The Anostomidae fishes are restricted to South America, and they are economically important to fisheries in many regions. Studies conducted in Central Amazon, where they are widely distributed, demonstrated that these fishes have high feeding plasticity. In this study we analyzed nine species of Anostomidae and we discussed ecological interactions in relation to their feeding and distribution in the Planicie do Bananal, a Cerrado region which is subject to periodic floods and it is drained by Araguaia/Tocantins basin. Niche breadth was low among the six species analyzed (0,125 and 0,355). Schizodon vittatum (Valencienes, 1894) has the widest niche breadth and it is also the most widely distributed species. Qualitative analyses comparing species feeding among habitats demonstrate great variation in the proportion of ingested items from one environment to another, while quantitative analyses show relatively higher similarities. Laemolyta petiti Géry, 1964 and Laemolyta taeniata (Kner 1859) are the most specialized species in relation to ingested items, as well as the proportion of each item founded in the stomach contents.
Fish ecology; Araguaia river; Cerrado; niche
