Abstract
Aquaculture is a growing sector due to the high rising demand for fish,
shrimp, oysters, and other products, which is partially conflicted by various infectious
diseases. The infectious diseases affecting the production and inducing high mortalities
cause substantial economic losses in this sector. Also, parasitic infections may induce
severe mortality and morbidity in fish farms. Therefore, most farmers apply several
kinds of antibiotics to control the problems induced by bacterial diseases and, to some
extent, parasitic infections. The extensive usage of antibiotics to control or prevent
pathogens may lead to the development of pathogenic resistant strains that might cause
hazards to human health. Besides, there is a global trend toward reducing the
application of antibiotics in aquaculture farms. Thus, there is a great effort to discover
new natural and safe products with pharmaceutical properties, such as natural essential
oils (EO). Essential oils are secondary metabolites of many plants (roots, flowers,
seeds, leaves, fruits and peels) and their molecular structures provide a high
antimicrobial and antiparasitic efficiency against pathogens. Consequently, it is
essential to provide sufficient knowledge about the mode of action of EO against fish
parasites and its future applications and directions in aquaculture.