A total of 120 meagre, Argyrosomus regius, larvae (0.37 ± 0.02 g) were assigned to four treatments (three replicates each) to determine the optimum dietary level of PUFAs, at which there will be the best growth performance, feed utilization, fatty acids composition and antioxidant status. The treatments were a control group (fed a basal diet 3% PUFAs of total fatty acids) and another three groups fed PUFAs supplemented diets at levels 4.55, 6% and 7% for 21 days.
The results indicated that increasing dietary PUFAs levels up to 4.5% significantly improved growth and survival compared to the control group. Feed intake, feed conversion ratio and protein utilization were significantly increased with 4.5% PUFAs followed by the control group. The results revealed significant differences in PUFAs among treatments and the best value was reported for the 4.5% PUFAs supplemented diet followed by the control. There is a significant increase in TBARs levels with increasing dietary PUFAs concentration. Meanwhile, the SOD and CAT activities decreased significantly with increasing PUFAs levels. However, TAS decreased significantly with higher PUFAS level (6%) only compared to other treatments. Therefore, the dietary requirements of A. regius larvae is 4.5% PUFAs of total fatty acids.