As alternative to antibiotics, fish nutritionists are exploring potential candidates to boost immune system of test animals and better prepare them to withstand opportunistic pathogens. Phytobiotics are increasingly being tested and the results are a mixed grill of success stories and not so successful ones.
In the tropics where many plants seem to have been recommended, which ones seem promising, which, when added in the diet, culture water for fish or administered to fish any other way, would be expected to produced effects?