Pathogenic effects of Vibrio alginolyticus on larvae and postlarvae of the red abalone Haliotis rufescens

The pathogenicity of Vibrio alginolyticus on Haliotis rufescens veliger larvae and 4 d old postlarvae was tested in small-scale static bioassays with different bacterial concentrations (10(2) to 10(6) cells ml(-1)). Larval and postlarval survival were evaluated at 24 and 48 h. Results suggest that V. alginolyticus can cause massive mortality in larvae of H. rufescens within 24 h at concentrations above 10(5) cell ml(-1), while a concentration of 10(6) cell ml(-1) is required to produce the same effect in abalone postlarvae. The potential application of these results to hatchery conditions is discussed.