Feeding of the auchenipterichthys punctatus (Siluriformes, auchenipteridae) in lakes of the cuiuni river, amazonas, Brazil

Abstract

Auchenipterichthys punctatus is a very abundant species of fish during the period of low waters in the Cuiuni River. This study investigated the feeding of A. punctatus in Cuiuni River lakes. The stomach content, degree of repletion, food index (IAi), preferential items and trophic niche amplitude (BA ) of 130 individuals were analyzed. The results show that 26.9% of the individuals present stomachs with low degree of filling, 23.0% moderate, 13.0% half and 10.7% completely full. It was possible to identify three categories of stomach content considering its origin: animal, plant and unidentified material. The most consumed and diverse items are within the animal category, represented by different orders of autochthonous and allochthon insects. According to the diet data, the food composition of A. punctatus during the drought period in the Cuiuni River lakes shows the carnivorous habit with an insectivorous tendency. Trophic niche amplitude values were considered low in all lakes. The food activity showed that during the drought period there was a restriction due to the high consumption of a single item. We emphasize the need for further studies on the species A. punctatus, and other auchenipterids, involving trophic ecology during all phases of the flood pulse in black water lakes in the Amazon to fill in the existing gaps in the ecology of these fishes.