Ascorbic acid and α-tocopherol levels in larvae of Atlantic halibut before and after exogenous feeding |
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Authors: | I Rønnestad K Hamre Ø Lie R Waagbø ‡ |
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Institution: | Institute of Nutrition, Directorate of Fisheries, P.O. Box 185, N-5804 Bergen, Norway |
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Abstract: | Ascorbic acid (AA) and α-tocopherol (α-TOH) levels in whole Atlantic halibut larvae were constant during the yolk sac stage at 170 and 131 ng individual−1, respectively. At hatching c . 80% of the AA and 97% of the α-TOH were contained within the yolk-sac compartment. With development, AA and α-TOH levels in the yolk decreased, at different rates. At first feeding (at 200 day degrees post hatch, D°PH)>95% of AA but <30% of α-TOH in the yolk at hatching had been transferred to the larval body. Transfer of α-TOH was completed at 360 D°PH, when the yolk was completely absorbed. The plankton offered to the larvae at first feeding (chiefly Temora longicornis ) contained 756 μg g−1 AA and 120 μg g−1α-TOH (dry weight). The AA content increased to 472 ng individual−1 within one week after first feeding, while it declined slightly in unfed larvae. In fed larvae the AA content reached c . 3500 ng individual−1 at 580 D)PH. The α-TOH content increased only slightly in the first week of feeding (206 to 431 D°PH), but then increased to > 800 ng individual−1 at 483 D°PH. |
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Keywords: | ascorbic acid α-tocopherol Atlantic halibut Hippoglossus hippoglossus yolk-sac larvae copepods |
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