TIn general, marine fish larvae require omega-3 HUFA, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Larval growth, survival and larval activity are affected by dietary levels of essantial fatty acids. Some pathological signs, such as abnormal pigmentation, hydrops etc. and low feed conversion efficiency, poor growth, mass mortality are related to omega-3 HUFA series fatty acids deficiency in larvae food. EPA/DHA ratio in live foods or microencapsuled diets is an important factor in larval development and survival.