The first record of \(\textit{Kudoa yasunagai}\) (Hsieh & Chen, 1984) (Myxosporea: Multivalvulida) parasitizing the brain of barhead spinefoot \(\textit{Siganus virgatus}\) (Valenciennes) from Vietnam

Nguyen Ngoc Chinh, Sho Shirakashi
Author affiliations


  • Nguyen Ngoc Chinh Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Ha Noi, Vietnam
  • Sho Shirakashi Aquaculture Research Institute, Kindai University, 3153, Shirahama, Nishimuro, Wakayama 649-2211, Japan



Kudoidae, brain, marine fish, SSU rDNA, Khanh Hoa province.


A brain-infecting myxozoan, Kudoa yasunagai (Hsieh & Chen, 1984), was identified using both morphological and molecular methods in a marine fish from Van Phong Bay, Khanh Hoa province, Vietnam. Cysts containing spores were observed in the brain of one out of 10 Siganus virgatus (Valenciennes) individuals (10%). The myxospores were radially symmetrical, containing a majority of 7 equal shell valves and polar capsules. The spores measured 6.6 ± 0.1 (6.4‒6.7) µm in length, 7.6 ± 0.5 (7.0‒8.4) µm in width, and 7.0 ± 0.4 (6.5‒7.7) µm in thickness. Polar capsules measured 2.8 ± 0.2 (2.6‒3.0) µm in length and 1.4 ± 0.1 (1.2‒1.5) µm in width, containing a filament inside. The SSU rDNA sequence from the Vietnamese specimen showed > 99.94 % identity with K. yasunagai from Japan and Australia. This report marks a new geographical and host record for K. yasunagai.


Download data is not yet available.


Metrics Loading ...


Abdel-Ghaffar F., Morsy K., Mehlhorn H., Bashtar A. R., Shazly M. A., Saad A. H., Abdel-Gaber R., 2012. First report of Kudoa species (Myxozoa: Kudoidae) infecting the spotted coral grouper Plectropomus maculates from the Red Sea. A light and ultrastructural study. Parasitology Research, 111(4): 1579‒1585.

Burger M. A. A., Adlard R. D., 2010. Phenotypic variation in a significant spore character in Kudoa (Myxosporea: Multivalvulida) species infecting brain tissue. Parasitology, 137(12): 1759‒1772.

Burger M. A. A., Cribb T. H., Adlard R. D., 2007. Patterns of relatedness in the Kudoidae with descriptions of Kudoa chaetodoni n. sp. and K. lethrini n. sp. (Myxosporea: Multivalvulida). Parasitology, 134(5): 669‒681.

Buron I., Hill-Spanik K. M., Haselden L., Atkinson S. D., Hallett S. L., Arnott S. A., 2017. Infection dynamics of Kudoa inornata (Cnidaria: Myxosporea) in spotted seatrout Cynoscion nebulosus (Teleostei: Sciaenidae). Diseases of Aquatic Organisms, 127(1): 29‒40.

Cheung P. J., Nigrelli R. F., 1990. Coccomyxa (Myxosporea: Bivalvulida) and Septemcapsula (Myxosporea: Multivalvulida) infections, the possible cause of death of coral catfish Plotosus anguillaris in captivity. Journal of Aquatic Animal Health 2(2): 112−118.

Chinh N. N., Ha N. T. H., Doanh P. N., Eiras J. C., Whipps C. M., Shirakashi S., 2023. Synopsis of myxosporean species (Cnidaria: Myxozoa) parasitizing fishes from Vietnam. Systematic Parasitology, 100(4): 325‒344.

Eiras J. C., Cruz C. F., Saraiva A., Adriano E. A., 2021. Synopsis of the species of Myxobolus (Cnidaria, Myxozoa, Myxosporea) described between 2014 and 2020. Folia Parasitologica, 68: 012

Eiras J. C., Saraiva A., Cruz C., 2014. Synopsis of the species of Kudoa Meglitsch, 1947 (Myxozoa: Myxosporea: Multivalvulida). Systematic Parasitology, 87(2): 153–180.

Egusa S., 1986a. A myxosporean of the order Multivalvulida from the brains of Lateolabrax japonicus and some other marine fishes. Fish Pathology, 21(4): 233−238

Egusa S., 1986b. The order Multivalvulida Schulman, 1959 (Myxozoa, Myxosporea): a review. Fish Pathology, 21(4): 261−274 (in Japanese).

Fiala I., 2006. The phylogeny of Myxosporea (Myxozoa) based on small subunit ribosomal RNA gene analysis. International Journal for Parasitology, 36(14): 1521–1534.

Fiala I., Bartošová-Sojková P., Whipps C. M., 2015. Classification and Phylogenetics of Myxozoa. In: Okamura B, Gruhl A, Bartholomew J (eds). Myxozoan evolution, ecology and development. Springer, New York, pp. 85–110.

