Lake Michigan sponge phospholipid variations with habitat: A P-31 nuclear magnetic resonance study

The sponge Eunapius fragilis, which is common in Lake Michigan's southern basin, exhibits a complex phospholipid profile containing 18 different phospholipids that can be used to differentiate among sponge habitats. Sponges from three habitats, a coastal lagoon at the Hammond marina, the shipwreck of the Material Service Barge in the open waters of Lake Michigan and an industrial section of the Calumet River, showed significant Variations in the following phospholipids: glycerol plasmalogen, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine, an uncharacterized phospholipid, lysoalkylacylphosphatidylcholine, lysophosphatidylcholine, phosphatidylinositol, alkylacylphosphatidylcholine and phosphatidylcholine. Phospholipids that did not vary statistically among the three environments were the diacylglyceryl-(2-aminoethyl)phosphonates, lysophosphatidic acid, lysoethanolamine plasmalogen, lysophosphatidylethanolamine, phosphatidic acid, diphosphatidylglycerol, dihydrosphingomyelin and the ethanolamine plasmalogen. The quantitative phospholipid concentration data in conjunction with numerical indexes derived therefrom demonstrate that P-31 nuclear magnetic resonance (NMR) phospholipid profiling can be used to distinguish among habitats using a single species as a bioindicator. Because the cellular membrane is fundamental to all life, its precise evaluation through phospholipid P-31 NMR provides a new tool for the study of phylogeny at the molecular level.