Biologia alimentar e reprodutiva na comunidade de peixes do rio Passa Cinco (SP)
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Data
2007-03-16
Autores
Rondineli, Giulianna Rodrigues [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo desse trabalho foi realizar um estudo da alimentação e da reprodução da comunidade de peixes do rio Passa Cinco, que é um dos principais rios da sub-bacia do rio Corumbataí. Foram amostradas cinco ordens existentes no rio, desde a área de cabeceira, com ordem 2, até sua foz, com ordem 6. As amostragens foram realizadas ao longo de um ano e os seguintes apetrechos de pesca foram utilizados: peneira na vegetação marginal, aparelho de pesca elétrica, redes de espera e covos. Foram capturados 5082 indivíduos, distribuídos em 62 espécies, 18 famílias e 6 ordens. A estrutura em comprimento das espécies mais abundantes revelou que a maioria não ultrapassou os 15 cm de comprimento. Foram analisados 576 estômagos de 28 espécies. Os recursos autóctones de origem animal compuseram a maior parte das dietas, havendo um predomínio de espécies insetívoras. As variações sazonal e espacial estiveram presentes na dieta de algumas espécies e foi verificada uma alta sobreposição alimentar. Os valores calculados do índice de intensidade reprodutiva combinados com a porcentagem de jovens e adultos indicaram que o sistema é utilizado pelas espécies tanto como área de reprodução como de alimentação. Em relação à fecundidade e tipo de desova, as espécies apresentaram estratégias reprodutivas que visam suas permanências em ambientes de riachos, onde a instabilidade ambiental é um importante fator a ser considerado. As alterações na condição corporal apresentadas pelas espécies estiveram associadas à mudanças fisiológicos que ocorreram em função do ciclo reprodutivo, como a atividade alimentar e acúmulo de gordura.
The aim of this work was to research the diet and reproduction of fish community of Passa Cinco river, a main river of Corumbataí river sub-basin. This study analyzed five orders of this river, since the headwater, at order 2, until its mouth, at order 6. The sample collection was performed during one year and the following fishery equipment was used: a sieve used on bank vegetation, electric fishery equipment, waiting nets and fish-traps. It was captured 5082 individuals, distributed into 62 species, 18 families and 6 orders. The length structure of most abundant species revealed that most of them didn't pass a measure of 15 cm. 576 stomachs of 28 species were analyzed and revealed that autochthonous resources composed most of part of fish diet, where insect species predominated. The season and spatial variations appeared on the diet of some species and a high feeding overlap was found. The calculated values of the reproduction intensity rate, combined to the percentage of young and adult fishes, indicated that the river system is used by the species both as reproduction area and feeding area. Relating to fecundity and type of spawn, the species presented reproduction strategies that aim to their permanence in stream environmental, considering that environmental instability is an important factor. The changes in body condition presented by the species were associated to physiological alterations that occurred as a consequence of reproduction cycle, as feeding activity and fat accumulation.
The aim of this work was to research the diet and reproduction of fish community of Passa Cinco river, a main river of Corumbataí river sub-basin. This study analyzed five orders of this river, since the headwater, at order 2, until its mouth, at order 6. The sample collection was performed during one year and the following fishery equipment was used: a sieve used on bank vegetation, electric fishery equipment, waiting nets and fish-traps. It was captured 5082 individuals, distributed into 62 species, 18 families and 6 orders. The length structure of most abundant species revealed that most of them didn't pass a measure of 15 cm. 576 stomachs of 28 species were analyzed and revealed that autochthonous resources composed most of part of fish diet, where insect species predominated. The season and spatial variations appeared on the diet of some species and a high feeding overlap was found. The calculated values of the reproduction intensity rate, combined to the percentage of young and adult fishes, indicated that the river system is used by the species both as reproduction area and feeding area. Relating to fecundity and type of spawn, the species presented reproduction strategies that aim to their permanence in stream environmental, considering that environmental instability is an important factor. The changes in body condition presented by the species were associated to physiological alterations that occurred as a consequence of reproduction cycle, as feeding activity and fat accumulation.
Descrição
Palavras-chave
Peixe, Alimentação e reprodução de peixes, Fish - Diet and reproduction
Como citar
RONDINELI, Giulianna Rodrigues. Biologia alimentar e reprodutiva na comunidade de peixes do rio Passa Cinco (SP). 2007. xiii, 127 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências, 2007.