Population structure and stock assessment of Hoplias malabaricus (Characiformes: Erythrinidae) caught by artisanal fishermen in river-reservoir transition area in Brazil
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Data
2011-03-01
Autores
Costa Novaes, Jose Luis
Carvalho, Edmir Daniel [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Revista de Biologia Tropical
Resumo
Hoplias malabaricus is a viable economic alternative for artisanal fishermen who used to live on the banks of rivers that now are dammed in Brazil. In order to preserve the species' natural stock, the main objectives. of this study were to obtain bio-ecological information on this species reproduction, feeding dynamics and the description of the extent of its exploitation in river-reservoir transition area in Brazil. This way, from January to December 2005, different fishery catches were made with gill nets by artisanal fishermen, and a total of 426 individual H. malabaricus were obtained and sampled. From each specimen, the following biometric and biological data were analyzed: standard length, total weight. stomach contents, reproductive Caul such as sex, weight and gonadal maturation stage; with these data we estimated sex ratio, reproduction period and feeding habits. To assess growth parameters and infer on the degree of exploitation, the standard length frequency data were analysed using the FISAT (ELEFAN I) computer program. Data revealed a sex ratio of 0.8:1 (M:F), that reproduction occurs all year around, being more intense during spring and summer; it also showed that H. malabaricus is piscivorous. The growth parameters and mortality were estimated at: L(infinity)=35.18cm, k=0.32 year longevity=9.3 years, Z=1.25 years, M=0.63 year and F=0.62 year. The weight-length relation hip was: In Wt=-3.1.663+2.7456 In Lp. The yield-per-recruit analysis produced the following values: E=0.496, E(max)=0.916, E(0.1)=0.701 and E(0.5)=0.378. Overall, our data suggest that the stock of H. malabaricus is not yet overfished in the studied area. Rev. Biol. Trop. 59(1): 71-83. Epub 2011 March 01.
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Palavras-chave
mortality, reproduction, feeding, Hoplias malabaricus, Upper Parana, yield-per-recruit, growth
Como citar
Revista de Biologia Tropical. San Jose: Revista de Biologia Tropical, v. 59, n. 1, p. 71-83, 2011.