PHOSPHOLIPID IN PLANKTON SAMPLES FROM TOK YO BAY AND SAGAMI BAY

To evaluate the role of phospholipid in the phosphorus cycle of marine ecosystems, diatom and zooplankton samples from Tokyo Bay and Sagami Bay were used to determine phospholipid-phosphorus (phospholipid-P) an d their classification. The concentration of phospholipid-P in plankto n population ranged from 28.0 to 67.6 mu mol P/g for dry samples, corr esponding 10.4 to 22.2% for the total phosphorus: Tokyo Bay samples ha d a higher concentration than those from Sagami Bay. In the Tokyo Bay samples, the phospholipid-P concentraions had a good correlation with the percentage of copepoda, while no correlation was found in the Saga mi Bay samples. Phosphatidylcholine, phosphatidylinositol and other un known components were isolated and identified for classification of ph spholipids using silica gel chromatography, (1)HNMR and gas chromatogr aphy. These phosphorus compounds were concluded to play an important r ole in the downward conveying systems of phosphorus in marine ecosyste ms.