CHARACTERIZATION OF PHOSPHORUS-METABOLISM DURING 6 STAGES OF DEVELOPMENT IN THE EARTHWORM EISENIA-FOETIDA USING P-31-NMR

1. Changes in the metabolism of phosphorus-containing compounds were studied during embryonic development of earthworms (Eisenia foetida) at cocoon, juvenile, and adult stages using phosphorus-31 nuclear magnetic resonance spectroscopy (P-31-NMR). 2. The albumen of the cocoon contained apparent storage compounds (probably phosphodiesters), resonating at 0.0 and 1.3 ppm, that were ingested by embryos and shuttled into phosphorus-containing metabolites. including the phosphagen, phospholombricine. 3. The onset of storage compound depletion and correlated appearance of metabolites occurred before hatching (10-14 days after cocoon deposition). Subsequent increases in metabolite peaks coincided with rapid increases in muscle mass as embryos reached the crawling stage of development.