 nm at 7 and 14 μg L -1 as Ti). Several bivalve mollusks (clams, cockles, mussels, razor clams, oysters and variegated scallops) were analyzed for total titanium (ICP-MS after microwave assisted acid digestion), and for TiO 2 NPs by the proposed method. TiO 2 NPs concentrations were within the 2.36 × 10 7 -1.25 × 10 8 NPs g -1 range, and the most frequent sizes were from 50 to 70 nm. Copyright © 2018 Elsevier B.V. All rights reserved.

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

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

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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

A developmental and energetic basis linking larval oyster shell formation to acidification sensitivity

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Waldbusser, George G.; Brunner, Elizabeth L.; Haley, Brian A.; Hales, Burke; Langdon, Christopher J.; Prahl, Frederick G.

2013-05-01

Acidified waters are impacting commercial oyster production in the U.S. Pacific Northwest, and favorable carbonate chemistry conditions are predicted to become less frequent. Within 48 h of fertilization, unshelled Pacific oyster (Crassostrea gigas) larvae precipitate roughly 90% of their body weight as calcium carbonate. We measured stable carbon isotopes in larval shell and tissue and in algal food and seawater dissolved inorganic carbon in a longitudinal study of larval development and growth. Using these data and measured biochemical composition of larvae, we show that sensitivity of initial shell formation to ocean acidification results from diminished ability to isolate calcifying fluid from surrounding seawater, a limited energy budget and a strong kinetic demand for calcium carbonate precipitation. Our results highlight an important link between organism physiology and mineral kinetics in larval bivalves and suggest the consideration of mineral kinetics may improve understanding winners and losers in a high CO2 world.

Rhythmic patterns in ancient shells: Can we reconstruct sub-annual cyclicity in trace element and stable isotope profiles from rudist bivalves?

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de Winter, N.; Sinnesael, M.; Vansteenberge, S.; Goderis, S.; Snoeck, C.; Van Malderen, S. J. M.; Vanhaecke, F. F.; Claeys, P.

2017-12-01

Well-preserved shells of Torreites rudists from the Late Campanian Saiwan Formation in Oman exhibit fine internal layering. These fine (±20 µm) laminae are rhythmically bundled (±400 µm) and subdivide the shells' larger scale annual lamination (±15 mm), suggesting the presence of several interfering cycles in shell growth rate. The aim of the present study is to determine the duration and chemical signature of these rhythmic variations in shell composition. To achieve this, a range of micro-analytical techniques is applied on cross sections through the shells. Firstly, microscopy-based layer counting and colorimetric analysis are carried out on thin sections of shell calcite. Secondly, X-Ray Fluorescence (XRF) and Fourier Transform InfraRed (FTIR) mapping of cross sections of the shells reveal chemical and structural differences between laminae in 2D. Thirdly, high-resolution XRF (25 µm) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS; 10 µm) trace element profiles are used to quantify variations in chemical composition between shell laminae. Fourthly, annual chronology is established based on micro-sampled stable carbon and oxygen stable isotope measurements (250 µm) along the growth axis of the shells. Finally, spectral analysis routines are applied to extract rhythmic patterns matched to the shell laminae from the structural, chemical and colorimetric data. Combining these methods allows for a full evaluation of the structural and chemical characteristics as well as the timing of sub-annual lamination in rudist shells. The results of this study shed light on the external factors that influenced growth rates in rudist bivalves. A better understanding of the timing of deposition of these laminae allows them to be used to improve age models of geochemical records in rudist shells. Characterization of small scale variations in shell composition will characterize the uncertainties contained within lower resolution proxy records from

Nitrogenous compounds changes in emersed oysters: Crassostrea gigas

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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

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

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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.

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.

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 ...

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

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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.

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

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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.

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)

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.

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)

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

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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.

Characterization of freshwater bivalves as radio contamination (57Co, 110mAg, 134Cs) bio-indicators in a metallic multi pollution context (Cd, Zn)

International Nuclear Information System (INIS)

Fraysse, B.

2001-07-01

This study concerns freshwater bio-indicators of radio-contamination, in a metallic multi-pollution context. Metals, such as cadmium (Cd) and zinc (Zn), are widely represented in aquatic ecosystems, and their concentrations can induce physiological effects. This chronicle exposure generates both metabolic and behaviour stress of individuals, and can also yield to detoxification mechanisms induction. The main goal of this work was to estimate the influence of metals on the radionuclides ( 57 Co, 110m Ag, 134 Cs) bioaccumulation by two different bivalve species (Corbicula fluminea et Dreissena polymorpha), by studying the contamination level, the kinetic of the radionuclide transfer and the soft-body repartition. As the exploratory feature of this study, two parts have been developed: (i) testing the problematic suitability in a really bio-monitoring situation, and (ii) analysing the metal/radionuclide interaction mechanisms under controlled and standardised conditions (laboratory). For the different experimental conditions explored (laboratory and field), radionuclide bioaccumulation by freshwater bivalves has been influenced by metal exposure. This result was obtained after assessing a decrease of the organisms contamination level by radionuclide and their accumulation rate, an increase of their depuration rate and tissue and cellular repartition changes. (author)

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

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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.

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...

Ecological studies of wood-boring bivalves in the vicinity of the Oyster Creek Nuclear Generating Station. Progress report Sep-Nov 81

International Nuclear Information System (INIS)

Hoagland, K.E.; Crocket, L.

1982-06-01

The species composition, distribution, and population dynamics of wood-boring bivalves are being studied in the vicinity of the Oyster Creek Nuclear Generating Station, Barnegat Bay, New Jersey. Untreated wood test panels are used to collect organisms at 12 stations. Physiological tolerances of 3 species are also under investigation in the laboratory. Competition among the species is being analyzed. In the fall of 1981, Teredo bartschi remained in Oyster Creek despite continuous prolonged outages of the Oyster Creek Nuclear Generating Station

Manganese in the shell of the bivalve Mytilus edulis: Seawater Mn or physiological control?

Science.gov (United States)

Freitas, Pedro S.; Clarke, Leon J.; Kennedy, Hilary; Richardson, Christopher A.

