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Orientador: Roberto Goitein / Banca: Leandro Muller Gomiero / Banca: Paula Maria Gênova de Castro / Banca: João Batista Kochenborger Fernandes / Banca: Teresa Cristina Ribeiro Dias Koberstein / Resumo: Conhecido como matrinxã, Brycon sp.n. "Cristalino" é uma das espécies ainda não descritas pela ciência. Mesmo sendo apontada como uma das mais promissoras para a piscicultura por apresentar enorme potencial de crescimento e carne nobre. Diante disso, esta pesquisa teve como objetivos: contribuir para o conhecimento da biologia alimentar de Brycon sp. n "Cristalino", no rio Cristalino - Parque Estadual Cristalino/MT. As coletas foram mensais (03/2004 a 02/2006), em um trecho de coleta no rio Cristalino. Foram obtidas as medidas dos peixes (comprimento padrão, altura, peso, largura da boca, comprimento do intestino). As análises dos conteúdos estomacais foram realizadas segundo métodos de freqüência de ocorrência, freqüência gravimétrica e índice alimentar. Foram coletados 886 exemplares divididos em cinco classes de tamanhos, sendo 117 peixes da classe 1, 131 da classe 2, 199 da classe 3, 273 da classe 4 e 166 da classe 5. A freqüência de ocorrência dos itens encontrados aponta para que a espécie tenha uma dieta bastante variada com 29,64%, 25,76% e 22,70% de estômagos contendo restos vegetais, sementes e insetos, respectivamente. O índice alimentar (IAi) apresenta valores acentuados para os itens restos vegetais (IAi 0,5817%) e insetos (IAi 0,1748%) nos peixes menores. Foram identificados 48 taxons que fazem parte da dieta da espécie. Os dados de dieta alimentar apontam que a espécie é onivoria com tendência à herbívora, com amplo espectro alimentar nas fases adultas, sendo dependente de alimentos alóctones durante a época da cheia e tendo disponível na época da seca, em sua maioria, alimentos de origem autóctone. Com base nos dados analisados da dieta da espécie, sugere-se que as matas alagadas e matas ciliares são os principais fornecedores da energia que sustentam esta espécie. / Abstract: This fish is commonly called "matrinxã" in the amazonian region, but has not yet been described. Even so, it is expected to be a highly promising species for fish pond rearing activities, as it presents a highly growth potential and a very appreciated flesh. Such a fact motivated a study whose main purposes were to contribute to the knowledge about its feeding biology. It is for now called Brycon sp. n "Cristalino", as it occurs in the Cristalino river, inside the Cristalino State Park/MT. Collections were made every month during two years from march 2004 to february 2006 at three points (places?) in the Cristalino river. Some measurements were obtained for each specimen, such as standard length, height, weight, mouth width and intestine length. Stomach contents were analyzed using current methods, totalizing 886 individuals for these observations. For more precise information individuals were separated for analyses in five length classes. The occurrence methods used for items found in the stomach contents indicate the species to present a considerably varied diet mainly composed by plant remains, seeds and insects, in a decrescent sequence. The alimentary index points to a predominance for plant remains and insects for the smaller individuals, but some distinctions were observed when larger individuals were studied. The number of taxa found within the stomach contents attained 48, and their numbers clearly increased for the larger individuals. Results permit one to conclude that Brycon sp. n "Cristalino" is an omnivorous fish presenting a tendency to herbivorous habits, with a relatively large food composition spectrum. Many of the components of the species diet are aloctonous, mainly during the rainy season, but autochthonous components were also present, whose importance increased during the drier season. So, the surrounding vegetation constitutes the main source for this species energy incorporation. / Doutor

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Made available in DSpace on 2014-06-11T19:30:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-27Bitstream added on 2014-06-13T18:40:44Z : No. of bitstreams: 1 silva_saa_dr_jabo.pdf: 720344 bytes, checksum: 569ce726b2c155b31120045716eb4270 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Conhecido como matrinxã, Brycon sp.n. “Cristalino” é uma das espécies ainda não descritas pela ciência. Mesmo sendo apontada como uma das mais promissoras para a piscicultura por apresentar enorme potencial de crescimento e carne nobre. Diante disso, esta pesquisa teve como objetivos: contribuir para o conhecimento da biologia alimentar de Brycon sp. n “Cristalino”, no rio Cristalino – Parque Estadual Cristalino/MT. As coletas foram mensais (03/2004 a 02/2006), em um trecho de coleta no rio Cristalino. Foram obtidas as medidas dos peixes (comprimento