Comparative Study on Electric Fish Handling Gloves and Immersion Anesthesia for the Surgical Implantation of Transmitters in Brook Trout

Abstract

AbstractAlthough the use of electric fish handling gloves (EFHGs) has been advocated as a no‐residue alternative to chemical immobilization for field studies, the impact of their use on fish welfare remains uncertain for surgical procedures. The effects of EFHGs (10–16 mV), with and without local infiltration of lidocaine (6 mg/kg), on stress and muscle integrity after the surgical implantation of an intracoelomic transmitter in adult Brook Trout Salvelinus fontinalis were compared to the effects of two immersion anesthetics (buffered tricaine methanesulfonate at 60 mg/L and eugenol at 40 mg/L) using blood markers. Lower plane of anesthesia and inconsistent immobilization made surgeries with EFHGs more challenging to perform than surgeries conducted using immersion anesthesia. Plasma cortisol and lactate levels were significantly higher at 1–2 h postprocedure than at the end of the surgery (time 0) for all experimental groups (+210% and +121%, respectively), but no significant differences were detected for the magnitude of these increases between groups. Plasma creatine kinase concentrations significantly increased at 2 h postprocedure for the EFHG treatment groups (+206%), whereas they significantly decreased over the same period for the immersion anesthesia groups (−89%). Residues of lidocaine were not detected in fillets, suggesting the absence of significant systemic diffusion. This study suggests that the use of EFHGs for intracoelomic surgical procedures in Brook Trout induces higher disturbances to muscular physiology compared to immersion anesthesia. Differences in the level of stress, muscular anaerobic activity, or oxidative stress were not documented. Further research is needed to evaluate the analgesic properties of EFHGs and local infiltration with lidocaine.