Histopathological examination of lipid accumulation in liver tissues of cultured european sea bass (Dicentrarchus labrax L. 1758) feeding with different commercial feeds in Turkey

The aim of the study was to determine the effect of diet on the fatty acids composition of cultured european sea bass (initial mean body weight 54 g) liver tissues and histology when compared with wild sea bass (initial mean body weight 52 g) caught in Eagean Sea. Fish were fed the commercial feed for 91 days. The amount of fish total lipid was higher in farmed than in wild fish in liver tissue samples. Henicosanoic fatty acid was found in coommercial feed but not found in fish liver. Fatty acid profiles in the livers reflected the fatty acid profiles of the commercial feeds. The dominant fatty acids in livers of farmed and wild sea bass were 16:0, 18:1n9, 18:2n6, C20:5n3 and 22:6n3. The results showed that farmed fish contained a higher level of EPA?DHA ratio and oleic acids, monounsaturated fatty acids, n-6 polyunsaturated fatty acids, whereas wild fish contained a higher level of saturated fatty acids, eicosapentaenoic acids, n-3 polyunsaturated fatty acids and n-3/n-6 ratio (P<0,05).Commercial feed had effect on hepatic lipid droplets accumulation degree and pattern of vacuolization in the observed liver sections. The marked hepatic cell membrane degeneration and haemorrhagy on the liver observed in farmed sea bass was caused by the accumulation of very large lipid droplets. The hepatocyte nucleus size of fish was higher in farmed than in wild fish liver tissue (P<0,05). Hepatocytes enlarged irregular nucleus located at the periphery of the cells.Hepatic lipid droplets accumulation was higher in farmed than in wild fish in liver tissue samples.