Aquaculture, which constitutes one of the largest food production sectors in the world, is preferably practiced with natural organic products rather than with synthetic chemicals or antibiotics. In addition to the daunting challenge of providing food and livelihood to the exponentially increasing world population, the aquaculture industry is key to ensuring that development is based on environmentally sustainable practices, specifically in the production of aquafeeds. Terrestrial microorganisms that act as natural defence systems of cultured species have been identified as the main producer for the beneficial bacterial candidates. Probiotics have recently gained popularity as beneficial microbes candidates in cultured organisms to maintain the health condition and well-being of different aquatic animals. This review aimed to understand the necessity of using probiotics as a sustainable alternative to regulate the growth performance, feed utilisation and general health condition for sustainable aquaculture. Also, explanatory discussion about the host microbiota and its ability to produce different probiotic strains and the probiotic functionality to ameliorate the host immunity to provide the interactive effects on the host-derived probiotics. By presenting the results obtained from the previous studies about the ability of probiotics to sustain the aquatic animal's performances, this study condensed the current knowledge and information for future research and development of the probiotic application in aquaculture.

Using synthetic antibiotics/chemicals for infectious bacterial pathogens and parasitic disease control causes beneficial microbial killing, produces multi-drug resistant pathogens, and residual antibiotic impacts in humans are the major threats to aquaculture sustainability. Applications of herbal products to combat microbial and parasitic diseases are considered as alternative approaches for sustainable aquaculture. Essential oils (EOs) are the secondary metabolites of medicinal plants that possess bioactive compounds like terpens, terpenoids, phenylpropenes, and isothiocyanates with synergistic relationship among these compounds. The hydrophobic compounds of EOs can penetrate the bacterial and parasitic cells and cause cell deformities and organelles dysfunctions. Dietary supplementation of EOs also modulate growth, immunity, and infectious disease resistance in aquatic organisms. Published research reports also demonstrated EOs effectiveness against Ichthyophthirius multifiliis, Gyrodactylus sp., Euclinostomum heterostomum, and other parasites both in vivo and in vitro. Moreover, different infectious fish pathogenic bacteria like Aeromonas salmonicida, Vibrio harveyi, and Streptococcus agalactiae destruction was confirmed by plant originated EOs. However, no research was conducted to confirm the mechanism of action or pathway identification of EOs to combat aquatic parasites and disease-causing microbes. This review aims to explore the effectiveness of EOs against fish parasites and pathogenic bacteria as an environment-friendly phytotherapeutic in the aquaculture industry. Moreover, research gaps and future approaches to use EOs for sustainable aquaculture practice are also postulated.

No abstract

No abstract

No abstract