15 OCTOBER 1999
ASCORBIC ACID AND ALPHA-TOCOPHEROL LEVELS IN LARVAE OF ATLANTIC HALIBUT BEFORE AND AFTER EXOGENOUS FEEDING
I. Ronnestad, K. Hamre, O. Lie, R. Waagbo-1999
Journal of Fish Biology, 55(4): 720-731
Abstract:
Ascorbic acid (AA) and alpha-tocopherol (alpha-TOH) levels in whole Atlantic halibut larvae were constant during the yolk sac stage at 170 and 131 ng/individual, respectively. At hatching c. 80% of the AA and 97% of the alpha-TOH were contained within the yolk-sac compartment. With development, AA and alpha-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 alpha-TOH in the yolk at hatching had been transferred to the larval body. Transfer of alpha-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 micro g/g AA and 120 micro g/g alpha-TOH (dry weight). The AA content increased to 472 ng/individual within one week after first feeding, while it declined slightly in unfed larvae. In fed larvae the AA content reached c. 3500 ng/individual at 580 D PH. The alpha-TOH content increased only slightly in the first week of feeding (206 to 431 D PH), but then increased to > 800 ng/individual at 483 D PH.
(Institute of Nutrition, Directorate of Fisheries, P.O. Box 185, N-5804 Bergen, Norway, e-mail of R. Waagbo: rune.waagbo@nutr.fiskeridir.no; article No. jfbi.1999.1028, available online at http://www.idealibrary.com)