Comparison of the Behavioral Consequences and Recovery Patterns of Largemouth Bass Exposed to MS‐222 or Electrosedation

Abstract

Fish are commonly sedated to render them immobile and thus easier to handle for research, veterinary, and aquaculture practices. Since sedation itself imposes a significant challenge on the targeted fish, the selection of sedation methods that minimize physiological and behavioral disturbance and recovery time is essential. Two popular sedation methods include the chemical tricaine methanesulfonate (MS‐222) and electrosedation. Although many studies have already investigated the physiological consequences of these methods, there is limited research examining the latent behavioral effects on fish. Using Largemouth Bass Micropterus salmoides as a model species, we compared the postsedation behaviors of fish that were sedated with either MS‐222 or electrosedation to those of a control group exposed to the same handling protocol. Immediately after sedation, fish exposed to either treatment demonstrated lower reflex scores than the control group. Time to resume regular ventilation did not differ between chemically sedated and electrosedated fish; however, electrosedated fish regained equilibrium faster (mean ± SE = 154 ± 20 s) than fish that were exposed to MS‐222 (264 ± 30 s). Locomotor activity and swimming performance were assessed at 5‐, 30‐, or 60‐min intervals, beginning after individuals had recovered from sedation sufficiently to regain equilibrium. For all postsedation intervals, locomotor activity was two times greater in the electrosedated group than in the control and MS‐222 groups. Other behavioral measures (refuge emergence time, activity level, and flight initiation distance) and swimming performance did not differ at 5, 30, or 60 min postrecovery for any of the treatment groups. Our results indicate that while both chemical and electrical sedation methods result in impairment (i.e., sedation) immediately after treatment, these behavioral effects do not persist beyond 5 min postrecovery, and the two methods have similar impacts on Largemouth Bass. However, we caution that these results cannot be extrapolated to other fish species without further study. Received September 27, 2016; accepted January 17, 2017 Published online April 3, 2017

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

“…However, Largemouth Bass that were exposed to FHGs and the PES had significantly lower opercular rates than those in the control treatment during simulated surgery ( Figure 2B); after treatment, their opercular rates increased toward the rate observed in the control group. Similar to the findings of Trushenski et al (2012b) and Prystay et al (2017), suppressed opercular rates associated with electrosedation were relatively shortlived once the fish were removed from sedation and their nervous system was able to recover.…”

“…() and Prystay et al. (), suppressed opercular rates associated with electrosedation were relatively short‐lived once the fish were removed from sedation and their nervous system was able to recover.…”

Best practices for non‐lethal blood sampling of fish via the caudal vasculature

“…Finally, long recovery durations associated with the use of many sedation agents (Trushenski et al, 2013) can be a significant issue for the live release of fish back into the wild. Any lingering effects of the sedation agent may contribute to alterations in natural behaviour (Losey & Hugie, 1994;Mettam et al, 2011;Prystay et al, 2017) or lead to postrelease predation (reviewed in Raby et al, 2014). Lingering effects would be suboptimal for studies in which post-release behaviour is monitored (i.e., telemetry studies; see Brownscombe et al, 2019) g., Chatakondi & Kelly, 2019;Nguyen et al, 2018;Rucinque et al, 2018;Trushenski et al, 2017).…”

“…Appropriately, many anaesthetics have strict legal requirements on their use and disposal (reviewed in Trushenski et al ., 2013), meaning using anaesthetics in remote environments and field applications is difficult given the numerous legal and logistical challenges of chemical anaesthetics. Chemical anaesthetics in field settings are not recommended and, as an alternative, the use of low‐voltage electricity is suggested [either as electric gloves (Abrams et al ., 2018) or as a portable electrosedation system unit (Prystay et al ., 2017)]. Low‐voltage electricity has been proposed as an anaesthetic to aid in fish restraint because of relatively short recovery times after exposure ( i.e ., seconds; Vandergoot et al ., 2011; Trushenski & Bowker, 2012; Ward et al ., 2017; Abrams et al ., 2018; Reid et al ., 2019).…”

Comparative Behavior of Wild Bluegill Captured Inside and Outside of a Long‐Standing Aquatic Protected Area

“…The stimulus device consisted of a long plastic rod that was tipped with a novel object (a brightly colored orange and yellow fishing float). This float was comparable in size and color to those that were used in prior works (a simple orange ball) as a standardized means of conducting an FID trial (see Kim et al 2009;Elvidge et al 2013;Cooke et al 2017;Prystay et al 2017). This is a well-established methodological approach for conducting an FID trial.…”