| 麻醉阶段 Stages of anaesthesia | 行为特征 Behavioral characteristics |
| A0正常期 | 呼吸频率正常，对外界刺激反应迅速 Normal opercular open and close, react to extemal stimuli |
| A1轻度镇定期 | 呼吸频率降低，对外界刺激反应降低，身体平衡性较好 Decrease in opercular open and close rate, slightly loss of reactivity to extemal stimuli, equilibrium open normal |
| A2深度镇定期 | 呼吸频率有规律缓慢，对外界刺激反应弱，身体失去平衡 Slow but regular opercular rate, loss of reactivity to extemal stimuli except strong pressure, loss of equilibrium |
| A3中度麻醉期 | 吸呼频率微弱无规律，失去反应能力，不再持续游动 Slow opercular movements and irregular, complete loss of reactivity without continuously swimming |
| A4深度麻醉期 | 呼吸停止，鱼侧躺底部 Opercular movements cease, the fish lay on its side at the bottom |