Improved Growth Rate and Disease Resistance in Farmed Abalone Haliotis midae through Probiotic Treatment
Brett Macey, Grice Marine Laboratory, College of Charleston
23 Sep 2005
Disease has had a severe impact on the international aquaculture industry and is anticipated to become an increasingly important factor, together with the slow growth rate of Haliotis midae, that will negatively impact on the further development and success of the South African abalone mariculture industry. Thus, the future of H. midae mariculture in South Africa depends in part on the development of methods to enhance the growth rate and disease resistance of farmed abalone. The use of probiotics in aquaculture is proving to be highly effective in improving disease resistance, nutrition and/or growth of cultured organisms. I have isolated three enteric microorganisms from the digestive tract of H. midae that are capable of hydrolyzing various protein and starch substrates included in formulated abalone feeds. The three microorganisms significantly increased the amount of protein digestion and absorption in the abalone gut and an assessment of different immune parameters demonstrated the immunostimulatory effect of the three putative probionts included in the diet fed to farmed abalone. Furthermore, I have shown that H. midae fed the probiotic-supplemented diet have an improved survival and growth rate compared to animals not fed probiotics. The microorganisms tested in this study therefore have tremendous potential as probiotics for commercially produced Haliotis midae.