Assessing the efficacy of tricaine methanesulfonate (MS-222) on sedation of Nile tilapia (Oreochromis niloticus) fingerlings during transportation

Abstract

The efficacy of the anaesthetic agent tricaine methanesulfonate (MS-222) was evaluated in the Nile tilapia (Oreochromis niloticus) fingerlings during transportation. MS 222 is an anaesthetic agent that is approved for use in the United States, Canada, the United Kingdom and other European countries. MS-222 is used to suppress the central and peripheral nervous systems of fish to immobilize them for transportation and experimental purposes to avoid mortality and injury. In the present study, juvenile Nile tilapia of length 7-10 cm were subjected to different concentrations (0-20 mg/L and 100-500 mg/L) of MS-222. O. niloticus subjected to 0 and 20 mg/L (trial experiment) of MS-222 in this study did not reach stage IV anaesthesia (Total loss of equilibrium) within 1 hour, indicating that none of the fish exposed to these concentrations of MS-222 was induced. At 20 mg/L, the buffered MS-222 slowly rendered the fingerlings physiologically inactive (calm) for a prolonged time (> 1 h) and the fish were almost instantly reactivated in untreated water. Sedation time for the fingerlings decreased significantly (p