Consulta: creatorFacets:"Chagot, Dominique"
Registros recuperados: 18
Data/hora: 11/06/2024 04:35:23

Mortalités d'huîtres japonaises sur le Banc de Ronce Les Bains : rapport provisoire au 4/8/88
Provedor de dados: 5
Autores: Bodoy, Alain; Garnier, Jacqueline; Geairon, Philippe; Chagot, Dominique; Grizel, Henri; Comps, Michel; Razet, Daniel.
Depuis le mois de juin 1988, les ostréiculteurs ont fait part de la présence de mortalités importantes sur le banc de Ronce (bassin de Marennes-Oléron), d'abord auprès de l'Ifremer et des Affaires Maritimes, puis des pouvoirs publics. Ces problèmes ont été évoqués lors d'une réunion en Préfecture de Charente-Maritime, le 4 juillet 1988. Il s'est alors avéré nécessaire de réaliser un constat de la situation notamment sur le banc de Ronce, et de faire le point sur les causes pouvant être à l'origine de la situation sur les mortalités survenues dans cette zone. Cette décision a été confirmée le 12 juillet, lors d'une réunion à la Sous-Préfecture de Rochefort. Le présent rapport présente les résultats scientifiques actuellement disponibles, ainsi que les...
Tipo: Text
Palavras-chave: Mortalité; Météorolgie; Paramètres hydrologiques; Physiologie; Croissance; Bivalvia; Crassostrea gigas; Bassin de Marennes Oléron.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/00086/19765/17406.pdf

Rapport sur les causes des mortalités d'huîtres creuses observées en juin 1992 sur le Banc de Ronce Les Bains (Bassin de Marennes-Oléron)
Provedor de dados: 5
Autores: Heral, Maurice; Bacher, Cedric; Razet, Daniel; Prou, Jean; Galgani, Francois; Renault, Tristan; Bodoy, Alain; Garnier, Jacqueline; Geairon, Philippe; Chagot, Dominique; Grizel, Henri; Comps, Michel; Masson, Daniel; Noinin, Michel.
Dès le 4 JUIN 1992, un ostréiculteur digne de confiance avait signalé aux services d'IFREMER, une situation anormale sur le banc de Ronce les Bains. Un premier prélèvement a été effectué le jour même. En effet, ce secteur avait déjà été le lieu de mortalités d'huitres estimées à 7 000 tonnes, au printemps 1988, et s'est révélé par le passé comme étant un endroit sensible. Pour information, figure en annexe le rapport établi en 1988, à destination du Préfet de la Charente Maritime. Ces mortalités ayant rapidement pris de l'ampleur, un dépôt de plainte contre X a été effectué par la Section Régionale de la Conchyliculture. A la suite de quoi, les services d'IFREMER ont été requis par la Gendarmerie Nationale (Brigade de Marennes) le 10 juin 1992, pour...
Tipo: Text
Palavras-chave: Ostréiculture; Huîtres creuses; Crassostrea gigas; Mortalité; Banc de Ronce Les Bains; Bassin de Marennes Oléron.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/00048/15899/13327.pdf

Sublethal and histopathological effects of trace levels of tributyltin fluoride on adult oysters Crassostrea gigas
Provedor de dados: 5
Autores: Chagot, Dominique; Alzieu, Claude; Sanjuan, Jane; Grizel, Henri.
Shell malformations and histological effects of environmental concentrations of TBTF (2, 13.1 and 64.8 ng/!) were assessed on adult oysters Crassostrea gigas during a I-month experiment, incIuding both an exposure and a depuration phase. The results showed that the digestive gland is the primary target organ. Recoverable modifications were observed at the lowest concentration. Limited necrosis was observed at the highest concentration and a longer exposure could have led to extensive and irreversible tissue lesions. Shell malformations (chambering) were observed during the depuration phase. Finally the authors suggest that safe TBT levels in mariculture waters should be lower than 2 ng/l.
Tipo: Text
Palavras-chave: Histopathological effects; Crassostrea gigas; Tributyltin; Effets histopathologiques; Crassostrea gigas; Tributylétain.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/1990/publication-2754.pdf

Branchial Rickettsiales-like infection associated with a mass mortality of sea scallop Pecten maximus
Provedor de dados: 5
Autores: Legall, Ghyslaine; Chagot, Dominique; Mialhe, Eric; Grizel, Henri.
A branchial infection of Pecten maximus is histologically and ultrastructurally described. Gill epithelial cells were heavily infected with colonies of procaryotes, believed ta belong to the Rickettsiales.
Tipo: Text
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/publication-3125.pdf

