Comparison between Eicosapentaenoic and Docosahexaenoic Acids in Terms of Essential Fatty Acid Efficiency in Juvenile Striped Jack Pseudocaranx dentex

Abstract

A feeding experiment was conducted to compare the essential fatty acid (EFA) efficiency between eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for juvenile striped jack. The fish fed an EFA-deficient diet began to show a high mortality together with poor appetite and swimming activity around 10 days after feeding, although there was no marked external deficiency sign. The growth and feed efficiency were improved by addition of EPA and DHA to the diet. However, the supplementation of EPA alone was not effective in preventing high mortality or improving the growth rate of the fish. A replacement of one half of EPA with DHA effectively improved the growth and feed efficiency as well as reducing mortality. On the other hand, the growth and feed efficiency were highest in the fish fed the diet containing DHA and the mortality due to the EFA-deficiency was almost completely prevented by DHA alone. The fatty acid analyses of whole body lipids have shown that EPA is converted to 22: 5n-3, but not to DHA, and that DHA is not retroconverted to 22: 5n-3 and EPA. © 1989, The Japanese Society of Fisheries Science. All rights reserved.