A comparison of the fatty acid composition of the phospholipid and neutral lipid of Unio elongatulus (Bourguignat, 1860) (Bivalvia: Unionidae) mussels from 4 different localities in southeastern Anatolia, Turkey

The quantitative and qualitative fatty acid compositions of phospholipid and neutral lipid were investigated and compared for specimens of the freshwater mussel Unio elongatulus. Samples were collected from 4 different localities in Turkey: Çağçağ Brook in Nusaybin (Mardin), Fabrika Brook in Çınar (Diyarbakır), the Tigris River under the Sadi Bridge (Diyarbakır), and Kırkçeşme Spring in Sultanköy (Mardin). Phospholipids and neutral lipids of the mussels’ whole tissues were fractionated by thin layer chromatography (TLC) and fatty acid analyses were done by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Both in the phospholipid and neutral lipid fractions, C16:0 (17.20%-22.17%), C16:1ω7 (9.21%-15.31%), C18:1ω9 (12.21%-23.12%), C18:2ω6 (12.12%- 16.10%), and C20:4ω6 (5.86%-13.10%) acids were found to predominate. The percentage of C20:4ω6 acid, a precursor of eicosanoids, was shown to be high in the phospholipid fractions. In the neutral lipids, total monounsaturated fatty acids (ΣMUFA) levels were determined to be higher than total saturated fatty acids (ΣSFA) and total polyunsaturated fatty acids (ΣPUFA) levels. In the phospholipid total, however, ΣPUFA levels were noted to be higher than ΣMUFA and ΣSFA levels. As is characteristic of freshwater mussels, Σω6/Σω3 ratios were found to be high in all lipid fractions.