Effects of different levels of phospholipids on fatty acid composition, body lipid content and lipase activity in stellate fish (Acipenser stellatus) stellatus)

Abstract
This study was conducted to investigate the effect of different levels of phospholipids on fatty acid profile, lipid content of body and lipase activity in stellate fish (Acipenser stellatus) fed different levels of lecithin as phospholipid source. The fish with average weight of 11.25 ± 0.06 g were fed seven different diets having identical levels of protein and lipid content but different levels of soy bean lecithin (1, 2, 4, 6, 8 and 10 percent) for 11 weeks. The fish were fed at satiety during experimental period. The results showed that using up to 10% soy bean lecithin in the fish diet increased linoleic, saturated fatty acids (SFA) and n-6 highly unsaturated fatty acids (n-6 HUFA) significantly in the fish body (p<0.05), whereas there was no significant difference in EPA and DHA levels. The results revealed that the body fat composition is significantly influenced with the fat content in the diet, however, maximum lipid was observed in fish fed 6% lecithin. The lipase activity in the digestive system of stellate fish increased significantly in the groups fed 2-4% lecithin. Therefore, we can conclude that increase in soy bean lecithin level of diet up to 4 and 6% can significantly increase the lipase activity and SFA, al MUFA and n-6 HUFA fatty acids level in the stellate fish at this weight range respectively.