Eight species of nematodes and one larval cestode were recovered from 88 specimens of 12 species of fishes captured in the reservoir of "Salto Osório". Capillaria sp., Contracoecum sp., (larval forms), Procamallanus peraccuratus pinto et al., 1976, Procamallanus petterae Kohn & Fernandes, 1988, Raphidascaris sp., Spirocamallanus intermedius Pinto et al., 1974 and Spirocamallanus pintoi Kohn & Fernandes, 1988. From 83 specimens of 12 species of fishes from the reservoir of "Salto Santiago", only one species of cestode and three species of nematodes were recovered: Contracoecum sp. (larval forms), procamallanus peraccuratus and Raphidascaris sp. Pimelodus ortmanni is a new host record for P. peraccurants and S. intermedius.
parasites of fishes; helminths; nematodes