ABSTRACT
In order to enhance the survival rate of abalone larvae, antibiotic susceptibility tests were performed on the bacteria isolated from whitened postlarvae, biofilm and the pond water of abalone (Haliotis diversicolor superteta) and proven to be virulent pathogens by challenge tests. API tests indicated that the isolates were mainly comprised of Vibrio alginolyticus, vibrio cholerae, Vibrio parahaemolyticus, the total Vibrio number of which was seventeen and made up about 50% of the total population. Among vibrios, Vibrio alginolyticus was the dominant strain (11 isolates) and made up 70%. Antibiotic susceptibility tests demonstrated that while majority isolates exhibited relatively high sensitivities toward streptomycin, erythromycin and gentamycin, they nevertheless displayed resistance to tetracycline and novobiocin. Results clearly indicated that streptomycin, erythromycin and gentamycin could be potentially used to suppress vibrio growth and hence improve abalone postlarval survival rate.