Re-evaluating eurahaline nature of Nile tilapia, Oreochromis niloticus: A hatchery perspective

Abstract

This study re-examined Nile tilapia adaptability for various salinity uses by determining survival rates and growth parameters in 0 ppt to full 40 ppt seawater at 5 ppt treatment increments (Three replicates each) and at a 2.5 ppt daily acclimation rate. Our findings indicate that Nile tilapia could be raised at all salinity levels, including full 40 ppt seawater, but mortality could be expected at 20 ppt and above during acclimation. The Kaplan-Meier log-rank test revealed that the acclimation mortality of the 40 ppt treatment was significantly lower (p 0.05) than the other treatments, whereas there was no significant difference in the acclimation survival rates of the 20-35 ppt treatments. However, the growth parameters of the surviving fish at 40 ppt were significantly higher (p<0.05) than those in the other treatments. We recommend the production of Nile tilapia fingerlings in freshwater and their gradual acclimatization for higher salinity applications.