Lipids and fatty acids composition in the tissues and by-products of two Tunisian shrimp species from the north and south regions.

Total lipid and fatty acid composition was determined in the muscle and by-products (heads, shells and tails) of Penaeus kerathurus and Metapenaeus monoceros caught off the North and South coasts of Tunisia. Shrimp total lipid levels in by-products ranged between 2 to 3.15% (p < 0.05) and were higher than fat tissue levels in both groups. No significant difference was found between tissue and by-product lipid contents of M.monoceros from both regions. However, significantly higher lipid content was found in P.kerathurus from the South than the North area. The percentage of polyunsaturated fatty acids were important in the tissues and by-products of both species from both regions. Thus, polyunsaturated fatty acids constitute the major fraction followed by saturated fatty acids and monounsaturated. The main fatty acids in both shrimp species muscle and by-products were C16:0, C20:5n-3, C22:6n-3, C18:1n-9, C18:0, C16:1, C20:4 and C18:1n-7.