Research Article

Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea

Volume: 43 Number: 3 June 18, 2026
EN TR

Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea

Abstract

Photobacterium damselae subsp. damselae is a significant pathogen that cause severe bacterial septicemia in a broad range of hosts. This study presents the first comprehensive analysis of Photobacterium damselae subsp. damselae affecting farmed Atlantic bluefin tuna (Thunnus thynnus) stocks in Aegean Sea, Türkiye. The total mortality rate of the farm was calculated as 18% exhibiting clinical signs of the disease, characterised by lethargic swimming and loss of equilibrium in bluefin tuna cages. Although external clinical signs were not determined, hemorrhages were observed in liver, swim bladder and heart. Microbiological examinations resulted in the isolation of a total of four bacterial strains, including two isolates from the summer sampling period and two isolates from the autumn sampling period. Among these, representative strains designated as THAS1 and THAS2 were selected for further biochemical and molecular characterization, through which Photobacterium damselae subsp. damselae was identified. Histopathological examinations of liver, heart, spleen, and kidney tissues associated with the infection revealed the presence of melanomacrophage centers in histological sections of the spleen and kidney. Consequently, this study reveals the epizootic and impact of P. d. subsp. damselae infection in farmed Atlantic bluefin tuna with clinical and microbiological results associated with pathological changes. Further research on the epidemiology and epizootiology of this disease is essential for sustainable aquaculture of tuna fish stocks, especially in Mediterranean.

Keywords

Ethical Statement

This study did not require ethical approval as no live vertebrate animals or human subjects were involved.

References

  1. Alolod, G.A.L., Matsumoto, S., Koiwai, K., Kondo, H., & Hirono, I. (2024). First report of white muscle disease caused by Photobacterium damselae subsp. damselae in Kuruma shrimp (Penaeus japonicus). Aquaculture, 593, 741278. https://doi.org/10.1016/j.aquaculture.2024.741278
  2. Austin, B., & Austin, D.A. (2016). Bacterial fish pathogens: Disease of farmed and wild fish. Springer.
  3. Chuchird, N., Chongprachavat, N., Suanploy, W., Kitsanayanyong, L., Phansawat, P., Keetanon, A., Wimanhaemin, P., & Rairat, T. (2024). Investigation of pale shrimp disease in Pacific white shrimp (Litopenaeus vannamei) caused by Photobacterium damselae subsp. damselae in low salinity culture conditions. Aquaculture Reports, 39: 102416. https://doi.org/10.1016/j.aqrep.2024.102416
  4. Essam, H.M., Abdellrazeq, G.S., Tayel, S.I., Torky, H.A., & Fadel, A.H. (2016). Pathogenesis of Photobacterium damselae subspecies infections in sea bass and sea bream. Microbial Pathogenesis, 99, 41-50. https://doi.org/10.1016/j.micpath.2016.08.003
  5. Fouz, B., Larsen, J.L., Nielsen, B., Barja, J.L., & Toranzo, A.E. (1992). Characterization of Vibrio damsela strains isolated from turbot Scophthalmus maximus in Spain. Diseases of Aquatic Organisms, 12, 155-166.
  6. Gouife, M., Chen, S., Huang, K., Nawaz, M., Jin, S., Ma, R., Wang, Y., Xue, L., & Xie, J. (2022). Photobacterium damselae subsp. damselae in mariculture. Aquaculture International, 30(3), 1453 1480. https://doi.org/10.1007/s10499-022-00867-x
  7. Gupta, N., Partridge, G.J., Buller, N.B., Pilmer, L., Currie, A., & Lymbery, A.J. (2021). Genetic diversity of Australian isolates of Photobacterium damselae subsp. damselae is associated with virulence to yellowtail kingfish (Seriola lalandi). Aquaculture, 538, 736552. https://doi.org/10.1016/j.aquaculture.2021.736552
  8. Hassanzadeh, Y., Bahador, N., & Baseri-Salehi, M. (2015). First time isolation of Photobacterium damselae subsp. damselae from Caranx sexfasciatus in Persian Gulf, Iran. The Iranian Journal of Microbiology, 7(3), 178.

Details

Primary Language

English

Subjects

Fish Pests and Diseases

Journal Section

Research Article

Publication Date

June 18, 2026

Submission Date

April 6, 2026

Acceptance Date

May 19, 2026

Published in Issue

Year 2026 Volume: 43 Number: 3

APA
Dinçtürk, E., & Tanrıkul, T. (2026). Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea. Ege Journal of Fisheries and Aquatic Sciences, 43(3), 233-240. https://doi.org/10.12714/egejfas.43.3.06
AMA
1.Dinçtürk E, Tanrıkul T. Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea. EgeJFAS. 2026;43(3):233-240. doi:10.12714/egejfas.43.3.06
Chicago
Dinçtürk, Ezgi, and Ttansel Tanrıkul. 2026. “Photobacteriosis in Farmed Atlantic Bluefin Tuna (Thunnus Thynnus): The First Comprehensive Study of the Aegean Sea”. Ege Journal of Fisheries and Aquatic Sciences 43 (3): 233-40. https://doi.org/10.12714/egejfas.43.3.06.
EndNote
Dinçtürk E, Tanrıkul T (June 1, 2026) Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea. Ege Journal of Fisheries and Aquatic Sciences 43 3 233–240.
IEEE
[1]E. Dinçtürk and T. Tanrıkul, “Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea”, EgeJFAS, vol. 43, no. 3, pp. 233–240, June 2026, doi: 10.12714/egejfas.43.3.06.
ISNAD
Dinçtürk, Ezgi - Tanrıkul, Ttansel. “Photobacteriosis in Farmed Atlantic Bluefin Tuna (Thunnus Thynnus): The First Comprehensive Study of the Aegean Sea”. Ege Journal of Fisheries and Aquatic Sciences 43/3 (June 1, 2026): 233-240. https://doi.org/10.12714/egejfas.43.3.06.
JAMA
1.Dinçtürk E, Tanrıkul T. Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea. EgeJFAS. 2026;43:233–240.
MLA
Dinçtürk, Ezgi, and Ttansel Tanrıkul. “Photobacteriosis in Farmed Atlantic Bluefin Tuna (Thunnus Thynnus): The First Comprehensive Study of the Aegean Sea”. Ege Journal of Fisheries and Aquatic Sciences, vol. 43, no. 3, June 2026, pp. 233-40, doi:10.12714/egejfas.43.3.06.
Vancouver
1.Ezgi Dinçtürk, Ttansel Tanrıkul. Photobacteriosis in farmed Atlantic bluefin tuna (Thunnus thynnus): The first comprehensive study of the Aegean Sea. EgeJFAS. 2026 Jun. 1;43(3):233-40. doi:10.12714/egejfas.43.3.06