Comparing Immobilization, Recovery, and Stress Indicators Associated with Electric Fish Handling Gloves and a Portable Electrosedation System

Abstract Fish sedation facilitates safer handling of fish during scientific research or fisheries assessment practices, thus limiting risk of injury to fish and reducing stress responses. In recent years, there has been growing interest in using electricity to sedate fish; two methods include (1) lower‐voltage, non‐pulsed‐ DC fish handling gloves ( FHG s) that tend to only sedate fish while the gloves are touching the animal; and (2) a comparatively high‐voltage, pulsed‐ DC Portable Electrosedation System ( PES ) that leads to galvanonarcosis. This study compared the physiological consequences of exposure to FHG s and PES in teleost fish. Bluegills Lepomis macrochirus and Largemouth Bass Micropterus salmoides were exposed to FHG s, PES , or a handling control for a 3‐min simulated surgery. Blood was then sampled at 0.5 and 4.5 h postexposure and was analyzed for blood glucose, blood lactate, and plasma cortisol concentrations. Opercular rates were monitored during surgery, at 2 min postsurgery, and 0.5 h postsurgery. At 24 h postsurgery, time to exhaustion (via a standardized swimming chase protocol) was assessed. Fish exposed to FHG s tended to exhibit lower opercular rates than fish that were sedated with the PES during simulated surgery. Cortisol levels of Largemouth Bass treated with FHG s were higher than those of fish sedated with the PES . Glucose levels recorded for Bluegills at 4.5 h postsurgery were higher with FHG s than with the PES . In both species, lactate was lower for fish treated with FHG s than for those treated with the PES . At 24 h posttreatment, Bluegills sedated with FHG s exhibited a longer time to exhaustion than those subjected to the PES , whereas Largemouth Bass sedated with the PES exhibited a longer time to exhaustion than those sedated with FHG s. Physiological responses to treatments were inconsistent between species. Further investigation to determine the optimal electrosedation method is required.