Effectiveness of Sodium Bicarbonate as an Anaesthetic for different sizes of Nile tilapia (Oreochromis niloticus L., 1758) Juveniles

Abstract

The effectiveness of sodium bicarbonate as an anaesthetic for Nile tilapia (Oreochromis niloticus) juveniles ranging from 2 to 27g was investigated. The juveniles were exposed to different concentrations of 0 (control), 5, 10, 15,20, 25, 30, 35, 40, 45 and 50 g/L of sodium bicarbonate solution. Fish were bath immersed in each of the different concentrations of sodium bicarbonate solution for 5 min. Generally, induction time decreased while recovery time increased with increase in sodium bicarbonate concentration. Induction and recovery times increased significantly (P < 0.05) with increasing body weight. All fish reached full anaesthesia in less than 2 min in higher concentrations of 50 g/L and no mortality occurred under any of the concentrations tested. The most optimal concentration leading to full anaesthesia in 2 min and recovery in less than 4 min was 45 g/L.