Effect of pH on Egg Hatching, Larval Growth Performance, and Enzymatic Activity of the Nile tilapia Oreochromis niloticus

The present study aimed to show the effect of pH on egg hatching, growth performance, and enzymatic activity of the Nile tilapia Oreochromis niloticus larvae.  The results showed that the percentage of mortality of the newly hatched larvae increased with increasing pH for a period of 96h of incubation. However, the lowest value of mortality rate was recorded between the percentage of control and that treated with pH 7.5. In comparison with the abnormalities between the groups of the control group and those exposed to the different degrees of pH, significant differences were recorded (P>0.05). However, a non-significant difference was recorded between the control group and that exposed to pH 7.5 (P<0.05). The effect of pH on the incubation time showed that a considerably long period of incubation was observed towards the high acidity and high alkalinity of pH. The effect of pH on the growth of larvae is more significant after 35 days of post-hatching than that recorded after 20 days of post-hatching (P>0.05). The enzymatic activity is more affected towards low pH (4-5) or towards the more alkaline medium. Finally, the best concentration of pH on enzyme activity and growth performance ranged from 7.5 to 8.5.