Effects of short and long exposure to the anesthetic 2-phenoxyethanol mixed with ethyl alcohol on common carp (Cyprinus carpio L., 1758) fingerlings

Common carp fingerlings (Cyprinus carpio L., 1758; 7.70 +/- 0.4 g; 8.38 +/- 0.8 cm) were exposed to different concentrations of 2-phenoxyethanol mixed with pure ethyl alcohol (1:1) in an open system for a short (until induction of anesthesia) or long (48 h) duration, then transferred to clean water and maintained for 96 h. The effects of the anesthetic on induction time, anesthetic stage, opercular rate, recovery time, recovery stage, and mortality were observed. For short exposure, the most suitable concentrations were 0.8, 1, and 1.2 ml/l. For long exposure, transportation, and deep sedation and partial loss of equilibrium (anesthetic stages 2 and 3), the preferable concentrations were 0.4 and 0.6 ml/l. No mortality was observed at any concentration.