When tilapia were acclimated to FW, SW or 200% SW at 20, 28, or 35 °C for 7 days, plasma osmolalities increased significantly with the increase in environmental salinity and temperature. Plasma osmolalities in fish acclimated to SW and 200% SW displayed a significant positive correlation with temperature, whereas no temperature effect was seen in FW-acclimated fish. There are only a few reports on effects of ambient temperature with salinity tolerance in tilapia