2016-12-01

Manganese in the shell calcite of marine bivalves has been suggested to reflect ambient seawater Mn concentrations, thus providing a high-resolution archive of past seawater Mn concentrations. However, a quantitative relationship between seawater Mn and shell Mn/Ca ratios, as well as clear understanding of which process(es) control(s) shell Mn/Ca, are still lacking. Blue mussels, Mytilus edulis, were grown in a one-year duration field experiment in the Menai Strait, U.K., to study the relationship between seawater particulate and dissolved Mn2+ concentrations and shell calcite Mn/Ca ratios. Shell Mn/Ca showed a well-defined intra-annual double-peak, with maximum values during early spring and early summer and low values during autumn and winter. Seawater particulate Mn peaked during winter and autumn, with a series of smaller peaks during spring and summer, whereas dissolved Mn2+ exhibited a marked single maximum during late-spring to early-summer, being low during the remainder of the year. Consequently, neither seawater particulate Mn nor dissolved Mn2+ concentrations explain the intra-annual variation of shell Mn/Ca ratios. A physiological control on shell Mn/Ca ratios is evident from the strong similarity and timing of the double-peaked intra-annual variations of Mn/Ca and shell growth rate (SGR), the latter corresponding to periods of increased metabolic activity (as indicated by respiration rate). It is thus likely that in M. edulis SGR influences shell Mn/Ca by altering the concentration or activity of Mn2+ within the extra-pallial fluid (EPF), by changing the flux of Mn into or the proportion of protein bound Mn within the EPF. By linking shell Mn/Ca ratios to the endogenous and environmental factors that determine growth and metabolic activity, this study helps to explain the lack of a consistent relationship between shell Mn/Ca in marine bivalve shell calcite and seawater particulate and dissolved Mn2+ concentrations. The use of Mn content from M. edulis

Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer

International Nuclear Information System (INIS)

Fournier, E.

2005-10-01

Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

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

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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

Modulation of pumping rate by two species of marine bivalve molluscs in response to neurotransmitters: Comparison of in vitro and in vivo results.

Science.gov (United States)

Frank, Dana M; Deaton, Lewis; Shumway, Sandra E; Holohan, Bridget A; Ward, J Evan

2015-07-01

Most studies regarding the neuroanatomy and neurophysiology of molluscan ctenidia have focused on isolated ctenidial tissue preparations. This study investigated how bivalve molluscs modulate their feeding rates by examining the effects of a variety of neurotransmitters, including serotonin, dopamine, and the dopamine agonist apomorphine on both isolated ctenidial tissue and in intact members of two commercially important bivalve species: the blue mussel, Mytilus edulis; and the bay scallop Argopecten irradians. In particular, we examined the effect of changes in: 1) beat of the lateral cilia (in vitro), 2) distance between ctenidial filaments and/or plicae (in vivo), and 3) diameter of the siphonal openings (in vivo) on alteration of bulk water flow through the mantle cavity. Important differences were found between isolated tissue and whole animals, and between species. Drugs that stimulated ciliary beat in vitro did not increase water processing rate in vivo. None of the treatments increased water flow through the mantle cavity of intact animals. Results suggest that A. irradians was primarily modulating lateral ciliary activity, while M. edulis appeared to have a number of ways to control water processing activity, signifying that the two species may have different compensatory and regulatory mechanisms controlling feeding activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Metabolic Energy Demand Is Not Increased during Initial Shell Formation of Bivalves Exposed to Aragonite Undersaturation

Science.gov (United States)

Pan, F.; Frieder, C.; Applebaum, S.; Manahan, D. T.

2016-02-01

The Pacific oyster, Crassostrea gigas, is a major commercial species in global aquaculture. Ocean acidification is having a negative effect on larval production of this species, so the mechanisms of this impact are of considerable interest. Formation of new shell in C. gigas during the first 2-days post-fertilization results in a rapid six-fold increase in total mass. This period of early development has high sensitivity to changes in carbonate chemistry, in particular aragonite saturation state (Ω). An elevated energy cost for calcification at low Ω is often invoked as a mechanism. In this study, we characterized the developmental progression of first shell formation, total metabolic expenditure, and underlying biochemical processes of energy allocation during early development of C. gigas, under control (Ω >> 1) and undersaturated conditions (Ω pump activity (Na+, K+-ATPase) between the two treatments. We conclude that early development to the shelled-veliger larval stage does not require more energy at undersaturation. This finding helps constrain potential mechanisms of larval sensitivity to ocean acidification and narrows the focus for possible mitigation strategies for oyster aquaculture production.

Calibration of hydroclimate proxies in freshwater bivalve shells from Central and West Africa

Science.gov (United States)

Kelemen, Zita; Gillikin, David P.; Graniero, Lauren E.; Havel, Holly; Darchambeau, François; Borges, Alberto V.; Yambélé, Athanase; Bassirou, Alhou; Bouillon, Steven

2017-07-01

Freshwater bivalve shell oxygen and carbon stable isotope ratios (δ18O, δ13C) may act as recorders of hydroclimate (e.g., precipitation-evaporation balance, discharge) and aquatic biogeochemistry. We investigate the potential of these hydroclimate proxies measured along the growth axis of shells collected from the Oubangui River (Bangui, Central African Republic) and the Niger River (Niamey, Niger). Biweekly water samples and in situ measurements collected over several years, along with daily discharge data from both sites allowed a direct comparison with proxies recorded in the shells. Data from a total of 14 unionid shells, including three species (Chambardia wissmanni, Aspatharia dahomeyensis, and Aspatharia chaiziana), confirmed that shells precipitate carbonate in oxygen isotope equilibrium with ambient water. Because water temperature variations were small, shell δ18O values (δ18Oshell) also accurately record the seasonality and the range observed in water δ18O (δ18Ow) values when calculated using an average temperature. Calculated δ18Ow values were in good agreement over the entire record of measured δ18Ow values, thus δ18Oshell records can be reliably used to reconstruct past δ18Ow values. Discharge and δ18Ow values from both rivers fit a logarithmic relationship, which was used to attempt reconstruction of past hydrological conditions, after calculating δ18Ow values from δ18Oshell values. A comparison with measured discharge data suggests that for the two rivers considered, δ18Oshell data are good proxies for recording discharge conditions during low(er) discharge levels, but that high discharge values cannot be accurately reconstructed due to the large scatter in the discharge-δ18Ow relationship. Moreover, periods of bivalve shell growth cessation due to high turbidity or air exposure should be taken into account. While δ13C values of dissolved inorganic carbon in both rivers showed clear seasonality and correlated well with discharge

Bioacessibilidade in vitro das biotoxinas marinhas ácido ocadaico, dinofisistoxina-2 e seus derivados em bivalves crus e cozinhados

OpenAIRE

Manita, Diana Filipa Pereira

2017-01-01

Dissertação de Mestrado em Segurança Alimentar As biotoxinas marinhas mais frequentes e abundantes em Portugal são as toxinas lipofílicas, nomeadamente as toxinas do grupo do ácido ocadaico (AO), que inclui as dinofisistoxinas (DTX1 e DTX2) e os seus derivados (DTX3), responsáveis pela intoxicação diarreica (DSP diarrhetic shellfish poisoning). A investigação da presença, variabilidade e transformação de biotoxinas marinhas em moluscos bivalves é de elevada importância não só p...

