The author studies some plerocercus specimens collected from freshwater and estuarine fishes from Pará, Amazonian Region: Brachyplatystoma flavicans, B. vaillanti and Bagrus marinus. These larvae were compared with plerocercur collected from Cynoscion and Micropogonias, marine fishes from Rio de Janeiro and they were identified to Pterobothrium crassicolle Diesing, 1850. A redescription of P. crassicolle is given since most of the species described in the last century are poorly known.
Trypanorhynchs cestodes; plerocercus; Pterobothrium crassicolle; fishes; Brachyplatystoma; Cynoscion; Micropogonias