padrão, altura, peso, largura da boca, comprimento do intestino). As análises dos conteúdos estomacais foram realizadas segundo métodos de freqüência de ocorrência, freqüência gravimétrica e índice alimentar. Foram coletados 886 exemplares divididos em cinco classes de tamanhos, sendo 117 peixes da classe 1, 131 da classe 2, 199 da classe 3, 273 da classe 4 e 166 da classe 5. A freqüência de ocorrência dos itens encontrados aponta para que a espécie tenha uma dieta bastante variada com 29,64%, 25,76% e 22,70% de estômagos contendo restos vegetais, sementes e insetos, respectivamente. O índice alimentar (IAi) apresenta valores acentuados para os itens restos vegetais (IAi 0,5817%) e insetos (IAi 0,1748%) nos peixes menores. Foram identificados 48 taxons que fazem parte da dieta da espécie. Os dados de dieta alimentar apontam que a espécie é onivoria com tendência à herbívora, com amplo espectro alimentar nas fases adultas, sendo dependente de alimentos alóctones durante a época da cheia e tendo disponível na época da seca, em sua maioria, alimentos de origem autóctone. Com base nos dados analisados da dieta da espécie, sugere-se que as matas alagadas e matas ciliares são os principais fornecedores da energia que sustentam esta espécie. / This fish is commonly called “matrinxã” in the amazonian region, but has not yet been described. Even so, it is expected to be a highly promising species for fish pond rearing activities, as it presents a highly growth potential and a very appreciated flesh. Such a fact motivated a study whose main purposes were to contribute to the knowledge about its feeding biology. It is for now called Brycon sp. n “Cristalino”, as it occurs in the Cristalino river, inside the Cristalino State Park/MT. Collections were made every month during two years from march 2004 to february 2006 at three points (places?) in the Cristalino river. Some measurements were obtained for each specimen, such as standard length, height, weight, mouth width and intestine length. Stomach contents were analyzed using current methods, totalizing 886 individuals for these observations. For more precise information individuals were separated for analyses in five length classes. The occurrence methods used for items found in the stomach contents indicate the species to present a considerably varied diet mainly composed by plant remains, seeds and insects, in a decrescent sequence. The alimentary index points to a predominance for plant remains and insects for the smaller individuals, but some distinctions were observed when larger individuals were studied. The number of taxa found within the stomach contents attained 48, and their numbers clearly increased for the larger individuals. Results permit one to conclude that Brycon sp. n “Cristalino” is an omnivorous fish presenting a tendency to herbivorous habits, with a relatively large food composition spectrum. Many of the components of the species diet are aloctonous, mainly during the rainy season, but autochthonous components were also present, whose importance increased during the drier season. So, the surrounding vegetation constitutes the main source for this species energy incorporation.

Les spatangoïdes (échinides détritivores fouisseurs) possèdent un volumineux caecum qui s’ouvre au début de l’estomac, le caecum gastrique. Ce caecum est ‘distendu’ :il est toujours gorgé d’un liquide incolore dont la nature est inconnue. Les sédiments ingérés par ces oursins et qui occupent le reste du tube digestif, ne pénètrent jamais dans le caecum. La fonction du caecum gastrique n’est pas claire: il sécréterait des enzymes dans l’estomac, serait un site d’absorption, ou encore abriterait une microflore cellulolytique. En prenant pour modèle l’un des échinides fouisseurs les plus étudiés, Echinocardium cordatum, ce travail tente d’élucider le rôle du caecum gastrique, et s’intéresse plus particulièrement à l’étude de son contenu.<p>Les résultats indiquent que le caecum gastrique d’E. cordatum contient de l’eau de mer. L’entrée d’eau de mer dans le caecum a été visualisée en la colorant et des caractéristiques communes au liquide caecal et à l’eau de mer environnante ont été observées: une même osmolarité, les mêmes particules détritiques en suspension et les mêmes communautés bactériennes. Le caecum gastrique contient de la matière organique en suspension (détritus, bactéries transitoires); il est également absorbant. Ses capacités d’absorption ont été comparées à celles de l’estomac et de l’intestin grâce à un dispositif expérimental particulier :les chambres de Ussing. Les résultats ont montré que les entérocytes du caecum et de l’intestin participent davantage au transfert de glucose vers la cavité coelomique que ceux de l’estomac.