This paper presents the sexual cycle occurring in the artificially bred rudd (Scardinius erythrophthalmus). In females, endogenic vitellogenesis took place between autumn and spring and the exogenic vitellogenesis was observed in May. At the end of May and at the beginning of both June and July, synchronised and unsynchronised oocyte development was observed in the females. Oocytes with a complete exogenic vitellogenesis and previtellogenic oocytes were found in the synchronised development. Besides the two above oocyte stages, oocytes in the vacuolisation stage were found in the unsynchronised development. The male testicles contained spermatocytes from July to April. Spermatids were observed in May and June. At the beginning of July, new spermatocyte generations were formed. The obtained results indicate that the rudd is a species with a spring exogenic vitellogenesis and that both synchronised and unsynchronised oocyte development can occur in the period preceding reproduction.

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