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

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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.

Insights from the Shell Proteome: Biomineralization to Adaptation.

Science.gov (United States)

Arivalagan, Jaison; Yarra, Tejaswi; Marie, Benjamin; Sleight, Victoria A; Duvernois-Berthet, Evelyne; Clark, Melody S; Marie, Arul; Berland, Sophie

2017-01-01

Bivalves have evolved a range of complex shell forming mechanisms that are reflected by their incredible diversity in shell mineralogy and microstructures. A suite of proteins exported to the shell matrix space plays a significant role in controlling these features, in addition to underpinning some of the physical properties of the shell itself. Although, there is a general consensus that a minimum basic protein tool kit is required for shell construction, to date, this remains undefined. In this study, the shell matrix proteins (SMPs) of four highly divergent bivalves (The Pacific oyster, Crassostrea gigas; the blue mussel, Mytilus edulis; the clam, Mya truncata, and the king scallop, Pecten maximus) were analyzed in an identical fashion using proteomics pipeline. This enabled us to identify the critical elements of a "basic tool kit" for calcification processes, which were conserved across the taxa irrespective of the shell morphology and arrangement of the crystal surfaces. In addition, protein domains controlling the crystal layers specific to aragonite and calcite were also identified. Intriguingly, a significant number of the identified SMPs contained domains related to immune functions. These were often are unique to each species implying their involvement not only in immunity, but also environmental adaptation. This suggests that the SMPs are selectively exported in a complex mix to endow the shell with both mechanical protection and biochemical defense. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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.

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

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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.

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.

Adaptabilidad ecofisiológica de organismos acuáticos tropicales a cambios de salinidad

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Kyung S. Chung

2001-03-01

Full Text Available Physiological response of tropical organisms to salinity changes was studied for some marine, estuarine and freshwater fishes (Astyanax bimaculatus, Petenia karussii, Cyprinodon dearborni, and Oreochromis mossambicus, marine and freshwater crustaceans (Penaeus brasiliensis, Penaeus schmitti and Macrobrachium carcinus, and marine bivalves (Perna perna, Crassostrea rhizophorae, and Arca zebra collected from Northeast Venezuela. They were acclimated for four weeks at various salinities, and (1 placed at high salinities to determine mean lethal salinity, (2 tested by increasing salinity 5 ‰ per day to define upper lethal salinity tolerance limit, or (3 observed in a saline gradient tank to determine salinity preference. Acclimation level was the most significant factor. This phenomenon is important for tropical aquatic organisms in shallow waters, where they can adapt to high salinity during the dry season and cannot lose their acclimation level at low salinity during abrupt rain. For saline adaptation of tropical organisms, this behavior will contribute to their proliferation and distribution in fluctuating salinity environments.

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.

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.

Differing responses of the estuarine bivalve Limecola balthica to lowered water pH caused by potential CO2 leaks from a sub-seabed storage site in the Baltic Sea: An experimental study.

Science.gov (United States)

Sokołowski, Adam; Brulińska, Dominika; Mirny, Zuzanna; Burska, Dorota; Pryputniewicz-Flis, Dorota

2018-02-01

Sub-Seabed CCS is regarded as a key technology for the reduction of CO 2 emissions, but little is known about the mechanisms through which leakages from storage sites impact benthic species. In this study, the biological responses of the infaunal bivalve Limecola balthica to CO 2 -induced seawater acidification (pH7.7, 7.0, and 6.3) were quantified in 56-day mesocosm experiments. Increased water acidity caused changes in behavioral and physiological traits, but even the most acidic conditions did not prove to be fatal. In response to hypercapnia, the bivalves approached the sediment surface and increased respiration rates. Lower seawater pH reduced shell weight and growth, while it simultaneously increased soft tissue weight; this places L. balthica in a somewhat unique position among marine invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of anthropogenic sound on digging behavior, metabolism, Ca2+/Mg2+ ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta

Science.gov (United States)

Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

2016-01-01

Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams. PMID:27063002

Effects of anthropogenic sound on digging behavior, metabolism, Ca(2+)/Mg(2+) ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta.

Science.gov (United States)

Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

2016-04-11

Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca(2+)/Mg(2+)-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.

Effects of anthropogenic sound on digging behavior, metabolism, Ca2+/Mg2+ ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta

Science.gov (United States)

Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

2016-04-01

Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.

Hypoxia and acidification have additive and synergistic negative effects on the growth, survival, and metamorphosis of early life stage bivalves.

Science.gov (United States)

Gobler, Christopher J; DePasquale, Elizabeth L; Griffith, Andrew W; Baumann, Hannes

2014-01-01

Low oxygen zones in coastal and open ocean ecosystems have expanded in recent decades, a trend that will accelerate with climatic warming. There is growing recognition that low oxygen regions of the ocean are also acidified, a condition that will intensify with rising levels of atmospheric CO2. Presently, however, the concurrent effects of low oxygen and acidification on marine organisms are largely unknown, as most prior studies of marine hypoxia have not considered pH levels. We experimentally assessed the consequences of hypoxic and acidified water for early life stage bivalves (bay scallops, Argopecten irradians, and hard clams, Mercenaria mercenaria), marine organisms of significant economic and ecological value and sensitive to climate change. In larval scallops, experimental and naturally-occurring acidification (pH, total scale  = 7.4-7.6) reduced survivorship (by >50%), low oxygen (30-50 µM) inhibited growth and metamorphosis (by >50%), and the two stressors combined produced additively negative outcomes. In early life stage clams, however, hypoxic waters led to 30% higher mortality, while acidified waters significantly reduced growth (by 60%). Later stage clams were resistant to hypoxia or acidification separately but experienced significantly (40%) reduced growth rates when exposed to both conditions simultaneously. Collectively, these findings demonstrate that the consequences of low oxygen and acidification for early life stage bivalves, and likely other marine organisms, are more severe than would be predicted by either individual stressor and thus must be considered together when assessing how ocean animals respond to these conditions both today and under future climate change scenarios.

