Disturbance of Synchronous Oocyte Development in Bream Abramis brama L. from the Rybinsk Reservoir

The seasonal dynamics of oocyte sizes in bream has been studied. Asynchronous oocyte development causes the formation of the second batch of eggs in some specimens in the sample. The dynamics of the formation of the second oocyte batch, the high variability of their number and proportion of the total number of oocytes, and the resorption of the first batch of eggs after spawning differ from a typical asynchronous oocyte development in species with portioned spawning. The repeated spawning of bream is currently unlikely.