A comparative study of the composition of fatty acids in muscles, liver and internal fat in rainbow trout Parasalmo mykiss (Walbaum, 1792) grown on various diets in the period from April to July was effected. Differences in content of dietary fatty acids in diet 1 and diet 2 were found. A significantly lower level of long-chain polyunsaturated fatty acids (including physiologically significant eicosapentaenoic 20: 5(n-3) and docosapentaenoic 22: 6(n-3) acids) was detected in diet № 2, compared to diet № 1. As a result, deficiency of dietary eicosapentaenoic and docosapentaenoic acids leads to a slow rate of fishes growth. A significant influence of the trophic factor on the distribution of fatty acids in muscles and internal fat of fish is shown, because lipids in rainbow trout accumulate in these tissues. The degree of accumulation of different dietary fatty acids in muscles and internal fat of trout was depended on fatty acids that prevailed in the diet on which the rainbow trout was grown. A high degree of influence of the trophic factor on the level of polyunsaturated fatty acids of families n-9 and n-4 was found, the content of which in trout tissues was about 1%. Composition of fatty acids in trout liver, as the most metabolically active organ, is less conditioned by the influence of the factors studied. The degree of assimilation of docosahexaenoic 22: 6 (n-3) acid in rainbow trout probably depended on the level of eicosapentaenoic 20: 5 (n-3) acid in the diet. It has been stated that changing the level of fatty acids in muscles and internal fat of trout during seasonal changes is associated with an increase in the frequency of feeding of fishes in the summer.
The modern condition of rainbow trout Parasalmo mykiss in the
Kolsai lakes
