Influence of Different levels of Water pH on Survival rates of Laboratory reared Clarias anguillaris Fingerlings in Minna, Nigeria

Abstract

A 42 days study was conducted to determine the influence of different levels of water pi 1 on survival rates of Clarias anguillaris fingerlings. The experiment consisted of 4 treatments with 2 replicates each in a a complete randomised design and stocked with fifty 28 days old Clarias anguillaris fingerlings. Eight plastic indoor aquaria tanks (5.1 x 35 x 22) cin1 were filled with dechlorinated borehole water at pi 14,5,6,7.3 (control). The stock solutions of 2% concentrated Hydrochloric acid (HCl) and 0.01 M of sodium Hydroxide solution were used to determine the pH treatments. Physiochemical parameters were determined weekly, While the survival rates were recorded daily. Fingerlings were fed twice daily to satiation, while the exchange of water and fixing of the treatments were done twice a week. Results showed that there were no significant differences (P>0.05) in the survival rates of C.anguillaris fingerlings cultured in pH 6.0 and pH 7.30. Weekly survival rales and the dissolved oxygen concentration were significantly lowest (p<0.005) at pH 4.0. Biochemical oxygen demand concentration (2.50 ± 0.17mg/L) at pH 14.00 was significantly higher (P<0.005). The optimal pH range for C.anguillaris fingerlings was within 6.0 to 7.3 (control).