Une parasitose nouvelle chez la palourde Ruditapes decussatus L.
Provedor de dados: 5
Autores: Comps, M; Chagot, Dominique.
Perkinsus-like parasite has been observed within the tissues of the Clam Ruditapes decussatus from Portugal. The structure of the vegetative stages is described.
Tipo: Text
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/publication-3116.pdf

Bonamiasis : a model study of diseases in marine molluscs
Provedor de dados: 5
Autores: Grizel, Henri; Mialhe, Eric; Chagot, Dominique; Boulo, Viviane; Bachere, Evelyne.
Research on bonamiasis, an epizootic disease of the edible oyster Ostrea edu/is caused by the protozoan Bonamia ostreae, is discussed in relation to oyster fanning, research technology, epizootiology, and management. Morphological and infectious characteristics of the parasite are described. Recent progress in isolation and purification of the parasite have permitted investigations into host defense mechanisms, parasite infectivity, and the development of a mol1usc-pathogen mode!.
Tipo: Text
Palavras-chave: Epizootic disease; Pathology; Protozoan; Bonamia ostreae; Oysters.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/publication-3120.pdf

An infection of Ruditapes decussatus (Bivalvia) by Rickettsia
Provedor de dados: 5
Autores: Mialhe, Eric; Chagot, Dominique; Boulo, Viviane; Comps, Michel; Ruano, Francisco; Grizel, Henri.
The authors report the presence of a Rickettsia in Ruditapes decussatus from natural populations of the Algarve (Portugal). Light microscopic shows infections of varying importance in gill tissues. Some enclose small procaryotic colonies (cp) scattered in all lamellae; in others, the colonies are scarce and hypertrophic (100 mu m). These different pictures suggest an amplification process. Digestive diverticulae may also be infected, but to a lesser extent. The ultrastructural features of this intravacuolar (mvd: densified vacuolar membrane) procaryote (P) and its multiplication by scission without a complex developmental cycle allows its classification in the order Rickettsiales.
Tipo: Text
Palavras-chave: Ruditapes philippinarum; Pathogens; Histopathology; Pathology.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/acte-3107.pdf

Study of a haplosporidian (Ascetospora), parasitizing the Australian flat oyster Ostrea angasi
Provedor de dados: 5
Autores: Bachere, Evelyne; Chagot, Dominique; Tige, Gilbert; Grizel, Henri.
Considering the epizootics which affect the French stock of flat oysters, Ostrea edulis (Grizel, 1985), trials to introduce an Australian oyster, Ostrea angasi, have been undertaken. The spat produced in a hatchery from breeders imported from Australia were reared in the south ofBrittany and in Normandy (Bougrier et al., 1986). Following mass mortalities (65% of individuals) a haplosporidian was observed in this species. Sporogenesis of the parasite was studied using Iight and electron microscopy.
Tipo: Text
Palavras-chave: Haplosporidian; Parasitology; Pathology; Ostrea angasi; Oysters.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/acte-3112.pdf

Toxicité sublétale du tétrachloroéthylène sur la crevette des marais Palaemonetes varians
Provedor de dados: 5
Autores: Lassus, Patrick; Chagot, Dominique; Miossec, Laurence; Bocquene, Gilles; Truquet, Philippe.
Tetrachloroethylene, a chlorinated solvent, is detected in the plume of East-Toulon domestic wastes treatment plant. Its subletal toxicity was tested du ring 31 days in a flow-through system at Pen Bron aquaculture centre, using swampshrimp Palaemonetes varians as test organism. Under expérimental conditions : natural variations in temperature and salinity , normal pH, ammonia and dissolved oxyg~n values, running tetrachloroethylene concentrations (10, 100 and 500 µg.l-1) induced neither mortalities nor any change in molting frequencies of experirnented animaIs. Histology of gills in contaminated animaIs showed several non specific deteriorations which could be observed either in control or assay animaIs. Necrosis levels nevertheless, seem to increase in...
Tipo: Text
Palavras-chave: Palaemonetes varians; Crustacés; Tetrachloroethylene; Flux continu; Rejets urbains; Histologie; Nécroses; Palaemonetes varians; Crustacees; Tetrachloroethylene; Flow through system; Urban wastes; Histology; Necrosis.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00156/26707/24782.pdf

