Antibacterial and Antifungal Activities of Water Hyacinth (Eichhornia crassipes) Against Fish Pathogens: A Comprehensive Review of Aquaculture Applications

Abstract

The rapid expansion of aquaculture has been accompanied by an increasing prevalence of infectious diseases caused by bacterial and fungal pathogens, which continue to constrain global fish production. Conventional disease management strategies rely heavily on antibiotics and synthetic chemotherapeutics; however, the emergence of antimicrobial resistance (AMR), environmental contamination, and regulatory restrictions on antibiotic use have stimulated interest in sustainable, plant-based alternatives. Among the aquatic plants investigated, water hyacinth (Eichhornia crassipes), an invasive aquatic macrophyte, has gained considerable scientific attention owing to its rich phytochemical composition and diverse biological activities. The plant contains an array of secondary metabolites, including phenolic compounds, flavonoids, alkaloids, tannins, saponins, and terpenoids, many of which exhibit documented antimicrobial properties. This review critically examines the published literature on the antibacterial and antifungal activities of E. crassipes against microorganisms relevant to aquaculture, with particular emphasis on fish-pathogenic species. The review addresses the phytochemical profile of water hyacinth, extraction methodologies, mechanisms underlying antimicrobial activity, and evidence from both in vitro and in vivo investigations. Furthermore, the potential application of water hyacinth-derived bioactive compounds as eco-friendly alternatives for disease management in cultured fish species is evaluated. Although existing findings indicate promising antimicrobial potential, significant knowledge gaps persist with respect to active compound identification, standardization of extraction procedures, toxicity profiling, and large-scale field validation. Future research integrating phytochemical characterization, molecular approaches, and aquaculture-based challenge studies is anticipated to facilitate the development of E. crassipes-derived therapeutics for sustainable fish health management.