Survival and growth potential of genetically male tilapia (GMT) fry in flow through system under different dietary protein concentrations

Study was conducted to evaluate the survival and growth potential of genetically male tilapia (gmt) in flow through system under different dietary protein concentrations. the fish was kept in cemented rectangular tanks @ 59 fish fry/ tank in mixed sex (xx/xy) culture system and 27 fish fry/tank in mono sex culture(super males yy). each treatment group in mixed sex had two replicates while mono sex had one replicate. artificial feeds containing 30%,35% and 40% crude protein were applied at 4% fish wet body weight twice a day to mixed sex while 35% and 40% to super males. the results of mixed sex were analyzed using one way anova while mono sex was compared by using t-test. results of mixed sex indicated significantly higher (p > 0.05) final body weight,net weight gain,percent weight gain in 40% compared to 30% and 35% feeds. feed conversion ratio (fcr) and specific growth rate (sgr %) were 1.21 and 4.83,respectively for 30%,and 1.24 and 3.59,respectively for 35% feeds and were significantly different compared to 1.33 and 3.23,respectively,for 40% feed in mixed-sex culture. the survival rate was 43% in 30%,83% in 35% and 68% in 40% feeds for mixed sex. in the case of mono-sex culture (yy),results indicated significantly higher (p > 0.05) values with 40% feed for final body weight,net weight gain,percent weight gain and sgr compared to that of 35% feed. the fcr values in 40% feed (3.65) was significantly different from that of 35% feed (4.74). survival rate of yy was 100% in 35%,while 81% in 40% feed. in conclusion mono sex (yy) gmt fry outperformed than mixed sex under both treatments of 35% and 40% crude protein in flow through system. copyright 2014 zoological society of pakistan.