Use of macroalgae supplemented with probiotics in the Haliotis rufescens (Swainson, 1822) culture in Northern Chile

In this study, we evaluate the use of macroalgae as vectors of probiotics bacteria into the digestive tract of abalone to improve their survival and growth. It is shown that when abalone Haliotis rufescens of different sizes were fed with a natural diet composed of fronds of the macroalga Macrocystis integrifolia supplemented with a mixture of Vibrio sp. C21‐UMA, Agarivorans albus F1‐UMA and Vibrio sp. F15‐UMA bacteria, there was a significant increase (P<0.05) in the average monthly growth rate and survival (%)in a period of 210 days, compared with the control without a probiotic supplement. The permanence of the probiotics in the digestive tract of the animals was monitored, and it was found that the number of culturable C21‐UMA and F1‐UMA bacteria decreased significantly (P<0.05) in recently weaned and adult abalone, and they almost disappeared completely on day 19 of the bioassay. However, the culturable Vibrio sp. F15‐UMA disappeared completely from the digestive tract on day 22 of the bioassay, and these were the bacteria that remained at the highest concentration compared with the other two bacterial strains over the experimental period. It is therefore shown that it is feasible to use a probiotic mixture to improve the profitability of the H. rufescens culture.