increased significantly (P < 0.05) with increasing Ulva level in fish diet up to 15%. Increasing the level of Ulva in the diets
from 15 to 25% did not exert any additional advantage to growth of fish. Best significant (P < 0.05) values of feed conversion ratio (FCR) were observed in fish fed diet with 20% Ulva (1.49) followed by diets with 15 and 10 % Ulva (1.52 and 1.53 respectively). Survival rate and fish body moisture content did not differ significantly among treatments. While lipid content in the fish body differ significantly. Fish fed diet containing 10% Ulva get the highest significant (P < 0.05) lipid content having the value of (7.57%). With increasing Ulva level in the fish diet, carcass protein concentration increased significantly (P < 0.05).The highest value was maintained at fish fed the diet containing 25% Ulva while the lowest was maintained at control
treatment. Feed utilization parameters were affected significantly by different Ulva
level in the diet. The highest significant (P < 0.05) values of protein efficiency ratio
(PER), protein productive value (PPV %) and energy retention (ER %) were obtained
with the fish maintained at 10, 15 and 20% dietary Ulva. Therefore, green seaweeds
(Ulva sp.) could be supplemented to red tilapia (Oreochromis sp.) diet at optimum
level of 15% to improve growth performance without any adverse effect on feed
efficiency or survival rate