Os resultados da produção comercial de quatro lotes de \'Ostras do Pacífico\', espécie Crassostrea gigas, correspondentes às safras dos anos 2005/06, 2006/07, 2007/08, 2008/09 foram obtidos de uma fazenda marinha localizada no sul da Ilha de Santa Catarina, no Estado que lidera a produção nacional de moluscos bivalves. Como o processo de engorda das ostras nestas áreas é totalmente realizado em águas marinhas, a relação das características do ambiente de cultivo e o sucesso da produção se fazem evidentes. Dados de temperatura superficial in situ, de concentração de clorofila a obtidos por sensoriamento remoto, de eventos de frentes frias e períodos de El Niño e La Niña foram analisados com o objetivo de estudar possíveis influências destas variáveis ambientais sobre o cultivo das ostras. Os resultados indicaram que os primeiros estágios de cultivo parecem ser decisivos para sobrevivência e rendimento final das safras. A temperatura parece ser o fator principal para a sobrevivência das ostras apresentando uma correlação negativa com a mesma, sendo a clorofila fator secundário, podendo, aparentemente, mitigar os efeitos negativos das altas temperaturas quando em concentrações elevadas. Para o desenvolvimento das ostras a clorofila foi o fator principal. Os eventos de frentes frias, associados a períodos de El Niño e La Niña, parecem influenciar na variação da clorofila na Baía Sul da Ilha de Santa Catarina. / Results of four allotments from a commercial culture of the Pacific oyster, Crassostrea gigas, relative to the 2005/06, 2006/07, 2007/08 and 2008/09 crops were obtained from a marine farm located in the South of Santa Catarina Island, in the main national area for bivalve production. As the grow-out phase of those mollusks is completely performed in the marine environment, the relation between environmental characteristics and the culture success is made clear. In situ sea surface temperature data, remote sensing chlorophyll a concentration data, cold fronts events and El Niño and La Niña periods were evaluated in order to study possible influences of the environmental characteristics upon oyster performance. Results indicated the performance in the first stages as critical regarding both final survival and output of the crops. Temperature seems to be the main responsible factor for survival, based on a negative regression, whereas chlorophyll plays a secondary role in survival but apparently can mitigate the negative effects of elevated temperatures when available in elevated concentrations. On the other hand, chlorophyll is apparently the main factor for oyster development. Cold fronts events associated with El Niño and La Niña periods seem to influence chlorophyll variation in the South Bay of Santa Catarina Island.

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / A tese trata da sexagem, reproduÃÃo, alevinagem e crescimento do pirarucu, Arapaima gigas. No primeiro capÃtulo foram revelados aspectos histÃricos da introduÃÃo e reintroduÃÃo do pirarucu nos aÃudes do nordeste do Brasil objetivando o desenvolvimento de pesquisas de manejo, crescimento e reproduÃÃo voltadas à produÃÃo aquÃcola. No segundo capÃtulo foram desenvolvidas diferentes tecnologias para a identificaÃÃo sexual do pirarucu: ultrassom, que gerou imagens distintas para gÃnadas masculinas e femininas; a laparoscopia que gerou imagens nÃtidas das gÃnadas, distinguindo-se inclusive estÃgios de ovÃcitos. Testou-se ainda as variaÃÃes nos nÃveis de estradiol e testosterona em alevinos e juvenis de pirarucu, nÃo sendo possÃvel a utilizaÃÃo deste mÃtodo para determinaÃÃo do sexo, em virtude de nÃo haver correlaÃÃo entre a concentraÃÃo dos hormÃnios e o comprimento dos pirarucus. ReaÃÃes de RAPD foram utilizadas buscando determinar polimorfismos entre sexo de espÃcimes de pirarucu, indicando a necessidade de estudos mais profundos e testes com novos primers. No terceiro capÃtulo foram estudados alguns aspectos do manejo reprodutivo: As precipitaÃÃes pluviais apresentaram correlaÃÃo positiva com a frequÃncia de desovas do pirarucu no CearÃ, sendo marÃo o mÃs de maior ocorrÃncia. Ainda neste capÃtulo, descreve-se a implantaÃÃo de transponders eletrÃnicos em pirarucus; A introduÃÃo dos transponders revelou uma nova dinÃmica comportamental de cortejo, com formaÃÃo de novos casais. Outro aspecto foi o treinamento alimentar. Foram observados dois sistemas de treinamento alimentar â o primeiro com utilizaÃÃo de transiÃÃo gradual de alimento vivo para raÃÃo comercial seca e o segundo com alevinos deixados nos viveiros de reproduÃÃo com cuidado parental, estes sofreram maior mortalidade apresentando ainda comprimento e peso superiores aos exemplares submetidos ao regime de transiÃÃo alimentar. O regime de transiÃÃo alimentar mostrou Ãndices de sobrevivÃncia superiores ao cuidado parental apresentando, porÃm, crescimento e peso inferiores. Foi testado o uso anestÃsicos (Mentol e clorofÃrmio); O mentol foi utilizado com sucesso em juvenis e adultos. O clorofÃrmio apresentou efeito anestÃsico imediato apÃs a inalaÃÃo, levando o espÃcime diretamente ao estÃgio de anestesia cirÃrgica. No quarto capÃtulo foram realizados estudos de crescimento e peso de alevinos e juvenis atà o