CHEMOTACTIC ATTRACTION BETWEEN HEMOCYTES OF THE OYSTER, CRASSOSTREA-VIRGINICA, AND BACTERIA

Experiments were conducted to ascertain whether there is chemotactic attraction by Bacillus megaterium and Micrococcus varians, both Gram-positive species, and Escherichia coli and Vibrio parahaemolyticus, both Gram-negative species, for hemocytes of the American oyster, C. virginica. Oyster hemocytes are attracted to live E. coli, B. megaterium and M. varians but not to heat-killed bacteria. Oyster cells are not attracted to either live or heat-killed V. parahaemolyticus. The chemoattractant is some molecule emitted by living vegetative cells of certain Gram-positive and Gram-negative bacteria.