COMPARISON OF SPERM LIPID COMPONENTS AMONG 4 SPECIES OF SEA-URCHIN BASED ON ECHINOID PHYLOGENY

Analyses were made of lipids extracted from the spermatozoa of the sea -urchins, Diadema setosum, Arbacia lixula, Paracentrotus lividus and C lypeaster japonicus which belong to the order Diadematoida, Arbacioida , Echinoida and Clypeasteroida, respectively. Diadema setosum and A. l ixula spermatozoa contained several kinds of phospholipids (phosphatid ylcholine, phosphatidylserine, phosphatidylethanolamine and caldiolipi n), cholesterol and triglyceride. In addition to similar phospholipids , cholesterol and triglyceride, cholesterol-ester was also detected in C. japonicus spermatozoa. In contrast, lipids of P. lividus spermatoz oa comprised phospholipids and cholesterol. In these species, the fatt y acid composition of phosphatidylcholine phosphatidylethanolamine and cardiolipin was of the unsaturated type for the most part, while phos phatidylserine and triglyceride, except in the case of P. lividus, com prised, to a considerable degree, saturated fatty acid.