Active Substance	Characteristics and Use
Tricaine [35] MS222, Finquel®	Anesthetic with analgesic effects Fast induction and recovery Available as a powder to be dissolved in water Used for fish in fresh water; it makes an acidic pH, and buffering of water is therefore necessary
Benzocain [35] Benzoak®	Anesthetic and sedative Lower safety margin at high temperatures
Isoeugenol [35] Aqui-S®	Sedation for transport, handling, sea lice counting, or vaccination
Metomidate [41] Aquacalm®	Short-acting hypnotic Poor analgesic effect Little cortisol rise or cardiovascular effect Providing unconsciousness
Some commonly used anesthesia substances used for fish and their characteristics