One hundred and ten specimens of Pseudoplatystoma corruscans (Agassiz, 1829) (Pimelodidae), "pintado", and 582 specimens of Schizodon borelli (Boulenger, 1900) (Anostomidae), "piava", collected in the floodplain of the high Paraná River were analyzed. P. corruscans presented 74.54% of parasitism while S. borelli presented 19.42%. Results of the present research show that in the case of P. corruscans, two species of proteocephalideans presented a significant relationship with the type of environment with regard to prevalence. Spasskyelina spinulifera (Woodland, 1935) was the only species that presented a relationship between the intensity of infection and the environment. In S. borelli only Cucullanus pinnai Travassos. Artigas & Pereira, 1928... |