SUMMARY
Host specificity, attachmente sites, infection rates and seasonal variation of Dolops striata Bouvier (1899) e Dolops carvalhoi Castro, 1949 were studied a one-year period, from March, 1979, to March, 1980, in the vicinity of Janauacá, a "varzea" lake in Central Amazônia. Seasonal variation was found to be closely related to water levels with maximun peaks of infestation for both species ocurring during high water (April & May), and minimum peaks during low water (September & October). D. carvalhoi showed low host specificity, was found to parasitize eight species of fishes representing four families, namely: three species of Pimelodidae, two of Serrasalmidae, one of Characidae and one of Clupeidae. D. striata showed high host specificity, was found to parasitize one unique familie, Anostomidae. Both species parasitize the external surfaces of their hosts.