Efficacy of AQUI‐S 20E as a Sedative for Handling and Cortisol Suppression in Pallid Sturgeon

Abstract

AbstractChallenges and regulations associated with handling fish during fisheries management activities have increased efforts to achieve U.S. Food and Drug Administration approval for an immediate‐release sedative for fish. The objectives of this study were to (1) identify the target concentration of AQUI‐S 20E for sedation of Pallid Sturgeon Scaphirhynchus albus to a handleable state followed by rapid recovery, and (2) to compare sedation and recovery times and cortisol stress response in sturgeon treated with the identified target concentration to those treated with MS‐222. Juvenile Pallid Sturgeon from two size‐classes were exposed to five concentrations of AQUI‐S 20E: 70, 153, 364, 598, and 779 mg/L of water. The target concentrations of AQUI‐S 20E for optimal sedation (<3 min) and recovery times (<5 min) identified for Pallid Sturgeon were 476 mg/L for small and 537 mg/L for large size‐classes. Cortisol secretion in relation to presedation plasma cortisol levels was suppressed at the AQUI‐S 20E target concentration of 500 mg/L but was not for MS‐222. These data suggest an AQUI‐S 20E concentration of 500 mg/L is efficacious while blocking the cortisol stress response for sedation to a handleable state in Pallid Sturgeon.Received February 6, 2013; accepted July 24, 2013