Thèse de doctorat : Sciences de la vie. Spécialité hydrobiologie : Metz : 2001. / Thèse : 2001METZ030S. Bibliogr. p. 219-230.

Th. 3e cycle--Sci. agron.--Nancy--I.N.P.L., 1983.

Reproduction de : Thèse doctorat : Sciences de la vie. Spécialité : hydrobiologie : Metz : 2003. / Titre provenant de l'écran-titre. Notes bibliographiques.

Ce projet s’est intéressé à l’impact qu’exerce l’ensemencement du Saumon atlantique sur le processus de recrutement des souches microbiennes commensales en milieu naturel. Puisque le taux de survie des saumons ensemencés reste faible par rapport à celui des individus sauvages de la même population génétique, il est essentiel d’évaluer dans quelle mesure l’acclimatation du microbiote aux conditions de pisciculture persiste après l’introduction des individus en milieu naturel. L’objectif de ce projet était de comparer la composition du microbiote de tacons de saumons, nés en pisciculture, deux mois suivant leur introduction en rivière avec celle des tacons sauvages. L’hypothèse était que l’élevage en pisciculture induit un effet à long terme sur le microbiote des individus ensemencés. Différents sites corporels ont été comparés; le mucus cutané, trois sections de l’intestin (proximale, médiane, et distale) ainsi que le bol alimentaire associé à chacune de ces trois sections, en plus du contenu stomacal. Enfin, tous les individus ont été génotypés à l’aide de 17 marqueurs microsatellites. Les résultats présentés montrent que les individus ensemencés ont un microbiote différent de celui de leurs congénères sauvages. Ces résultats mettent en évidence une empreinte sur le microbiote des conditions précoces. Une capacité d’acclimatation du microbiote cutané ainsi qu’une forte résistance à la colonisation du microbiote intestinal aux bactéries sauvages ont été notés. Ce projet génère des connaissances inédites dans le domaine de l’écologie microbienne, utilisables pour l’optimisation des méthodes de conservation et supporte les recommandations de reconstituer le plus possible l’environnement naturel lors de l’élevage de poissons destinés à la restauration de populations naturelles. Des études complémentaires seront nécessaires afin d’approfondir notre compréhension des processus moléculaires liés au recrutement du microbiote et sur la relation entre la faible survie des individus ensemencés et l’impossibilité de recruter certaines fonctions bactériennes clés après l’ensemencement. / Here we examine the impact exerted by the Atlantic salmon stocking methods on the microbiota recruitment processes of microbial commensals in the wild. Because mortality rate of stocked salmon remains higher than that of wild ones despite sharing the same genetic background, it becomes essential to assess to which extent the acclimation of the microbiota in hatchery persists after the introduction of fishes in the wild. Our objective was to compare hatchery reared and stocked parrs with wild parrs’ microbiota belonging to the same genetic population, two months after stocking. We hypothesized that rearing conditions in hatcheries had long-term effects on the microbiota of stocked parrs after stocking. To do so, we examined the microbiota composition from various samples of stocked and wild parrs; the cutaneous mucus, three sections of the intestine (proximal, median and posterior) and the food bowl associated to these sections, as well as the stomach content. In addition, all specimens were genotyped with 17 microsatellites markers. The results show that stocked parrs’ microbiota differs than that from their wild relatives and suggest that hatchery conditions have long term effects on the microbiota. Moreover, our results suggest an imprinting on the microbiota associated with early conditions. Moreover, a high adaptive capacity of the cutaneous mucus microbiota and a high colonization resistance of the intestinal microbiota were observed. In addition to generate knowledge regarding the long-term effects of early life conditions on the microbiota composition, this project support previous recommendation to mimic the natural environment (including the microbial environment) in hatchery for conservation programs. Further studies on the molecular processes occurring during the microbiota ontogeny in hatchery as well as on the contribution of the microbiota for stocked parrs’ survival after their introduction in the wildand their incapacity to recruit key symbionts in the wild would be needed.

Thèse de doctorat : Sciences agronomiques : Vandoeuvre-les-Nancy, INPL : 2005. / Titre provenant de l'écran-titre. Bibliogr.

