Comparative efficacy of four anesthetics on common carp Cyprinus carpio L

Anesthetics are often used to immobilise fishes in research. Many chemicals have been tested in anesthetisation of fishes and each chemical has its own merits and demerits. In the present study, four anesthetics namely, 2-phenoxyethanol, quinaldine, MS-222, and benzocaine were selected to test the efficiency in anesthetisation of common carp Cyprinus carpia. Results indicated that the induction time of the fish exposed in four anesthetic solutions significantly (P < 0.05) decreased with increasing concentration but recovery time was independent to concentration. The effective concentration which produced anesthesia within 3 minutes and allowed recovery within 5 minutes in common carp were 600 mm3/dm3 (2-phenoxyethanol), 6 mg/ dm3 {quinaldine), 50 mg/ dm3 (MS-222), and 50 mg/ dm3 (benzocaine). A brief comparison about the advantages and drawbacks of the four anesthetics are given in Tab. 4.