Response of Juvenile Danube Sturgeon (Acipenser gueldenstaedtii) to Aeromonas hydrophila: Histopathological and Hematological Findings

Document Type : Original Research

Authors
Mert Minaz
Akif Er
Department of Aquaculture, Faculty of Fisheries, Recep Tayyip Erdoğan University, Rize, Türkiye.
10.48311/jast.2026.16879
Abstract
This study investigated the physiological and pathological responses of juvenile Danube sturgeon to Aeromonas hydrophila infection. Fish were intraperitoneally injected with 0.1 mL of A. hydrophila suspension (1×10⁸ CFU mL-1). The experiment was conducted with three replicates per group (infected and control), each containing 10 fish. Based on the challenge test results, mortality in the infected group began on day 3 and continued progressively until day 13. Additionally, swim bladder deflation, hyperemia, and hemorrhaging in the visceral organs were observed. Hematological analysis revealed that LYM, HGB, MCH, and MCHC values were significantly higher in the control group, whereas WBC and MCV levels were elevated in the infected group. Histopathological examination of liver tissues revealed prominent melanomacrophage centers and signs of necrosis. According to a semi-quantitative scoring model, regressive changes and inflammation were significantly higher in the infected group compared to the controls (P< 0.01). In conclusion, Aeromonas hydrophila demonstrates a highly pathogenic potential for juvenile Danube sturgeon, inducing rapid systemic deterioration and significant tissue damage. The findings confirm that this bacterium is capable of causing disease and lethal outcomes within a week, emphasizing the urgent need for preventive strategies in conservation and aquaculture management of this endangered species.
Keywords
Challenge test
Fish
Hematology
Histopathology
Pathogen microorganism
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Journal of Agricultural Science and Technology
Volume 28, Issue 3
May and June 2026
Pages 601-613