Fatty Acid Content of Phospholipids and Triacylglycerols in Juvenile Atlantic Salmon Salmo salar L. Reared under Different Lighting and Feeding Regimes in Aquaculture (North Ossetia-Alania)

Abstract

The photoperiod is an important ecological factor synchronizing the endogenous rhythms of growth and development of the Atlantic salmon Salmo salar L. The changes in the FA content of phospholipids (PL) and triacylglycerols (TAG) during the growth and development of Atlantic salmon juveniles (fingerlings, parrs, and smolts) at different lighting and feeding regimes in aquaculture of the southern region (North Ossetia, Alania) were studied. A high content of saturated fatty acids (SFA) and a consistently high content of polyunsaturated fatty acids (PUFA) in PL (more than 40% of the total FA) were detected. An increase in the content of PUFA in TAG both in the salmon liver and in muscles during development from fingerlings to smolts indicated the biochemical changes in the fish organism preparing for smoltification and the transition to living in sea water. Among PUFA, n-3 PUFA dominated, while the content of n-6 PUFA was no more than 5% both in PL and TAG of juvenile salmon. At the same time, among PUFA the content of eicosapentaenoic acid 20:5(n-3) (EPA) in the muscles of both parrs and smolts was higher than in the liver, where docosapentaenoic acid 22:5(n-3) (DPA) dominated. The results of quantitative and qualitative changes in the FA components of lipids in juvenile salmon depending on changes in the lighting and feeding regimes are important for understanding the mechanisms of ecological and biochemical adaptations that determine the early development of salmon and its transition to the smoltification.