Biochemical Heterogeneity of the Lipid Status of the Prespawn Eggs of Pink Salmon Oncorhynchus gorbuscha (Walbaum 1792) (Varzuga River, White Sea basin)

Abstract

A comparative analysis of lipid and fatty acids contents in certain portions of female gonads—head, central, and caudal—of the prespawned pink salmon Oncorhynchus gorbusha has been performed. Heterogeneity of the lipid status of eggs located in certain portions of ovaries has been found: in the head portion, a high level of physiologically important eicosapentaenoic 20:5(n-3) and docosahexaenoic 22:6(n-3) fatty acids has been registered, which coincided with a higher intensity of lipid metabolism evidenced by higher ratio of 16:0/18:1(n-9); the central portion is characterized by a low level of total lipids due to phospholipids (including phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin) and cholesterol; in the caudal portion, a high amount of certain phospholipids (phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine, sphingomyelin, and phosphatidylinositol) has been found. Such heterogeneity in certain portions of ovaries indicates asynchronous biochemical processes in oocytes of these portions that finally affects fertilization, growth and development of embryos, and further differentiation of the young fish.