During investigation on the helminth parasites from
Brycon hilarii
Valenciennes, 1850 (Characiformes, Characidae), from River Juba, Tangará da Serra, state of Mato Grosso, Brazil, several specimens of the nematode
Neocucullanus Travassos, Artigas et Pereira, 1928 were detected. A detailed study of this material, including scanning electron microscopy, allowed to identify these nematodes as
N. neocucullanus Travassos, Artigas et Pereira, 1928 and to confirm
N. multipapillatus Petter, 1989 as a junior synonym of
N. neocucullanus.