Evaluating the anaesthetic efficacy of clove stem powder (Syzygium aromaticum) in Redbreast tilapia (Coptodon rendalli, Boulenger 1897) juveniles

Abstract

Anaesthetic agents play a crucial role in minimizing stress in fish and other animals while also enhancing animal welfare and ensuring proper care during routine handling procedures. The present study investigated the anaesthetic efficacy of clove stem powder (Syzygium aromaticum) on Redbreast tilapia (Coptodon rendalli) juveniles sourced from a local fish farm. The juveniles with an average weight of 39.68 ± 3.78 g, were exposed to varying concentrations (1, 3, 5, 7, 10 and 12 g/L) of clove stem powder in triplicate tanks under similar water conditions. The temperature was maintained at 21 ± 0.5°C, pH at 6.5 ± 0.2, and dissolved oxygen at 7.4 ± 0.1 mg/L. the induction and recovery times were carefully recorded using digital stopwatches. Results indicated a concentration-dependent effect. Higher clove stem powder concentrations resulted in significantly shorter induction times (P < 0.05). Conversely, recovery time exhibited a polynomial correlation with increasing concentration. The induction times varied from 10.46 ± 0.67 to 2.44 ± 0.49 min, while the recovery times ranged from 3.77 ± 0.69 to 19.76 ± 1.40 min, corresponding to the lowest and highest concentrations, respectively. Importantly, all fish displayed normal behaviour after the experiment and there was no observed mortality.