The anaesthesia effect of clove oil on common carp (Cyprinus carpio Linnaeus) and tilapia (Oreochromis spp)

In this experiment, different concentration of clove oil was used directly in the water to prepare anaesthetic for com- mon carp (Cyprinus carpio Linnaeus) and tilapia (Oreochromis spp.) with different body sizes under different water temperatures. The result showed that clove oil had good anaesthesia effect on both common carp and tilapia. At water temperature of 28℃, the anaes- thetic time of common carp and tilapia decreased when the concentrations of clove oil raised from 0.05 mL·L-1 to 0.1mL·L-1 and 0.15mL·L-1. And the recovery time of common carp increased, while that of tilapia decreased. At the concentration of 0.1mL·L-1, the anaesthesia time of both common carp and tilapia decreased when the water temperature raised from21℃ to 24℃, 26℃ and 28℃. And the recovery time of common carp increased, while that of tilapia decreased. Under the condition of 28℃ and 0.1mL·L-1 clove oil concentration, the anaesthetic time of small size carp was shorter than that of small size tilapia, but the recovery time was longer. The result indicates the clove oil is one effective but cheap anaesthetic.