Comparative Study on Salinity of Five Stocks of Tilapia

Comparisons of salt tolerance among five stocks of tilapia: GIFT strain of Nile tilapia, 78 strain of Nile tilapia, blue tilapia, Nile tilapia (♀) × blue tilapia () and red tilapia were conducted in laboratory. The result showed the range of salt tolerance was blue tilapia red tilapia Nile tilapia × blue tilapia GIFT strain 78 strain, at three indices of mean survival time ( MST ), 50% survival time ( ST 50 ) and ninty six hours median lethal salinity ( MLS 96 ). Culture test showed that, in survival rate, blue tilapia, red tilapia, GIFT strain and Nile tilapia × blue tilapia was higher than 78 strain significantly; absolute growth rate in body weight was GIFT strain red tilapia 78 strain and Nile tilapia × blue tilapia blue tilapia in 16‰ brackishwater .