Induction and recovery from anaesthesia in pike (Esox lucius L.) exposed to clove oil

The aim of this experiment was to investigate the possibilities for using clove oil as anaesthetic in pike (Esox lucius). The experiments were carried out under controlled laboratory conditions. The following four concentrations were experimented: 0.02 ml.l(-1) 0.04 ml.l(-1) 0.06 ml.l(-1) 0.08 ml.l(-1). Each concentration was tested with 12 pikes having an average body weight of 244.4 to 284.9 g, and the anesthesia was applied separately for each pike. The fish behavior was traced and analyzed, and the time for inducing anesthesia and recovery was timed with a stopwatch. At concentration of 0.02 ml.l(-1) complete immobilization of the pikes was not achieved. At 0.04 ml.l(-1) the fish were completely immobilized in 5'50 '' to 9'50 '' min. At concentration of 0.06 ml.l(-1) the fish were anaesthetized for 4'15 '' - to 9'20 '' min, at 0.08 ml.l(-1) the fish were anaesthetized for a period of 3'30 '' to 9'50 ''. There was an inverse proportional dependence between recovery time and clove oil concentration.