Temperature effects on lipid composition of the earthworms Lumbricus rubellus and Eisenia nordenskioeldi

Two earthworm species, the freeze-intolerant Lumbricus rubellus (Hoffmeiste r) and the freeze-tolerant Eisenia nordenskioeldi (Eisen), were compared wi th respect to the effects of temperature on lipid composition. The animals were incubated at either 0 degrees C or 20 degrees C for 28 days, and then analyzed for the composition of free and ester-linked long-chain fatty acid s, as well as other lipids with similar properties. Inter-species differenc es dominated the patterns of lipid composition, and the two species respond ed similarly to incubation temperature with respect to changes in lipid com position. In particular, polyunsaturated fatty acids were present in higher concentrations at ODC, while straight-chain saturated fatty acids were mor e common at 20 degrees C. The results did not implicate specialized lipid a djustments in the freeze-tolerance of E. nordenskioeldi. (C) 2000 Elsevier Science Ltd. All rights reserved.