This study was carried out with the aim to analyze the gonadal development of S. cephalus in Tödürge Lake, Sivas, Turkey.  Anatomical and histological structures of gonads, oogenesis and spermatogenesis processes along with the determination of sexual maturity age of female (n=43) and male (n=27) individuals and spawning periods of the species were determined. Seasonal variations of gonads were illustrated. Five different oogenesis phases (chromatin nucleolar, perinucleolar, cortical alveolar, vitellogenic and maturation) and three different spermatogenesis phases (immature, maturing and mature testis) were identified. Results indicated that chub has a group syncrone type ovary, has a short reproduction season and spawn at once or twice times per year. Males reached to sexual maturity at II and III ages, and females reached to sexual maturity at III age. In addition, spawning period started at the end of May and went on through the end of June. Both oocyte and spermatocyte development and maturation were similar with the species belong to the subfamily Leuciscinae.

Key words: Chub, Gonad development, Oogenesis, Spermatogenesis