HIGHLY UNSATURATED FATTY-ACID REQUIREMENTS OF PENAEUS-MONODON POSTLARVAE - AN EXPERIMENTAL APPROACH BASED ON ARTEMIA ENRICHMENT

Penaeus monodon postlarvae (PL-5 to PL-15) were fed 5 different diets consisting of enriched Artemia nauplii with a specific n-3 HUFA conten t. Although the postlarvae grew well on an Artemia diet with low HUFA- content, the ability of PL-10 to endure osmotic stress remained low. F eeding Artemia enriched with medium levels of n-3 HUFA (SIGMA n-3 HUFA = 12.5 5 mg/g DW) for 5 days considerably enhanced the resistance of PL-10 to osmotic stress and their survival recorded 5 days later. Howe ver, very high dietary levels of n-3 HUFA (31.2 mg/g DW) did not have any growth-promoting effect, thus suggesting that an excessive supply of n-3 may not be beneficial to the shrimp. Our data demonstrate that subjecting postlarvae to reduced salinities for 2 h provides a simple and rapid test for assaying the physiological condition of postlarval shrimp.