Fisheries Science

, Volume 76, Issue 6, pp 981–990 | Cite as

Myxosporean and microsporidian infections in cultured Pacific bluefin tuna Thunnus orientalis in Japan

  • Jinyong Zhang
  • Fei Meng
  • Hiroshi Yokoyama
  • Jiro Miyahara
  • Ikuo Takami
  • Kazuo Ogawa
Original Article Aquaculture


During the parasitological survey of cultured juvenile Pacific bluefin tuna (PBT) Thunnus orientalis in 2007 and 2008, two myxosporeans and one microsporidian were found. Morphological and molecular analysis showed that the heart-infecting and brain-infecting myxosporeans are identified as Kudoa shiomitsui and K. yasunagai, respectively. This is a new host record for both species. High prevalence of infection (77–100%) with K. shiomitsui was observed in October to December (1–2 months post-transfer to sea cages), whereas only a few fish were infected with K. yasunagai. A microsporidian observed as white “cysts” in the trunk muscle of PBT had a resemblance to Microsporidium seriolae, the causative parasite of beko disease in yellowtail. Phylogenetic analysis showed that the microsporidian from PBT is closely related to but distinct from several other muscle-infecting species such as M. seriolae, Microsporidium sp. RSB, and Microsporidium sp. SH. Additionally, the spore dimension (2.7 × 1.5 μm on average) was remarkably smaller than the others. These results suggest that the present microsporidian is an undescribed species and designated Microsporidium sp. PBT. Prevalence and intensity of infection with Microsporidium sp. PBT reached a maximum of 100% and 20 cysts/fish, respectively. Although pathogenic effects of the two Kudoa species on fish health remain unknown, the microsporidian could be of concern to PBT aquaculture due to unsightly cysts in the musculature, reducing the market value of the fish.


Kudoa shiomitsui Kudoa yasunagai Microsporidium Pacific bluefin tuna Thunnus orientalis Myxosporean Microsporidian 



We thank D. Ayado, Y. Kishimoto, and Y. Miyazaki, The University of Tokyo, for their help in dissecting samples. This study was partly supported by the Grant-in-Aid for JSPS Fellowships (19-07796).


