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| Registros recuperados: 22 | |
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| Tanniou, A.; Vandanjon, L.; Incera, M.; Serrano Leon, Esteban; Husa, V.; Le Grand, Jacqueline; Nicolas, Jean-louis; Poupart, N.; Kervarec, N.; Engelen, A.; Walsh, R.; Guerard, F.; Bourgougnon, N.; Stiger-pouvreau, Valerie. |
| Sargassum muticum, an invasive brown macroalga presently distributed along European Atlantic coasts from southern Portugal to the south coast of Norway, was studied on a large geographical scale for its production of phenolic compounds with potential industrial applications and their chemical and biological activities. S. muticum can produce high biomass in Europe, which could be exploited to supply such compounds. S. muticum was collected in Portugal, Spain, France, Ireland and Norway (three sites/country) to examine the effect of the latitudinal cline and related environmental factors. Assays focused particularly on polyphenols and their activities. Crude acetone–water extracts were purified using solid phase extraction (SPE) and antioxidant and... |
| Tipo: Text |
Palavras-chave: Antioxidant activities; Antibacterial activities; Latitudinal gradient; Phenolic compounds; Solid phase extraction; Sargassum muticum. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00171/28221/32175.pdf |
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| Le Grand, Jacqueline. |
| En 1983, l'IFREMER met en place un REseau de surveillance PHYtoplanctonique (REPHY) sur tout le littoral français dont l'un des objectifs est la protection de la santé publique. Il permet de suivre continuellement l'évolution de la flore phytoplanctonique dans l'eau et de cerner les risques dus à l'apparition d'espèces toxiques (Dinophysis). En Normandie, l'évolution de la production phytoplanctonique est caractérisée par un bloom printanier et parfois un second plus faible en automne. Le phytoplancton est essentiellement composé de diatomées. Les 5 points de suivi présentent des compositions floristiques à peu près similaires malgré des situations géographiques assez différentes (estuaire, milieu plus océanique). Dinophysis est la seule algue toxique qui... |
| Tipo: Text |
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| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00119/23061/20898.pdf |
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| Suquet, Marc; Pouvreau, Stephane; Queau, Isabelle; Boulais, Myrina; Le Grand, Jacqueline; Ratiskol, Dominique; Cosson, Jacky. |
| n brooding mollusc species that incubate larvae before their release in seawater, the biology of gametes remains poorly explored. The present study describes some biological characteristics of sperm of the European flat oyster, a native species that has been over-exploited in the past and is nowadays classified as an endangered species in Europe. Flat oysters were collected by divers in the Rade de Brest (Finistère, France), during its natural reproduction period. Gonadal pH is acidic (6.31 ± 0.10). Spermatozoa are clustered in spermatozeugmata, an acellular structure in which the sperm heads are embedded. After their transfer in seawater, spermatozeugmata have a mean diameter of 64 ± 3 μm and they release free spermatozoa for a mean duration of... |
| Tipo: Text |
Palavras-chave: Oyster; Ostrea edulis; Brooding species; Sperm; Spermatozeugmata; Endangered species. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00454/56539/58245.pdf |
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| Suquet, Marc; Queau, Isabelle; Le Grand, Jacqueline; Ratiskol, Dominique; Pouvreau, Stephane. |
| The biology of gametes and larvae in brooding mollusc species remains little explored. The aim of this study is to present the results obtained in 2016, on biological characteristics of gametes and larvae of European flat oyster. Measurements were carried out on 50 oysters, collected by divers in the Rade de Brest (Finistère, France), during the spawning period of this species. Gonad pH is acidic (6.58±0.54). After the dissociation of spermatozeugmata, an acellular structure to which the spermatozoa are clustered, the percentage of motile spermatozoa ranged from 20 to 34% and the Velocity of the Average Path from 70 to 85µm/s. Spermatozeugmata were shed after serotonin injection. Oocytes (mean diameter: 129.4±19.1µm) were rarely observed (2... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00383/49390/49803.pdf |
