1-O-Alkylglyceryl ether lipids of the gut walls and contents of an abyssal holothurian (<i>Oneirophanta mutabilis</i>)

A study of the glyceryl ether composition of free lipids of gut walls and contents of an abyssalholothurian species, Oneirophanta mutabilis has been carried out. A series of saturated and unsaturated1-O-alkylglyceryl ethers with alkyl side chains ranging from C15 to C21 were detected in the gut walls and contents of O. mutabilis. Glyceryl ethers accounted for 5-12% of the total free lipids contents. Foregut, midgut and hindgut walls and contents have identical 1-O-alkylglyceryl ether compositions. The C16:0, C16:1, C17:0, C18:0 and C18:1 are the main glyceryl ethers with C18:0 being dominant. The total organic carbon (TOC) and nitrogen (N) contents were also evaluated in gut contents of the digestive tract of O. mutabalis and these decreased from foregut to hindgut. The average assimilation efficiencies were estimated to be 40 and 55% for TOC and N respectively