High incorporation of esential fatty acids by the Rotifer Brachionus plicatilis fed on the Prymnesiophyte Alga Pavlova lutheri

Abstract

The lipid and fatty acid compositions of rotifers (Brachionus plicatilis) fed on yeast or on the unicellular prymnesiophyte Pavlova lutheri, an alga commonly used in Australian hatcheries, were compared by TLC-FID, GC and GC-MS. Significantly higher relative proportions of energy-rich triacylglycerol were present in the Pavlova-fed rotifers than in the yeast-fed animals, and total lipid content reached a maximum between 12 and 24 h. High incorporation of the essential fatty acids eicosapentaenoic acid (EPA; 20: 5ω3) and docosahexaenoic acid (DHA; 22:6ω3) occurred in the Pavlova-fed rotifers. EPA and DHA content was 11.6% of total fatty acids after 3 h of feeding and reached 20 and 23% after 24 and 48 h respectively. The proportion of essential fatty acids in rotifers fed Pavlova compares very favourably with data obtained by overseas workers using a variety of microalgae and dietary supplements. On the basis of fatty acid composition alone, these results confirm the suitability of P. lutheri as a feedstock for Australian mariculture operations.