The development of gonads in females of the common perch Perca fluviatilis from the lower Dnister in the vegetative period

The present paper presents the scientific results regarding the particularities of the oogenesis of the common perch in the lower sector of the Dniester river. In the mentioned species, the development of the oocytes is synchronous, which determines a unitary mode of spawning. Differences in the character of oocyte development were established in breeders of different sizes, indicating earlier spawning by breeders of perch in smaller gravimetric groups. In sevenyearold females with ovaries in developmental stages II and II-III, resorption of oocytes was found in the phase of protoplasmic growth and in the initial phases of vacuolation of the cytoplasm, which indicates the attenuation of reproductive function in higher age groups. In May, an individual hermaphrodite perch with an abnormal development of germ cells was captured.