The effect of triploidy on the efficacy and physiological response to anesthesia with MS 222 and isoeugenol in Atlantic salmon post-smolts

Sterile triploid fish are increasingly being used in salmon aquaculture and fisheries. For production, welfare, and experimental reasons, it is important to understand the efficacy of anesthetics and the physiological response to anesthesia in triploid fish. The efficacy (time to anesthesia and recovery) of 30, 40, 50, and 80 mg Finquel® (MS 222) L−1 and 12.5, 20, and 30 mg (active ingredient) Aqui-S® (isoeugenol) L−1 and the acute hematocrit and plasma (cortisol, glucose, osmolality, lactate) response to 30, 50, and 80 mg Finquel® L−1 and 12.5 mg Aqui-S® L−1 was therefore measured in diploid and triploid post-smolt Atlantic salmon, Salmo salar. Ploidy had no effect on the efficacy of Finquel® or Aqui-S®. Although triploidy had significant transient effects on all physiological parameters measured following anesthesia, the differences were small and likely biologically negligible with respect to the ability of Atlantic salmon to recover from the range of anesthetics tested.