<p>Un schéma de la circulation de l’eau de mer dans le tube digestif est proposé. L’eau de mer qui circule à la surface du corps de l’oursin et qui provient de la surface des sédiments atteint la cavité buccale, une circulation entretenue par la ciliature des clavules (piquants ciliés). Le péristaltisme de l’œsophage et celui du siphon assurent l’entrée d’eau de mer dans le tube digestif. Une partie de cette eau entre dans le siphon qui l’amène dans l’intestin d’où elle est entraînée à l’extérieur avec le bol alimentaire. L’eau de mer qui n’est pas prélevée par le siphon peut atteindre l’entrée du caecum gastrique. Un système de gouttières a été mis en évidence à l’entrée du caecum. Il s’étend de l’estomac au début du caecum où les gouttières sont flagellées, et acheminerait l’eau de mer dans la lumière caecale. Les différences de pression osmotique entre le liquide caecal et le liquide cœlomique permettraient le transfert d’eau depuis le caecum vers la cavité cœlomique. Une quantité d’eau similaire devrait alors être éliminée de la cavité coelomique. Cette élimination semble se faire dans le caecum intestinal, l’eau serait ensuite éliminée par l’anus. <p>D’après nos observations, le caecum gastrique pourrait être le site d’une digestion et d’une absorption de la matière organique détritique de l’eau de mer. Si cette hypothèse est exacte, E. cordatum serait alors un détritivore particulièrement ‘complet’, digérant non seulement la fraction détritique des sédiments mais aussi celle en suspension dans l’eau de mer. Ce modèle pourrait correspondre à tous les échinides atélostomes (spatangoïdes & holastéroïdes) qui, outre la présence d’un caecum gastrique bien développé et rempli de liquide, ont en commun d’être fouisseurs, et d’entretenir une circulation d’eau dans leur terrier grâce à des clavules groupés en fascioles.<p><p>Spatangoids (burrowed deposit-feeding echinoids) have a large caecum, which opens at the beginning of the stomach, the gastric caecum. It is always swollen, filled with a colorless liquid whose nature is unknown; sediments ingested by sea urchins fill the rest of the digestive tract but never enter in the caecum. The function of the gastric caecum is unclear: it would secrete enzymes in the stomach, would be a site of absorption, and/or would harbor a cellulolytic microflora. By taking as model one of the most studied burrowing echinoids, Echinocardium cordatum, this study attempts to highlight the role of the gastric caecum by examining its contents.<p>Results indicate that the gastric caecum of E. cordatum contains seawater. Seawater inflow into the caecum was visualized using dye. The caecal liquid and the surrounding seawater were demonstrated to have similar characteristics: the same osmolarity, the same suspended particles and the same bacterial communities. The gastric caecum contains suspended organic matter (detritus, transient bacteria) and is also involved in absorption. Absorption and transfer of glucose were compared between the gastric caecum, the stomach and the intestine, using a particular experimental device: the Ussing chamber. The results showed that the enterocytes of the caecum and of the intestine were more involved in glucose transfer to the coelomic cavity than those of the stomach.<p>Seawater circulation in the digestive tube is tentatively described. Seawater currents along the body of the sea urchin originate from the sediment surface and reach the mouth; this circulation is generated by ciliae of specialized spines, the clavules. Peristalsis of the esophagus and of the siphon induces seawater to enter the mouth and to move along the digestive tube. Part of this water enters the siphon, being then transported to the intestine, and driven outside via the anus. Seawater that has not been taken by the siphon can reach the opening of the gastric caecum. A system of grooves occurring at the entrance of the caecum extends from the anterior stomach to the proximal part of the caecum where it is flagellated; these grooves could transport seawater in the caecal lumen. Differences in osmotic pressures between the caecal liquid and the coelomic liquid could transfer water from the caecum to the coelomic cavity. A similar uptake of water could then be removed from the coelom through the wall of the intestinal caecum, and water be eliminated from the digestive tube via the anus.<p>According to our observations, the gastric caecum could be specialized in digestion and absorption of detrital organic matter occurring in seawater. If this hypothesis is correct, E. cordatum would be a deposit-feeder feeding both on the detritus fraction of the sediments and on that of seawater. This model could fit all Atelostomata echinoids (spatangoids & holasteroids) which, besides the presence of a well-developed gastric caecum filled with liquid, have in common the burrowing behaviour, and the maintenance of seawater currents in their burrows owing to the action of clavules grouped into fascioles.<p><p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

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