Hikasa et al. (1986) recommended 25–100 ppm clove oil as effective anaesthesia for the common carp (Cyprinus carpio). It has been demonstrated that onset times of individual stages of clove oil anaesthesia as well as recovery times (Figure 1) were concentration-dependant. The same effect of anaesthetic concentration levels on anaesthesia onset times has been described by Hirata et al. (1970) for the crucian carp (Carassius carassius) and by Hamackova et al. (2004) for the tench (Tinca tinca).