Common in creeks and interconnected ponds in Matto Grosso, Brazil, where it influences distribution and feeding of other fish (Ref. 9080) and in areas of high primary production in Rio Machado and Rio Negro (Ref.9096). Adults feed mainly at dusk and dawn. Feeds on insects, worms and fish (Ref. 7020). Medium-sized to large individuals (15-24 cm length) forage mainly at dawn, late afternoon and night up to about 2200H, whereas smaller fish (8-11 cm) are active mainly during the day (Ref. 9080). Teeth replacement on alternating sides of jaw allows continuous feeding. Its powerful dentition can inflict serious bites. Has a highly evolved auditory capacity and a 'lurking', then 'dashing' behavior during daytime. Shows hierarchies within small schools (Ref. 9077). Available information on body composition of 'piranha caju' flesh is 8.2% fat, 15.0% protein and 4.4% ash (Ref. 9251).