Selected nutrient profiles in first larvae and postlarvae of American lobster (Homarus americanus)

Initiatives to enhance natural stock of lobster imply the production of high-quality postlarvae. The aim of this study was to evaluate the physiological condition of postlarvae produced under hatchery conditions by comparing the nutrient profiles of larvae stage I and postlarvae stage IV of American lobster (Homarus americanus) fed frozen adult Artemia with a mixture of dry commercial products. Body sterols, acetone mobile polar lipids and phospholipids levels were lower in stage IV than in stage I, while cholesterol was nearly 400 % higher in the former. The C20 mono-unsaturated acids and C22 n-3 decreased between stage I and IV in both neutral and polar lipids, while linoleic (18:2n-6 cis) and linolenic (18:3n-3) acids increased concomitantly. The levels of docosahexaenoic acid (DHA) in the polar fraction were twice lower in postlarvae compared to stage I larvae and almost completely depleted in the neutral fraction while eicosapentaenoic acid levels were reduced by nearly 30 % in the polar lipids and by over 70 % in the neutral lipids. Results suggested possible dietary phospholipids and DHA deficiencies that lead to the low levels observed in the postlarvae stage IV.