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| Registros recuperados: 92 | |
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| Gerard, Andre. |
| Des élevages d'Artemia salina en milieux non renouvelés sont réalisés au Centre Océanologique de Bretagne pour l'étude de la nutrition et le contrôle des taux physiologiques, Sur ces élevages, un certain nombre de paramètres sont mesurés en continu ou semi-continu : pH, température, oxygène dissous, nitrites, ammoniaque, biomasse chlorophylienne... Les premières expériences avaient mis en évidence des variations dans le temps des paramètres mesurés avec des seuils d'équilibre résultant vraisemblablement d'une auto-régulation par les bactéries. Dans tous les écosystèmes aquatiques ou terrestres le rôle de la microflore bactérienne est primordial ; le métabolisme bactérien est un maillon essentiel des cycles vitaux du carbone, de l'azote et du soufre... Nous... |
| Tipo: Text |
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| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/00444/55535/57124.pdf |
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| Gerard, Andre. |
| Le nom de "population" désigne l'ensemble des individus d'une même espèce vivant dans un espace déterminé et partageant le même "pool de gènes". L'individu ne détient qu'une infime partie de ce pool de gènes il représente l 'unité de sélection. Sa contribution est minime par rapport à l'ensemble des génomes de la population, mais il peut, grâce à la mutation, apporter des gènes nouveaux ou accroître légèrement la fréquence de certains gènes du pool s'il possède un génome particulièrement viable et productif. La population est l'unité évolutive qui assure constamment l'échange et la recombinaison de la réserve génétique constituée par l'ensemble des génomes individuels . Elle est le champ d'expérimentation des nouveaux gènes et des nouvelles combinaisons... |
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| Ano: 1978 |
URL: http://archimer.ifremer.fr/doc/00444/55532/57121.pdf |
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| Buestel, Dominique; Cochard, Jean-claude; Dao, Jean-claude; Gerard, Andre. |
| Artificial production from natural spawners could be a way of getting big quantities of spat of Pecten maximus, ln the method described, larval phase (until a size of 250 microns) occurs in a hatchery, post-Iarval phase (from 250 µ until 3 millimeters) in a nursery, and first growth period directly into the sea (from 2 mm to a size of 25-30 mm), The fifst results obtained, production of several thousand of individuals good enough for reseeding, seem to be transposable to a larger scale. |
| Tipo: Text |
Palavras-chave: Restocking; Intermediate culture; Hatchery; Nursery; Pecten maximus; Repeuplement; Prégrossissement; Ecloserie; Nurserie; Pecten maximus. |
| Ano: 1982 |
URL: http://archimer.ifremer.fr/doc/1982/publication-6529.pdf |
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| Buestel, Dominique; Cochard, Jean-claude; Gerard, Andre. |
| Des travaux expérimentaux menés depuis 1977 en rade de Brest ont permis la mise au point d'une méthode de production de naissain de coquille Saint-Jacques dont la fiabilité a été démontrée en 1982. La filière d'élevage comprend quatre phases nécessitant chacune la mise en ouvre de techniques originales sur des sites distincts. La première étape réalisée en écloserie (température 17°C - eau de mer filtrée à 1µ) produit des larves pédiveligères de 250µ. Ces larves reprises dans une nurserie (eau de mer brute filtre à 125µ) donnent des postlarves de 1 à 3 mm. Les deux dernières phases se passent directement en mer ; un premier stade permet de produire des animaux de 10 mm environ qui sont ensuite portés à une taille de 30 mm et plus. Les résultats de l'année... |
| Tipo: Text |
Palavras-chave: Pecten maximus; Coquille Saint Jacques; Production artificielle. |
| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/00019/13019/9996.pdf |
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| Dao, Jean-claude; Gerard, Andre; Buestel, Dominique. |
| Research on the black scallop followed that on the king scallop. Indeed, over the 1973-1975 " spadework » period, it has been demonstrated that the roadsted of Brest was: - an overexploited king scallop deposit; the broodstock not being able to ensure a satisfying renewal of the species. - a black scallop production deposit (hundreds of tonnes). In parallel, the collection trials provided null results for the king scallop but very interesting results for the black scallop (thousands of spats per collector). From 1976 onwards, the spat collecting operations did not focus on king scallop juveniles anymore, but on black scallop. |
| Tipo: Text |
Palavras-chave: Reproduction; Captage; Physiologie; Pétoncle; Chlamys varia. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/acte-6538.pdf |
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| Buestel, Dominique; Gerard, Andre; Guenole, Annie. |
| Six batches of king scallop juveniles of different origins and obtained either by collection in their natural habitat (Saint-Brieuc, Scotland, Ireland), or by hatchery production in Brest in 1981, 1982, 1983, have been sown, at a size of 3 cm, in the roadsted of Brest between 1977 and 1983. Their growth, strongly linked to the evolution of the temperature, is well-described by a model, including a sinusoidal modulation, by Von Bertalanffy. The growth of the scallops collected in Saint-Brieuc, Scotland and Ireland, differentiates from that of the individuals from their original area and shows similarities with that of the scallops produced in Brest. Consequently, there must be an adaptation of the growth to the environmental conditions of the roadsted of... |
| Tipo: Text |
