Lipid class and fatty acid composition of eggs of Atlantic halibut, Hippoglossus hippoglossus (L.), in relation to egg quality in captive broodstock

Abstract. Lipid class and fatty acid analyses were carried out on eight batches of pre-fertilized eggs of Atlantic halibut, Hippoglossus hippoglossus (L.). These batches were classified as ‘viable’ or ‘non-viable’ according to fertilization rate, blastomere symmetry and incubation success. The lipid class and fatty acid compositions were very similar between egg categories with exception of cholesterol which was shown to be significantly greater in the ‘non-viable’ eggs. Polar lipid classes predominated (67·1% and 67·0% of the total lipid for ‘viable’ and ‘non-viable’ egg batches respectively), with phosphatidylcholine (PC) being the major class (43·2% and 43·5%) and triacylglycerol (TAG) the main neutral lipid class (18·8% and 17·8%). Gas liquid chromatography of fatty acid methyl esters from the total lipid revealed no significant differences in fatty acid composition. The fatty acid profiles of viable egg batches showed five major fatty acids 16:0 (17·3%), 18:0 (4·8%), 18:1n-9 (9%), 20:5n-3 (119%) and 22:6n-3 (25·9%). The results are discussed in terms of the potential role of lipids as egg quality determinants in fish.