The efficacy and effect of repeated exposure to 2-phenoxyethanol, clove oil and tricaine methanesulphonate as anesthetic agents on juvenile Angelfish (Pterophyllum scalare)

• Three anesthetic agents were tested in juvenile Angelfish.
• The lowest effective dose was determinate for each anesthetic.
• Repeated exposures showed changes in the induction and recovery times.
• Clove oil could be the least noxious of them and economically affordable for this species.

The use of anesthetics in Angelfish (Pterophyllum scalare) has not been fully explored. The aim of this study is to determine the lowest effective dose (LED) of three anesthetics (2-phenoxyethanol, clove oil and tricaine methanesulphonate (MS-222)) and their effect after multiple exposures at 24 and 48 h. Each agent was tested on ten juvenile angelfish at four different doses. Considering the effect criteria of complete anesthetic induction time within 3 min and recovery time within 5 min, LEDs were established at 800 mg L− 1 for 2-phenoxyethanol, 100 mg L− 1 for clove oil and 140 mg L− 1 for MS-222. Different anesthesia and recovery times should be considered when repeated exposures during consecutive days are performed on juvenile angelfish.