Low Stress Response Exhibited by Juvenile Yellowtail Kingfish (Seriola Ialandi Valenciennes) exposed to Hypercapnic Conditions Associated with Transpotation

Low stress response exhibited by juvenile yellowtail kingfish exposed to hypercapnic conditions associated with transportation was studied. The rapid increase in carbon dioxide (CO sub(2)) concentration and concomitant decrease in pH during transport closely mimicked that observed in commercial transports of yellowtail kingfish from the National Institute of Water and Atmospheric Research (NIWA) hatchery to on-growing operations. The anesthetic effects of hypercapnia on juvenile kingfish were observed when the degassing rate was reduced. The maximum CO sub(2) concentration was estimated to be approximately 75 mg L super(-1), which corresponded to a relatively severe hypercapnia for marine species. Muscle pH increased during transport in transported fish, indicating there was no acidosis occurring in the muscles.