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| Registros recuperados: 52 | |
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| Labreuche, Yannick; Soudant, Philippe; Goncalves, Madeleine; Lambert, Christophe; Nicolas, Jean-louis. |
| Vibrio aestuarianus strain 01/32 was previously shown to be pathogenic to Crassostrea gigas juveniles. To investigate virulence mechanisms of this pathogen, we studied the toxicity to oysters of its extracellular products (ECPs). ECPs displayed lethality to animals, with a LD50 value of 3.3 mu g/g body weight. To determine the oyster cellular immune responses induced by these ECPs, we further examined in vitro their effects on C. gigas hemocytes, using flow cytometric-based hemocyte assays. Treatment of hemolymph with ECPs caused a significant inhibition of hemocyte phagocytosis and adhesive capabilities. In contrast, the pathway of reactive oxygen species production was enhanced by higher ECP concentrations. Exposure of hemocytes to live bacteria induced... |
| Tipo: Text |
Palavras-chave: Vibrio aestuarianus; ECPs; Crassostrea gigas; ROS production; Adhesion; Phagocytosis; Flow cytometry; Bivalve immunity. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1035.pdf |
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| Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Gueguen, Marielle; Moal, Jeanne; Palacios, Elena; Lassus, Patrick; Soudant, Philippe. |
| The effects of an artificial bloom of the toxin-producing dinoflagellate, Alexandrium minutum, upon physiological parameters of the Pacific oyster, Crassostrea gigas, were assessed. Diploid and triploid oysters were exposed to cultured A. minutum and compared to control diploid and triploid oysters fed T. Isochrysis. Experiments were repeated twice, in April and mid-May 2007, to investigate effects of maturation stage on oyster responses to A. minutum exposure. Oyster maturation stage, Paralytic Shellfish Toxin (PST) accumulation, as well as several digestive gland and hematological variables, were assessed at the ends of the exposures. In both experiments, triploid oysters accumulated more PSTs (approximately twice) than diploid oysters. Significant... |
| Tipo: Text |
Palavras-chave: Oysters; Ploidy; Physiology; Harmful-algal bloom; Alexandrium minutum; PST accumulation. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11378/7988.pdf |
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| Moriceau, Brivaela; Iversen, Morten H.; Gallinar, Morgane; Evertsen, Antti-jussi O.; Le Goff, Manon; Beker, Beatriz; Boutorh, Julia; Corvaisier, Rudolph; Coffineau, Nathalie; Donval, Anne; Giering, Sarah L. C.; Koski, Marja; Lambert, Christophe; Lampit, Richard S.; Le Mercier, Alain; Masson, Annick; Stibor, Herwig; Stockenreiter, Maria; De La Rocha, Christina L.. |
| The fraction of net primary production that is exported from the euphotic zone as sinking particulate organic carbon (POC) varies notably through time and from region to region. Phytoplankton containing biominerals, such as silicified diatoms have long been associated with high export fluxes. However, recent reviews point out that the magnitude of export is not controlled by diatoms alone, but determined by the whole plankton community structure. The combined effect of phytoplankton community composition and zooplankton abundance on export flux dynamics, were explored using a set of 12 large outdoor mesocosms. All mesocosms received a daily addition of minor amounts of nitrate and phosphate, while only 6 mesocosms received silicic acid (dSi). This resulted... |
| Tipo: Text |
Palavras-chave: Biogenic silica; POC; Marine snow; Zooplankton; Mesocosm; Bay of Hopavagen; Plankton community; Biological pump. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00469/58029/60433.pdf |
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| Gay, Melanie; Waechter, Magali; Lambert, Christophe; Escoubas, Jean-michel; Cochennec, Nathalie; Nicolas, Jean-louis; Berthe, Franck; Le Roux, Frédérique. |
| Nowadays, cupped oyster, Crassostrea gigas, production is the main shellfish production in France. Spats cultivated on most farms are usually collected in the wild, but hatchery spats are becoming more numerous, and represent around 10% of today's cultivated spats. During the summer period, when the temperatures are higher, high mortality rates have been regularly observed in cupped in oyster C. gigas (60 to 100%) spats since 1991, both in hatcheries-nurseries and in their natural habitat. Over the last five years, these episodes have become a big concern for all the professionals. |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Pathogène; Vibrio splendidus; Bactériologie. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/acte-3277.pdf |
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| Lambert, Christophe; Soudant, Phillippe; Degremont, Lionel; Delaporte, Maryse; Moal, Jeanne; Boudry, Pierre; Jean, Frédéric; Huvet, Arnaud; Samain, Jean-francois. |
