Plasma-dependent chemotactic activity of hemocytes derived from a juvenile estuarine gastropod mollusc, Clithon retropictus, to Vibrio parahaemolyticus and Escherichia coli strains.

Hemocytes of adult Clithon retropictus were attracted chemotactically to live Vibrio parahaemolyticus and Escherichia coli strains. The chemotaxis was stimulated by the plasma of adult C. retropictus. Hemocytes of the juvenile specimen were attracted chemotactically to V. parahaemolyticus and E. coli strains in the presence of the plasma of the juvenile and only to E. coli strain in the absence of the plasma. These evidences suggest that hemocytes of juvenile C. retropictus might be defective to recognize V. parahaemolyticus strains and that the hemocytes would display full activities in the presence of the plasma factor(s).