tamanho comercial, utilizando inicialmente exemplares com peso mÃdio de 1g, finalizando, apÃs 18 meses de cultivo, com peso mÃdio de 10kg. / The present study deals with aspects of sexing, breeding, nursery and growth of pirarucu, Arapaima gigas, presented in four chapters. The first chapter revealed historical aspects of introduction and reintroduction of pirarucu. Now, the reintroduction of pirarucu in the past decade had another purpose, which was the development of studies in research management, growth and reproduction. In the second chapter we have developed different technologies for pirarucu sex identification: ultrasound, which generated different images for male and female gonads; laparoscopy that generated clear images of the gonads, and can distinguish gonadal stages. Was a tested variation in levels of estradiol and testosterone hormones in fingerling and juvenile, not being able to use this methodology to determine the sex because there is no correlation between the concentration of hormones and the length of pirarucus. RAPD reactions were used to determine polymorphisms with sex of Arapaima gigas, indicating the need for further studys. In third chapter we studied some of the many aspects that helped the reproduction management: The rainfall showed a positive correlation with the frequency of spawn pirarucu in Ceara state, Brazil; This chapter also describes the utilization of electronic transponders; No mortality was recorded during two years study, the introduction of electronic transponders also revealed a new dynamic of courtship behavior, with resultant formation of new pirarucu couples. Another aspect described in the third chapter was the pirarucu food training, step of importance in pirarucu fish farming. There were two systems of training food â The first one use gradual transition from live food to commercial food and seconds left fingerling in parental care. The system of weaning showed lower survival rates, however, righter growth and weight. The gradual transition showed higher survival and lower growth and weight. Anesthetics were tested (chloroform and menthol); Menthol has been used successfully in adults and juveniles with administration by spray gills. The chloroform was effective anesthetics immediately after inhalation, running directly to the stage of surgical anesthesia. The fourth chapter studies were performed growth and weight of pirarucu fry and juveniles to commercial size, initially using samples with an average weight of 1g, ending after 19 months of cultivation, with an average weight of 10,000 g.

Marine aquaculture is already vital to global food security and will continue to become more important in the coming years. Crassostrea gigas (Pacific oysters) is the primary oyster species cultivated worldwide. The FAO and IPCC predict that climate change will create uncertainty and challenges for marine aquaculture. Baynes Sound, British Columbia, is a productive region for aquaculture, producing >50% of British Columbia’s total annual bivalve production by live weight and value. Major summer mortality events have been documented in farmed Crassostrea gigas globally since the 1950’s. These events are believed to be caused by a multiplicity of factors including changes induced by anthropogenic climate change. One of the major contributors to summer mortality is the proliferation of Vibrio bacteria, specifically Vibrio aestuarianus, which has been shown to increase in abundance and virulence when seawater temperatures rise. Despite this connection and the economic importance of oyster farming in the region, little is known about the presence of V. aestuarianus in Baynes Sound. Our 17-month study sampled 7 sites in Baynes Sound on 33 occasions from May 2019 to September 2020. We found a positive correlation between seawater temperature and total Vibrio detected in water samples in Baynes Sound, an association that was stronger when the overall temperature regime was warmer. We found no significant correlation between any of the bacterial assays tested and salinity, pH, or Ωarag saturation. We also did not identify a geographic pattern to bacterial abundance or virulence amongst test C. gigas in the field. Understanding that flagellates are the predominant type of microalgae present in Baynes Sound when summer mortality events occur, in lab trials, we found that incorporating V. aestuarianus into marine aggregates with flagellate microalgae caused higher mortality than aggregates with diatoms or planktonic V. aestuarianus. These results were not statistically significant but led us to look at how exposure to husbandry stress pre and post inoculation with V. aestuarianus incorporated into marine aggregates affects mortality. We found that stress was a significant driver of mortality, particularly when administered 24h post inoculation, suggesting that farmers should avoid sorting or tumbling their oysters in the summer, and particularly immediately after a marine heatwave. Oysters lack adaptive immune systems and are grown in an open ocean environment where it is not possible to eliminate their exposure to pathogens. These factors make it impossible to use vaccines or antibacterial disinfectants