Ornamental fish production is an important component of the aquaculture industry and the ornamental fish trade is a foreign exchange earner besides being a source of employment. Goldfish, Carassius auratus are in demand in world markets due to their attractive colours. When aquaculture production becomes more intensive, the incidence of disease including infectious diseases has increased. The use of antibiotics and other chemotherapeutics for controlling diseases has been criticized for their negative impacts. Immunostimulants could not be used widely because of various disadvantages....