DIET-INDUCED CHANGES IN LIPID AND FATTY-ACID COMPOSITION OF ARTEMIA-SALINA

The influence of diet on lipid and fatty acid composition of the brine shrimp Artemia salina nauplii was investigated. Various diets with di fferent lipid composition and fatty acid profiles were fed to nauplii for 2 weeks. The lipid composition of microalgal diets, Isochrysis gal bana, Phaeodactylum tricornutum and Nannochloropsis oculata and baker' s yeast was analyzed. Newly hatched nauplii were examined before the f eeding experiment. It was shown that Artemia was able to incorporate a nd selectively concentrate some dietary lipids. Depot lipids were more sensitive to changes in the dietary lipid composition than the main s tructural lipids, polar lipids and sterols. Variations in the content of the lipid classes correlated with stage of development of the anima l. The fatty acid composition of the animal varied with that of diet. The concentrations of saturated fatty acids were apparently supported in the nauplii by biosynthesis de novo. The acid 16:1(n-7) originated from the food. The concentration range of n-6 polyunsaturated fatty ac ids (PUFAs) remained constant through the accumulation from the diet. The proportion of n-3 PUFAs varied with their level in the diet. The d ynamics of alteration of 20:5(n-3) content in Artemia fed on Isochrysi s, which is poor in this acid, suggested a limited capacity for elonga tion and desaturation of 18:3(n-3) to 20:5(n-3). None of the diets pro vided dietary input of 22:6(n-3). (C) 1998 Elsevier Science Inc. All r ights reserved.