Histological study of a cellular reaction in Ruditpaes decussatus infected by a protozoan
Provedor de dados: 5
Autores: Chagot, Dominique; Comps, Michel; Boulo, Viviane; Ruano, Francisco; Grizel, Henri.
An infection caused by a Perkinsus -like parasite has been observed in Ruditapes decussatus from Portugal (Comps and Chagot, 1987). Following a pathological study carried out on clams affected by mortalities in the Algarve area, this parasite was found again, inducing a reaction process in the host. Histological examination reveals the parasite in the connective tissue of different organs. The adjoining tissues, particularly the epithelia, are not affected.
Tipo: Text
Palavras-chave: Cells; Histology; Pathology; Ruditapes decussatus.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/acte-3109.pdf

Diversification des productions conchylicoles en Poitou-Charentes. L'élevage du pétoncle noir Chramys Varias
Provedor de dados: 5
Autores: Bodoy, Alain; Garnier, Jacqueline; Heurtebise, Serge; Nollet, V.; Chagot, Dominique.
La croissance et la reproduction du pétoncle noir, Chlamys varia, ont été suivies sur un cycle biologique complet, dans un marais maritime. Cette croissance s'est avérée être nettement, plus rapide qu'en rade de Brest, puisque la taille commerciale de 35 mm a été atteinte en un an. Les individus se sont reproduits au bout de la même période. Ceci montre qu'il est possible d'obtenir un cycle biologique très rapide. Lors du cycle de production, des mortalités importantes ont été constatées entre le prégrossissement en nurserie et la mise en élevage. Ces mortalités ne se sont pas renouvelées sur le cycle en cours d'étude. Un agent parasite nouveau a été décrit sur cette espèce, sans que les certitudes puissent être établies quant à son rôle pathogène....
Tipo: Text
Palavras-chave: Croissance; Composition biochimique; Elevage; Pétoncle; Marais maritime; Charente-Maritime.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/00048/15905/13333.pdf

Localisation and characterization of acid phosphate activity in Bonamia ostreae (Ascetospora), an intrahemocytic protozoan parasite of the flat oyster Ostrea edulis (Bivalvia)
Provedor de dados: 5
Autores: Hervio, Dominique; Chagot, Dominique; Godin, Pierre; Grizel, Henri; Mialhe, Eric.
Acid phosphatase activity was cytochemically detected at the ultrastructural level in the protozoan Bonamia ostreae, an intrahemocytic parasite of the flat oyster Ostrea edulis. Lead nitrate was used as capture agent for phosphate liberated during the hydrolysis of the subtrate (cytidine 5' monophosphate). Lead phosphate precipiation, indicative of enzyme activity, was located in membrane-bound organelles corresponding to the cytoplasmic inclusions known as "dense bodies". Acid phosphatase activity level and sodium L-tartrate inhibition were measured spectrophotometrically from a purified parasite suspension. The possible involvement of this enzyme in intracellular survival of B. ostrea is discussed.
Tipo: Text
Palavras-chave: Acid phosphate activity; Ostrea edulis; Bonamia ostreae.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-2755.pdf

Mortalité du tourteau Cancer pagurus provoquée par le dinoflagelle parasite : Hematodinium sp.
Provedor de dados: 5
Autores: Latrouite, Daniel; Morizur, Yvon; Noel, Philippe; Chagot, Dominique; Wilhelm, G.
Unusural crab mortality in winter led us to identify a Hematodinium like parasitic dinoflagellate in the blood of edible crabs Cancer pagurus. Crabs from several fishing areas (the English Channel, the Iroise sea, the bay of Biscay, off Scotland) and from one area of the Channel shore were examined. The crab parasit was found everywhere we investigated and throughout the year. The prevalence which was found independant of the intermolt stage, sex and size of crabs was higher inshore than offshore. The pathogenicity is assumed to differ according to season.
Tipo: Text
Palavras-chave: Edible crab; Pathology; Bay of Biscay; Iroise sea; Channel; Parasite; Mortality; Hematodinium; Bitter crab desease; Dinoflagelle; Aquiculture; Cancer pagurus; Mortalité; Hematodinium; Cancer pagurus; Tourteau; Pathologie.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/acte-1418.pdf

