Biologia reprodutiva e estrutura da população do Tucunaré Cichla vazzoleri (Perciformes: Cichlidae) no Reservatório da Hidrelétrica de Balbina, Amazonas, Brasil.

Abstract

This study aimed to assess the population structure, reproductive parameters and abundance of Cichla vazzoleri from Balbina Reservoir, between October/2011 and September/12. Fish were caught using baited hook and seinenet. The population structure was analyzed by size distribution, sex ratio and mean length at first maturity; reproductive characteristics were estimated by means spawning type and period, fecundity and body indices. The population structure showed a prevalence of small and medium sized individuals, the mean size at first maturity for the species was 26.7 cm and all individuals above 34 cm of total length were breeding adults. The reproduction of C. vazzoleri occurred throughout the year, being more intense between October and January; the species is a multiple spawner and it showed mean fecundity of 5713 oocytes. Fish sampled from the left reservoir margin showed higher mean size, reproductive activity, abundance and biomass when compared to fish from the opposite margin. Other approaches are needed to improve understanding of population dynamics on both sides. The results presented here may be useful as basis for the planning of fishery resources in Balbina Reservoir.