Antigenic specificity of the sea urchin sperm surface

The antigenic composition of the sperm surface in Paracentrotus lividus Lam. and Sphaerechinus granularis Lam. was studied using the sperm agglutination test with homologous and heterologous antisera. The results indicated that sperm of both species have at least one antigenic determinant located on their surface and shared by both species. In addition, Paracentrotus sperm bear at least one species specific determinant on their surface. The existence of antigenic determinants common to gametes of both species was demonstrated.