The bivalve Anopaea (Inoceramidae) from the Upper Jurassic-lowermost Cretaceous of Mexico

Science.gov (United States)

Zell, Patrick; Crame, J. Alistair; Stinnesbeck, Wolfgang; Beckmann, Seija

2015-07-01

In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian-lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic-earliest Cretaceous, between Mexico and the Antarctic Realm.

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

Bioaccumulation of selenium and induced biological effects in the filter feeding bivalve Corbicula fluminea: influence of ventilatory activity, selenium speciation and route of transfer; Bioaccumulation du selenium et effets biologiques induits chez le bivalve filtreur Corbicula fluminea: prise en compte de l'activite ventilatoire, de la speciation du selenium et de la voie de contamination

Energy Technology Data Exchange (ETDEWEB)

Fournier, E

2005-10-15

Selenium is an essential micro-nutrient for most of living organisms. However, toxic effects in several ecosystems have been reported in the literature. Toxicity comprehension is difficult due to the complexity of Se oxidation states in the environment. The aim of this thesis work was to acquire knowledge on the physiological and environmental factors involved in bioaccumulation and toxicity processes in the freshwater filter-feeding bivalve C. fluminea. The aims were: i) to define what the factors involved in Se bioaccumulation processes in the bivalve are, ii) to characterize Se bioaccumulation at different biological organisation levels, iii) to investigate Se toxic effects. First experiments, carried out for short term exposure duration (3 days), have permitted to underline the importance of Se chemical speciation in bioaccumulation processes in C. fluminea. It has been shown that the organic form, seleno-methionine, was much more bio-available than the inorganic forms, selenite and selenate. Moreover, the route of transfer was determinant in those processes. Inorganic forms have been better extracted by trophic route, whereas seleno-methionine has been better extracted by the direct route. In our experimental conditions, ventilation of the bivalve has not been a limiting factor for Se bioaccumulation by the direct route, whereas it has been for bioaccumulation by the trophic route. Ventilation has been largely modified by the presence of dissolved selenite and seleno-methionine. We have shown that the kinetics of seleno-methionine bioaccumulation are much more fast than those of selenite. Moreover, when introduced as SeMet, internalized Se appeared to be relatively remanent in soft tissues of C. fluminea in comparison with Se internalized when introduced as selenite. Subcellular and molecular distributions of these forms were very different. Finally, it has been shown that seleno-methionine and selenite could generate weak alterations of the anti

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

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

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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.

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

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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.

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

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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.

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.

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

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.

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

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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

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.

Mobile Element Evolution Playing Jigsaw—SINEs in Gastropod and Bivalve Mollusks

Science.gov (United States)

Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

2016-01-01

SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc—snail and SCoica—mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain—Snail—is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5′ end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves—extending the distribution range of this superfamily. PMID:26739168

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.

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.

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.

Intrinsic hierarchical structural imperfections in a natural ceramic of bivalve shell with distinctly graded properties.

Science.gov (United States)

Jiao, Da; Liu, Zengqian; Zhang, Zhenjun; Zhang, Zhefeng

2015-07-22

Despite the extensive investigation on the structure of natural biological materials, insufficient attention has been paid to the structural imperfections by which the mechanical properties of synthetic materials are dominated. In this study, the structure of bivalve Saxidomus purpuratus shell has been systematically characterized quantitatively on multiple length scales from millimeter to sub-nanometer. It is revealed that hierarchical imperfections are intrinsically involved in the crossed-lamellar structure of the shell despite its periodically packed platelets. In particular, various favorable characters which are always pursued in synthetic materials, e.g. nanotwins and low-angle misorientations, have been incorporated herein. The possible contributions of these imperfections to mechanical properties are further discussed. It is suggested that the imperfections may serve as structural adaptations, rather than detrimental defects in the real sense, to help improve the mechanical properties of natural biological materials. This study may aid in understanding the optimizing strategies of structure and properties designed by nature, and accordingly, provide inspiration for the design of synthetic materials.

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

Effects of arctic temperatures on distribution and retention of the nuclear waste radionuclides 241Am, 57Co, and 137Cs in the bioindicator bivalve Macoma balthica

Science.gov (United States)

Hutchins, D.A.; Stupakoff, I.; Hook, S.; Luoma, S.N.; Fisher, N.S.

1998-01-01

The disposal of radioactive wastes in Arctic seas has made it important to understand the processes affecting the accumulation of radionuclides in food webs in coldwater ecosystems. We examined the effects of temperature on radionuclide assimilation and retention by the bioindicator bivalve Macoma balthica using three representative nuclear waste components, 241Am, 57Co, and 137Cs. Experiments were designed to determine the kinetics of processes that control uptake from food and water, as well as kinetic constants of loss. 137Cs was not accumulated in soft tissue from water during short exposures, and was rapidly lost from shell with no thermal dependence. No effects of temperature on 57Co assimilation or retention from food were observed. The only substantial effect of polar temperatures was that on the assimilation efficiency of 241Am from food, where 10% was assimilated at 2??C and 26% at 12??C. For all three radionuclides, body distributions were correlated with source, with most radioactivity obtained from water found in the shell and food in the soft tissues. These results suggest that in general Arctic conditions had relatively small effects on the biological processes which influence the bioaccumulation of radioactive wastes, and bivalve concentration factors may not be appreciably different between polar and temperate waters.

