Meeting Abstract
California Yellowtail, Seriola dorsalis, are highly migratory yet few studies have looked at the impacts of hatchery rearing on muscle characteristics and swim capacity of these fish. Glycolytic (lactate dehydrogenase, LDH, and pyruvate kinase, PK) and oxidative (citrate synthase, CS) enzyme activities in juvenile wild caught and age matched hatchery-spawned yellowtail were compared at capture and after an eight-month period in standard aquaculture tanks. Wild yellowtail had a lower standard metabolic rate and higher aerobic scope at capture, but no difference in muscle CS activity. Hatchery-spawned fish had higher PK and LDH activities than wild caught fish upon capture, but most differences in glycolytic activities seen initially dissipated in captivity. Only PK activity remained higher in the white muscle of hatchery-spawned fish after 8 months. Following the hatchery rearing period, wild caught yellowtail had 15% lower CS activity in both white and red muscle than hatchery-spawned fish, indicating a relatively lower maximum aerobic capacity in the muscle. However, the reduction in CS was fairly modest considering an assumed substantial loss of daily activity in the hatchery setting compared to the wild. Overall, there was little difference in these biochemical indicators of muscle metabolism in hatchery reared versus wild caught yellowtail.
