J.R. Sargent, L.A. McEvoy, A. Estevez, J.G. Bell
In the last two decades, research on the dietary requirements of marine fish larvae has evolved from considerations of optimal dietary levels of n-3 HUFA to considerations of optimal dietary ratios of the two principal HUFAs, 22:6n-3 (DHA) and 20:5n-3 (EPA), and more recently to considerations of optimal dietary levels and ratios of all three dietary essential fatty acids, DHA, EPA and arachidonic acid (AA). Our present state of understanding of this area will be reviewed and related to recent findings in an equally important but less studied area, namely the apparent dietary requirements of marine fish larvae for phospholipids. The issue will then be addressed of how to relate desirable or optimal dietary levels of DHA, EPA and AA to desirable or optimal dietary levels of phospholipids and triacylglycerols, this to ensure desirable or optimal levels of both dietary essential fatty acids and dietary energy. Practical approaches to resolving this issue using live prey enrichment feeding strategies and currently available speciality lipids will be considered.
(NERC Unit of Aquatic Biochemistry, University of Stirling, Stirling FK9 4LA, UK)