Biologia populacional de Corydoras flaveolus (Siluriformes, Callichthyidae) no Rio Passa Cinco, sub-bacia do Rio Corumbataí, São Paulo, Brasil
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Data
2009-12-01
Autores
Rondineli, Giulianna Rodrigues [UNESP]
Braga, Francisco Manoel de Souza [UNESP]
Título da Revista
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Editor
Instituto Virtual da Biodiversidade (BIOTA/FAPESP)
Resumo
O objetivo desse trabalho foi caracterizar a população de Corydoras flaveolus do Rio Passa Cinco com relação à estrutura em comprimento, proporção sexual e aspectos reprodutivos de acordo com os períodos de seca e cheia, bem como analisar sua condição corporal. Seis amostragens foram realizadas em cinco pontos distintos no Rio Passa Cinco (contemplando trechos de ordem dois, três, quatro, cinco e seis) com o uso de peneira, pesca elétrica e covos. Foram capturados 70 indivíduos, sendo 35 machos e 35 fêmeas. Não houve variação significativa nos graus de repleção e de gordura acumulada na cavidade visceral dos exemplares analisados entre os períodos considerados. O período reprodutivo de C. flaveolus foi extenso, sendo mais intenso na cheia, visto a maior porcentagem de indivíduos com gônadas maduras e o maior valor da relação gonadossomática durante esse período. A fecundidade absoluta média foi de 137 ovócitos, sendo a desova do tipo intermitente. As fêmeas foram maiores e relativamente mais pesadas do que os machos. Não houve diferença significativa na condição corporal de ambos os sexos entre os períodos considerados.
The aim of this work was to characterize the population of Corydoras flaveolus in Passa Cinco stream, regarding length structure, sex ratio and reproductive aspects, in accordance with drought and rainy season periods, as well as to analyze its corporal condition. Six samplings were accomplished in five different points of Passa Cinco stream (contemplating sites of orders two to six) through use of a sieve, electric fishery equipment and fish-traps. It was captured 70 individuals, composed by 35 males and 35 females. There was not significant variation in repletion degree and accumulated fat in visceral cavity of the individuals analyzed during the considered periods. The reproductive period of C. flaveolus was extensive and more intense in the rainy season due to the largest percentage of individuals with mature gonads and higher value of gonadossomatic relationship founded in that period. The average of absolute fecundity was of 137 oocytes, and the intermittent type of spawning was performed. The females were larger and heavier than males in the same lenght. There was no difference in corporal condition of both sexes between the periods considered.
The aim of this work was to characterize the population of Corydoras flaveolus in Passa Cinco stream, regarding length structure, sex ratio and reproductive aspects, in accordance with drought and rainy season periods, as well as to analyze its corporal condition. Six samplings were accomplished in five different points of Passa Cinco stream (contemplating sites of orders two to six) through use of a sieve, electric fishery equipment and fish-traps. It was captured 70 individuals, composed by 35 males and 35 females. There was not significant variation in repletion degree and accumulated fat in visceral cavity of the individuals analyzed during the considered periods. The reproductive period of C. flaveolus was extensive and more intense in the rainy season due to the largest percentage of individuals with mature gonads and higher value of gonadossomatic relationship founded in that period. The average of absolute fecundity was of 137 oocytes, and the intermittent type of spawning was performed. The females were larger and heavier than males in the same lenght. There was no difference in corporal condition of both sexes between the periods considered.
Descrição
Palavras-chave
estrutura populacional, reprodução, fecundidade, condição corporal, population structure, reproduction, fecundity, corporal condition
Como citar
Biota Neotropica. Instituto Virtual da Biodiversidade | BIOTA - FAPESP, v. 9, n. 4, p. 45-53, 2009.