THE LIVER LIPID FATTY ACID COMPOSITION OF TWO CARTILAGINOUS FISH, THE THORNBACK RAY (Raja clavata) AND THE COMMON SMOOTH-HOUND (Mustelus mustelus)

We have evaluated the fatty acid composition of the livers from two cartilaginous fish species Rajaclavata (thornback ray) and Mustelus mustelus (common smooth-hound) caught off the NorthernAegean Sea. While there was generally little variation between species, Mustelus mustelus indicated low saturated (SFA) in summer (29.61%), in spring (32.57%), in autumn (30.07%) and inwinter (31.81%) and high polyunsaturated fatty acid (PUFA) in summer (40.35%), in spring(36.50%), in autumn (30.21%) and in winter (27.26%) levels. The dominant fatty acids were palmitic acid (C16:0), oleic acid (C18:1 (n-9)), eicosapentaenoic acid (EPA; C20:5 (n-3)), and docosahexaenoic acid (DHA; C22:6 (n-3)) in both cartilaginous fish species in all seasons. The ratioof DHA/EPA with respect to the total of fatty acids in livers oils was ranged from 2.66% to 4.44%for Mustelus mustelus and 2.89% to 4.46% for Raja clavata. The n:3/n:6 ratio of thornback raywas higher compared to smooth-hound shark in all seasons. The liver oil of R. clavata and M.mustelus represent a valuable source of omega-3 PUFA that can be used for human and animalnutrition.