I. Ronnestad, O. Lie, R. Waagbo-1997
Aquaculture, 157: 337-345
Abstract:
A single batch of Atlantic halibut larvae was reared in floating plastic enclosures, offered natural plankton collected from a lagoon and sampled regularly for measurements of vitamin B6. At hatching individual whole larvae contained 9.0 +/- 0.2 ng of vitamin B6, of which 95% was present in the yolk. At the onset of first feeding 50% of the vitamin B6 present in the yolk at hatching had been transferred to the larval body. There was a relatively constant weight specific content of vitamin B6 in the larval body from hatching until first feeding at 206 Day degrees post hatch (D°PH) at 3.5 +/- 0.3 micro g/g DW. During this period there was a net decline of 2.3 ng vitamin B6 per larvae. After onset of first feeding the vitamin B6 content in the larvae continued to decline and reached its lowest level at 300 D°PH with 5.0 ng/individual. With continued development the feeding larvae increased their content of vitamin B6. However, in weight specific terms the content of vitamin B6 in halibut larvae above a DW weight of 5 mg stabilized at 5.1 +/- 0.2 micro g/g DW, about the same value as the plankton feed offered. The data in this study represents vitamin B6 status in halibut larvae and planktonic prey in semi-intensive culture systems with a high outcome of metamorphosed larvae and may therefore serve as a basis for feed formulation in intensive farming of Atlantic halibut.
(Institute of Nutrition, Directorate of Fisheries, PO. Box. 185, Bergen N-5002 Norway)