Abstract 
 
1. Background 
Aquaculture is one of the fastest-growing food-producing sectors globally; however, its sustainability is challenged by disease outbreaks, high production costs, and the increasing reliance on antibiotics. In Nigeria, Tilapia (Oreochromis niloticus) is one of the most commercially important aquaculture species. Excessive antibiotic use has raised concerns regarding antimicrobial resistance and environmental contamination, creating the need for sustainable and environmentally friendly alternatives. This study evaluated the antibacterial efficacy of plant extracts from Moringa oleifera and Musa spp. (banana) leaves against Aeromonas hydrophila infection in tilapia. 
 
2. Methods 
The study was conducted in 2026 at the Federal University of Maiduguri, Nigeria. Fresh leaves of Moringa oleifera and Musa spp. were collected, authenticated, shade-dried, and processed into powder. Ethanol extracts were prepared by soaking 100 g of each powdered sample in 500 mL of 95% ethanol for 72 hours, followed by filtration and concentration. Seventy infected tilapia exhibiting clinical signs of Aeromonas infection were obtained from local fish farms. Aeromonas hydrophila was isolated from kidney and liver tissues using standard microbiological procedures and identified through morphological and biochemical characterization. Experimental fish were challenged with A. hydrophila and subsequently treated with the plant extracts. Survival rate, clinical signs, bacterial load, growth performance, and selected hematological and immunological parameters were assessed. 
 
3. Results 
Both Moringa and banana leaf extracts demonstrated antibacterial activity against Aeromonas hydrophila. Treated fish showed improved survival rates, reduced clinical symptoms, and lower bacterial loads compared with untreated controls. Moringa leaf extract exhibited stronger antibacterial effects than banana leaf extract alone, while the combined treatment produced enhanced protective benefits. Improvements were also observed in fish health status and selected physiological indicators. 
 
4. Conclusions 
The findings indicate that Moringa oleifera and Musa spp. leaf extracts have significant potential as natural and eco-friendly alternatives to conventional antibiotics for controlling Aeromonas hydrophila infections in tilapia culture. Their use could contribute to reducing antibiotic dependence, improving fish health, and supporting sustainable aquaculture production. Further studies are recommended to determine optimal dosages, mechanisms of action, and long-term performance under commercial farming conditions. 
 
5. Support / Acknowledgment 
The authors acknowledge the support of the Department of Fisheries and Aquaculture and all individuals who contributed to sample collection and laboratory analyses. 
 
Keywords: Aeromonas hydrophila; Moringa oleifera; Musa spp.; Oreochromis niloticus; phytobiotics.