Lipid composition of the mantle and digestive gland of Octopus vulgaris juveniles (Cuvier, 1797) exposed to prolonged starvation

Lipid composition of the mantle and digestive gland of Octopus vulgaris that were not fed for 27 days were determined. Every 3 days, three octopuses were killed and samples of the mantle and the digestive gland (DG) were taken, in order to determine total lipids as well as lipid classes and fatty acids. Composition in total lipids (TL) for the mantle was similar until day 21, then decreased and remained similar until the end of the experiment. Composition in total lipids for the DG decreased significantly after 3 days, then remained similar until day 21, and then decreased until the end of the experiment. As for the lipid classes, in the DG the main components were triglycerides and sterol esters. Sterol esters suffered strong reductions after 10 days of starvation, while triglycerides remained similar until day 21 and then decreased until the end of the experiment. Cholesterol decreased gradually throughout the experimental period. For polar lipids, phosphatidylcholine and phosphatidylethanolamine increased during the first 3 days and then decreased throughout the experiment. In the mantle, the only neutral classes that decrease were triacylglycerols and sterol esters, while no polar lipid classes decreased in this organ. It was noticeable the decrease in almost all fatty acids in the DG after 3 days of starvation, while in the mantle there were no differences in fatty acid concentrations during the experiment.