The efficacy of sodium bicarbonate as an anaesthetic agent in Oreochromis macrochir juveniles

Abstract

The ever increasing demand for fish and fishery products in Zambia has resulted in the culture of many tilapia species including greenhead tilapia (Oreochromis macrochir). This increase in aquaculture entails an increase in routine procedures being performed which require anaesthetizing fish to reduce stress. In this study, we examined the efficacy of sodium bicarbonate commonly known as ‘baking soda’ as an anaesthetic agent for greenhead tilapia juveniles (7.2 ± 1.10 g weight and 27.64 ± 4.44 mm length). The juvenile fish were subjected to different concentrations of baking soda namely 0 (control), 5, 10, 15, 20, 25 and 30 g/L of sodium bicarbonate solution. In each of these different concentrations of the anaesthetic agent, fish were bath-immersed. Generally, the time of induction decreased while the time of recovery from anaesthesia increased with an increase in sodium bicarbonate concentration. The time of induction and recovery depended significantly (p < 0.05) on the concentration of the anaesthetic agent. All the fish reached full anaesthesia in less than 4 min in higher concentrations (above i.e. 15 g/L) and no mortality occurred under any of the concentrations tested. The most optimal concentration leading to full anaesthesia in 4 min and recovery in less than 10 min was 20 g/L.

Keywords

• Sodium bicarbonate
• Anaesthesia
• Aquaculture
• Fisheries
• Greenhead tilapia
• Zambia