A comparative analysis of the anaesthetic effect of sodium bicarbonate (NaHCO3) on male and female three spotted tilapia (Oreochromis andersonii)

Abstract

The anaesthetic effect of sodium bicarbonate (NaHCO3) on male and female three spotted tilapia (Oreochromis andersonii) was investigated. A total of 210 broodstock O. andersonii (weight: 160 ± 10 g) of different sexes were immersed in NaHCO3 at concentrations of 0, 5, 10, 15, 20, 25 and 30.0 g/L in triplicates. The induction and recovery times were monitored using a stopwatch. The induction and recovery times at all stages of anaesthesia for both sexes were significantly higher at concentrations ≥10 g/L. The induction times were significantly longer in the male fish than in the female at concentrations of 15 g/L for stages 1, 20 g/L for stages 1 and 2, 25 g/L for all the stages and 30 g/L for stage 2. The recovery time for male fish was significantly longer than that of the female fish at concentrations of 10 g/L for stages 2 and 3, 15 g/L for stage 1 and 20–30 g/L for stages 1 and 2. Overall, the induction and recovery times of the three spotted tilapia broodstock exposed to different concentrations of NaHCO3 could be affected by sex. Therefore, 30 and 25 g/L of NaHCO3 concentrations are recommended for use in male and female broodstock, respectively.