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| Labry, Claire; Erard-le Denn, Evelyne; Chapelle, Annie; Fauchot, Juliette; Youenou, Agnes; Crassous, Marie-pierre; Le Grand, Jacqueline; Lorgeoux, Benedicte. |
| The understanding of the dominance of one species with respect to others is a pertinent challenge in HAB growth dynamics studies and the nutrient supply mode is one of the factors potentially involved. The competition for phosphorus (P) between a toxic species, Alexandrium minutum, and a non-toxic species, Heterocapsa triquetra, was studied (1) along a gradient of P depletion, (2) testing different P depletion degrees before a single PO4 supply and (3) experimenting different PO4 supply frequencies. In conditions Of PO4 depletion, H. triquetra stopped growing after two days both in monospecific and mixed batch cultures whereas A. minutum grew progressively from day 2 until the end of the experiment. This time-lag growth of A. minutum is associated to its... |
| Tipo: Text |
Palavras-chave: Semi continuous culture; Batch culture; Ecophysiology; Pulse; Phosphorus storage; Dinoflagellates; Heterocapsa triquetra; Alexandrium minutum. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4067.pdf |
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| Asmani, Katia; Petton, Bruno; Le Grand, Jacqueline; Mounier, Jerome; Robert, Rene; Nicolas, Jean-louis. |
| The first aim of this study was to determine the stocking density limits for Pacific oyster Crassostrea gigas larvae reared in flow-through system (FTS) and recirculating aquaculture systems (RAS). The second aim was to examine biofilm formation on the larval tank wall and its interaction with larvae growth. Three larvae concentrations were tested: 50, 150, and 300 mL−1. Chemical parameters and larvae performance were measured. The biofilm was observed by scanning electron microscopy, and its bacterial composition was investigated by pyrosequencing analysis of part of the 16S rRNA gene. The highest growth (13 µm day–1), survival (87%) and metamorphosis (50%) rates were observed in FTS at 50 larvae mL–1, while lower and similar performances occurred at... |
| Tipo: Text |
Palavras-chave: Pacific oyster; Larval culture; High stocking density; Biofilm; Filamentous bacteria. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00395/50611/51324.pdf |
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| Asmani, Katia; Petton, Bruno; Le Grand, Jacqueline; Mounier, Jerome; Robert, Rene; Nicolas, Jean-louis. |
| This study has two main objectives: (1) to implement a recycling aquaculture system (RS) for the larvae of the oyster Crassostrea gigas, and (2) to characterise the bacterial communities established in different compartments of this system. An RS with 25% fresh seawater addition per hour and another with no addition (0%) were compared with a flow-through system (FT). Larval survival was equivalent in RS and FT, but growth rate was 17% slower in RS than in FT. The physical chemical parameters remained stable, except for pH that decreased to 7.75 and salinity that increased to 37.5‰ in the RS 0%. In both systems, the cultivable bacteria were present in similar numbers in seawater (around 105 ml− 1) and in larvae (103 larva− 1) on day 15. Bacterial... |
| Tipo: Text |
Palavras-chave: RAS; Bivalve larvae; Microbiota; Pyrosequencing; Hatchery. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00346/45691/45311.pdf |
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| Labry, Claire; Erard-le Denn, Evelyne; Chapelle, Annie; Youenou, Agnes; Crassous, Marie Pierre; Martin-jezequel, Véronique; Le Grand, Jacqueline. |
| Suite à un premier criblage des facteurs environnementaux favorables à la croissance d'Alexandrium minutum comparativement à celle d'une espèce compétitrice en rivière de Penzé, Heterocapsa triquetra (rapport ART3 2002-2003) cette étude vise à préciser et quantifier les réponses physiologiques respectives des deux espèces à différentes conditions d'apports en phosphate (taux de croissance, vitesse d'assimilation des phosphates, capacité à stocker le phosphore intracellulaire). Elle montre qu'Alexandrium minutum a plutôt une stratégie de « stockage », capable d'assimiler rapidement le phosphate après un apport mais le stockant pour une meilleure croissance ultérieure quand la ressource sera à nouveau épuisée. Comparativement, Heterocapsa triquetra aurait,... |