to combat diseases. Therefore, breeding genetic resistance to V. aestuarianus may be the most effective way to fight summer mortality. Creating a repeatable and accurate protocol for inoculating oysters with marine bacteria is key to accurate heritability measurements and the estimation of breeding values of different families. Key factors include controlling for dose per animal, laboratory efficiency, and inoculation via a mechanism that mimics real-world infection and does not bypass the animal’s immune defenses. We designed a protocol which controls for these factors, separating each animal into individual containers and adding a controlled dose of planktonic bacteria to each. Previously used methods of injection or using an infected “donor” animal in a group tank do not control for dose or bypass parts of the oysters’ natural immune system, potentially creating inaccuracies in survival data generated with these methods. After designing this protocol, we tested 32 full-sib families and estimated the heritability of survival to V. aestuarianus on the observed and underlying liability scales to be 0.095 (SE = 0.043), and 0.15 (SE = 0.068) respectively. We also found a strong negative correlation between oyster size and survival, with a gram of additional weight creating a 73% increase in the risk of death. Fast growth and large size are two traits which have been explicitly bred into C. gigas stock. Our work suggests that breeding a slower-growing, smaller animal may reduce summer mortality. / Graduate / 2022-09-15

Le “coût de la reproduction” est un concept qui définit qu’un investissement à la reproduction élevé a un prix qui se paye ultérieurement par une accélération de la sénescence. Cela peut notamment traduire des compromis entre la reproduction et d’autres fonctions physiologiques comme la défense antioxydante. Chez l’huître creuse Crassostrea gigas, la reproduction représente une fonction physiologique majeure. Dans le cadre des études effectuées pour comprendre les mortalités estivales affectant cette espèce, une corrélation négative entre effort reproducteur et survie a été observée. D’autre part, des gènes antioxydants ont été mis en évidence comme différentiellement exprimés entre les lignées d’huîtres sélectionnées pour leur résistance ou leur sensibilité aux mortalités estivales. Certaines études proposent que la susceptibilité au stress oxydant puisse représenter un coût de la reproduction participant au processus de sénescence. Dans ce contexte, nous avons analysé la capacité antioxydante des huîtres en fonction de leur investissement reproducteur. Pour cela, la technique d’ARN interférence a été utilisée pour manipuler l’effort reproducteur des huîtres. L’expression des principales enzymes antioxydantes (taux de transcrits et activités enzymatiques) et le dosage de dommages oxydatifs ont ensuite été mesurés dans différents tissus et cellules de l’organisme (branchies, gonade, hémocytes et gamètes). Les résultats obtenus dans le cadre de cette thèse suggèrent que la capacité antioxydante de C. gigas est particulièrement efficace et que la reproduction seule n’est pas suffisante pour induire un stress oxydant. Cette capacité antioxydante apparaît comme tissu-spécifique voire cellule-spécifique et le métabolisme du glutathion semble jouer un rôle majeur dans cette protection. Cette grande résistance au stress oxydant contribuerait à faire de C. gigas une espèce particulièrement adaptée à la vie dans des environnements stressants. / The “cost of reproduction” is a concept defining that a high reproductive investment has a price that is paid later by an acceleration of senescence. That may translate tradeoff between reproduction and other physiological functions such as antioxidant defense. In the Pacific oyster Crassostrea gigas, reproduction is a major physiological function. In a study led to understand the summer mortalities affecting this species, a negative correlation between reproductive effort and survival was observed. Moreover, some antioxidant genes were identified as differentially expressed between lines of oysters selected for resistance or susceptibility to summer mortalities. Some studies suggest that the susceptibility to oxidative stress may represent a cost of reproduction taking part to the process of senescence. In this context, we analyzed the antioxidant capacity of oysters according to their reproductive investment. For this, the technique of RNA interference was used to manipulate the reproductive effort of oysters. The expression of the main antioxidant enzymes (transcript levels and enzyme activities) and the dosage of oxidative damages were then measured in different tissues and cells of the organism (gills, gonad, hemocytes and gametes). The results obtained in this thesis suggest that the antioxidant capacity of C. gigas is particularly effective and that reproduction alone is not sufficient to induce oxidative stress. This antioxidant capacity appears to be tissue-specific even cell-specific and glutathione metabolism would to play a major role in this protection. This resistance to oxidative stress would make C. gigas be a species particularly adapted to life in stressful environments.

