Comparison of native, lyso and hydrogenated soybean phosphatidylcholine as phospholipid source in the diet of postlarval Penaeus japonicus Bate

摘要

Postlarval P. japonicus were obtained from Maresa, Mariscos de Esteros, Spain, and acclimated for 2 days prior to experiments. The initial stocking density was 6 animals/litre and 2.5 animals/litre for phase 1 and 2. Five semipurified and isolipidicdiets were formulated using casein as a protein source. The postlarvae were exposed to a 12 h light:12 h dark photoperiod and fed ad libitum 3 times a day. Growth, survival and stress resistance of the shrimp was evaluated at the termination of each phase. A stress test was performed by means of a salinity shock. P. japonicus fed on the diet containing native soyabean phosphatidylcholine had significantly better growth and resistance to osmotic shock than the other diets. The total lipid content of thetissue was significantly increased by the supplementation of soyabean phosphatidylcholine. The content of highly unsaturated fatty acids in the shrimp tissue were higher in shrimp fed native and hydrogenated soyabean phosphatidylcholine than in those fed phosphatidylcholine-free and 1-acyl lyso phosphatidylcholine-based diets. It is concluded that the functionality of phosphatidylcholine in the diet of postlarval P. japonicus requires the presence of unsaturated fatty acids and an intact fatty acid moiety.