Variation in fatty acid composition of Artemia salina nauplii enriched with microalgae and baker's yeast for use in larviculture

The high content of the essential fatty acids in some microalgae and baker's yeast has made them excellent diets for boosting the fatty acid content of livefood Artemia. The influences of baker's yeast (Saccharomyces cerevisiae) and three microalgae, viz., Chlorella salina, Chaetoceros calcitrans, and Nannochloropsis salina, were tested as diet components in marine livefeed brine shrimp Artemia salina nauplii to improve the polyunsaturated fatty acid (PUFA) composition. Artemia nauplii submerged in these diets for four different enrichment intervals (3, 6, 8, and 24 h) were found to incorporate essential fatty acids, and the percentage composition of different fatty acids was measured in the enriched Artemia nauplii and enrichment diets. N. salina produced higher levels of arachidonic acid (AA, 20:4n6, 9.50%), eicosapentaenoic acid (EPA, 20:5n3, 25.80%), and docosahexaenoic acid (DHA, 22:6n3, 4.18%) as compared to other diets. The total PUFA content of the enriched Artemia by N. salina increased by 56.50% with enrichment periods up to 8 h, followed by a significant reduction in the final 24 h. N. salina yielded Artemia nauplii with considerable EPA (8.05%), AA (14.15%), and DHA (1.85%) after 8 h of enrichment, which are significantly higher levels than in nauplii fed with the other three diets (p = 0.05). The DHA/EPA values in Artemia enriched for 6 h by N. salina and C. calcitrans were found to be, respectively, 88.46 and 25% higher than freshly hatched Artemia. Artemia enriched by C. salina and baker's yeast exhibited a reduction in PUFA content even at 6 h of enrichment. Significant relative decreases in DHA, EPA, and total PUFA in Artemia enriched with all of the diets were apparent, with a corresponding increase in the total saturated fatty acid content (26.95 +/- 9.75%) in the final stages (24 h) of enrichment (p = 0.05).