Crassostrea gigas est l’espèce d’huître la plus cultivée au monde. Depuis 2008, des évènements de mortalité massive touchent les huîtres âgées de moins d’un an en Europe et en Océanie et ont été associés à l’émergence d’un nouveau variant de l’Ostréid herpèsvirus type 1, OsHV-1 μvar. Les huîtres sont naturellement présentes dans les écosystèmes estuariens et côtiers, caractérisés par des fluctuations de salinité et de pH. Dans le cadre de ce travail, l’effet de la salinité (10, 15, 25, 35‰) et du pH (7.8, 8.1) sur la réponse de l’huître à une infection par OsHV-1 a été étudié. La survie d’huîtres acclimatées à une salinité de 10‰ préalablement à l’exposition à une source infectieuse est de 95% et s’explique par une diminution de l’infectiosité d’OsHV-1. En revanche, la survie d’huîtres non-acclimatées simultanément soumises à un choc de salinité à 10‰ et exposées à une source infectieuse n’est que de 23%, ce qui reflète un affaiblissement physiologique. La survie (S) des huîtres aux autres salinités est classée de la manière suivante : S15‰ > S35‰ > S25‰ et selon le pH comme suit : SpH 7.8 < SpH 8.1. Dans les deux études ces contrastes de survie ne sont pas expliqués par un différentiel d’infectiosité du virus mais par celui de la réponse métabolique de l’hôte. Le métabolisme des sucres et l’activité antioxydante d’huîtres acclimatées à 25 et 35‰ sont supérieurs à celui d’huîtres à 10-15‰ et pourraient expliquer leur moindre survie. La plus faible activité antioxydante observée chez des huîtres maintenues à pH 7.8 suggère une production réduite d’espèces réactives de l’oxygène et le maintien d’une production basale d’espèces réactives de l’azote malgré l’infection, ce qui aurait pu réduire la capacité de défense des huîtres face au virus et expliquer leur moindre survie en comparaison à ce qui est observé à pH 8.1. / Crassostrea gigas is the most cultivated oyster species around the world. Since 2008, mass mortality events have been affecting oysters aged less than one year old in Europe, and Oceania and have been associated with a new variant of the ostreid herpesvirus type 1, OsHV-1 μvar. Oysters live in estuaries and bays where they are exposed to fluctuations of salinity and pH. In the present work, the effect of salinity (10, 15, 25, 35 ‰) and pH (7.8, 8.1) on the response of oysters to infection by OsHV-1 was investigated. The survival of oysters acclimated to 10 ‰ prior to be exposed to a source of infection is 95% and is explained by a reduction of OsHV-1infectivity. In contrast, the survival of non-acclimated oysters simultaneously submitted to a salinity stress at 10 ‰ and exposed to a source of infectious is only 23%, likely reflecting physiological impairment. The survival (S) of oysters in other salinity treatment is ranked as follow: S15‰ > S35‰ > S25‰ and according to pH as follows: SpH 7.8 < SpH 8.1. In both studies these contrasts of survival are not explained by differences in OsHV-1 infectivity but in host metabolic response. The carbohydrate metabolism and antioxidant activity of oysters acclimated to 25 and 35‰ is higher than in oysters at 10-15 ‰ and could explain the lower survival. Lower antioxidant activity is observed in oysters maintained at pH 7.8 likely reflecting a reduced production of reactive oxygen species and the maintenance of a basal production of nitrogen reactive species despite infection. This might impair the defense ability of oysters to OsHV-1 explaining the reduced survival at pH 7.8 in comparison to what observed at pH 8.1.