| High variability among individuals is often encountered when hemocyte characteristics are measured in bivalves. Such variability is suspected to result partly from genetic factors. In this study, hemocyte characteristics of six families of Crassostrea gigas were compared by flow cytometry at one sampling date in October 2001. These families were obtained from a nested, half-sibling cross design, and reared from July to October 2001 at three sites distributed along the French Atlantic coast from north to south: Baie des Veys (Normandy), Riviere d'Auray (Brittany) and Ronce (Marennes-oleron Basin, Poitou Charentes). Among the 15 measured hemocyte characteristics, production of reactive oxygen species (ROS) of untreated hemocytes (maintained in filtered... |
| Tipo: Text |
Palavras-chave: Genetic; Flow cytometry; Reactive oxygen species ROS; Adhesion; Hemocyte; Crassostrea gigas; Summer mortality. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3054.pdf |
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| Paul-pont, Ika; Lacroix, Camille; Gonzalez Fernandez, Carmen; Hegaret, Helene; Lambert, Christophe; Le Goic, Nelly; Frere, Laura; Cassone, Anne-laure; Sussarellu, Rossana; Fabioux, Caroline; Guyomarch, Julien; Albentosa, Marina; Huvet, Arnaud; Soudant, Philippe. |
| The effects of polystyrene microbeads (micro-PS; mix of 2 and 6 μm; final concentration: 32 μg L−1) alone or in combination with fluoranthene (30 μg L−1) on marine mussels Mytilus spp. were investigated after 7 days of exposure and 7 days of depuration under controlled laboratory conditions. Overall, fluoranthene was mostly associated to algae Chaetoceros muelleri (partition coefficient Log Kp = 4.8) used as a food source for mussels during the experiment. When micro-PS were added in the system, a fraction of FLU transferred from the algae to the microbeads as suggested by the higher partition coefficient of micro-PS (Log Kp = 6.6), which confirmed a high affinity of fluoranthene for polystyrene microparticles. However, this did not lead to a modification... |
| Tipo: Text |
Palavras-chave: Microplastics; Fluoranthene; Mussel; Depuration; Oxidative system. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00344/45502/45848.pdf |
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| Tallec, Kevin; Huvet, Arnaud; Di Poi, Carole; Gonzalez-fernandez, Carmen; Lambert, Christophe; Petton, Bruno; Le Goic, Nelly; Berchel, Mathieu; Soudant, Philippe; Paul-pont, Ika. |
| In the marine environment, most bivalve species base their reproduction on external fertilization. Hence, gametes and young stages face many threats, including exposure to plastic wastes which represent more than 80% of the debris in the oceans. Recently, evidence has been produced on the presence of nanoplastics in oceans, thus motivating new studies of their impacts on marine life. Because no information is available about their environmental concentrations, we performed dose-response exposure experiments with polystyrene particles to assess the extent of micro/nanoplastic toxicity. Effects of polystyrene with different sizes and functionalization (plain 2-μm, 500-nm and 50-nm; COOH-50 nm and NH2-50 nm) were assessed on three key reproductive steps... |
| Tipo: Text |
Palavras-chave: Oyster; Embryos; Gametes; Microplastics; Nanoplastics. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56419/58090.pdf |
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| Remize, Marine; Planchon, Frederic; Loh, Ai Ning; Le Grand, Fabienne; Lambert, Christophe; Bideau, Antoine; Bidault, Adeline; Corvaisier, Rudolph; Volety, Aswani; Soudant, Philippe. |
| The synthetic pathways responsible for the production of the polyunsaturated fatty acids 22:6n-3 and 20:5n-3 were studied in the Dinophyte Alexandrium minutum. The purpose of this work was to follow the progressive incorporation of an isotopic label (13CO2) into 11 fatty acids to better understand the fatty acid synthesis pathways in A. minutum. The Dinophyte growth was monitored for 54 h using high-frequency sampling. A. minutum presented a growth in two phases. A lag phase was observed during the first 30 h of development and had been associated with the probable temporary encystment of Dinophyte cells. An exponential growth phase was then observed after t30. A. minutum rapidly incorporated 13C into 22:6n-3, which ended up being the most 13C-enriched... |
| Tipo: Text |
Palavras-chave: PUFA synthesis; 22:6n-3; DHA; PKS pathway; Dinophyte; Alexandrium minutum; Encystment. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00654/76562/77688.pdf |
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| Foulon, Valentin; Le Roux, Frederique; Lambert, Christophe; Huvet, Arnaud; Soudant, Philippe; Paul-pont, Ika. |
| Microplastics collected at sea harbour a high diversity of microorganisms including some Vibrio genus members, raising questions about the role of microplastics as a novel ecological niche for potentially pathogenic microorganisms. In the present study we investigated the adhesion dynamics of Vibrio crassostreae on polystyrene microparticles (micro-PS) using electronic and fluorescence microscopy techniques. Micro-PS were incubated with bacteria in different media (Zobell culture medium and artificial seawater) with or without natural marine aggregates. The highest percentage of colonised particles (38-100%) was observed in Zobell culture medium, which may be related to nutrient availability for production of pili and exopolysaccharide adhesion structures.... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00351/46210/45908.pdf |
