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Aeromonas veronii is an important pathogen in aquaculture, causing high mortality rates in farmed species. Phage therapy, which uses bacteriophages to specifically target and lyse bacteria, has gained attention owing to its promising therapeutic potential. In this study, A. veronii was isolated from aquaculture water, and its biological characteristics were examined. To counteract this pathogen, the bacteriophage pAEv1 was isolated from aquaculture water using A. veronii as the host. The phage pAEv1 belongs to the Podoviridae family and is characterized by its short tail. The optimal multiplicity of infection (MOI) was 0.01, with a latent period of 10 min and potency of 1.3×108 PFU/mL. The phage demonstrated stability across a temperature range of -80℃ to 55°C and a pH range of 5-9, indicating its robustness under varying environmental conditions. Genomic analysis revealed that pAEv1 has a circular double-stranded DNA genome, closely related to the Aeromonas phage pAEv1812 (ID: OL964754.1). Functional annotation of its proteins, based on UniProtKB, categorizes them into DNA modification and structural proteins. Further analysis using COG and KEGG databases indicated that the genome contained genes related to nucleic acid and purine metabolism, which are likely involved in the phage assembly process. Importantly, no resistance or virulence genes were identified, thereby confirming the biosafety of pAEv1 at the genetic level. In vitro antimicrobial tests showed that phage pAEv1 effectively inhibited A. veronii. Additionally, in vivo experiments demonstrated that grass carp treated with pAEv1 had an 80% survival rate after seven days of exposure to a double minimum lethal dose (MLD) of the bacterium.