Dynamics of Lipid and Fatty Acid Content at Early Ontogenesis Stages in Pink Salmon Oncorhynchus gorbuscha (Walbaum, 1792) in a Natural Environment (Indera River, Kola Peninsula)

Abstract

A comparative study of lipid and fatty acid status at the early stages of pink salmon’s ontogenesis has been carried out in prespawn eggs, at the stage of eye pigmentation, and in the hatched prelarvae under ecological conditions of a natural environment (Indera River, Kola Peninsula). It is shown that the high plasticity of pink salmon is due to the activation and combination of complex biochemical mechanisms at the early stages of development, providing both the sensitivity and the sustainability of the species, which contributes to the formation of the species’ high potential at high latitudes. Metabolically mature pink salmon eggs are characterized by a high level of total lipids with a high amount of the structural and energetic components that provide optimal development of the embryos. Metabolic processes are activated at the stage of eye pigmentation in autumn, which affects the changes in the spectrum of individual classes of lipids and fatty acids and their ratio indicators. The prelarvae that hatched in winter at temperatures below zero have a low content of phospholipids, triacylglycerols, and 16:1ω-7, 18:3ω-3, and 20:5ω-3 fatty acids as well as high level of cholesterol, cholesterol esters, and a ratio index of 20:4ω-6/18:2ω-6 fatty acids, while the high content of dominant 18:1ω-9 and 22:6ω-3 fatty acids remains the same. Multidirectional changes of lipid and fatty acid levels at the stage of eye pigmentation (the most sensitive stage of embryogenesis) and in pink salmon prelarvae after hatching are caused by specific processes of metabolism intensification of the developing organism.