Hillis D. M., Dixon M. T., 1991. Ribosomal DNA: molecular evolution and phylogenetic inference. Quarterly review of biology, 66(4): 411‒453.

Hoai T. D., Nhinh D. T., Giang N. T. H., Senapin S., Dong H. T., 2022. Detection and characterization of Kudoa thunni from uncooked yellowfin tuna (Thunnus albacares) in Southeast Asia. Parasitology International, 87: 102536.

Hsieh S. R., Chen C. L., 1984. Septemcapsula yasunagai gen. et sp. nov., representative of a new family of the class Myxosporea. Acta Zootaxonomica Sinica, 9: 225–227.

Ishimaru K., Matsuura T., Tsunemoto K., Shirakashi S., 2014. Seasonal monitoring of Kudoa yasunagai from sea water and aquaculture water using quantitative PCR. Diseases of Aquatic Organisms, 108(1):45‒52.

Iwashita Y., Kamijo Y., Nakahashi S., Shindo A., Yokoyama K., Yamamoto A., Omori Y., Ishikura K., Fujioka M., Hatada T., Takeda T., Maruyama K., Imai H., 2013. Food poisoning associated with Kudoa septempunctata. Journal of emergency medicine, 44(5): 943‒945.

Kawai T., Sekizuka T., Yahata Y., Kuroda M., Kumeda Y., Iijima Y., Kamata Y., Sugita-Konishi Y., Ohnishi T., 2012. Identification of Kudoa septempunctata as the causative agent of novel food poisoning outbreaks in Japan by consumption of Paralichthys olivaceus in raw fish. Clinical infectious diseases, 54(8): 1046–1052.

Levsen A., Jørgensen A., Mo T. A., 2008. Occurrence of postmortem myoliquefactive kudoosis in Atlantic mackerel, Scomber scombrus L., from the North Sea. Journal of fish diseases, 31(8): 601‒611.

Li Y. C., Inoue K., Tanaka S., Zhang J. Y., Sato H., 2020a. Identification of four new Kudoa spp. (Myxozoa: Myxosporea: Multivalvulida) in commercial fishes collected from South China Sea, Atlantic Ocean, and Bering Sea by integrated taxonomic approach. Parasitology Research, 119(7): 2113–2128.

Li Y. C., Inoue K., Zhang J. Y., Sato H., 2020b. Phylogenetic relationships of three Kudoa spp. with morphologically similar myxospores (K. iwatai, K. lutjanus, and K. bora), with the redescription of K. uncinata and K. petala and description of a new species (K. fujitai n. sp.) in fishes in the South China Sea. Parasitology Research, 119(4): 1221–1236.

Lom J., Arthur J. R., 1989. A guideline for the preparation of species descriptions in Myxosporea. Journal of Fish Disease, 12(2): 151–156.

Lom J., Dyková I., 2006. Myxozoan genera: definition and notes on taxonomy, life-cycle terminology and pathogenic species. Folia Parasitologica, 53(1): 1–36.

Matsukane Y., Sato H., Tanaka S., Kamata Y., Sugita-Konishi Y., 2010. Kudoa septempunctata n. sp. (Myxosporea: Multivalvulida) from an aquacultured olive flounder (Paralichthys olivaceus) imported from Korea. Parasitology Research, 107: 865–872.

Miller T. L., Adlard R. D., 2012. Brain infecting kudoids of Australia's coral reefs, including a description of Kudoa lemniscati n. sp. (Myxosporea: Kudoidae) from Lutjanus lemniscatus (Perciformes: Lutjanidae) off Ningaloo Reef, Western Australia. Parasitology international, 61(2): 333–42.

Okamura B., Hartigan A., Naldoni J., 2018. Extensive uncharted biodiversity: The parasite dimension. Integrative and Comparative Biology, 58(6): 1132–1145.

Patashnik M., Groninger H. S. J., Barnett H., Kudo G., Koury B., 1982. Pacific whiting, merluccius productus: Abnormal muscle texture caused by myxosporidian-induced proteolysis. Marine Fisheries Review, 44(5): 1–12.

Sakai H., Kawai T., Zhang J., Sato H., 2018. New host records of three Kudoa spp. (K. yasunagai, K. thalassomi, and K. igami) with notable variation in the number of shell valves and polar capsules in spores. Parasitology research, 118(1): 143‒157.

Shin S. P., Shirakashi S., 2017. Investigation of Kudoa yasunagai (Hsieh & Chen, 1984) infection kinetics in Seriola lalandi (Valenciennes, 1833) by quantitative PCR. Journal of Fish Disease, 40(2): 287‒291.