Preparation and characterization of monoclonal antibodies against neoplastic hemocytes of Mytilus edulis (Bivalvia)
Provedor de dados: 5
Autores: Noel, Danielle; Boulo, Viviane; Chagot, Dominique; Mialhe, Eric; Paolucci, Francis; Clavies, Christine; Hervaud, Eric; Elston, Ralph.
Mytilus edulis develop progressive and fatal hemocytic neoplasia. We have generated monoclonal antibodies using neoplastic hemocytes from highly infected individuals collected from Puget Sound in Washington State (USA). Twenty-seven monoclonal antibodies against neoplatic cell antigens were obtained. Specificity of 2 purified antibodies, 14F1 and 16G10, was demonstrated by immunofluorescence when  incubated with neoplastic hemocytes, whereas these anbidodies did not react with normal cells. This specificity was confirmed by immunogold labelling and electron microscopic visualization. The technique permitted localization of the epitopes recognized by the monoclonal antibodies on the plasma membrane. These monoclonal antibodies are suitable reagents for...
Tipo: Text
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/publication-2757.pdf

Cell separation by centrifugal elutriation
Provedor de dados: 5
Autores: Bachere, Evelyne; Chagot, Dominique; Grizel, Henri.
There is an ongoing need to isolate and purify ceIls in bivalve mollusc disease research. Many separation techniques differentiate cells solely by a single factor and usually require additives in the medium that may damage live cells. Centrifugai elutriation is a technique that separates particles by size and density simultaneously and can be conducted in physiological media without additives. Living cells can be separated without chemical damage and, because the procedure can be conducted aseptically, cells can be maintained in vitro after elutriation. A description of the technique, methods to determine flow rates and rotor speeds, and a preliminary separation of oyster hyalinocytes is presented
Tipo: Text
Palavras-chave: Bivalve mollusc; Centrifugal elutriation; Cell separation.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/publication-3118.pdf

Mantle histology, histochemistry and ultrastructure of the pearl oyster Pinctada margaritifera (L.)
Provedor de dados: 5
Autores: Jabbour-zahab, Roula; Chagot, Dominique; Blanc, François; Grizel, Henri.
The edge and isthmus of the mantle of Pinctada margaritifera (Mollusc, Bivalvia) were studied using light and electron microscopy from a morphological and histochemical point of view. Six areas with several subareas were differentiated in the mantle edge. One of these areas is similar to the epithelium isthmus, Trials to elucidate the nature of the pigment responsible for the black colour of the shell and pearl indicate a melanin-like material. Possible functions of the distinctive epithelial areas in Pinctada margartifera mantle are discussed according to available data on the secretion of organic matrix of the shell, protein sclerotization and deposition of crystals in some pearl-forming molluscs. Three different epithelial areas in the outer mantle edge...
Tipo: Text
Palavras-chave: Bivalvia; Mollusc; Pinctada margaritifera; Pigment; Ultrastructure; Structure; Mantle; Bivalves; Mollusques; Pinctada margaritifera; Pigment; Ultrastructure; Structure; Manteau.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/1992/publication-2770.pdf

Ultrastructural study of sporulated instars of a haplosporidian parasitizing the clam Ruditapes decussatus
Provedor de dados: 5
Autores: Chagot, Dominique; Bachere, Evelyne; Ruano, Francisco; Comps, Michel; Grizel, Henri.
In 1951, Vilela pointed out the presence of a haplosporidian parasitizing Ruditapes decussatus from Portuguese waters and created the species Haplosporidium tapetis. Later, a haplosporidian was found in the same species originating from the pound of Thau (France).
Tipo: Text
Palavras-chave: Haplosporidian paratizing; Ruditapes decussatus; Pathology.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/acte-3110.pdf

Contrôle de la ploidie par imagerie numérique dans des expériences d'induction de la triploidie chez les mollusques bivalves
Provedor de dados: 5
Autores: Gerard, Andre; Peignon, Jean-marie; Chagot, Dominique.
Individual determination of ploidy level in experimentally induced triploid bivalve molluscs using image cytometry. The sexual maturation in bivalve molluscs causes decreased growth and sometimes increased mortalities. These drawbacks can be avoided by genetic sterilization (triploidy). Triploïdy induction require a egg treatment and a ploidy control at each generation. The ploidy level is usually determined by counting the chromosomes, a technique which is relatively easy for the trochophora stage and for juveniles measuring from 5 mm to 3 cm only.  ln order to be able to follow up the evolution of the ploidy rate during any stage of animallife, we have developed an estimation method based on image cytometry. Individual DNA content is determined by...
Tipo: Text
Palavras-chave: Image cytometry; Caryology; Triploidy; Bivalve; Imagerie numérique; Caryologie; Triploïdie; Bivalve.
Ano: 1991
URL: http://archimer.ifremer.fr/doc/1991/acte-3202.pdf