The effects of eugenol anaesthesia on the behavioural and cardiovascular responses of doctor fish (Garra rufa) (2.0 ± 0.2 g mean weight) were studied. Two experiments were performed. In experiment 1, G. rufa was exposed to eugenol baths at different concentrations (0, 12.5, 25, 50, 75, 100 and 150 μl/L) to record induction and recovery times and fish behavioural responses. Experiment 2 was performed to evaluate the effects of different eugenol concentrations (50, 100 and 150 μl/L) on the electrocardiographic parameters of anaesthetized fish. Induction and recovery times were recorded for each fish separately, and 10 fish were used per eugenol concentration. During the induction stage, video recordings were taken to evaluate fish behaviour. Thereafter, electrocardiographic (ECG) records were taken with the help of electrodes attached to the anaesthetized fish. A strong relationship between eugenol concentrations and induced anaesthesia was verified (R² = 0.8583), but this relationship decreased slightly during recovery time (R² = 0.6481). Distance movement, movement duration, swimming speed (velocity) and mobility significantly decreased with an increase in eugenol concentration. ECG results indicated that G. rufa had higher heart rates when anaesthetized with a high concentration of eugenol than with a low concentration (150 μl/L, 94.4 ± 7.3 beats/min; 50 μl/L, 69.0 ± 3.7 beats/min). The QT interval was significantly higher for G. rufa anaesthetized with 100 and 150 μl/L eugenol concentrations. In conclusion, 25 and 50 μl/L eugenol concentrations can be used for general aquaculture procedures in G. rufa, and 75 μl/L is suitable for rapid blood sampling.

中文翻译：

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丁香酚对医生鱼 (Garra rufa) 的麻醉效果：行为和心血管反应

研究了丁香酚麻醉对医生鱼 ( Garra rufa )（平均体重 2.0 ± 0.2 g）的行为和心血管反应的影响。进行了两个实验。在实验 1 中，G. rufa暴露于不同浓度（0、12.5、25、50、75、100 和 150 μl/L）的丁香酚浴中，以记录诱导和恢复时间以及鱼类行为反应。进行实验2以评估不同丁香酚浓度（50、100和150μl/L）对麻醉鱼心电图参数的影响。分别记录每条鱼的诱导和恢复时间，每个丁香酚浓度使用 10 条鱼。在诱导阶段，拍摄录像以评估鱼的行为。此后，在连接到麻醉鱼的电极的帮助下记录心电图 (ECG)。验证了丁香酚浓度与诱导麻醉之间的密切关系 ( R ² = 0.8583)，但这种关系在恢复期间略有下降 ( R ²  = 0.6481)。随着丁香酚浓度的增加，距离运动、运动持续时间、游泳速度（速度）和活动能力显着降低。心电图结果表明，与低浓度（150 μl/L，94.4 ± 7.3 次/分钟；50 μl/L，69.0 ± 3.7 次/分钟）相比，用高浓度丁香酚麻醉时， G. rufa的心率更高。对于用 100 和 150 μl/L 丁香酚浓度麻醉的G. rufa，QT 间期明显更高。总之，25 和 50 μl/L 的丁香酚浓度可用于普通红花养殖操作， 75 μl/L 适合快速采血。