Feeding of <em>Astyanax bimaculatus</em> (Characiformes, Characidae), in the influence area of the Corumbá Reservoir, state of Goiás, Brazil

Abstract

The study of the feeding of Astyanax bimaculatus was undertaken from March 1996 to February 1997. Collections were made monthly in the influence area of the Corumbá Reservoir, in three environments: Corumbá, Córregos and Rio do Peixe. Gill and drag nets were used for collections. Occurrence and volumetric methods were used to determine diet which was composed of twenty-seven items. Feeding index for total fish analyzed (n = 401) indicated that 62.85% of the diet was composed of vegetal matter and 37.13% of animal matter. Main items were Dicotiledoneae (IAi = 58.70%) among vegetation and insects (IAi = 34.65%) among animals. Seasonal, area and fish size variations influenced diet variation and suggest the opportunistic habit of the species