DIET RELATED TO BODY SIZE IN Serrasalmus brandtii 117 DIET SHIFTS RELATED TO BODY SIZE OF THE

(With 6 figures) This study aimed to identify shifts in the Serrasalmus brandtii Lütken, 1875 diet related to body size. Specimens were collected from April 1992 to January 1993 at the Cajuru Reservoir, in the Pará River, São Francisco River Basin, by seining the shore with nets of nylon, 1 mm opening, and with gill nets. Stomach contents of 152 individuals measuring 15-192 mm SL were examined. Food items were identified and weighed separately. For qualitative analysis, the frequency of occurrence method was used. The relative importance of each food component was determined based on the alimentary in-dex (IAi). The frequencies of occurrence data were subjected to cluster analysis using the Canberra coefficient of dissimilarity and UPGMA as the cluster method. Distinctive gradual changes in food habits, associated with body size, were identified in this species. The smaller individuals fed predomi-nantly on microcrustaceans and insect larvae. The intermediate size classes ingested insects, fish fins, fish scales, and chunks of fish flesh, in this order of importance. For the larger pirambebas, fish wa