LAUSR

Abstract The bacterium Vibrio midae SY9, shown to enhance the nutrition and health of juvenile Haliotis midae, was investigated as a probiotic for H. midae during the post-larval phase of development. Using a randomized box design, we conducted three independent laboratory-scale experiments in which post-larval H. midae (mean shell length 2.7 mm) were fed three different artificial biofilm diets. The diets consisted of alginate and either the probiotic V. midae K811 only (diet 1), a mixture of the benthic diatom Cocconeis sp. and Vibrio midae K811 (diet 2) or Cocconeis sp. only (diatom control diet). Abalone survival was monitored over 25 days, and growth was quantified by measuring abalone shell length. Results confirmed that V. midae K811 has a probiotic effect on post-larval H. midae by significantly improving survival and promoting a three-fold increase in the growth rate of these animals. This study also demonstrated that post-larval H. midae can survive and grow on a bacterial biofilm diet lacking diatom cells which might suggest that bacteria could replace diatoms as the principle food source for post-larval H. midae.