Efficacy of tricaine methanesulfonate (MS-222) as an anesthetic agent for short-term anesthesia in juvenile yellow perch (Perca flavescens)

Authors: ZHAI, S-W - Water Institute; YANG, S - Water Institute; ZHAO, H - Water Institute; JIANG, M - Water Institute; Shepherd, Brian; DENG, D-F - Water Institute

Submitted to: Israeli Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2018
Publication Date: 9/26/2018
Citation: Zhai, S., Yang, S., Zhao, H.H., Jiang, M., Shepherd, B.S., Deng, D. 2018. Efficacy of tricaine methanesulfonate (MS-222) as an anesthetic agent for short-term anesthesia in juvenile yellow perch (Perca flavescens). Israeli Journal of Aquaculture. 70(2018):1515-1525.

Interpretive Summary: Anesthetics are an integral part of farmed fish production and research as they allow fish to be handled easily during procedures that are known to induce a stress response, including transport, grading, sorting, tagging, artificial reproduction procedures, and surgery. It is well known that the responses to the same anesthetic can vary considerably within and among various species, and it is inappropriate to extrapolate optimal anesthetic concentrations between different species. For yellow perch, there are no published guidelines. To address this, we conducted studies in juvenile yellow perch to identify an optimal dose of the anesthetic tricaine methanesulfonate (MS-222) that enables rapid anesthesia and recovery for brief periods of time. We found that an immersion dose of 250 mg/L of MS-222, with an equivalent amount of sodium bicarbonate buffer (1:1), resulted in the most rapid anesthesia response and recovery times and lowered handling stress response in juvenile yellow perch. We also found that this response increased as the body weight of the fish increased, suggesting that as fish grow, care must be exercised when using this dose. These results give fish handlers an optimal combination for minimizing handling disturbance in juvenile yellow perch which could improve the welfare of juvenile perch subjected to frequent handling events in the research and commercial production settings.

Technical Abstract: The aim of the present experiments were to determine an optimal dose of tricaine methansulfonate (MS-222) that provided rapid (brief) anesthesia and enabled full recovery in juvenile yellow perch (Perca flavescens). To assess anesthesia efficacy, we evaluated the effects of various concentrations of MS-222 on anesthetic induction time, anesthesia recovery, effects on the secondary stress response (blood glucose and hematocrit), and how these parameters varied with the use of bicarbonate buffer and body size in juvenile yellow perch. Yellow perch (7.0 g) exposed to increasing concentrations of unbuffered MS-222 (100, 150, 200, 250 and 300 mg/L) showed significant (P < 0.05) decreased anesthetic induction and increased recovery time with increasing MS-222 dose. Specifically, the 250 mg/L MS-222 dose showed the shortest anesthetic induction and recovery times among those tested. Using slightly larger fish (11.0 g), and the same unbuffered MS-222 doses, blood glucose and hematocrit levels were significantly (P < 0.05) lower in juvenile yellow perch exposed to the 250 mg/L MS-222 dose (unbuffered), than the other MS-222 doses tested. Treatment of juvenile yellow perch (9.7 g) with the 250 mg/L MS-222 dose, and various bicarbonate buffer ratios (w/w: 1:0.5, 1:1 and 1:2), showed significantly (P < 0.05) reduced anesthesia induction and recovery times using the 1:1 MS-222 to buffer ratio, among the combinations tested. To assess the effects of body size, juvenile yellow perch (6.4 ± 1.1, 12.7 ± 2.1 and 19.2 ± 2 g) were exposed to the optimal MS-222:buffer ratio (1:1), and anesthesia induction time and recovery time were measured. Anesthesia induction and recovery times were significantly (P < 0.05) increased with body size of the yellow perch used. These results suggest that a brief exposure (< 3 min) to a 250 mg/L MS-222:sodium bircarbonate (w/w) dose appears to be an optimal combination for minimizing handling disturbance in juvenile yellow perch (> 20 g) and could improve welfare of juvenile perch which are subjected to frequent handling (sorting) events (stressors) in the research and commercial production settings.