| Tipo: Text |
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| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/00105/21598/19178.pdf |
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| Tayale, Alexandre; Gueguen, Yannick; Treguier, Cathy; Le Grand, Jacqueline; Cochennec-laureau, Nathalie; Montagnani, Caroline; Ky, Chin-long. |
| Producing high quality cultured black pearls from Pinctada margaritifera is one of the major challenges for the "pearl oyster" industry in French Polynesia. In order to assess donor effect on cultured pearl quality, wild Pinctada margaritifera originating from the Tuamotu Archipelago were used in a duplicated grafting experiment. After 12 months of culture, nucleus retention was assessed and seven pearl quality traits recorded on the 454 cultured pearls harvested from the experiment. The traits scored were nacre thickness and pearl weight, surface defects, lustre, grade, and the colour components: 1) darkness of cultured pearl colour, and 2) visual perception of colour class (bodycolor and/or overtone). Our results demonstrate for the first time that... |
| Tipo: Text |
Palavras-chave: Cultured pearl oyster; Pearl quality; Nacre; Donor mollusc; Genetic selection; Pteriidae; Blacklip pearl oyster; Pinctada margaritifera; French Polynesia. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00116/22757/20541.pdf |
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| Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Miner, Philippe; Le Grand, Jacqueline; Lambert, Christophe; Le Goic, Nelly; Hegaret, Helene; Fabioux, Caroline. |
| The Pacific oyster Crassostrea gigas is an important commercial species cultured throughout the world. Oyster production practices often include transfers of animals into new environments that can be stressful, especially at young ages. This study was undertaken to determine if a toxic Alexandrium bloom, occurring repeatedly in French oyster beds, could modulate juvenile oyster cellular immune responses (i.e. hemocyte variables). We simulated planting on commercial beds by conducting a cohabitation exposure of juvenile, “specific pathogen-free” (SPF) oysters (naïve from the environment) with previously field-exposed oysters to induce interactions with new microorganisms. Indeed, toxic Alexandrium spp. exposures have been reported to modulate bivalve... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Alexandrium; Harmful algal blooms; Hemocyte; Microbial challenge. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00314/42523/41894.pdf |
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| Suquet, Marc; Malo, Florent; Quere, Claudie; Ledu, Christophe; Le Grand, Jacqueline; Benabdelmouna, Abdellah. |
| Triploidy induction in shellfish aims to obtain faster growth and sterility of reared individuals. Triploid Pacific oysters are most often not totally sterile, but have greatly reduced reproductive capacities compared to those recorded in diploid individuals. The description of gamete output in triploid aquatic animals is most often confined to the assessment of fecundity in females. The present work aims at further describing gamete quality of triploid Pacific oysters and comparing it to values observed in diploid individuals. Diploid and triploid oysters (produced by mating tetraploid males × diploid females) were reared in standard conditions and then transferred to the wild to allow the offspring to attain reproductive maturity. At the end of... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Reproduction; Triploidy; Gamete. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00277/38835/37581.pdf |
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| Merceron, Michel; Bentley, Daniel; Le Grand, Jacqueline; Lamort-datin, Laure; Kempf, Marc. |
| The environmental impact of a brown trout farm located in the Grande Rade de Cherbourg (Normandy) is reported. During observations the fish stock evolved within the range of 140 to 350 metric tons. Farm influence was researched on water column through hydrochemistry, phytoplankton, faecal bacteria and, on bottom, through grain size, organic matter, metals, macrobenthos. This report only deals with water column. Except ammonia, no hydrological parameter seems to be affected, even near to the net pens. Phytoplankton and coliform bacteria were not altered. An extra concentration of ammonia was detected at some tens meters from the raft, with favourable conditions. But generally it was impossible to observe it unless close to the farming structure, downward... |