North Atlantic Oscillation dynamics recorded in shells of a long-lived bivalve mollusk

Science.gov (United States)

Schöne, Bernd R.; Oschmann, Wolfgang; Rössler, Jochen; Freyre Castro, Antuané D.; Houk, Stephen D.; Kröncke, Ingrid; Dreyer, Wolfgang; Janssen, Ronald; Rumohr, Heye; Dunca, Elena

2003-12-01

Existing reconstructions of the winter North Atlantic Oscillation (WNAO) are based on terrestrial proxies and historical documents. No direct high-resolution, long-term rec ords from marine settings are available for this major climate-dictating phenomenon, which severely affects a variety of economic aspects of our society. Here we present a 245 yr proxy WNAO index based on shells of the long-lived marine bivalve mollusk Arctica islandica. Variations in annual rates of shell growth are positively correlated with WNAO-related changes in the food supply. Maximum amplitudes in frequency bands of 7 9 and 5 7 yr fall exactly within the range of instrumental and other proxy WNAO indices. These estimates were obtained for specimens collected live, 2000 km apart, in the central North Sea and on the Norwegian Shelf. Hence, the WNAO influences hydrographic regimes of large regions of the ocean. Our study demonstrates that A. islandica can reliably reconstruct WNAO dynamics for time intervals and regions without instrumental records. Our new tool functions as a proxy for the WNAO index prior to the twentieth-century greenhouse forcing and has the potential to further validate other proxy-based WNAO records.

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

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

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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

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

[Proceedings of the symposium 'Molluscan Palaeontology' : 11th International Malacological Congress, Siena (Italy) 30th August - 5th September 1992 / A.W. Janssen and R. Janssen (editors)]: The Mesozoic Marine Revolution and epifaunal bivalves

NARCIS (Netherlands)

Harper, E.M.; Skelton, P.W.

1992-01-01

The well documented dramatic increase in predation pressure which started during the early Mesozoic, termed the Mesozoic Marine Revolution (MMR), had an important impact on the evolution of prey organisms (Vermeij, 1983). Epifaunal bivalves in particular are at considerable risk to predation. In

Anatomical study on Myoforceps aristatus, an invasive boring bivalve in S.E. Brazilian coast (Mytilidae

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Luiz Ricardo L. Simone

2006-01-01

Full Text Available The bivalve Myoforceps aristatus (Dillwyn, 1817, also known as Lithophaga aristata, have been recently collected in the coasts of Rio de Janeiro and São Paulo, Brazil; a species that bores shells of other mollusks. This occurrence has been interpreted as an invasion of this species, originally from the Caribbean. The distinguishing character of the species is the posterior extensions of the shell crossing with each other. Because specimens with this character have also been collected in the Pacific Ocean, they all have been considered a single species. However, it is possible that more than one species may be involved in such worldwide distribution. With the objective of providing full information based on Atlantic specimens, a complete anatomical description is provided, which can be used in comparative studies with specimens from other oceans. Additional distinctive features of M. aristatus are the complexity of the incurrent siphon, the kidney opening widely into the supra-branchial chamber (instead of via a nephropore, and the multi-lobed auricle.O bivalve Myoforceps aristatus (Dillwyn, 1817, também conhecido como Lithophaga aristata, tem sido recentemente coletado nas costas do Rio de Janeiro e São Paulo, Brasil; uma espécie que perfura conchas de outros moluscos. Esta ocorrência está sendo interpretada como uma invasão de uma espécie originada do Caribe. O caráter distintivo da espécie é a região posterior da concha, com extensões que se cruzam. Como espécimes com esta característica também têm sido coletados no oceano Pacífico, eles tem sido considerados como pertencentes à mesma espécie. Entretanto, é possível que mais de uma espécie possam estar envolvidas nesta suposta distribuição mundial. Com o objetivo de fornecer informação completa baseada em material do Atlântico, uma descrição anatômica completa é dada, a qual pode ser usada em estudos comparativos com espécimes de outros oceanos. As caracter

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.

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

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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.

Validation of the flow-through chamber (FTC and steady-state (SS methods for clearance rate measurements in bivalves

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Poul S. Larsen

2011-09-01

To obtain precise and reliable laboratory clearance rate (filtration rate measurements with the ‘flow-through chamber method’ (FTC the design must ensure that only inflow water reaches the bivalve's inhalant aperture and that exit flow is fully mixed. As earlier recommended these prerequisites can be checked by a plot of clearance rate (CR versus increasing through-flow (Fl to reach a plateau, which is the true CR, but we also recommend to plot percent particles cleared versus reciprocal through-flow where the plateau becomes the straight line CR/Fl, and we emphasize that the percent of particles cleared is in itself neither a criterion for valid CR measurement, nor an indicator of appropriate ‘chamber geometry’ as hitherto adapted in many studies. For the ‘steady-state method’ (SS, the design must ensure that inflow water becomes fully mixed with the bivalve's excurrent flow to establish a uniform chamber concentration prevailing at its incurrent flow and at the chamber outlet. These prerequisites can be checked by a plot of CR versus increasing Fl, which should give the true CR at all through-flows. Theoretically, the experimental uncertainty of CR for a given accuracy of concentration measurements depends on the percent reduction in particle concentration (100×P from inlet to outlet of the ideal ‘chamber geomety’. For FTC, it decreases with increasing values of P while for SS it first decreases but then increases again, suggesting the use of an intermediate value of P. In practice, the optimal value of P may depend on the given ‘chamber geometry’. The fundamental differences between the FTC and the SS methods and practical guidelines for their use are pointed out, and new data on CR for the blue mussel, Mytilus edulis, illustrate a design and use of the SS method which may be employed in e.g. long-term growth experiments at constant algal concentrations.

Spatial and temporal distribution of tributyltin (TBT) in seawater, sediments and bivalves from coastal areas of Korea during 2001-2005.

Science.gov (United States)

Choi, Minkyu; Choi, Hee-Gu; Moon, Hyo-Bang; Kim, Gui-Young

2009-04-01

Tributyltin (TBT) concentrations were determined in seawater, sediments and bivalve samples collected from Korean coastal areas during 2001-2005, to investigate the levels and temporal variation in TBT contamination in relation to the timing of the imposition of regulations on TBT use in Korea. TBT concentrations ranged from TBT were found at locations close to intensive shipping traffic and industrial complexes, and the contamination at some hot spot areas was high enough to cause harmful effects on marine organisms. TBT concentrations and their occurrence in Korean coastal waters have been decreasing annually. In particular, TBT concentrations in seawater have dramatically decreased. This result is consistent with regulations and bans on the use of TBT in Korea.

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.

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®

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.