Palavras-chave: Pectiniculture; Croissance; Pecten maximus L.; Coquille Saint Jacques. |
| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/1986/acte-6189.PDF |
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| Cochard, Jean-claude; Gerard, Andre. |
| The analysis of the Pecten maximus larval productions carried out between 1982 and 1986 in the framework of the repopulating program of the roadsted of Brest demonstrated the existence of a number of factors affecting larval growth in hatcheries: - Larval growth shows important seasonal fluctuations. It is minimal in February-March (3 to 4 µm.D-1) and maximal in June (6 to 8 µm.D-1). The growth of larvae from conditioned spawners does not differ from that of larvae from mature genitors collected in their natural habitat. Growth is favoured by an unknown factor present in sea water and held with a filtration of 0,2 µm. - The growth of the larvae cultivated in slack water in flat bottom ponds is higher than that of the larvae cultivated in bubbling water in... |
| Tipo: Text |
Palavras-chave: Larve; Ecloserie; Croissance organisme; Coquille Saint Jacques; Pecten maximus L.; Production. |
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/1987/acte-6534.pdf |
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| Gerard, Andre. |
| Following the development of the hatchery tool, different triploidy induction techniques have been tried out in vitro. The method using cytochalasin B was selected and successfully applied to cupped oysters, Crassostrea gigas and especially to clams, Ruditapes philippinarum. Larval survival rates were lower than control rates. On the other hand, larvae's growth speed was comparable. These methods will now be used to produce significant test populations which will then be cultivated in French coastal waters. |
| Tipo: Text |
Palavras-chave: Palourdes; Huîtres creuses; Polyploïdisation; Conchyliculture. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/rapport-3853.PDF |
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| 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 |
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| Martin, Anne-genevieve; Gerard, Andre; Cochennec, Nathalie; Langlade, Aime. |
| In 1989, a selected strain of flat oyster. Ostrea edulis, was produced from breeders that survived Bonamia ostreae and that were over selected by injection of purified parasites. This generation (G 1) was compared to native oysters which had settled during the same year. After a growing period of 21 months, the oysters were tested according to three procedures: exposure to natural infection in an intertidal area, maintenance at the laboratory in tanks near heavily infested oysters, injection of parasites. The test lasted 7 months. In each procedure, oysters of the first generation (G1) showed a better survival rate than control oysters (72 to 94% versus 48 to 66%). On the other hand, the highest mortalities were observed among injected oysters (G1 and... |
| Tipo: Text |
Palavras-chave: Genetics; Ostrea edulis; Bonamia ostreae; Parasite resistance. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/1993/acte-3201.pdf |
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| Gerard, Andre; Naciri, Yamama; Peignon, Jean-marie; Ledu, Christophe; Phelipot, Pascal; Bodoy, Alain; Heurtebise, Serge; Garnier, Jacqueline; Baud, Jean-pierre; Nourry, Max; Haure, Joel; Martin, Anne-genevieve; Claude, Serge; Barret, Jean; Devauchelle, Nicole; Joly, Jean-pierre; Goulletquer, Philippe; Coatanea, Denis; Oheix, Jocelyne; Zanette, Yvan; Blachier, Philippe. |
| This fourth part of the polyploidisation program reports the experiments that were conducted in 1992 and that were devoted to : - the acquiring of a new method using an epifluroescent microscope - the development o a new technique for inducing polyploidy - the triploidy induction for the Europena clam Ruditapes decussatus - the settlement of performance controls conducted on diploid and triploid populations of Ostrea edulis - results of performance controls conducted on diploid and triploid populations of Crassostrea gigas and Ruditapes philippinarum |
| Tipo: Text |
Palavras-chave: Ruditapes decussatus; Ruditapes philippinarum; Ostrea edulis; Crassostra gigas; Cytongenetics; Polyploidy; Ruditapes decussatus; Ruditapes philippinarum; Ostrea edulis; Crassostrea gigas; Cytogénétique; Polyploïdie. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/1993/rapport-3859.PDF |
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| Gerard, Andre; Naciri, Yamama; Peignon, Jean-marie; Ledu, Christophe; Phelipot, Pascal; Baud, Jean-pierre; Nourry, Max; Renault, Tristan; Cochennec, Nathalie. |
| Premier volet du programme d'essai d'acclimatation de l'huître américaine Crassostrea virginica, ce rapport présente les actions et les résultats de l'année 1992 qui a été consacrée à : • l'importation selon les normes du CIEM d'un lot de 50 huîtres en provenance d'Angleterre, • leur élevage en salle de quarantaine et leur conditionnement en vue d'une accélération de la maturation sexuelle, • l'obtention d'une première génération, ainsi que son suivi en élevage larvaire et en micronurserie à l'URGE-La Tremblade, • au contrôle des performances comparées des deux populations de C. virginica et de C. gigas en nurserie de prégrossissement à l'URRA-Bouin pendant toute la période automnale et hivernale. Au terme de cette première année d'étude il apparait que la... |
| Tipo: Text |
Palavras-chave: Mollusques; Acclimatation; Crassostrea virginica; Crassostrea gigas; Génétique; Pathologie. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00077/18843/16417.pdf |
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| Registros recuperados: 92 | |
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