This study was conducted to examine the effects of varying salinity levels (0‰-30‰ with 5% increment) on breeding of red tilapia. Brood fish were stocked in hapa nets suspended in cemented rectangular tanks (11×7×4 feet) . Three females (mean weight 145 g) and one male (140 g) were kept per tank with 2 replications. They were fed with commercial floating pellets having 35% crude protein at 2% body weight twice a day for 60 days and eggs were collected weekly. Results showed that fertilized eggs were found to be greater in number at low salinity level as compared to higher salinity level. Survival of fry ranged from 1058 to 1100 at salinity level of 0‰ – 20‰ with 5% increment, after which fry number decreased significantly (P<0.05). The fertilized eggs did not differ for the fish at salinity of 0‰ –20‰, but decreased significantly when salinity levels were increased above 25‰. Water quality parameters remained as temperature (28.1±0.2°C), dissolved oxygen (6.10±0.1 ml/l), pH (6.6±0.1 ml/l) and ammonia (0.02±0.004 ml/l) throughout the study period. Taking into consideration the number of fertilized eggs and survival of fry data attained in the present study, a salinity level of 20% is suggested for red tilapia breeding in concrete tanks.
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