The stability of docosahexaenoic acid in two Artemia species following enrichment and subsequent starvation

Two Artemia species( Artemia franciscana, GSL strain and a population from Artemia sinica, ARC No. 1188) were enriched with two different emulsions containing high levels of docosahexaenoic acid (DHA) (23 and 44% of total fatty acids, respectively) in filtered seawater (30 ppt) at 28 degrees C. After enrichment nauplii were starved for 72 h at three different temperatures (6.1, 12.2 and 22 degrees C). Following enrichment the DHA content and DHA/EPA ratio reached a maximum 41.2 and 42.8 mg g(-1) dry weight and 1.88 and 2.09 in A. franciscana and A. sinica, respectively. During starvation at 12.2 degrees C the DHA content in A. franciscana decreased steadily throughout the starvation period towards 1.11-2.89 mg g(-1) dry weight (DHA/EPA ratio of 0.4) after 72 h, whereas in A. sinica the DHA content was > 20 mg g(-1) dry weight (DHA/EPA ratio of 1.7-2). A quantitative reduction of DHA in A. sinica was observed only during the first 24 h of the starvation period. The degradation rate of DHA in A. franciscana increased with rising temperature (22 degrees C) and decreased at the lowest temperature (6.1 degrees C). This was not the case for A. sinica, during starvation at different temperatures the DHA level in A. sinica remained at a relatively high and constant level. (C) 1997 Elsevier Science B.V.