Evaluation of lemon balm (Melissa officinalis) leaf powder as a natural anaesthetic during transportation of red belly tilapia (Coptodon zillii)

Abstract

Transportation of fish is a crucial process in aquaculture but often induces stress that affects physiological stability and survival of fish. This study evaluated the effectiveness of lemon balm (Melissa officinalis) leaf powder as a natural anaesthetic during transportation of red belly tilapia (Coptodon zillii). Lemon balm leaves were collected, dried and ground into powder. Ninety tilapias with an average weight of 23.1 g were randomly distributed into three treatments: T1 (control, without anaesthetic), T2 (5 drops palm oil/7.5 L water), and T3 (10 g/7.5 L Melissa officinalis powder) respectively. Ten fish were stocked in each of nine plastic containers (10 L capacity). Thereafter, the fish were transported over a distance of approximately 210 km (Minna-Suleja route, to and fro). Mild induction time and faster recovery time were observed in treatment T3. No significant difference (p>0.05) was recorded in water temperature across the treatments. However, significant differences (p<0.05) were recorded in dissolved oxygen, pH, ammonia, and phosphorus levels. The control group had the highest mortality, while T3 showed the highest survival rate. These findings suggest that Melissa officinalis leaf powder could serve as a promising natural anaesthetic for tilapia transportation in aquaculture.