Abstract
Anaesthetics are needed when handling fish, especially during tagging. However, most anaesthetics applied at present have a strong toxic effect on fish. For this reason it is only permissible to keep fish anaesthetized for a short time. A new anaesthetic, Propiscin, which allows fish to be anaesthetized for up to 0.5 h, has been successfully tested. It contains a 0.2% stabilized solution of etomidate and can be used as a bath. When administered correctly, the required disappearance of sense perception and motor reflexes in the fish can be obtained in about 2-4 min. The low toxicity of this pharmacological confection has been proved according to a full set of clinical, toxicological, hematological and biochemical criteria. Clinical tests have been conducted on with many fish species, mainly salmonids.