Summary
The genus Caballerotrema Prudhoe, 1960, was redefined and C. brasiliense Prudhoe, 1960, from the "pirarucú", Arapaima gigas (Cuvier), was redescribed. C. arapaimense n. sp. from the "pirarucu" and C. aruanense n. sp. from the "aruanã", Osteoglossum bicirrhosum Vandeli, were described. Both hosts are fishes of the family Osteoglossidae collected near Manaus, Amazonas, Brazil. Caballerotrema was transferred from the subfamily Singhiinae Yamaguti, 1958, and placed in Himasthlinae Odhner, 1910. A key to the three known species of the genus was presented.