Fatty acid changes in
enriched and subsequently starved Artemia franciscana nauplii
enriched with different essential fatty acids
K.
Han, I. Geurden, P. Sorgeloos-2001
Aquaculture, 199(1-2): 93-105
Abstract:
The present study aims to evaluate differences in the
incorporation efficiency and the possible interactions among highly
unsaturated fatty acids (HUFA) during enrichment and starvation of Artemia
nauplii. Artemia franciscana nauplii were enriched with emulsions
containing docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid
(EPA, 20:5n-3) or arachidonic acid (AA, 20:4n-6) as sole HUFA
or with different ratios of these HUFA during 24 h at 28°C and subsequently
starved for 24 h at the same temperature.
The comparison of HUFA incorporation efficiency when
supplying the three HUFA separately showed a less efficient enrichment of
DHA as compared to AA or EPA. DHA incorporation was always accompanied by an
EPA increase, indicating the metabolic conversion of DHA to EPA by the
nauplii during the enrichment process. When offering the HUFA together, we
found no competitive interaction of EPA or of AA on DHA incorporation. Only
in the case of the 97% (% total fatty acids) n-3 HUFA emulsion, some
negative interference might have occurred between the HUFA, as it gave a
lower incorporation of 22:6n-3 and 20:5n-3 than the emulsions
with lower n-3 HUFA content.
During the subsequent starvation of EPA- or
DHA-enriched Artemia, relative EPA and DHA losses were similarly high
in both treatments. In contrast, the presence of DHA in naupliar lipids
increased the EPA retention, which might however be related to DHA
retroconversion.