Importance of lateral lagoons for the ichthyofauna in a large tropical reservoir

Brazilian Journal of Biology

M. Ferrareze¹  Mg. Nogueira¹ 

[1] ,Universidade Estadual Paulista Instituto de Biociências Departamento de ZoologiaBotucatu SP ,Brazil

关键词: small fish;    juveniles;    Rosana Reservoir;    Paranapanema River;    limnological variables;    peixes de pequeno porte;    reservatório de Rosana;    rio Paranapanema;    variáveis limnológicas;   

DOI  :  10.1590/S1519-69842011000500002

来源: SciELO

【 摘 要 】

This study aimed to analyse the composition and the ecological attributes of small-sized fish assemblages in four lagoons and in the main channel of Rosana Reservoir (SE Brazil). Fieldwork was carried out in September and November/2004 and January, March, May and August/2005. In each sampling station and period five manual throws were performed towards aquatic macrophyte stands, using a hand net (1.5 × 5 m; 0.3 cm of mesh size). The ichthyofauna collected was represented by 42 species, totalizing 3,424 individuals, 2,186 g in weight. The order Characiformes was dominant, mainly in the lagoons with low connectivity with the river. The main taxon (Importance Index) was Hemigrammus marginatus. Higher richness, abundance, biomass, diversity and lower individual mean length were observed in the lagoons, especially during the rainy period. Spatial segregation of some species was showed by the canonical correspondence analysis indicating the habitat complexity. The results validate the hypotheses that lateral lagoons have a prominent ecological role in the life cycle of juveniles and small fish and demonstrate how the connectivity river/lagoons may be important for assemblages maintenance.

【 授权许可】

CC BY   
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