EN
Adult specimens of Stephanoprora uruguayense Holcman-Spector et Olagüe, 1989 were obtained experimentally by infecting chicks with cysts from the gills of Galaxias maculatus (Jenyns, 1842) from Andean Patagonian lakes. Specimens of this species were found in nature parasitising Larus dominicanus (Lichtenstein, 1823) in the same area. The species is redescribed and the validity of Stephanoprora spp. from birds of South America as well as the status of Stephanoprora manei Holcman- Spector et Olagüe, 1986 are discussed. Beaverostomum Gupta, 1963 is considered synonymous with Stephanoprora Odhner, 1902. Stephanoprora dogieli Holcman-Spector et Olagüe, 1989, S. podicipei Etchegoin et Martorelli, 1997 and S. denticulata described by Torres et al. 1983, are synonymised with S. uruguayense.