Fatty Acid Composition of Selected Tissues of Unio elongatulus (Bourguignat, 1860) (Mollusca: Bivalvia) Collected from Tigris River, Turkey

The total lipid, fatty acid content of some organs and whole specimen of freshwater mussel Unio elongandus were investigated. The mussels were collected in July in 2007 from Tigris River, Turkey. Fatty acid content of selected tissues and whole mussel was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In the analyses, predominant fatty acids were C16:0, C16:1 omega 7, C18:1 omega 9, C20:1 omega 9, C20:4 omega 6 and C20:5 omega 3. Analyses of selected organs (mantle, gills, foot and whole body) presented different and characteristic fatty acids profiles. In the gills C16:1 omega 7 (30.2%), C16:0 (17.4%) acids; in the mantle C18:1 omega 9 (20.3%), C16:0 (25.4%) acids; in the foot C16:0 (20.8%), C16:1 omega 7 (15.9%), C18:1 omega 9 (15.4%) acids and in whole body C16:1 omega 7 (27.6%), C16:0 (23.6%) acids were the most abundant constituents. Also the percentages of C20:4 omega 6 and C20:5 omega 3 acids, precursors of eicosanoids, were apparently high in the gills and foot. It is presumed that the chief fatty acids present in a particular organ are related to specific functions of the organ. In all of the tissue analyses, Sigma MUFA levels were higher than Sigma PUFA and Sigma SFA levels.