Irradiated bivalve mollusks: Use of EPR spectroscopy for identification and dosimetry

Energy Technology Data Exchange (ETDEWEB)

Alberti, Angelo, E-mail: aalberti@isof.cnr.it [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy); Chiaravalle, Eugenio [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Fuochi, Piergiorgio; Macciantelli, Dante [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy); Mangiacotti, Michele, E-mail: michelemangiacotti@libero.it [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Marchesani, Giuliana [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Plescia, Elena [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy)

2011-12-15

High energy radiation treatment of foodstuff for microbial control and shelf-life extension is being used in many countries. However, for consumer protection and information, the European Union has adopted the Directives 1999/2/EC and 1999/3/EC to harmonize the rules concerning the treatment and trade of irradiated foods in EU countries. Among the validated methods to detect irradiated foods the EU directives also include Electron Paramagnetic Resonance (EPR/ESR) spectroscopy. We describe herein the use of EPR for identification of four species of bivalve mollusks, i.e. brown Venus shells (Callista chione), clams (Tapes semidecussatus), mussels (Mytilus galloprovincialis) and oysters (Ostrea edulis) irradiated with {sup 60}Co {gamma}-rays. EPR could definitely identify irradiated seashells due to the presence of long-lived free radicals, primarily CO{sub 2}{sup -}, CO{sub 3}{sup 3-}, SO{sub 2}{sup -} and SO{sub 3}{sup -} radical anions. The presence of other organic free radicals, believed to originate from conchiolin, a scleroprotein present in the shells, was also ascertained. The use of one of these radicals as a marker for irradiation of brown Venus shells and clams can be envisaged. We also propose a dosimetric protocol for the reconstruction of the administered dose in irradiated oysters. - Highlights: > EPR spectroscopy is confirmed a valuable identification tool for irradiated mollusks. > A conchiolin-derived radical can be used as irradiation marker for some mollusks. > A reliable protocol is outlined for dose reconstruction of irradiated oysters.

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

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.

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.

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

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

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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.

Environmental influence on population dynamics of the bivalve Anomalocardia brasiliana

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Corte, Guilherme Nascimento; Coleman, Ross A.; Amaral, A. Cecília Z.

2017-03-01

Understanding how species respond to the environment in terms of population attributes (e.g. abundance, growth, mortality, fecundity, and productivity) is essential to protect ecologically and economically important species. Nevertheless, responses of macrobenthic populations to environmental features are overlooked due to the need of consecutive samplings and time-consuming measurements. We examined the population dynamics of the filter-feeding bivalve Anomalocardia brasiliana on a tidal flat over the course of one year to investigate the hypothesis that, as accepted for macrobenthic communities, populations inhabiting environments with low hydrodynamic conditions such as tidal flat should have higher attributes than populations inhabiting more energetic habitats (i.e. areas more influenced by wave energy such as reflective and intermediate beaches). This would be expected because the harsh conditions of more energetic habitats force organisms to divert more energy towards maintenance, resulting in lower population attributes. We found that A. brasiliana showed moderate growth and secondary production at the study area. Moreover the recruitment period was restricted to a few months. A comparison with previous studies showed that, contrary to expected, A. brasiliana populations from areas with low hydrodynamic conditions have lower abundance, growth, recruitment and turnover rate. It is likely that morphodynamic characteristics recorded in these environments, such as larger periods of air exposure and lower water circulation, may affect food conditions for filter-feeding species and increase competition. In addition, these characteristics may negatively affect macrobenthic species by enhancing eutrophication processes and anoxia. Overall, our results suggest that models accepted and applied at the macrobenthic community level might not be directly extended to A. brasiliana populations.

Facultative parasitism by the bivalve Kurtiella pedroana in the sand crab Emerita analoga

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Bhaduri, Ritin; Valentich-Scott, Paul; Hilgers, Mark; Singh, Rajvir; Hickman, Mikaila; Lafferty, Kevin D.

2017-01-01

It is rare that an organism capable of independent or commensalistic existence can also become endoparasitic on a host. In this study, we documented a potential step toward parasitism in the commensal clam Kurtiella pedroana (Bivalvia: Galeommatoidea). Galeommatoideans are known commensals of various invertebrates, including crustaceans. Emerita analoga (Decapoda: Hippidae) is an abundant intertidal decapod inhabiting sandy beaches of the Pacific coast of North and South America. Crabs collected from Monterey Bay, California, were measured and examined externally and internally for associated molluscs. Out of the 520 crabs, 37 large female individuals harbored 49 bivalves (prevalence of 7.11% and mean intensity of 1.3). Forty-one ectocommensal clams were either inside the crab's branchial chambers or on their lateroventral surfaces, and were attached by byssal threads. Our key finding was eight clams that lacked byssal threads and were living in the hemocoel. These internal clams were significantly smaller than the ectocommensals. Because these internal clams lacked access to their normal food, we hypothesize they might have fed on their host's hemolymph as would a parasite. This clam species likely can't reproduce inside its host, implying that endoparasitism is a dead-end state for K. pedroana. Facultative parasitism in a free-living or an ectocommensal is uncommon and suggests a pathway to parasitism.

Assessing the effects of seawater temperature and pH on the bioaccumulation of emerging chemical contaminants in marine bivalves.

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Maulvault, Ana Luísa; Camacho, Carolina; Barbosa, Vera; Alves, Ricardo; Anacleto, Patrícia; Fogaça, Fabiola; Kwadijk, Christiaan; Kotterman, Michiel; Cunha, Sara C; Fernandes, José O; Rasmussen, Rie R; Sloth, Jens J; Aznar-Alemany, Òscar; Eljarrat, Ethel; Barceló, Damià; Marques, António

