A Comparative Study of Lipids and it’s Dynamic during Embryogenesis and Early Post-Embryonic Development of Atlantic Salmon ( Salmo salar L.) and Brown Trout ( Salmo trutta L.)

A comparative study of the content of total lipids and lipid classes (total phospholipids and certain fractions, triacylglycerols, diacylglycerols, cholesterol esters, cholesterol, non-esterified fatty acids) in unfertilized eggs, during embryogenesis (fertilized eggs, blastula, gastrula, organogenesis, eye pigmentation, pre-hatching larvae) and early postembryonic development (alevin) of Atlantic salmon ( Salmo salar L.) and Brown trout ( Salmo trutta L.) was carried out. The significantly high content of the total lipids (due to the storage triacylglycerols) in unfertilized eggs, especially in Atlantic salmon, is a necessary prerequisite for their further embryonic and postembryonic development. The dynamic of the lipids in the studied species during embryogenesis also differed, which may indicate the feature of lipid metabolism in these species. At the stages of active cell division (blastula, gastrula, and organogenesis) during embryogenesis of Atlantic salmon and Brown trout, the content of lysophosphatidylcholine increased. At the later stages of embryogenesis (eye pigmentation, pre-hatching larvae) and early postembryonic development (alevin), the amount of phosphatidylserine increased. The biochemical heterogeneity due to the quantitative content of individual lipid classes at the studied stages of development, is apparently associated with the feature of embryogenesis of the studied species, in particular, the differences in time-scale of these processes.