Review of the lipid and essential fatty acid requirements of rockfish (Sebastes schlegeli )

Abstract

In order to investigate the effects of dietary lipid and essential fatty acids (EFA) on growth and biochemical change of rockfish (Sebastes schlegeli), a series of studies was conducted. Juvenile rockfish required 0.9% n-3 highly unsaturated fatty acids (n-3HUFA) in the diet. The requirements of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were both 1%, and DHA was superior to EPA as an EFA. Fatty acid compositions in polar lipid of fish were directly reflected from those of dietary fatty acids. The levels of protein, glucose, cholesterol, LDH, GPT and GOT in the serum of rockfish were significantly affected by dietary n-3HUFA levels. Abnormal and necrotic hepatic cells were found in rockfish fed the n-3HUFA-deficient diets. Ca2+-ATPase activities in the liver microsomal membrane were lower in fish fed the n-3HUFA-deficient diets than in those fed the n-3HUFA-sufficient diets. Apparent digestibilities of lipid and saturated fatty acids of rockfish fed the diet were affected by water temperature and fish size, especially in the diet containing beef tallow. These results may be used in developing feed formulation and improving the health of rockfish.