Ecologia alimentar das espécies de peixes de pequeno porte em diferentes biótopos da bacia do Rio Verde, Alto Rio Paraná, Brasil

• Autor(a) principal: Silva, Jislaine Cristina da
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do UNIOESTE
• Texto Completo: http://tede.unioeste.br:8080/tede/handle/tede/683
• topic: Dieta; Rio Verde; Peixes pequeno porte; Variações espaciais; Sazonalidade; Diet; Verde River; Fish small; Spatial variations; Sasonality; CNPQ::CIENCIAS BIOLOGICAS

Variations in spatial and temporal scale in the provision of food resources play a central role in changing patterns of food utilization by fish species. Thus, the aim of this study was to evaluate the spatial and temporal variations in the use of food resources for species of small fish in the Verde River, the Upper Paraná River basin, Mato Grosso do Sul. Samples were collected during the rainy season and dry from November 2010 to August 2012, using trawls, cast nets and gillnets. Nine sampling sites were grouped into three biotopes: upstream and downstream of the Branca Waterfall and tributarie. The stomach contents of 3,263 individuals belonging to 12 species of small size were analyzed according to the volumetric method. Altogether 31 food items were recorded. For all biotopes analyzed the consumption of seeds was higher in the rainy season, and plant (leaves) in the dry season. Hymenoptera was an important item in the diet of fish species, but the proportions were different in consumption between periods and biotopes. The consumption of Coleoptera and Isoptera was significant only in the downstream Branca Waterfall in the rainy season and aquatic plant was consumed more in tributarie in the dry season. The Principal Coordinate Analysis (PCoA) and indicate spatial and temporal segregation of species in the diet, showed the interaction between these two factors. Significant differences were observed in the composition of the diet among biotopes, rainy and dry seasons and interaction. Resources allochthonous origin was clearly the most consumed by the species in all biotopes in both hydrological periods. The dietary overlap between species, even with significant seasonal and spatial differences, was considered low (< 0.4 ) for about 60 % of species pairs . Thus, we conclude that spatial and seasonal changes occurred in the use of food resources for species of small fish and these variations were related to differences physiographic channel and environment that contributed to seasonal changes in the diet were significant, reflecting also the low overlap feed between species