Crassostrea gigas est la principale espèce d’huître cultivée dans le monde. Depuis 2008, de sévères épisodes de mortalités affectent les huîtres âgées de moins d’un an en Europe et en Océanie et sont associées à l’émergence de l’Ostreid herpèsvirus μVar (OsHV-1 μVar). En Europe, ces mortalités sont saisonnières et surviennent lorsque la température de l’eau de mer est comprise entre 16°C et 24°C. Dans le cadre de ce travail, l’effet des hautes températures (21°C, 26°C et 29°C) est évalué sur la sensibilité des huîtres à OsHV-1 mais aussi sur la persistance et la virulence du virus. La survie des huîtres infectées maintenues à 29°C (86%) est supérieure à la survie des huîtres placées à 21°C (52%) et à 26°C (43%).Les températures élevées (29°C) diminuent la sensibilité des huîtres à OsHV-1 sans altérer l'infectivité du virus et sa virulence. L’exposition des huîtres infectées à 29°C pourrait réduire l’expression des gènes viraux et la synthèse de virions par la réduction de l’expression de gènes hôtes codant pour des protéines impliquées dans la transcription et la traduction, la réduction de l’expression de gènes impliqués dans le catabolisme, le transport des métabolites, et synthèse de macromolécules.Finalement, l’induction conjointe de l’apoptose, des processus d’ubiquitinylation et de la réponse immunitaire, pourrait permettre l’élimination d’OsHV-1. / Crassostrea gigas is the main species of oyster cultivated in the world. Since 2008, mass mortality events have been affecting oysters aged less than one year old in Europe and Oceania and have been associated with the emergence of the Ostreid herpes virus μVar (OsHV-1 μVar). In Europe, these events are seasonal and occur when the seawater temperature is between 16°C and 24°C. In this work, the effect of high temperatures (21°C, 26°C and 29°C) was evaluated on the susceptibility of oysters to OsHV- 1 but also on the virulence of virus.High temperatures (29°C) reduce the susceptibility of oysters to OsHV-1 without altering the infectivity of the virus and its virulence. High temperature could reduce viral infection and virus synthesis by reducing the expression of host genes that encode proteins involved in transcription and translation, catabolism, metabolites transport, and macromolecules biosynthesis. Finally, the induction of apoptosis, ubiquitinylation processes and immune response could lead to the elimination of OsHV-1.

L’ostréiculture française repose essentiellement sur l’élevage de l’huître creuse, Crassostrea gigas confronté cependant à des épisodes de mortalités anormales, touchant les différents stades de vie de l'huître. Plusieurs études ont démontré l’implication d’agents infectieux comme des bactéries du genre Vibrio dans ces mortalités. En France, V. aestuarianus est une bactérie connue depuis les années 2000 pour impacter la survie des huîtres. Sa fréquence de détection dans les cas de mortalités d’huîtres adultes analysés par le réseau REPAMO (REseau de PAthologie des Mollusques) est cependant en augmentation depuis 2011. Dans ce contexte, afin d’étudier le développement de la maladie induite par V. aestuarianus chez C. gigas, un modèle d’expérimentation par balnéation dans de l’eau de mer contenant des bactéries fraichement excrétées, au plus proche des modes de contaminations naturelles, a été développé. Le suivi de la présence de la souche 12/016 (souche virulente) et son mutant 12/016ΔvarS (souche non-virulente) dans l’eau de mer, dans les différents tissus et dans l’hémolymphe des animaux vivants et moribonds a montré que le cycle infectieux est constitué de I) une phase de pénétration rapide de la bactérie dans l’hôte (moins de 24h) et de colonisation initiale de l’hémolymphe et des branchies, II) une phase d’incubation de 3-4 jours au cours de laquelle la souche virulente se multiplie dans l'ensemble des tissus d'huître et III) une phase de mortalités aiguës (mort de l'animal par septicémie). A ce stade, le recrutement et la lyse hémocytaire ainsi que différentes lésions tissulaires comme la lyse du tissu conjonctif sous-épithélial au niveau du manteau et l’atrophie de diverticules digestives ont été observés. D'autre part, l'étude d’expression relative de 18 gènes de virulence connus chez d’autres Vibrion a montré que l’expression des facteurs de virulence de V. aestuarianus est régulée différemment au cours de différentes étapes de l'infection et nous avons observé que la métalloprotéase vam est significativement sur-exprimée dans l’hémolymphe des animaux contaminés à j4 post infection (étape intermédiaire de l’infection) par rapport à son niveau d’expression au premier jour de l’infection (étape précoce). / Oyster-farming in France is mainly based on pacific cupped oysters, Crassostrea gigas culture. Currently, oyster culture is confronted by several abnormal episodes of mass mortality affecting all life stages. These outbeaks involve, among other factors, infectious agents including bacteria of the genus Vibrio. In France, since 2000, V. aestuarianus is known as a bacterium that impacts the survival of C. gigas. Since 2011, its detection frequency in adult oyster mortalities cases reported by REPAMO network (REseau de PAthologie des Mollusques), is constantly increasing. In this context, to study V. aestuarianus disease development in C. gigas, an experimental infection model based on immersion in sea water containing freshly shed bacteria was developed. By monitoring the presence of strain 12/016 (virulent strain) and its mutant 12/016 ΔvarS (non-virulent strain) in the seawater, in the different tissues and in the haemolymph of live and moribund animals, we showed that the infectious cycle consists of several successive phases: I) rapid penetration of the bacterium into the host (less than 24 hours) and initial colonization of the haemolymph and gills, II) 3-4 days of incubation during which the virulent strain multiplies in whole oyster tissues and III) acute mortalities (animal death due to septicemia). At this stage, recruitment and haemocyte lysis as well as different tissue lesions such as lysis of the sub-epithelial connective tissue in the mantle and atrophy of digestive diverticula were observed. On the other hand, relative expression of 18 virulence genes (known in other Vibrion) were analyzed by RT-QPCR. Virulence factors are regulated differently during different stages of infection and vam metalloprotease is significantly over-expressed in the haemolymph of infected animals at day 4 post infection (intermediate stage of infection) compared to its level of expression at day 1 post infection (early stage).

