Morphophysiological and Biochemical Characteristics of the Gonads in the Kalkan Scophthalmus maeoticus torosus (Scophthalmidae) during Maturation and Spawning in the Sea of Azov.

Abstract

Morphophysiological parameters of oocytes were studied in the Azov turbot (kalkan) Scophthalmus maeoticus torosus during maturation and spawning in the Sea of Azov. The fatty acid composition was additionally determined in three (cranial, middle, and caudal) regions of the gonad in each individual fish. The dynamics of the morphophysiological characteristics and the fatty acid composition of eggs was observed over the spawning period. Two physiologically significant fatty acids, oleic and docosahexaenoic, were found to dominate in eggs. Opposite trends were detected in their contents, i.e., the docosahexaenoic acid content at the beginning of spawning was higher than in the peak spawning period, when oleic acid prevailed.