Fatty acid composition of the rotifer Brachionus plicatilis fed selected microalgae or yeast, alone or in combination with various oils. In：L.M. Chou et al. (ed.)

Abstract

The fatty acid composition of rotifers fed selected feeds was analyzed by gas chromatography to evaluate their dietary value and to select the most suitable enrichment method. The rotifers were fed selected microalgae or yeast either alone or in combination with various oils, namely, methyl esters of n-3 HUFA, cuttle fish liver oil or dry Selco. The fatty acid profiles of the rotifers suggested that there had been some transfer of specific fatty acids from the diets to the rotifers. Incorporation of eicosapentaenoic acid (EPA;20:5n3) occurred in most of the microalgae-fed rotifers, with Nannochloropsis giving the highest content of this fatty acid, followed by Chaetoceros, Imantonia, Tetraselmis, Isochrysis, Dunaliella, and Chlorella. Incorporation of docosahexaenoic acid (DHA; 22:6n3) occurred in Imantonia-, Isochrysis-and Nannochloropsis-fed rotifers. The absolute amount of EPA and DHA in all microalgae-fed rotifers was less than 1.0 mg/g wet weight except in Nannochloropsis-fed rotifers. The addition of the various oils all increased the concentrations and the absolute amount of EPA and DHA in rotifers. Enrichment with the methyl esters of n-3 HUFA resulted in the highest content, followed by dry Selco and cuttle fish liver oil. Salinity appeared to have some effect on the incorporation of fatty acids by rotifers; lower salinity generally gave higher levels of incorporation. At temperatures of 28°C and higher some mortality of rotifers occurred.