Spawning and Season Affect Lipid Content and Fatty Acid Composition of Ovary in Chondrostoma Regium

Abstract

This study aimed to investigate the seasonal changes in fatty acid composition and total lipid content of different lipid fractions (total lipids, phospholipids, triacylglycerols, and phospholipid subclasses) in the gonads of female C. regium . Samples were collected in July, November, January, and April. Fish specimens were transported to the laboratory in insulated containers with ice, and gonadal tissues were dissected for biochemical analysis. Total lipids were extracted using the Folch method, and lipid fractions were separated by thin-layer chromatography. Fatty acid methyl esters (FAMEs) were prepared and analyzed using gas chromatography with a flame ionization detector (GC-FID). The results showed significant seasonal variation in the total lipid content and fatty acid profiles. The highest total lipid content was recorded in January (5.77 ± 0.29%), while the lowest was observed in April (2.39 ± 0.14%). Among polyunsaturated fatty acids, docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) were dominant across all fractions. Notably, the n-3/n-6 ratio varied considerably between seasons, reaching its peak in November. In general, phospholipid subclasses such as phosphatidylethanolamine and phosphatidylserine exhibited marked seasonal changes in both saturated and unsaturated fatty acid content. These findings provide insights into the reproductive physiology of C. regium and suggest that seasonal dynamics strongly influence the nutritional quality of its gonadal lipids. The results may have implications for aquaculture, reproductive biology, and the dietary value of this freshwater species.