Research on n-3 highly unsaturated fatty acids (n-3 HUFA), such as eicosapentaenoic acid (EPA) and especially docosahexaenoic acid (DHA), demonstrated that they play a key role for the normal growth, survival, pigmentation, stress and disease resistance of many species of marine finfish (Watanabe, 1993; Rainuzzo et al., 1994).

M ore than 95% of the marketed cysts belong to the species Artemia franciscana. Contrary to other prey organisms, like rotifers, A. franciscana cannot obtain high DHA/EPA ratio after enrichment and it degrades DHA during starvation following enrichment (Dhert et al., 1993; Danielsen et al., 1995). Recent studies (Evjemo et ai., 1995) suggested that DHA metabolism may be species and/or strain dependent. The genus Artemia comprises many other bisexual species and parthenogenetic populations that are not used in aquaculture so far. In this paper we screen representatives of various bisexual and parthenogenetic Artemia populations, following the fate of DHA, EPA and n-3 highly unsaturated fatty acids (HUFA) after enrichment with an experimental emulsion containing high levels of DHA.