Family Polyacanthorhynchidae Golvan, 1956

Polyacanthorhynchus macrorhynchus (Diesing, 1856) —adult

Host and habitat: Arapaima gigas (FW)

Locality: Amazon River basin

References: Diesing (1856), Travassos (1919), Travassos et al. (1928), Machado Filho (1947), Golvan (1956), Travassos and Freitas (1964), Thatcher (1991, 2006)

Polyacanthorhynchus rhopalorhynchus (Diesing, 1851) —adult Host and habitat: Arapaima gigas (FW)

Localities: Amazon River basin, Mato Grosso

References: Diesing (1851), Baylis (1927), Travassos (1919), Travassos et al. (1928), Machado Filho (1947), Thatcher (1991, 2006)