Anaesthetic effect of eugenol at different concentrations and temperatures on blank tiger shrimp (Penaeus monodon)

The anaesthetic effects of eugenol on Penaeus monodon were investigated at the different eugenol concentrations (60, 110, 160 and 210 mg/L), water temperature (21, 26 and 31 degrees C), air exposure time (3, 6, 9 and 12 min) and body weight (2.62 +/- 0.27, 6.34 +/- 0.36 and 11.43 +/- 0.33 g). The anaesthesia and recovery time were recorded. The results showed that the anaesthesia time of the shrimp decreased with the increase in the eugenol concentration and water temperature, and the recovery time increased with the increase of the eugenol concentration and the decrease of water temperature. Under the same eugenol concentrations, the recovery time increased with the increase of air exposure time and body weight. Under the eugenol concentration range of 60-210 mg/L, the recovered rate was 100%. The results indicated that eugenol is a safe and efficient anaesthetic for P. monodon.