The fishes Colossoma macropomum (Cuvier, 1818) from a farm fish stopped to eat and begun to die. Seventy-two fishes caught were examined. All fishes had a high intestinal infestation for Acanthocephala. The species was Neoechinorhynchus buttnerae Golvan, 1956. The prevalence was 100%, intensity range 30-406 and mean intensity and relative density (abundance) were 125,26. In the high infestations occurred the total occlusion of the gut lumen.
Acanthocephala; fish parasites; tambaqui; fish mortality; aquaculture