| Tipo: Text |
Palavras-chave: Channel; Current; Faecal bacteria; Phytoplankton; Hydrology; Impact; Salmonid; Fish farm; Manche; Courant; Bactéries fécales; Phytoplancton; Hydrologie; Impact; Salmonidé; Aquaculture. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/rapport-3342.pdf |
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| Lassudrie, Malwenn; Soudant, Philippe; Nicolas, Jean-louis; Fabioux, Caroline; Lambert, Christophe; Miner, Philippe; Le Grand, Jacqueline; Petton, Bruno; Hegaret, Helene. |
| Blooms of toxic dinoflagellates can co-occur with mass mortality events associated with herpesvirus OsHV-1 μVar infection that have been decimating Pacific oyster Crassostrea gigas spat and juveniles every summer since 2008 in France. This study investigated the possible effect of a harmful dinoflagellate, Alexandrium catenella, a producer of Paralytic Shellfish Toxins (PSTs), upon the oyster spat–herpesvirus interaction. Oyster spat from a hatchery were challenged by cohabitation with oysters contaminated in the field with OsHV-1 μVar and possibly other pathogens. Simultaneously, the oysters were exposed to cultured A. catenella. Infection with OsHV-1 μVar and PST accumulation were measured after 4 days of experimental exposure. Exposure to Alexandrium... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; OsHV-1 mu Var; Harmful algal blooms; Alexandrium; Host-pathogen interaction; PST accumulation. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00269/38000/36101.pdf |
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| Pauletto, Marianna; Segarra, Amelie; Montagnani, Caroline; Quillien, Virgile; Faury, Nicole; Le Grand, Jacqueline; Miner, Philippe; Petton, Bruno; Labreuche, Yannick; Fleury, Elodie; Fabioux, Caroline; Bargelloni, Luca; Renault, Tristan; Huvet, Arnaud. |
| Double-stranded RNA (dsRNA)-mediated genetic interference (RNAi) is a widely used reverse genetic tool for determining the loss-of-function phenotype of a gene. Here, the possible induction of an immune response by long dsRNA was tested in a marine bivalve (Crassostrea gigas), as well as the specific role of the subunit 2 of the nuclear factor kappa B inhibitor (I kappa B2). This gene is a candidate of particular interest for functional investigations in the context of oyster mass mortality events, as Cg-I kappa B2 mRNA levels exhibited significant variation depending on the amount of ostreid herpesvirus 1 (OsHV-1) DNA detected. In the present study, dsRNAs targeting Cg-I kappa B2 and green fluorescent protein genes were injected in vivo into oysters... |
| Tipo: Text |
Palavras-chave: Anti-viral response; RNA interference; Inhibitor of NF-kappa B; Marine bivalve; Ostreid herpesvirus 1. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00409/52011/52698.pdf |
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| Suquet, Marc; Malo, Florent; Gourtay, Clemence; Ratiskol, Dominique; Riobe, Marion; Le Grand, Jacqueline; Queau, Isabelle; Mingant, Christian. |
| A basic cryopreservation protocol for great scallop sperm was recently published, with which thawed sperm survival remained limited to 25% of control values (Suquet et al. 2014). We designed here a set of five experiments to test ways of improving thawed sperm survival and storage by studying the effects of (1) cryoprotectant concentration; (2) sugar incorporation in the extender; (3) egg yolk addition to the extender; (4) sperm dilution rate; and (5) storage capacity of thawed sperm at 4 degrees C. A sixth experiment was then performed to compare rearing performances of larvae produced using thawed sperm from the optimal protocol defined in the present study with those produced using fresh sperm. During the first experiment, a significantly higher... |
| Tipo: Text |
Palavras-chave: Pecten maximus; Mollusc; Sperm; Cryopreservation; Larval rearing. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00359/47033/46946.pdf |
