Juvenile Nile tilapia, Oreochromis niloticus (Linneaus) (average weight 4.60 to 4.83 g) were raised in 36 75-1 glass tanks at a stocking density of 15 fish per tank and fed a 50% protein diet for 56 days. Combined effects of temperature (24, 28, and 32°C) and salinity (0, 8, 12, and 16 g l-1) on growth and feed utilization under a 12L:12D photoperiod were studied. Significant (P < 0.05) effects of temperature, salinity, and their interaction on growth were observed. Final mean weights were significantly (P < 0.05) higher at 32 and 28°C than 24°C at 12 g l-1 salinity, where fish increased their weights seven-fold and four-fold, respectively. Feed conversion efficiencies and protein efficiency ratios were highest at 32°C and 8 g l-1 salinity, and lowest at 28°C and 16 g l-1 salinity. At all salinities, growth increased with temperature, but at all temperatures an increase in salinity generally inhibited growth. At 32°C and 16 g l-1 salinity, fish developed body lesions. The study suggested that growth rates of juvenile O. niloticus may be comparably high at 28 or 32°C in waters of 0 and 8 g l-1 salinity.
All Science Journal Classification (ASJC) codes
- Aquatic Science