  1. 1.
    Ottolenghi F (2008) Captured-based aquaculture of bluefin tuna. In: Lovatelli A, Holthus PF (eds) Capture-based aquaculture. Global overview. FAO Fisheries Technical Paper, no. 508. FAO, Rome, pp 169–182Google Scholar
  2. 2.
    Sawada Y, Miyashita S, Murata O, Kumai H (2004) Seedling production and generation succession of the Pacific bluefin tuna, Thunnus orientalis. Mar Biotech 6:1–5CrossRefGoogle Scholar
  3. 3.
    Sawada Y, Okada T, Miyashita S, Murata O, Kumai H (2005) Completion of the Pacific bluefin tuna Thunnus orientalis (Temminck et Schlegel) life cycle. Aquacult Res 36:413–421CrossRefGoogle Scholar
  4. 4.
    Ishibashi Y, Honryo T, Saida K, Hagiwara A, Miyashita S, Sawada Y, Okada T, Kurata M (2009) Artificial lighting prevents high night-time mortality of juvenile Pacific bluefin tuna, Thunnus orientalis, caused by poor scotopic vision. Aquaculture 293:157–163CrossRefGoogle Scholar
  5. 5.
    Munday BL, Sawada Y, Cribb T, Hayward CJ (2003) Diseases of tunas, Thunnus spp. J Fish Dis 26:187–206CrossRefPubMedGoogle Scholar
  6. 6.
    Colquitt SE, Munday BL, Daintith M (2001) Pathological findings in southern bluefin tuna, Thunnus maccoyii (Castelnau), infected with Cardicola forsteri (Cribb, Danitith & Munday, 2000) (Digenea: Sanguinicolidae), a blood fluke. J Fish Dis 24:225–229CrossRefGoogle Scholar
  7. 7.
    Nowak BF (2004) Assessment of health risks to southern bluefin tuna under current culture conditions. Bull Eur Ass Fish Pathol 24:45–51Google Scholar
  8. 8.
    Deveney MR, Bayly TJ, Johonston CJ, Nowak BF (2005) A parasite survey of farmed Southern bluefin tuna, Thunnus maccoyii (Castelnau). J Fish Dis 28:279–284CrossRefPubMedGoogle Scholar
  9. 9.
    Hayward CJ, Akin HM, Nowak BF (2008) Epizootics of metazoan gill parasites did not threaten feasibility of farming southern bluefin tuna (Thunnus maccoyssi) in a trial extending over summer months. Vet Parasitol 154:122–128CrossRefPubMedGoogle Scholar
  10. 10.
    Hayward CJ, Bott J, Nowak BF (2009) Seasonal epizootics of sea lice, Caligus spp., on southern bluefin tuna, Thunnus maccoyii (Castelnau), in a long-term farming trial. J Fish Dis 32:101–106CrossRefPubMedGoogle Scholar
  11. 11.
    Munday BL, O’Donoghue PJ, Watts M, Rough K, Hawkeford T (1997) Fatal encephalitis due to the scuticociliate Uronema nigricans in sea-caged, southern bluefin tuna Thunnus maccoyii. Dis Aquat Org 3:17–25CrossRefGoogle Scholar
  12. 12.
    Sugaya T, Mori K, Nishioka T, Masuma S, Oka M, Mushiake K, Okinaka Y, Nakai T (2009) Genetic heterogeneity of betanodaviruses in juvenile production trials of Pacific bluefin tuna, Thunnus orientalis (Temminck & Schlegel). J Fish Dis 32:815–824CrossRefPubMedGoogle Scholar
  13. 13.
    Ogawa K, Tanaka S, Sugihara Y, Takami I (2010) A new blood fluke of the genus Cardicola (Trematoda: Sanguinicolidae) from Pacific bluefin tuna Thunnus orientalis (Temminck & Schlegel, 1844) cultured in Japan. Parasitol Int 59:44–48CrossRefPubMedGoogle Scholar
  14. 14.
    Lom J, Arthur JR (1989) A guideline for the preparation of species descriptions in Myxosporea. J Fish Dis 12:151–156CrossRefGoogle Scholar
  15. 15.
    Yokoyama H, Kim JH, Sato J, Sano M, Hirano K (1996) Fluorochrome Uvitex 2B stain for detection of the microsporidian causing beko disease of yellowtail and goldstriped amberjack juveniles. Fish Pathol 31:99–104Google Scholar
  16. 16.
    Hillis DM, Dixon MT (1991) Ribosomal DNA: molecular evolution and phylogenetic inference. Q Rev Biol 66:411–453CrossRefPubMedGoogle Scholar
  17. 17.
    Whipps CM, Kent ML (2006) Phylogeography of the cosmopolitan marine parasite Kudoa thyrsites (Myxozoa: Myxosporea). J Euk Microbiol 53:364–373CrossRefPubMedGoogle Scholar
  18. 18.
    Vossbrinck CR, Baker MD, Didier ES, Debrunner-Vossbrinck BA, Shadduck JA (1993) Ribosomal DNA sequences of Encephalitozoon hellem and Encepalitozoon cuniculi: species identification and phylogenetic construction. J Euk Microbiol 40:354–362CrossRefPubMedGoogle Scholar
  19. 19.
    Bell AS, Aoki T, Yokoyama H (2001) Phylogenetic relationships among microsporidia based on rDNA sequence data, with particular reference to fish-infecting Microsporidium Balbiani 1884 species. J Euk Microbiol 48:258–265CrossRefPubMedGoogle Scholar
  20. 20.
    Thompson JD, Gibson TJ, Plewniak F, Jeanmougin F, Higgins DG (1997) The CLUSTAL X Windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Res 25:4876–4882CrossRefPubMedGoogle Scholar
  21. 21.
