The effects of exposure duration to optimal concentration of 2‐phenoxyethanol on primary and secondary stress responses in kutum ( R utilus frisii kutum )

Summary The goal of this study was to assess the anaesthetic induction and recovery time in kutum ( Rutilus frisii kutum ) after exposure to various concentrations (0.1, 0.3, 0.5, 0.7 and 0.9 ml/l) of 2‐ PE as an anaesthetic, as well as the effects of optimal concentration (0.7 ml/l) of 2‐ PE in relation to different exposure time (3, 10, 15 min) on some haematological and serum biochemical indices in this species. Moreover, the effects of 0.7 ml/l on blood parameters were assessed 24 h after the longest exposure. Significant increase was determined in Hb, MCH and MCHC after 10‐min exposure to 2‐ PE (p < 0.05). Moreover, Hct, Hb and RBC levels increased significantly after 15 min‐exposure to 2‐ PE (p < 0.05). There were no prominent changes in WBC and MCV . The plasma concentrations of glucose, cholesterol and cortisol increased significantly after 10‐ and 15‐min exposure to 2‐ PE (p < 0.05) compared with the control group and all other exposure times. The activity of ALT and AST were significantly increased after 10‐ and 15‐min exposure respectively (p < 0.05). In this study, it appears that anaesthetizing kutum with 2‐ PE at 0.7 ml/l for 3 min had no effect on the stress markers.