2018-02-01

Emerging chemical contaminants [e.g. toxic metals speciation, flame retardants (FRs) and perfluorinated compounds (PFCs), among others], that have not been historically recognized as pollutants nor their toxicological hazards, are increasingly more present in the marine environment. Furthermore, the effects of environmental conditions (e.g. temperature and pH) on bioaccumulation and elimination mechanisms of these emerging contaminants in marine biota have been poorly studied until now. In this context, the aim of this study was to assess, for the first time, the effect of warmer seawater temperatures (Δ = + 4°C) and lower pH levels (Δ = - 0.4 pH units), acting alone or combined, on the bioaccumulation and elimination of emerging FRs (dechloranes 602, 603 and 604, and TBBPA), inorganic arsenic (iAs), and PFCs (PFOA and PFOS) in two estuarine bivalve species (Mytilus galloprovincialis and Ruditapes philippinarum). Overall, results showed that warming alone or combined with acidification promoted the bioaccumulation of some compounds (i.e. dechloranes 602, 604, TBBPA), but also facilitated the elimination of others (i.e. iAs, TBBPA). Similarly, lower pH also resulted in higher levels of dechloranes, as well as enhanced iAs, PFOA and PFOS elimination. Data also suggests that, when both abiotic stressors are combined, bivalves' capacity to accumulate contaminants may be time-dependent, considering significantly drastic increase observed with Dec 602 and TBBPA, during the last 10 days of exposure, when compared to reference conditions. Such changes in contaminants' bioaccumulation/elimination patterns also suggest a potential increase of human health risks of some compounds, if the climate continues changing as forecasted. Therefore, this first study pointed out the urgent need for further research on the effects of abiotic conditions on emerging contaminants kinetics, to adequately estimate the potential toxicological hazards associated to these compounds and

Gene expression and physiological changes of different populations of the long-lived bivalve Arctica islandica under low oxygen conditions.

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Eva E R Philipp

Full Text Available The bivalve Arctica islandica is extremely long lived (>400 years and can tolerate long periods of hypoxia and anoxia. European populations differ in maximum life spans (MLSP from 40 years in the Baltic to >400 years around Iceland. Characteristic behavior of A. islandica involves phases of metabolic rate depression (MRD during which the animals burry into the sediment for several days. During these phases the shell water oxygen concentrations reaches hypoxic to anoxic levels, which possibly support the long life span of some populations. We investigated gene regulation in A. islandica from a long-lived (MLSP 150 years German Bight population and the short-lived Baltic Sea population, experimentally exposed to different oxygen levels. A new A. islandica transcriptome enabled the identification of genes important during hypoxia/anoxia events and, more generally, gene mining for putative stress response and (anti- aging genes. Expression changes of a antioxidant defense: Catalase, Glutathione peroxidase, manganese and copper-zinc Superoxide dismutase; b oxygen sensing and general stress response: Hypoxia inducible factor alpha, Prolyl hydroxylase and Heat-shock protein 70; and c anaerobic capacity: Malate dehydrogenase and Octopine dehydrogenase, related transcripts were investigated. Exposed to low oxygen, German Bight individuals suppressed transcription of all investigated genes, whereas Baltic Sea bivalves enhanced gene transcription under anoxic incubation (0 kPa and, further, decreased these transcription levels again during 6 h of re-oxygenation. Hypoxic and anoxic exposure and subsequent re-oxygenation in Baltic Sea animals did not lead to increased protein oxidation or induction of apoptosis, emphasizing considerable hypoxia/re-oxygenation tolerance in this species. The data suggest that the energy saving effect of MRD may not be an attribute of Baltic Sea A. islandica chronically exposed to high environmental variability (oxygenation

Molecular phylogeny of the bivalve superfamily Galeommatoidea (Heterodonta, Veneroida) reveals dynamic evolution of symbiotic lifestyle and interphylum host switching

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2012-01-01

Background Galeommatoidea is a superfamily of bivalves that exhibits remarkably diverse lifestyles. Many members of this group live attached to the body surface or inside the burrows of other marine invertebrates, including crustaceans, holothurians, echinoids, cnidarians, sipunculans and echiurans. These symbiotic species exhibit high host specificity, commensal interactions with hosts, and extreme morphological and behavioral adaptations to symbiotic life. Host specialization to various animal groups has likely played an important role in the evolution and diversification of this bivalve group. However, the evolutionary pathway that led to their ecological diversity is not well understood, in part because of their reduced and/or highly modified morphologies that have confounded traditional taxonomy. This study elucidates the taxonomy of the Galeommatoidea and their evolutionary history of symbiotic lifestyle based on a molecular phylogenic analysis of 33 galeommatoidean and five putative galeommatoidean species belonging to 27 genera and three families using two nuclear ribosomal genes (18S and 28S ribosomal DNA) and a nuclear (histone H3) and mitochondrial (cytochrome oxidase subunit I) protein-coding genes. Results Molecular phylogeny recovered six well-supported major clades within Galeommatoidea. Symbiotic species were found in all major clades, whereas free-living species were grouped into two major clades. Species symbiotic with crustaceans, holothurians, sipunculans, and echiurans were each found in multiple major clades, suggesting that host specialization to these animal groups occurred repeatedly in Galeommatoidea. Conclusions Our results suggest that the evolutionary history of host association in Galeommatoidea has been remarkably dynamic, involving frequent host switches between different animal phyla. Such an unusual pattern of dynamic host switching is considered to have resulted from their commensalistic lifestyle, in which they maintain filter

Molecular phylogeny of the bivalve superfamily Galeommatoidea (Heterodonta, Veneroida reveals dynamic evolution of symbiotic lifestyle and interphylum host switching

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Goto Ryutaro

2012-09-01

Full Text Available Abstract Background Galeommatoidea is a superfamily of bivalves that exhibits remarkably diverse lifestyles. Many members of this group live attached to the body surface or inside the burrows of other marine invertebrates, including crustaceans, holothurians, echinoids, cnidarians, sipunculans and echiurans. These symbiotic species exhibit high host specificity, commensal interactions with hosts, and extreme morphological and behavioral adaptations to symbiotic life. Host specialization to various animal groups has likely played an important role in the evolution and diversification of this bivalve group. However, the evolutionary pathway that led to their ecological diversity is not well understood, in part because of their reduced and/or highly modified morphologies that have confounded traditional taxonomy. This study elucidates the taxonomy of the Galeommatoidea and their evolutionary history of symbiotic lifestyle based on a molecular phylogenic analysis of 33 galeommatoidean and five putative galeommatoidean species belonging to 27 genera and three families using two nuclear ribosomal genes (18S and 28S ribosomal DNA and a nuclear (histone H3 and mitochondrial (cytochrome oxidase subunit I protein-coding genes. Results Molecular phylogeny recovered six well-supported major clades within Galeommatoidea. Symbiotic species were found in all major clades, whereas free-living species were grouped into two major clades. Species symbiotic with crustaceans, holothurians, sipunculans, and echiurans were each found in multiple major clades, suggesting that host specialization to these animal groups occurred repeatedly in Galeommatoidea. Conclusions Our results suggest that the evolutionary history of host association in Galeommatoidea has been remarkably dynamic, involving frequent host switches between different animal phyla. Such an unusual pattern of dynamic host switching is considered to have resulted from their commensalistic lifestyle, in

Shell extracts of the edible mussel and oyster induce an enhancement of the catabolic pathway of human skin fibroblasts, in vitro.