    Guindon S, Lethiec F, Duroux P, Gascuel O (2005) PHYML online—a web server for fast maximum likelihood-based phylogenetic inference. Nucleic Acids Res 1:557–559CrossRefGoogle Scholar
  22. 22.
    Egusa S, Shiomitsu T (1983) Two new species of the genus Kudoa (Myxosporea: Multivalvulida) from marine cultured fishes in Japan. Fish Pathol 18:163–171Google Scholar
  23. 23.
    Egusa S (1986) A myxosporean of the order Multivalvulida from the brain of Lateolabrax japonicus and some other marine fishes. Fish Pathol 21:233–238Google Scholar
  24. 24.
    Whipps CM, Grossel G, Adlard RD, Yokoyama H, Bryant MS, Munday BL, Kent ML (2004) Phylogeny of the Multivalvulidae (Myxozoa: Myxosporea) based on comparative ribosomal DNA sequence analysis. J Parasitol 90:618–622CrossRefPubMedGoogle Scholar
  25. 25.
    Yokoyama H, Yokoyama F, Zhang JY, Tsuruoka K, Ogawa K (2008) Microsporidian infection in the trunk muscle of hatchery-bred juvenile spotted halibut Verasper variegatus. Fish Pathol 43:137–143CrossRefGoogle Scholar
  26. 26.
    Mladineo I (2006) Microsporidia sp. in Atlantic bluefin tuna (Thunnus thynnus). Bull Eur Assoc Fish Pathol 26:153–156Google Scholar
  27. 27.
    Sano M, Sato J, Yokoyama H (1998) Occurrence of beko disease caused by Microsporidium seriolae (Microspora) in hatchery-reared juvenile yellowtail. Fish Pathol 33:11–16Google Scholar
  28. 28.
    Nakajima K, Egusa S (1978) Kudoa pericardialis n. sp. (Myxosporidea: Chloromyxidae) from cultured yellowtail, Seriola quinqueradiata Temminck et Schlegel. Bull Jap Soc Sci Fish 44:117–120Google Scholar
  29. 29.
    Blaylock RB, Bullard SA, Whipps CM (2004) Kudoa hypoepicardialis n. sp. (Myxozoa: Kudoidae) and associated lesions from the heart of seven perciform fishes in the northern Gulf of Mexico. J Parasitol 90:584–593CrossRefPubMedGoogle Scholar
  30. 30.
    Al Quraishy S, Koura E, Abdel-Baki AS, Bashtar AR, El Deed N, Al Rasheid K, Abdel Ghaffar F (2008) Light and electron microscopic studies on Kudoa pagrusi sp. n. (Myxosporea: Multivalvulida) infecting the heart of sea bream Pagrus pagrus (L.) from the Red Sea. Parasitol Res102:205–209Google Scholar
  31. 31.
    Block BA, Stevens ED (2001) Tunas: physiology, ecology and evolution. Academic Press, San Diego, p 468Google Scholar
  32. 32.
    Hsie S, Chen C (1984) Septemcapsula yasunagai gen. et sp. nov., representative of a new family of the class Myxosporea. Acta Zootaxon Sin 9:225–227Google Scholar
  33. 33.
    Burger MAA, Cribb TH, Adlard RD (2007) Patterns of relatedness in the Kudoidae with descriptions of Kudoa chaetodoni n. sp. and K. lethrini n. sp. Parasitology 134:669–681CrossRefPubMedGoogle Scholar
  34. 34.
    Adlard RD, Bryant MS, Whipps CM, Kent ML (2005) Multivalvulid myxozoans from eastern Australia: three new species of Kudoa from scombrid and labrid fishes of the Great Barrier Reef, Queensland, Australia. J Parasitol 91:1138–1142CrossRefPubMedGoogle Scholar
  35. 35.
    Arai Y, Matsumoto K (1953) On a new sporozoa, Hexacapsula neothunni gen. et sp. nov., from the muscle of yellowfin tuna, Neothunnus macropterus. Bull Jpn Soc Sci Fish 18:293–298Google Scholar
  36. 36.
    Koura EA (2000) Kudoa aegyptia sp. n. (Myxozoa: Multivalvulida), in the heart muscle of haffara fish Rhabdosargus haffara. Egypt J Zool 34:1–26Google Scholar
  37. 37.
    Egusa S (1982) A microsporidian species from yellowtail juveniles, Seriola quinqueradiata, with “beko” disease. Fish Pathol 16:187–192Google Scholar
  38. 38.
    Egusa S, Hatai K, Fujimaki Y (1988) Notes on Microsporidium species, the etiological agent of “beko” disease in red sea bream juveniles, Pagrus major. Fish Pathol 23:263–267Google Scholar
  39. 39.
    Abela M, Brinch-Iversen J, Tanti J, Le Breton A (1996) Occurrence of a new histozoic microsporidian (Protozoa, Microspora) in cultured gilt head sea bream Sparus aurata L. Bull Eur Assoc Fish Pathol 16:196–199Google Scholar

Copyright information

© The Japanese Society of Fisheries Science 2010

Authors and Affiliations

  • Jinyong Zhang
    • 1
  • Fei Meng
    • 2
  • Hiroshi Yokoyama
    • 2
  • Jiro Miyahara
    • 3
  • Ikuo Takami
    • 3
  • Kazuo Ogawa
    • 2
  1. 1.State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of HydrobiologyChinese Academy of SciencesWuhanPeople’s Republic of China
  2. 2.Department of Aquatic Bioscience, Graduate School of Agricultural and Life SciencesThe University of TokyoTokyoJapan
  3. 3.Nagasaki Prefectural Institute of FisheriesNagasakiJapan

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