Seasonal study of the lipid composition in different tissues of the common octopus (Octopus vulgaris)Seasonal variation of octopus (Octopus vulgaris) lipid composition was investigated in four tissues: arm, mantle, ovary and digestive gland. A non-homogeneous fat distribution was observed, with the digestive gland exhibiting a higher (p ,0.05) lipid content than the other tissues. The ovary showed a higher (p ,0.05) fat content than both muscle tissues, reaching its highest (p ,0.05) value in winter. Neutral lipids -free fatty acids (FFA), triacylglycerols, and sterols (ST) -exhibited their highest (p ,0.05) concentrations in the digestive gland and their lowest (p ,0.05) values in muscle tissues. The phospholipid (PL) content of the ovary was the highest (p ,0.05) of all tissues analysed, with the PL content also being significantly (p ,0.05) higher in the digestive gland than in arm and mantle. The concentrations of most lipid classes (FFA, PL and ST) exhibited a seasonal variation. The fatty acid composition showed a remarkable difference between the digestive gland and all other tissues analysed. Thus, the digestive gland exhibited higher (p ,0.05) contents in monounsaturated fatty acids and also lower (p ,0.05) contents in both saturated (SFA) and polyunsaturated (PUFA) fatty acids. The highest mean values in SFA and PUFA were observed in ovary and muscle tissues, respectively. A seasonal effect was observed for SFA and PUFA.