Highly unsatured 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 content. Although the postlarvae grew well on an Artemia diet with low HUFA-content, the ability of PL-10 to endure osmotic stress remained low. Feeding Artemia enriched with medium levels of n-3 HUFA (sum n-3 HUFA =12,55mg/g DW) for 5 days considerably enhanced the resistance of PL-10 to osmotic stress and their survival recorded 5 days later. However, 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 2h provides a simple and rapid test for assaying the physiological condition of postlarval shrimp.