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| Paillard, Christine; Nicolas, Jean-louis; Le Chevalier, Patrick; Lambert, Christophe; Le Boulay, Christine; Berthe, Franck; Haras, Dominique. |
| The emergence of new vibriosis in the European Atlantic coasts has been associated with mass mortalities of molluscs causing important economic losses. For examples, Vibrio carchariae, a bacteria already isolated from shark, has been associated with a severe Haliotis epizooty in hatchery. In oysters, Crass()strea gigas, a strain closely related to Vibrio splendidus is suspected to be associated with summer mortalities. |
| Tipo: Text |
Palavras-chave: Pathogenic vibrios; Bivales; Vibriosis; Bacteriology. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/acte-3287.pdf |
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| Delaporte, Maryse; Chu, Fu-lin; Langdon, Chris; Moal, Jeanne; Lambert, Christophe; Samain, Jean-francois; Soudant, Philippe. |
| The aim of this study was to assess the effect of dietary eicosapentaenoic acid (20:5n-3) on hemocyte parameters such as hemocyte concentration, phagocytosis, and non-stimulated reactive oxygen species (ROS) production in Pacific oysters Crassostrea gigas, as well on proximate biochemical and fatty acid compositions. One-year-old oysters (C. gigas) were fed T-Isochrysis aff. galbana(T-Iso), which is low in 20:5n-3, either alone or with supplements of a lipid emulsion rich in 20:5n-3 at 1%, 10% or 50% (dry weight of the algal ration) for up to 7 weeks. Changes in gill fatty acid composition demonstrated that the lipid emulsion was well ingested by oysters during the dietary conditioning. Biochemical analysis indicated that oysters fed supplements of 50%... |
| Tipo: Text |
Palavras-chave: Polyunsaturated fatty acids; Immunology; Hemocytes; Eicosapentaenoic acid 20 : 5n 3; Crassostrea gigas; Bivalves. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2604.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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| Soletchnik, Patrick; Le Moine, Olivier; Faury, Nicole; Guilpain, Patrice; Geairon, Philippe; Razet, Daniel; Seugnet, Jean-luc; Robert, Stephane; Ropert, Michel; Simonne, Charlotte; Hugonnet, Virginie; Moal, Jeanne; Pouvreau, Stephane; Huvet, Arnaud; Samain, Jean-francois; Lambert, Christophe; Soudant, Philippe; Frouel, Stephane; Choquet, Gwenaelle; Delaporte, Maryse; Paillard, Christine. |
| Four laboratories are involved in this multidisciplinary study: the Conchological Laboratory of Normandie (LCN), the Invertebrates Physiology Laboratory (LPI), the Université Bretagne Occidentale (LEMAR IHP) and the Conchological Laboratory of Poitou-Charentes (LCPC). The part of the study which is presented here (thematics "Coastal ecology") was produced in collaboration with the LCN. The data on the Bay of Veys was collected by Michel Ropert. This study aims at observing the "sites" effect on mortality and on the general biology of the animal, as well as measuring some environmental elements (e.g. water temperature, etc.). The geographical sites are Gefosse in the Bay of Veys (East Cotentin) and the Ronce bank in the south of the Marennes Oléron Bay. The... |
| Tipo: Text |
Palavras-chave: Immunologie; Physiologie; Paramètres environnementaux; Croissance; Ecologie côtière; Baies des Veys Cotentin; Ronce Charente Maritime; Comparaison sites; Reproduction; Mortalités; Crassostrea gigas; Huîtres. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/acte-3405.pdf |
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| Haberkorn, Hansy; Lambert, Christophe; Le Goic, Nelly; Quere, Claudie; Bruneau, A; Riso, Ricardo; Auffret, Michel; Soudant, Philippe. |
| Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd-Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd-Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd-Cu induced significant changes in neutral lipids (increase in... |
| Tipo: Text |
Palavras-chave: Harmful algae; Metals; Oysters; Toxin accumulation; Physiological effects. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00169/28071/26286.pdf |
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| Long, Marc; Paul-pont, Ika; Hegaret, Helene; Moriceau, Brivaela; Lambert, Christophe; Huvet, Arnaud; Soudant, Philippe. |
| To understand the fate and impacts of microplastics (MP) in the marine ecosystems, it is essential to investigate their interactions with phytoplankton as these may affect MP bioavailability to marine organisms as well as their fate in the water column. However, the behaviour of MP with marine phytoplanktonic cells remains little studied and thus unpredictable. The present study assessed the potential for phytoplankton cells to form hetero-aggregates with small micro-polystyrene (micro-PS) particles depending on microalgal species and physiological status. A prymnesiophycea, Tisochrysis lutea, a dinoflagellate, Heterocapsa triquetra, and a diatom, Chaetoceros neogracile, were exposed to micro-PS (2 μm diameter; 3.96 μg L−1) during their growth culture... |
