Sialosphingolipids of sea urchin eggs and spermatozoa showing a characteristic composition for species and gamete.

1. Sialosphingolipids of four species of the Japanese sea urchin were compared. The composition of sialosphingolipids was characteristic for species and gamete. 2. It is suggested that sialosphingolipids may have a common carbohydrate backbone composed solely of hexoses and sialic acids.