use of medicinal herbs in fish aquaculture as an alternative to chemotherapy (case study: beluga; huso huso)

fast development of aquaculture and increasing fish demand lead to intensification of fish culture, magnifying stressors for fish and thus heightening the risk of disease until now, chemotherapy has been widely used to prevent and treat disease outbreaks, although use of chemical drugs has multiple negative impacts on environment and human health e.g. resistant bacterial strains and residual accumulation in tissue. hence, disease management in aquaculture should concentrate on environmentally friendly and lasting methods. recently, increasing attention is being paid to the use of plant products for disease control in aquaculture as an alternative to chemical treatments. plant products have been reported to stimulate appetite and promote weight gain, to act as immune stimulant and to have antibacterial and anti-parasitic properties in fish and shellfish aquaculture due to active molecules such as alkaloids, terpenoids, saponins and flavonoids. however, as it is a relatively emerging practice there is still little knowledge on the long-term effects of plant extracts on fish physiology as well as a lack of homogenization in the extract preparation and fish administration of the plant extracts. this article aims to review the studies carried out on the use of plant products and their biological effects on growth, hematological and immunological parameters of giant sturgeon.