Lake Michigan sponge phosphatic metabolite variations with habitat: a P nuclear magnetic resonance study

The ³¹P NMR phosphatic profile of the sponge Eunapius fragilis differs considerably from profiles obtained from vertebrate tissues: phosphonic acids, glycan phosphates, and phosphoarginine are present in the sponge profile. Ethanolamine phosphate, a family of phosphodiesters, dinucleotides, and a family of pyrimidine-nucleotide-activated co-factors are elevated, while nucleoside monophosphates, inorganic orthophosphate, and nucleoside triphosphates are diminished with respect to vertebrate tissues. The profile contains 26 different phosphatic metabolite resonance bands, and all but one of these (phosphonates) can be used to differentiate among three southern Lake Michigan sponge habitats examined: a coastal lagoon; the shipwreck of the Material Service Barge in the open waters of Lake Michigan; and an industrial section of the Calumet River. The quantitative phosphatic metabolite concentration data, in conjunction with numerical indexes derived therefrom, demonstrate that, in analogy to sponge phospholipid profiling, ³¹P NMR phosphatic metabolites can be utilized to distinguish among habitats using a single species as a bioindicator. For the sponge, energy reserves are concentrated in nucleotide co-factors rather than nucleoside triphosphates. High concentrations of ethanolamine and choline phosphate intermediates are present suggesting that metabolic pathways leading to phospholipid biosynthesis are primed for rapid membrane biosynthesis leading to subsequent sponge growth.