Author(s): Khalid Javed Iqbal, Naureen Aziz Qureshi, Muhammad Ashraf, Hamid Majeed
A three months study was conducted in cemented tanks (2.896ft-00D7;0.762ft-00D7;0.914ft) to investigate the effect of different salinity levels on growth performance and survival of Nile tilapia (Oreochromis niloticus). Four salinity levels i.e. 1600 ppm in Treatment 1 (TI), 2400 ppm in TII, 3200 ppm in TIII and 4000 ppm in TIV were maintained while in control (T0) the salinity level was 800 ppm. Each treatment was replicated thrice with 15 fish. Initial average body weight of tilapia was 23.1 g -00B1; 3.51 SD, 22.5 g -00B1; 3.15 SD, 22.9 g -00B1; 3.29 SD, 23.9 g -00B1; 3.98 SD and 24.6 g -00B1; 4.71 SD in T0, TI, TII, TIII and TIV, respectively. Fish were fed with 24.45% crude protein (CP) diet @ 4% of its wet body weight on daily basis. Better growth rate was observed in TIV, food conversion ratio (FCR) was highest in TII while feed intake was poor in T0. Results indicate that the higher salinity (4000 ppm) levels have pronounced effect on fish growth which might be due to improved osmoregulation. Temperature, electrical conductivity and pH showed positive correlation with growth while the same was negatively correlated with dissolved oxygen (DO). Fish weight and length were linearly correlated.