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| Boulais, Myrina; Suquet, Marc; Arsenault-pernet, Marie Eve Julie; Malo, Florent; Queau, Isabelle; Pignet, Patricia; Ratiskol, Dominique; Le Grand, Jacqueline; Huber, Matthias; Cosson, Jacky. |
| 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. 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... |
| Tipo: Text |
Palavras-chave: Seminal fluid; Spermatozoa; Motility; PH; Salinity; Ions. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/53976/55137.pdf |
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| Andrieux-loyer, Francoise; Philippon, Xavier; Bally, Gabriel; Kerouel, Roger; Youenou, Agnes; Le Grand, Jacqueline. |
| The macrotidal estuary of Penze (Brittany, Western part of the Channel, France) has been subjected to recurrent annual toxic blooms of Alexandrium minutum since 1988. This study aims to specify the phosphorus dynamics and bioavailability in sediments in order to improve our understanding of Alexandrium occurrences. Sediment-P pools and diffusive phosphate fluxes were studied under similar hydrodynamic conditions, in the intermediate estuary in May, June and July 2003 and along the salinity gradient from August 2004 to June 2005. The results highlight a decrease in bioavailable phosphorus (iron and organic bound) from the inner part of the estuary seaward. The ratio of iron-bound phosphorus to iron-oxyhydroxides is lower in the inner and intermediate... |
| Tipo: Text |
Palavras-chave: Sequential extraction; Sediment phosphorus; Pore water; Phosphate fluxes; Estuary; Alexandrium minutum. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4306.pdf |
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| Petton, Bruno; Riobe, Marion; Koechlin, Hugo; Queau, Isabelle; Mingant, Christian; Ratiskol, Dominique; Le Grand, Jacqueline; Petton, Sebastien; Thomas, Yoann; Alunno-bruscia, Marianne; Pouvreau, Stephane; Pernet, Fabrice; Maurer, Daniele; D'Amico, Florence; Lagarde, Franck; Mortreux, Serge; Roque D'Orbcastel, Emmanuelle; Mille, Dominique; Geay, A.; Bouquet, A.-l.; Cochet, Helene. |
| Depuis 2008, des mortalités massives d’huîtres creuses âgées de moins d’un an sont relevées sur le littoral français dès que la température de l’eau de mer atteint le seuil de 16°C. Ces mortalités de naissains sont associées à la détection du virus OsHV-1 μVar. Des travaux de qualification zoo-sanitaire menés depuis 2010 ont montré qu’un lot de naissains issus du captage naturel sur deux était infecté par le virus bien avant l’apparition des mortalités dans le milieu naturel, mais qu’a contrario les naissains d’écloserie expertisés présentaient un moindre risque de contamination. Dans le contexte de crise sanitaire chronique, l’objectif de notre étude était d’ obtenir une information qualitative relative au statut zoo-sanitaire OsHV -1 μ V ar des... |
| Tipo: Text |
Palavras-chave: Huitre creuse; OsHV - 1μVar; Epreuve thermique.; Maladie; Naissain; Pacific oyster; Spat; Disease; Thermal challenge; OsHV-1 μVar. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38682/37180.pdf |
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| Petton, Bruno; Le Grand, Jacqueline; Riobe, Marion; Mingant, Christian; Ratiskol, Dominique; Petton, Sebastien; Alunno-bruscia, Marianne. |
| Depuis 2008, des mortalités massives d’huîtres creuses âgées de moins d’un an sont relevées sur le littoral français dès que la température de l’eau de mer atteint le seuil de 16°C. Ces mortalités de naissains sont associées à la détection du virus OsHV-1 μVar. Depuis 2010, des travaux de qualification zoo-sanitaire ont montré qu’environ un lot de naissains de captage sur deux était infecté par le virus avant l’apparition des mortalités dans le milieu naturel. En 2014, dans le cadre de la première action QUALIF, les résultats de la qualification zoo-sanitaire des naissains du captage de l’année 2013 à l’échelle nationale ont mis en évidence le caractère infectieux des maladies développées par ces naissains porteurs latents d’OsHV-1 μVar. L’objectif 2015 du... |
| Tipo: Text |
Palavras-chave: Huitre creuse; Naissain; Maladie; OsHV-1 μVar; Epreuve thermique.; Pacific oyster; Seed; Disease; OsHV-1 μVar; Thermal challenge.. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00335/44587/44305.pdf |
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| Registros recuperados: 22 | |
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