Comparison of the fatty acid profile of muscle neutral lipids and phospholipids of up-river anadromous sea lamprey (Petromyzon marinus L.) (Agnatha) from three Portuguese river basins

SUMMARY Composition of fatty acid profile of muscle neutral lipids (NL) and phospholipids (PL) of sea lamprey that enter the Portuguese rivers Minho, Tagus and Guadiana during their non-trophic spawning migration was analyzed. The fatty acid distribution in NL was similar and revealed that monounsaturated fatty acids (MUFA) were the most representative, followed by saturated fatty acids (SFA) and finally by polyunsaturated fatty acids (PUFA). Monoenic 16:1 and 18:19 formed a considerable percentage of total fatty acids, followed by SFA 14:0 and 16:0. EPA and DHA were the dominant PUFA fatty acids. Lampreys from Tagus river basin presented the highest percentages of fatty acids (P≤0.001). The fatty acid that contributed for the discrimination of the three river basins was 18:17. The fatty acid composition of PL fraction showed that animals from Minho river basin had a different profile characterized by low PUFA percentage when compared with lampreys from Tagus and Guadiana river basins. Monoenic acids were primarily represented by 16:1 and 18:19. A high level of 16:0 characterized the SFA followed by 14:0. Among PUFA, DHA was the most representative fatty acid. The fatty acids that contributed for the separation of the three river basins were 16:0, 18:43 and 24:19