Seasonal study of lipid composition in different tissues of the common octopus (Octopus vulgaris)

Abstract

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, 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; triglycerides; 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 ovary was the highest (p<0.05) of all tissues analysed, 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