Orientador: Sergio Ricardo Batlouni / Banca: Maria Inês Borella / Banca: Carlos Alberto Vicentini / Resumo: A reprodução de peixes migradores nativos apesar de já apresentar relativo sucesso, ainda apresenta diversos obstáculos. Entre eles podemos destacar as variações nas taxas de fertilidade, eclosão e sobrevivência de larvas entre desovas. Desta forma, o objetivo deste trabalho foi avaliar de forma inédita se o manejo pode interferir neste processo em machos de P. lineatus. Os resultados mostraram que os machos mantidos em tanques-rede (TR) com água de baixa qualidade durante 18 meses apresentam encurtamento do ciclo reprodutivo; redução significativa no IGS e no diâmetro de túbulos seminíferos (p<0,05) quando comparados com machos mantidos em viveiros escavados (VE). A concentração espermática e as taxas de fertilidade obtidas com o sêmen dos machos de TR foram inferiores às obtidas com o sêmen dos machos em VE (p<0,05). Além disso, os espermatozoides de TR apresentaram maior frequência de danos de DNA, mesmo apresentando taxas similares de motilidade e sobrevivência que os de VE (p<0,05). Os resultados mostraram de forma inédita que o manejo inadequado pode interferir na gametogênese e na qualidade de gametas masculinos nesta espécie. Além disso, demonstramos que práticas inadequadas de manejo podem prejudicar a função testicular ainda nos meses de inverno, muito antes dos meses de reprodução / Abstract: The reproduction of native migratory fish still presents several obstacles. Among them we can highlight the changes in fertility rates, hatching and survival of larvae among spawning. Thus, the objective of this study was to evaluate in an unprecedented way if the reproductive management can interfere in this process in males of P. lineatus. The results showed that males kept in cages (C) for 18 months have their reproductive cycle shortened; significant reduction in the GSI and in the diameter of seminiferous tubules (p<0.05) compared with males kept in earths ponds (EP). The sperm concentration and fertility rates obtained with semen from males of Cs were lower than those obtained with semen EP (p<0.05). In addition, the sperm of males maintained in Cs had higher frequency of DNA damage, even with similar rates of survival and motility of the EPs (p<0.05). The results showed by unprecedented manner that the improper management can interfere with gametogenesis and quality of male gametes in this species. Furthermore, we demonstrate inadequate management practices can affect the testicular development even in the winter months, long before the breeding season / Mestre

Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-30Bitstream added on 2014-06-13T20:48:48Z : No. of bitstreams: 1 souza_tg_me_jabo.pdf: 556522 bytes, checksum: 10d9f685779dd6eaf31aa9ddefd870ec (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A reprodução de peixes migradores nativos apesar de já apresentar relativo sucesso, ainda apresenta diversos obstáculos. Entre eles podemos destacar as variações nas taxas de fertilidade, eclosão e sobrevivência de larvas entre desovas. Desta forma, o objetivo deste trabalho foi avaliar de forma inédita se o manejo pode interferir neste processo em machos de P. lineatus. Os resultados mostraram que os machos mantidos em tanques-rede (TR) com água de baixa qualidade durante 18 meses apresentam encurtamento do ciclo reprodutivo; redução significativa no IGS e no diâmetro de túbulos seminíferos (p<0,05) quando comparados com machos mantidos em viveiros escavados (VE). A concentração espermática e as taxas de fertilidade obtidas com o sêmen dos machos de TR foram inferiores às obtidas com o sêmen dos machos em VE (p<0,05). Além disso, os espermatozoides de TR apresentaram maior frequência de danos de DNA, mesmo apresentando taxas similares de motilidade e sobrevivência que os de VE (p<0,05). Os resultados mostraram de forma inédita que o manejo inadequado pode interferir na gametogênese e na qualidade de gametas masculinos nesta espécie. Além disso, demonstramos que práticas inadequadas de manejo podem prejudicar a função testicular ainda nos meses de inverno, muito antes dos meses de reprodução / The reproduction of native migratory fish still presents several obstacles. Among them we can highlight the changes in fertility rates, hatching and survival of larvae among spawning. Thus, the objective of this study was to evaluate in an unprecedented way if the reproductive management can interfere in this process in males of P. lineatus. The results showed that males kept in cages (C) for 18 months have their reproductive cycle shortened; significant reduction in the GSI and in the diameter of seminiferous tubules (p<0.05) compared with males kept in earths ponds (EP). The sperm concentration and fertility rates obtained with semen from males of Cs were lower than those obtained with semen EP (p<0.05). In addition, the sperm of males maintained in Cs had higher frequency of DNA damage, even with similar rates of survival and motility of the EPs (p<0.05). The results showed by unprecedented manner that the improper management can interfere with gametogenesis and quality of male gametes in this species. Furthermore, we demonstrate inadequate management practices can affect the testicular development even in the winter months, long before the breeding season

Reproduction de : Thèse de doctorat : Sciences agronomiques et écosystèmes : Toulouse, INPT : 2008. / Titre provenant de l'écran-titre. Bibliogr. 292 réf.

Mémoire (M.Res.Renouv.)--Université du Québec à Chicoutimi, 1995. / Document électronique également accessible en format PDF. CaQCU

Th. doct.-ing.--Écol.--Rennes 1, 1985. N°: 192.