This study was carried out to investigate the: The possibility of acclimatization and rearing red tilapia fry under different water salinities (5, 10, 15 and 20 ppt) on growth performance, feed utilization and chemical composition. The effects of myo-inositol dose (300, 400 and 500 mg/kg diet) on growth performance, feed efficiency of red tilapia fingerlings. The responses of hybrid red tilapia fingerlings to rear in mono or polyculture conditions with striped mullet (Mugil cephalus) under different stocking ratio. The present study could conclude that: Hybrid red tilapia was able to tolerate high level of salinity,15 ppt best salinity that possessed the higher growth performance. Supplementation of dietary myo-inositol decreased of fat percentage fish body. Myo-inositol as fed additives improved growth performance of hybrid red tilapia fingerlings, 500 mg/kg diet the best level in diet. The polyculture system of red tilapia and striped mullet were higher than the monoculture every species in growth performance traits, and the best stocking ratio in polyculture was 3 red tilapia: 1 striped mullet with stocking density (40 fish/m3).