Abstract
Salmon is an important source of long-chain highly unsaturated fatty acids (LC-HUFAs) such as 22:6n-3 [docosahexaenoic acid (DHA)]. In the present study, we conducted two identical experiments on salmon in freshwater (FW) and seawater (SW) stages, with a diet switch from fish oil (high in LC-HUFA) to vegetable oil (low in LC-HUFA) and vice versa. Our aim was to investigate the diet and life stage-specific features of lipid uptake (gut), processing (liver), and deposition (muscle). The lipid composition changed much faster in the gut of SW fish relative to FW fish, suggesting that the former had a higher rate of lipid absorption and transport. SW fish also had higher expression of phospholipid synthesis and lipoprotein formation genes in the gut, whereas FW fish had higher expression of lipid synthesis genes in the liver. All phospholipids except PC-44:12 and PE-44:12 were less abundant in SW, suggesting that SW fish have a higher requirement for DHA.
Highlights
Farmed Atlantic salmon (Salmo salar) is a popular fish species for human consumption since it contains high amounts of long-chain highly unsaturated fatty acids (LC-HUFAs) such as docosahexaenoic acid (22:6n-3, DHA) and eicosapentaenoic acid (20:5n-3, EPA)
The present study has provided a systemic overview for the abundance and distribution of hundreds of lipids in Atlantic salmon and the dynamic remodeling of these lipids between diets and across life stages
Dietary TGs in salmon are mostly digested into sn-2-monoacylglycerol (2-MAG) and free fatty acids (FFAs), which are absorbed into enterocytes and re-synthesized into TG and PL before entering other parts of the body.[39,40]
Summary
Farmed Atlantic salmon (Salmo salar) is a popular fish species for human consumption since it contains high amounts of long-chain highly unsaturated fatty acids (LC-HUFAs) such as docosahexaenoic acid (22:6n-3, DHA) and eicosapentaenoic acid (20:5n-3, EPA). Atlantic salmon is anadromous, implying that it migrates from freshwater (FW) to seawater (SW) and back throughout its life cycle. During this migration, the fish undergo large-scale morphological, physiological, and endocrinological changes to adapt to differences between FW and SW habitats. A successful migration between FW and SW involves the coordination of several hormones such as growth hormones,[7] thyrotropin,[8] cortisol, and prolactin.[9] These hormones help the fish to tolerate salinity changes between SW and FW habitats and alter their metabolism of proteins, lipids, and carbohydrates, likely as an adaptation to the different dietary profile of marine prey.[10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
