Seasonal changes of the oocyte and determination of the spawning season of jundiá ( Rhamdia sapo ) were studied in this study, using IGS (gonado-somatic index), CPN (monthly ponderal ratio of oocyte proportion) and CPT (area occupied by oocytes at each stage). It was concluded that the females of Rhamdia sapo have a long reproductive period (August to February) with two phases of marked reproductive activity (August-September and January-February).