O Arapaima gigas, conhecido popularmente no Brasil como pirarucu, pertence ao grupo mais primitivo dos teleósteos, sendo um dos maiores peixes de água doce da América do Sul. Desde os anos 40 informações divergentes têm sido dadas em relação ao seu tamanho e peso máximo, porém todas concordam com o fato de que se trata de uma espécie de grande porte, com exemplares pesando de 125 a 200 quilos e um comprimento de 2 a 3 metros. Sua carne é desprovida de espinhas e apresenta baixo teor de gordura. Os níveis de rendimento da carcaça são elevados e o crescimento juvenil da espécie é consideravelmente rápido. Por isso, o pirarucu, apresenta um atraente valor de mercado e grande importância para o comércio de pescado amazônico. A pesca predatória tem reduzido significativamente a população dessa espécie nas regiões amazônicas ao longo dos anos. Sendo assim, desde os anos 2000, o pirarucu foi incluído na lista de animais sobre explorados ou em perigo de extinção do IBAMA. A ausência de um empreendimento de aquicultura capaz de produzir o pirarucu a preços competitivos, de forma previsível e em larga escala deve-se principalmente ao fato de que essa espécie, de um modo geral, apresenta dificuldades no processo reprodutivo em cativeiro, apresentando uma ovulação, espermiação e/ou maturação final gonadal insatisfatória. O hormônio folículo estimulante (FSH) é um hormônio gonadotrófico que exerce um papel importante na maturação folicular inicial das gônodas. Assim como os mamíferos, os peixes também apresentam hormônios gonadotróficos (GTHs) heterodiméricos, onde a subunidade &alpha; é comum entre os hormônios pertencentes a essa família e a subunidade &beta; determina a atividade hormonal específica. As subunidades &alpha; e &beta; do hormônio folículo estimulante de Arapaima gigas (ag-FSH) foram previamente isoladas pelo nosso grupo de pesquisa ao longo dos anos e possibilitaram um estudo de modelagem tridimensional baseada nas sequências de aminoácidos obtidas. Paralelamente, foi realizada a expressão do ag-FSH recombinante com níveis de rendimento satisfatórios (28 mg/L) através da expressão em células de embrião de rim humano (HEK 293), purificando-o e caracterizando-o a partir de técnicas cromatográficas padronizadas pelo nosso grupo de pesquisa. / Arapaima gigas, popularly known in Brazil as pirarucu, belongs to the most primitive group of teleosts, being one of the largest freshwater fish in South America. Since 1940, divergent information has been given regarding its size and maximum weight, but all agree that it is a large species, with specimens weighing from 125 to 200 kilograms and with a 2 to 3 meters of length. Its meat is devoid of fish bones and has low fat content. Carcass yield levels are high and juvenile growth of the species is considerably fast. Therefore, the pirarucu, presents an attractive market value and great importance for the Amazonian fish trade. Predatory fishing has significantly reduced the population of this species in Amazonian regions over the years. Thus, since 2000, pirarucu has been included in IBAMA\'s list of exploited or endangered animals. The absence of an aquaculture enterprise able to produce pirarucu at competitive prices in a predictable and large scale is mainly because this species, in general, presents difficulties in the reproductive process in captivity, presenting an unsatisfactory ovulation, spermiation and / or late gonadal maturation. The follicle-stimulating hormone (FSH) is a gonadotrophic hormone that plays an important role in the initial follicular maturation of the gonads. Like mammals, fish also have heterodimeric gonadotrophic hormones (GTHs), where the &alpha; subunit is common between the hormones belonging to this family and the &beta; subunit determines the specific hormonal activity. The &alpha; and &beta; subunits of the follicle stimulating hormone of Arapaima gigas (ag-FSH) were previously isolated by our research group over the years and provided a three-dimensional modeling study based on the obtained amino acid sequences. At the same time, the recombinant ag-FSH was expressed with satisfactory yields (28 mg/L) in human kidney embryonic cells (HEK 293), purified and characterized from chromatographic techniques, standardized by our group.

