Effect of salinity level on the drinking rate in atropical teleost, Oreochromis andersoni.

Abstract

A study was carried out to determine the euryhalinity and the effect of salinity changes on the drinking of tilapia, Oreochromis andersoni. Drinking rate of the fish in fresh water, and at 50%, 75% and 100% sea water was determined. O. andersoni acclimated to sea water without mortality and fish acclimated to sea water survived direct transfer back to fresh water. Drinking rate increased significantly (p<0.05) after the salinity was at least 75% sea water. It was concluded that O. andersoni is euryhaline and that its drinking rate increases with salinity upto a maximum at 75% sea water and thereafter remains significantly higher at full strength sea water. It may, therefore, be possible to culture the fish in environments of wide salinity ranges.