Effects of dietary lysine and methionine levels on growth performance and feed utilization in Sobeity juvenile, Sparidentex hasta

This study was conducted to determine the effects of dietary supplementation of lysine and methionine on growth and nutrient utilization of Sobaity sea bream, Sparidentex hasta. Therefore, 180 juvenile fish with an initial weight of 31.38 ±1.4 g were distributed randomly among eighteen tanks. Fish were fed to satiation three time per day(08:00, 13:00 and 18:00 hours) for 8 weeks with formulated diets containing six different levels of dietary methionine and / or lysine;Diet 1: a control diet without dietary amino acid supplementation; Diet 2: 100% methionine supplementation; Diet 3: 75% methionine and 25% lysine supplementation; Diet 4: 50% methionine and 50% lysinesupplementation; Diet 5: 25% methionine and 75% lysine supplementation and Diet 6: 100% lysine supplementation. The results of this study showed that use of dietary lysine and methionine supplementation in diet, significantly affected (P.