Results of experiments with clove oil utilization as an anaesthetic for fish realized in the
University of South Bohemia Research Institute of Fish Culture and Hydrobiology at Vodтany
are described. A series of observations was performed to evaluate the anaesthetic effects of
clove oil on a broad spectrum of fish species. In selected fish species, the effect of fish size,
temperature of aquatic environment, anaesthetics concentration and exposure time upon the
anaesthetic effects were studied. Within the realized experiments, concentration of 0.03 - 0.05
ml.l-1 can be generally recommended for fish. The only exception are salmonids and sturgeons
which need lower (0.02 - 0.03 ml.l-1) and higher (0.07 ml.l-1) concentrations, respectively. Exposure
period between 2 and 4 min. is sufficient for full anaesthesia and is strongly dependent on water
temperature.