The use of clove oil to induce anaesthesia, and its effects on blood chemistry, in <i>Lates niloticus</i> from Lake Victoria, Uganda

Abstract

The efficacy of clove oil as an anaesthetic and its effects on blood parameters in Nile perch Lates niloticus were evaluated in 2010. Clove oil concentrations of 49.3, 73.9 and 98.5 mg l⁻¹ induced anaesthesia in <3 min, while the average recovery time from anaesthesia was 11 min 22 s. The optimal oil clove oil concentration was 49.3 mg l⁻¹, inducing anaesthesia in 4 min 33 s, with recovery in 3 min 31 s. No stress response was elicited. Clove oil at a concentration of 24.6 mg l⁻¹ was an effective sedative, whereas a concentration of 49.3 mg l⁻¹ was sufficient for measuring fish and stripping gametes. A concentration of 73.9 mg l⁻¹ induced anaesthesia within 4 min and fish recovered in 10 min. Therefore, clove oil was an effective anaesthetic and sedative for the handling of Nile perch within a mass range of 0.4–12 kg fish−1.

Keywords: cortisol, efficacy, Eugenia caryophyllata, glucose, lactate, Nile perch, stress