Polar and neutral lipid composition of the gonads and serum of the plaice,Pleuronectes platessa L.

The individual polar and neutral lipids of plaice (Pleuronectes platessa L.) ovaries, testes and serum were determined, just before spawning, in February 1984 and March 1985. Serum was also assayed in June and September 1984. Phosphatidylcholine (PC) was found to be the major polar lipid in both male and female plaice serum throughout the year and in the ovaries. The testes, however, contained almost equal amounts of PC and phosphatidylethanolamine. The polar lipid levels in plaice gonads, expressed as a percentage of the total lipid present, were higher in the ovaries than in the testes, but in male plaice serum, the percentage of polar lipid was consistently higher than in the female. In plaice testes, 86% of the total neutral lipid occurred as cholesterol, but this represented only 49% of the total neutral lipid in the ovaries, with triacylglycerol as the other major ovarian neutral lipid.