Description stages of oogenesis in Chondrostoma regium (Heckel, 1843)

This study was conducted to determine the stages of oogenesis in Chondrostoma regium as a common type of fish in Diyala river .The histological study showed that this fish has a pair of cystic longitudinal ovaries which are surrounded by tunica albugina and from which folds are originated that divide the ovary into ovigerous lamellae, In addition it was observed in this study that the stages of oogensis can be summarized by seven stages depending on the shape of the nucleus , Viellogenesis , appearance of the surrounding envelopes , oogonia, primary oocyte, Multinucleated stage , yolk nucleus, cortical alveolar, vitellogenic and finally the maturation stage and the appearance of the surrounding envelopes .