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Latire, Thomas; Legendre, Florence; Bouyoucef, Mouloud; Marin, Frédéric; Carreiras, Franck; Rigot-Jolivet, Muriel; Lebel, Jean-Marc; Galéra, Philippe; Serpentini, Antoine

2017-10-01

Mollusc shells are composed of more than 95% calcium carbonate and less than 5% organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. In this study, we investigated the effects of matrix macromolecular components extracted from the shells of two edible molluscs of economic interest, i.e., the blue mussel Mytilus edulis and the Pacific oyster Crassostrea gigas. The potential biological activities of these organic molecules were analysed on human dermal fibroblasts in primary culture. Our results demonstrate that shell extracts of the two studied molluscs modulate the metabolic activities of the cells. In addition, the extracts caused a decrease of type I collagen and a concomitant increase of active MMP-1, both at the mRNA and the protein levels. Therefore, our results suggest that shell extracts from M. edulis and C. gigas contain molecules that promote the catabolic pathway of human dermal fibroblasts. This work emphasises the potential use of these shell matrices in the context of anti-fibrotic strategies, particularly against scleroderma. More generally, it stresses the usefulness to valorise bivalve shells that are coproducts of shellfish farming activity.

Determinação de coliformes na água e no tecido mole das ostras extraídas em Cananéia, São Paulo, Brasil

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Sonia Assami Doi

2015-03-01

Full Text Available Este estudo objetivou avaliar a qualidade microbiológica da água de várias localidades em que são produzidas ostras Crassostrea sp. no estuário de Cananéia, tanto como nos bivalves, por meio dos valores de coliformes baseados na Técnica dos Tubos Múltiplos. Foram realizadas coletas de água em dez localidades durante os anos de 2005 a 2011. A análise da água apresentou média geométrica de coliformes termotolerantes de 24,67 NMP 100 mL-1 e, nos tecidos das ostras, de 15,53 NMP g-1. Verificou-se uma diferença significativa entre as localidades analisadas quanto à densidade de coliformes totais e termotolerantes na água. Analisaram-se as variações das contagens bacterianas em relação à sazonalidade, verificando-se que o outono apresentou a maior média de coliformes nas ostras, sendo os maiores dados coletados em abril. Houve correlação positiva entre coliformes na água e na ostra.

CO2 sequestration using principles of shell formation

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Lee, Seung-Woo; Jang, Young-Nam [CO2 Sequestration Research Department, Korea Institute of Geoscience and Mineral Resources (Korea, Republic of); Lee, Si-Hyun; Lim, Kyoung-Soo; Jeong, Soon-Kwan [Energy Conservation Research Department of Clean Energy System Research Center, Korea Institute of Energy Research (Korea, Republic of)

2011-06-15

The biomimetic sequestration of carbon dioxide to reduce the CO2 emitted into the atmosphere is introduced in this paper. Bivalve shells are used as a good model of CO2 sequestration in this paper, because the shell is derived from the calcium ions and CO2 in seawater. Carbonic anhydrase, hemocyte from diseased shell (HDS) and extrapallial fluid (EFP) are involved in shell formation. This paper compares the soluble protein extracted from Crassostrea gigas with bovine carbonic anhydrase II in terms of their ability to promote CO2 hydration and the production of calcium precipitates. The result demonstrates that HDS has more functional groups to bind calcium ions in aqueous systems, and a different process of calcium precipitation, than does bovine carbonic anhydrase II. To understand molecular weight and secondary protein structure, mass-spectroscopic analysis (MALDI-TOF) and circular dichroism (CD) analysis were used. With regard to EPF, EPF related to shell formation is composed of several fractions and plays a role in sequestration of CO2.

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

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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

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

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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.

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

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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.

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

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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.

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

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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.

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

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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.

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

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

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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.

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

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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.

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

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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.

Polonium-210 in marine bivalves inhabiting a wedge bank region, South India

International Nuclear Information System (INIS)

Feroz Khan, M.; Godwin Wesley, S.; Rajan, M.P.

2013-01-01

Determination of background radiation dose-rate is important in the process of assessing risks to the environment from exposure to living organisms both in terms of deriving the incremental dose-rate and as a point of reference for evaluating the significance of the exposure level. In the present study, 210 Po was quantified in two species of bivalve mollusks commonly available from so called a 'wedge bank region' of southern tip of India. Based on the activity concentration in media and in the whole body, an external and internal dose rate assessment to green mussel Perna viridis and brown mussel Perna indica due to 210 Po was derived using ERICA assessment tool. The samples were collected at the intertidal region along the wedge bank region of southern tip of India during 2009 to 2010. The measurement contributes to a better knowledge of these elements, since no data exists in this region. 5-10 g of each tissue sample was wet-digested using 70% concentrated HNO 3 followed by the addition of 40% H 2 O 2 along with 20 8Po tracer (0.2 Bq). The normality of the data set was checked using Lilliefors test (ne''50) and potential outliers, if any, were tested using Walsh's test (n>60). Using the measured 210 Po activity in molluscs, sediments and seawater, dose assessment was performed using the Tier 2 ERICA environment dose assessment tool 1.0

Bivalve fouling of nuclear power plant service-water systems. Volume 2. Current status of biofouling surveillance and control techniques

International Nuclear Information System (INIS)

Daling, P.M.; Johnson, K.I.

1985-03-01

This report describes the current status of techniques for detection and control of cooling-water system fouling by bivalve mollusks at nuclear power plants. The effectiveness of these techniques is evaluated on the basis of information gathered from a literature review and in interviews with nuclear power plant personnel. Biofouling detection techniques examined in this report include regular maintenance, in-service inspection, and testing. Generally, these methods have been inadequate for detecting biofouling. Recommendations for improving biofouling detection capabilities are presented. Biofouling prevention (or control) methods that are examined in this report include intake screen systems, thermal treatment, preventive maintenance, chemical treatment alternatives, and antifoulant coatings. Recommendations for improving biofouling control methods at operating nuclear power plants are presented. Additional techniques that could be implemented at future power plants or that require further research are also described