Chemical and Electrical Approaches to Sedation of Hybrid Striped Bass: Induction, Recovery, and Physiological Responses to Sedation

Abstract

Currently, in the United States, there are few sedatives available to fisheries professionals that are safe, effective, and practical. Chemical sedatives, including tricaine methanesulfonate (MS‐222), carbon dioxide (CO2), benzocaine, and eugenol may be used to sedate fish, though none of these compounds are currently approved by the U.S. Food and Drug Administration as immediate‐release fish sedatives. Another option is the use of electricity to temporarily immobilize fish. Few studies have assessed the efficacy of these options for immediate‐release sedation in side‐by‐side comparisons. We evaluated the use of MS‐222 (150 mg/L), CO2 (∼400 mg/L), benzocaine (150 mg/L), eugenol (60 mg/L), and a commercially available electrosedation unit (30 Hz pulsed DC, 60 V, 25% duty cycle, 3‐s exposures) to induce hybrid striped bass (white bass Morone chrysops × striped bass M. saxatilis; 510 ± 12 g [mean ± SE]) to stage IV anesthesia or sedation. Induction times were shortest (0.2 ± 0.1 min) when electrosedation was used and longest (2.5 ± 0.1 min) when CO2 was used; the induction times for the other chemical sedatives varied (<2 min). Recovery times were longest for eugenol (5.2 ± 0.4 min postinduction) and benzocaine (4.0 ± 0.4 min); however, the difference in recovery time between these two treatments was not significant or between recovery times for benzocaine and the remaining sedatives (∼3–4 min). Physiological responses varied but were consistent with the generalized stress response. Circulating levels of cortisol, glucose, and lactate increased after sedation, and though response magnitude and duration varied somewhat among these variables, these changes were resolved within 6 h. Changes in plasma osmolality and hematocrit were less overt and varied less among the sedatives. Electrosedation may be a suitable tool for quickly sedating hybrid striped bass; however, all of the sedatives evaluated were effective at the doses and strengths used and some may be better suited to certain applications than to others.

Linking fatty acids in the diet and tissues to quality of larval southern flounder (Paralichthys lethostigma)

“…Electroanesthesia can be used in fresh water, but it requires a significant initial investment for equipment, which could be prohibitive for many fisheries professionals (Trushenski et al, 2012a).…”

Effect of anesthetic, tag size, and surgeon experience on postsurgical recovering after implantation of electronic tags in a neotropical fish: Prochilodus lineatus (Valenciennes, 1837) (Characiformes: Prochilodontidae)

“…Following the initial procedures, biometric measures were taken (less than 3 min) and fish were deployed at the surgical area where they were immobilized using eugenol (0.035 ml/L) or electroanesthesia (0-30 V). Electroanesthesia is not considered a true anesthetic because it does not affect the ability of fish to perceive pain and only causes their immobilization (Liedtke & Rub, 2012;Trushenski et al, 2012). Nevertheless the term "anesthesia" will be used for both treatments here.…”

“…To alleviate or suppress such complications, several studies have investigated the factors associated with the adverse effects from surgical tagging, including type of anesthetic used for anesthesia and immobilization (King et al, 2005;Carter, 2011;Vandergoot et al, 2011;Javahery et al, 2012;Trushenski et al, 2012;Kanani, 2013), transmitter type and size and its relationship with fish size (Penne et al, 2007;Thorstad et al, 2009), surgeon experience (Smith et al, 2009;Brown et al, 2011;Cooke et al, 2011b), as well as sterilization of transmitters and surgical instruments, attachment methods, incision type and location, and suture material and pattern (Cooke et al, 2003;Wagner et al, 2011;Brown et al, 2013).…”

Effects of Two Anesthetics on Survival of Juvenile Culter mongolicus during a Simulated Transport Experiment

“…Consequently, anesthetics generally reduce fish mortality during transportation (Estudillo and Duray 2003;Pramod et al 2010). Somewhat paradoxically, anesthetics have also been shown to cause an acute stress response immediately after sedation (Trushenski et al 2012;Zahl et al 2012). During this acute response, the stress hormone cortisol may increase, leading to increased levels of glucose and lactate in the blood after sedation.…”