Cette thèse présente une étude du métabolisme énergétique du spermatozoïde d’huître creuse, Crassostrea gigas. Les principaux objectifs sont (1) d’établir la dynamique des caractéristiques cellulaires et biochimiques du spermatozoïde de cette espèce durant la phase de mouvement, (2) d’identifier les voies de synthèse d’ATP et leurs substrats et (3) de déterminer l’implication du métabolisme énergétique dans le succès à la fécondation du spermatozoïde de cette espèce. Les résultats de ce travail montrent la longue durée du mouvement (de 24 à 72h) du spermatozoïde d’huître creuse et le maintien d’une concentration élevée en ATP intracellulaire, jusqu'à la fin du mouvement. Le rôle de la phosphorylation oxydative (OXPHOS) dans la synthèse d’ATP a été mis en évidence. Le spermatozoïde d’huître creuse montre une grande plasticité dans l’utilisation de ses voies de production d’énergie, assurant la synthèse d’ATP par d’autres voies qu’OXPHOS lorsque la mitochondrie est inhibée. L’accumulation de phosphoarginine en fin de mouvement montre une capacité de stockage de l’ATP synthétisé. La nature des substrats endogènes utilisés pour la synthèse d’ATP reste cependant à déterminer. La forte capacité de régulation du métabolisme énergétique du spermatozoïde d’huître creuse, associée à la possibilité de synthétiser de l’énergie au cours de sa longue phase de nage, contribuent probablement au succès du peuplement observé chez cette espèce. Ce travail apporte une première description du métabolisme énergétique du spermatozoïde d’huître creuse, améliorant la connaissance fine de cette cellule. / The present study aims at describing the energy metabolism of Pacific oyster, Crassostrea gigas, spermatozoon. The main objectives are: (1) describing the kinetic of cellular and biochemical characteristics of Pacific oyster spermatozoon during its movement phase, (2) identifying the metabolic pathways to produce energy and their substrates, (3) determining the involvement of energy metabolism in fertilization success. The results showed the long duration (ranging 24 to 72h) of the movement of Pacific oyster spermatozoon and the maintenance of a high intracellular ATP content until the end of the movement phase. The role of oxidative phosphorylation (OXPHOS) in ATP production was highlighted. Alternative ATP producing pathways might contribute to sustain energy production when OXPHOS is impaired, showing the high adaptation capacity of Pacific oyster spermatozoa. An increase of phosphoarginine content observed at the end of the movement phase suggests energy storage capacity. Endogenous substrates involved in ATP synthesis must be determined. Both the high regulation capacity of the energy metabolism of Pacific oyster spermatozoa and their ability to restore energy stores catabolized during movement likely contribute to the successful settlement observed in the wild. In conclusion, this work provided a fine description of energetic metabolism of Pacific oyster spermatozoon.

