Comparison of the fatty acid profile of muscle neutral lipids and phospholipids of up-river anadromous sea lamprey (&lt;i&gt;Petromyzon marinus&lt;/i&gt; L.) from three Portuguese river basins

Maria João Lança,Sara Pinela,Pedro Raposo De Almeida,Bernardo Ruivo Quintella

doi:10.3989/scimar.2009.73n4785

Abstract

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 analysed. The fatty acid profile exhibited differences in the percentage among NL and PL and between river basins. Similarities were found in the fatty acid profile of NL. 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 18:1ω9 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. In terms of NL, the fatty acid that contributed for the discrimination between the three river basins was 18:1ω7. Individuals from the Minho river basin exhibited a different fatty acid profile of PL characterised by a low PUFA percentage when compared with lampreys from the Tagus and Guadiana river basins. Muscle PL fraction showed that the two monoenes, 16:1 and 18:1ω9, occurred at high percentage, followed by 16:0 and 14:0 (SFA). Among PUFA, DHA was the most representative fatty acid. The fatty acids that contributed to the separation between the three river basins were 16:0, 18:4ω3 and 24:1ω9. Although the results point in the direction of a possible difference between the fatty acid composition of the NL and PL fractions in the muscle samples from the three river basins, further studies, especially in tissues where fatty acid composition will be less sensitive to diet and environmental factors, are necessary to confirm this hypothesis.

Highlights

The sea lamprey (Petromyzon marinus L.) is an anadromous species classified as “vulnerable” in the Portuguese red list of endangerous species (Rogado et al, 2005)
In terms of neutral lipids (NL), the fatty acid that contributed for the discrimination between the three river basins was 18:1ω7
Individuals from the Minho river basin exhibited a different fatty acid profile of polar lipid (PL) characterised by a low polyunsaturated fatty acids (PUFA) percentage when compared with lampreys from the Tagus and Guadiana river basins

Summary

Introduction

The sea lamprey (Petromyzon marinus L.) is an anadromous species classified as “vulnerable” in the Portuguese red list of endangerous species (Rogado et al, 2005). After four to seven years, a metamorphosis period occurs which transforms the microphagic filter-feeding larvae into pelagic juveniles This is a non-trophic period during which lamprey utilises the lipid reserves accumulated in the larval phase (Bird and Potter, 1983). Juvenile lampreys migrate downstream to the sea, where they begin the parasitic stage of their life cycle, feeding primarily on blood and muscle tissue of marine and anadromous fish for at least 24 months (Beamish, 1980) This marine phase is accompanied by the deposition of large amounts of lipids, in the musculature, the main store depot for these energy reserves (Sheridan, 1988), which act as the primary energy source during upstream spawning migration (Bird et al, 1993). It is well known that there are considerable changes in the chemical composition of the fish tissues in each period of the life cycle as a result of feeding and sexual maturation, the most important being the marked changes in tissue content and fatty acid composition (Huynh et al, 2007)

Objectives

Results

Discussion

Conclusion