| Tipo: Text |
Palavras-chave: Polystyrene; Microplastic; Aggregates; Microalgae; Marine; Phytoplankton. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00389/50016/50735.pdf |
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| Guesdon, Stephane; Stachowski-haberkorn, Sabine; Lambert, Christophe; Beker, Beatriz; Brach-papa, Christophe; Auger, Dominique; Bechemin, Christian. |
| This study aimed to describe seasonal variations of phytoplankton abundances in relation to the physical and chemical (nutrients and metals) environment under the influence of freshwater input in the Charente river estuary (Marennes-Oléron bay, France) over three years, from 2011 to 2014. Phytoplankton abundances were determined using microscopy and flow cytometry. Considering high frequency temperature and salinity data, breakpoints in each series led to the identification of two local hydroclimatic periods: the first (2011 and early 2012) being warmer and higher in salinity than the second (from spring 2012 to the beginning of 2014). A multiblock PLS analysis highlighted the significant contribution of the physical environment (temperature, salinity and... |
| Tipo: Text |
Palavras-chave: Hydroclimate; Estuary; Phytoplankton; Size composition; Nutrients; Trace metals. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00349/46005/45674.pdf |
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| Lambert, Christophe. |
| The control of diseases remains a question of major importance in order to reduce pathological risks in bivalve larval rearings. For such a purpose, the knowledge of diseases, pathogens and routes of infection is required. A new species of vibrio pathogenic to P. maximus larvae, Vibrio pectenicida, was described by phenotypic and genotypic characters. It belongs to the V. splendidus group, where sorne other new pathogenic species were already found. The pathogenesis of V. pectenicida was studied by histological methods and experimental exposures in conventional and axenic larval rearings. These studies assessed the pathogenic character of V. pectenicida strains and the lack of particular symptoms during the disease. The location ofbacteria in the tissues... |
| Tipo: Text |
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| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00034/14562/11860.pdf |
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| Long, Marc; Tallec, Kevin; Soudant, Philippe; Lambert, Christophe; Le Grand, Fabienne; Sarthou, Geraldine; Jolley, Dianne; Hegaret, Helene. |
| Harmful microalgal blooms are a threat to aquatic organisms, ecosystems and human health. Toxic dinoflagellates of the genus Alexandrium are known to produce paralytic shellfish toxins and to release bioactive extracellular compounds (BECs) with potent cytotoxic, hemolytic, ichtyotoxic and allelopathic activity. Negative allelochemical interactions refer to the chemicals that are released by the genus Alexandrium and that induce adverse effects on the physiology of co-occurring protists and predators. Releasing BECs gives the donor a competitive advantage that may help to form dense toxic blooms of phytoplankton. However BECs released by Alexandrium minutum are uncharacterized and it is impossible to quantify them using classical chemical methods.... |
| Tipo: Text |
Palavras-chave: Harmful algal bloom; Alexandrium; Allelopathy; Cytotoxicity; PAM fluorometry; Bioassay. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56424/58116.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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| Delaporte, Maryse; Moal, Jeanne; Soudant, Philippe; Lambert, Christophe; Pouvreau, Stephane; Enriquez, Martha; Degremont, Lionel; Soletchnik, Patrick; Gagnaire, Beatrice; Ropert, Michel. |
| In the frame of MOREST project, a common biological material, resulting of a mixture of different families produced in experimental hatchery, was reared in two different environmental fields : Normandy and Charente. Concomitantly, a pool was conditioned at the Ifremer Argenton hatchery with three different algae levels : 4%, 8% and 12% of algal dry weight per oyster dry weight. During the experiments, five immune parameters were studied in parallel with survival rate and reproductive status (stages and intensity). Site location, seasonal variations and experimental diet level clearly influenced oyster immune parameters. Haemocyte counts were higher for oysters reared in Normandy than those reared in Charente and in hatchery. Granulocyte percentage was... |
| Tipo: Text |
Palavras-chave: Defense mechanisms; Nutrition; Seasonal variations; Physiology; Crassostrea gigas; Pacific oysters. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/acte-3500.pdf |
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| Registros recuperados: 52 | |
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