CARREIRO, Carlos Riedel Porto. Inovações tecnológicas na sexagem, manejo reprodutivo e crescimento do pirarucu, Arapaima gigas (SCHINZ, 1822), (Actinopterygii, Arapaimidae) cultivado no Centro de Pesquisas em Aquicultura Rodolpho von Ihering (CPA) do DNOCS, Pentecoste, Estado do Ceará. 2012. 136 f. : Tese (doutorado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-26T12:16:50Z No. of bitstreams: 1 2012_tese_crpcarreiro.pdf: 18907754 bytes, checksum: 0908fc84040d7539c531f59a7e7ae49f (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-26T12:17:03Z (GMT) No. of bitstreams: 1 2012_tese_crpcarreiro.pdf: 18907754 bytes, checksum: 0908fc84040d7539c531f59a7e7ae49f (MD5) / Made available in DSpace on 2016-07-26T12:17:03Z (GMT). No. of bitstreams: 1 2012_tese_crpcarreiro.pdf: 18907754 bytes, checksum: 0908fc84040d7539c531f59a7e7ae49f (MD5) Previous issue date: 2012 / The present study deals with aspects of sexing, breeding, nursery and growth of pirarucu, Arapaima gigas, presented in four chapters. The first chapter revealed historical aspects of introduction and reintroduction of pirarucu. Now, the reintroduction of pirarucu in the past decade had another purpose, which was the development of studies in research management, growth and reproduction. In the second chapter we have developed different technologies for pirarucu sex identification: ultrasound, which generated different images for male and female gonads; laparoscopy that generated clear images of the gonads, and can distinguish gonadal stages. Was a tested variation in levels of estradiol and testosterone hormones in fingerling and juvenile, not being able to use this methodology to determine the sex because there is no correlation between the concentration of hormones and the length of pirarucus. RAPD reactions were used to determine polymorphisms with sex of Arapaima gigas, indicating the need for further studys. In third chapter we studied some of the many aspects that helped the reproduction management: The rainfall showed a positive correlation with the frequency of spawn pirarucu in Ceara state, Brazil; This chapter also describes the utilization of electronic transponders; No mortality was recorded during two years study, the introduction of electronic transponders also revealed a new dynamic of courtship behavior, with resultant formation of new pirarucu couples. Another aspect described in the third chapter was the pirarucu food training, step of importance in pirarucu fish farming. There were two systems of training food – The first one use gradual transition from live food to commercial food and seconds left fingerling in parental care. The system of weaning showed lower survival rates, however, righter growth and weight. The gradual transition showed higher survival and lower growth and weight. Anesthetics were tested (chloroform and menthol); Menthol has been used successfully in adults and juveniles with administration by spray gills. The chloroform was effective anesthetics immediately after inhalation, running directly to the stage of surgical anesthesia. The fourth chapter studies were performed growth and weight of pirarucu fry and juveniles to commercial size, initially using samples with an average weight of 1g, ending after 19 months of cultivation, with an average weight of 10,000 g. / A tese trata da sexagem, reprodução, alevinagem e crescimento do pirarucu, Arapaima gigas. No primeiro capítulo foram revelados aspectos históricos da introdução e reintrodução do pirarucu nos açudes do nordeste do Brasil objetivando o desenvolvimento de pesquisas de manejo, crescimento e reprodução voltadas à produção aquícola. No segundo capítulo foram desenvolvidas diferentes tecnologias para a identificação sexual do pirarucu: ultrassom, que gerou imagens distintas para gônadas masculinas e femininas; a laparoscopia que gerou imagens nítidas das gônadas, distinguindo-se inclusive estágios de ovócitos. Testou-se ainda as variações nos níveis de estradiol e testosterona em alevinos e juvenis de pirarucu, não sendo possível a utilização deste método para determinação do sexo, em virtude de não haver correlação entre a concentração dos hormônios e o comprimento dos pirarucus. Reações de RAPD foram utilizadas buscando determinar polimorfismos entre sexo de espécimes de pirarucu, indicando a necessidade de estudos mais profundos e testes com novos primers. No terceiro capítulo foram estudados alguns aspectos do manejo reprodutivo: As precipitações pluviais apresentaram correlação positiva com a frequência de desovas do pirarucu no Ceará, sendo março o mês de maior ocorrência. Ainda neste capítulo, descreve-se a implantação de transponders eletrônicos em pirarucus; A introdução dos transponders revelou uma nova dinâmica comportamental de cortejo, com formação de novos casais. Outro aspecto foi o treinamento alimentar. Foram observados dois sistemas de treinamento alimentar – o primeiro com utilização de transição gradual de alimento vivo para ração comercial seca e o segundo com alevinos deixados nos viveiros de reprodução com cuidado parental, estes sofreram maior mortalidade apresentando ainda comprimento e peso superiores aos exemplares submetidos ao regime de transição alimentar. O regime de transição alimentar mostrou índices de sobrevivência superiores ao cuidado parental apresentando, porém, crescimento e peso inferiores. Foi testado o uso anestésicos (Mentol e clorofórmio); O mentol foi utilizado com sucesso em juvenis e adultos. O clorofórmio apresentou efeito anestésico imediato após a inalação, levando o espécime diretamente ao estágio de anestesia cirúrgica. No quarto capítulo foram realizados estudos de crescimento e peso de alevinos e juvenis até o tamanho comercial, utilizando inicialmente exemplares com peso médio de 1g, finalizando, após 18 meses de cultivo, com peso médio de 10kg.