Salinity Has Limited Influence on Sedation of Sunshine Bass with AQUI-S 20E (10% Eugenol)

Abstract

We evaluated sedation and recovery of juvenile sunshine bass (male Striped Bass Morone saxatilis × female White Bass M. chrysops) exposed to AQUI-S 20E (10% eugenol; 60 mg/L) in freshwater or increasingly brackish salinities (nominal salinities of 0, 5, 10, 15, 20, and 25 g/L). Induction and recovery times were significantly affected by salinity, but the magnitude of the effects was relatively small. Induction was fastest (0.90 min) among fish tested at 25 g/L salinity and slowest (1.07 min) among those tested at 0 g/L salinity, but this was the only significant difference observed in induction times between treatments. Recovery was also faster among fish that were tested at higher salinities and slower among fish that were tested at lower salinities (range = 2.63–3.91 min), but significant differences were not noted for each pairwise comparison. Most fish (65%) exhibited slight agitation and gasping or piping at the surface during sedation, but these behaviors were less common among fish held at the highest salinities. Almost all fish (93%) behaved normally during recovery. Minor differences in timing aside, our results demonstrate that salinities ranging from 0 to 25 g/L have little practical influence on the effectiveness of AQUI-S 20E as a sedative for sunshine bass.

Received July 15, 2016; accepted October 27, 2016 Published online February 21, 2017

ACKNOWLEDGMENTS

We thank Andrew Ciuris for his assistance with data collection. All testing procedures were conducted in accordance with Southern Illinois University Carbondale’s Institutional Animal Care and Use Committee standards and in compliance with Animal Care and Use Protocol Number 13-050.