AQUAHERB CONDITIONERS: THE SILVER BULLET FOR ASIAN SEABASS Lates calcarifer AND SILVER POMPANO Trachinotus blochii PROTECTION AGAINST VIBRIOSIS

Alternative strategies for minimizing the detrimental effects of bacterial infection and prevention of diseases in aquaculture are necessary since the ongoing efficacy of antibiotics is proving to be unsustainable. One of the most promising approach is the use of aqua herbal conditioners to stimulate the immune system of fish to allow them to fight off infections. In this study, the protective effect of aqua herbal conditioners produced from, mainly, mangrove and neem plant extracts in marine fish, was tested on Asian Seabass Lates calcarifer and Silver Pompano Trachinotus blochii at 8-10 g of weight size. Challenge tests were performed by immersion with two pathogenic bacteria: Vibrio harveyi and Vibrio parahaemolyticus, at a concentration of 105 cells ml-1 for 60 minutes after 12 h, 24 h and 36 h conditioning treatment. The experimental trial show that after 72 h, commercially available aqua herbal conditioners (AquaHerb) was able to significantly increase the percentage survival of L. calcarifer and T. blochii and reduces their susceptibilityto the V.harveyi and V.parahaemolyticus. Significantly higher leukocytesnumber, monocyte, neutrophil andphagocyticindexwere detected in all conditioning group for Silver Pompano and Asian Seabass. These results suggest that the combination of herbal extracts together with other trace elements contained in AquaHerb were able to act as immunostimulants and appear to improve the immune status and disease resistance of Asian Seabass and Silver Pompano.