Among the specimens of the Cichlidae family, collected in the central region of Rio Grande do Sul, the genera represented by orbicular forms were studied: Aequidens , Cichlaurus and Geophagus . Of these genera, 4 species were found that occurred in quite varied proportions: Aequidens portalegrensis, Cichlaurus facetus, Geophagus brasiliensis and Geophagus gymnogenys .