Impact of inducing general anesthesia with Propiscin (etomidate) on the physiology and health of European perch (Perca fluviatilis L.)

The aim of the study was to describe the course and timing of the different stages of anesthesia induced with Propiscin (etomidate) on juvenile European perch (experiment I) and to describe the effect of immersing specimens of this species had on selected hematological and biochemical parameters (experiment II). The study was conducted on material with body weights (BW) of 162.98 (experiment I) and 171.60 g (experiment II). In experiment I, general anesthesia was induced with two different anesthetic concentrations (1 or 2 ml l−1; anesthesia time 10 min). In experiment II, blood was drawn for hematological and biochemical analyses from the fish that had been exposed to anesthetic immersion baths with two different concentrations of Propiscin (1 and 2 ml l−1) and for different exposure times (3 and 10 min). Blood samples were collected immediately following immersion (0 h) and 24 h later (24 h). Specimens that were immersed at the higher concentration of anesthetic achieved subsequent stages of general anesthesia two times faster (P ≤ 0.05). However, during recovery, some statistically significant differences were observed, but these lasted only until stage I was achieved. Among the hematological parameters (0 h), significant differences were observed in hematocrit (HCT) and mean corpuscular volume (MCV), while among the biochemical determinations (0 h), statistically significant differences were noted in the concentrations of glucose, calcium, lactate, and ammonia. After 24 h, the levels of these parameters in all fish groups returned to initial values. The hematological and biochemical tests conducted permit concluding that the anesthetic tested, at the concentrations (1 and 2 ml l−1) and the exposure times of up to 10 min at which it was tested, is safe and can be used successfully to induce general anesthesia in perch.