Shin S. P., Shirakashi S., Hamano S., Kato K., Lasso L. T., Yokoyama H., 2016. Phylogenetic study of the genus Kudoa (Myxozoa: Multivalvulida) with a description of Kudoa rayformis sp. nov. from the trunk muscle of Pacific sierra Scomberomorus sierra. Molecular phylogenetics and evolution. 98: 337‒345.

Shirakashi S., Morita A., Ishimaru K., Miyashita S., 2012. Infection dynamics of Kudoa yasunagai (Myxozoa: Multivalvulida) infecting brain of cultured yellowtail Seriola quinqueradiata in Japan. Diseases of Aquatic Organisms, 101(2): 123‒130.

Suzuki J., Murata R., Sadamasu K., Kai A., 2012. Cases of food poisoning caused possibly by Kudoa spp. in the Tokyo metropolitan area. IASR 33: 153–155. (in Japanese)

Suzuki J., Murata R., Yokoyama H., Sadamasu K., Kai A., 2015. Detection rate of diarrhoea-causing Kudoa hexapunctata in Pacific bluefin tuna Thunnus orientalis from Japanese waters. International Journal of Food Microbiology, 194: 1–6.

Tachibana T., Watari T., 2021. A novel case of food poisoning caused by the consumption of Pacific bluefin tuna infected with Kudoa hexapunctata. Clinical case reports, 9(6): e04222.

Tamura K., Stecher G., Peterson D., Filipski A., Kumar S., 2013. MEGA6: Molecular Evolutionary Genetics Analysis version 6.0. Molecular Biology and Evolution, 30(12): 2725–2729.

Tsuyuki H., Williscroft S. N., Kabata Z., Whitaker D. J., 1982. The relationship between acid and neutral protease activities and the incidence of soft cooked texture in the muscle tissue of Pacific hake (Merluccius productus) infected with Kudoa paniformis and/or K. thyrsites, held for varying times under different prefresh chilled storage conditions. Canadian Technical Report of Fisheries and Aquatic Sciences, 1130: 39.

Velasco M., Neto J. L. S., Videira M., Nascimento L. C. S., Gonçalves E. C., Matos E., 2019. Kudoa amazonica n. sp. (Myxozoa; Multivalvulida), a parasite of the esophageal musculature of the freshwater catfish, Hypophthalmus marginatus (Siluriformes: Pimelodidae), from a river of the Amazon region. Microbial pathogenesis, 130: 247‒252.

Wang M. M., Zhang J. E., Zhao Y. J., 2022. Morphological description and molecular identification of Myxobolus dajiangensis n. sp. (Myxozoa: Myxobolidae) from the gill of Cyprinus carpio in southwest China. PeerJ, 10: e13023.

Whipps C. M., Adlard R. D., Bryant M. S., Lester R. J. G., Findlay V., Kent M. L., 2003. First report of three Kudoa species from eastern Australia: Kudoa thyrsites from mahi mahi (Coryphaena hippurus), Kudoa amamiensis and Kudoa minithyrsites n. sp. from sweeper (Pempheris ypsilychnus). Journal of Eukaryotic Microbiology, 50(3): 215–219.

Whipps C. M., Grossel G., Adlard R. D., Yokoyama H., Bryant M. S., Munday B. L., Kent M. L., 2004. Phylogeny of the Multivalvulidae (Myxozoa: Myxosporea) based on comparative ribosomal DNA sequence analysis. Journal of Parasitology, 90(3): 618–622.

Yamamoto S., 2007. Chub mackerel. In: Kumai H., Mori K., Takashima T. (eds)., Aquaculture system 4 atlas. Kouseisya Kouseikaku, Tokyo, pp. 32–33.

Yasunaga N., Hatai K., Ogawa K., Yasumoto S., 1981. An unknown Myxozoa found in brain of cultured sea bass, Lateolabrax japonicus and cultured Japanese striped knifejaw, Oplegnathus fasciatus. Fish Pathology, 16: 51−54.

Yokoyama H., Whipps C. M., Kent M. L., Mizuno K., Kawakami H., 2004. Kudoa thyrsites from Japanese flounder and Kudoa lateolabracis n. sp. from Chinese sea bass: causative agent of post-mortem myoliquefaction. Fish Pathology, 39(2): 79‒85.

Yokoyama H., Suzuki J., Shirakashi S., 2014. Kudoa hexapunctata n. sp. (Myxozoa: Multivalvulida) from the somatic muscle of Pacific bluefin tuna Thunnus orientalis and re-description of K. neothunni in yellowfin tuna T. albacares. Parasitology International, 63(4): 571‒579.

Zhang J., Meng F., Yokoyama H., Miyahara J., Takami I., Ogawa K., 2010. Myxosporean and microsporidian infections in cultured Pacific bluefin tuna Thunnus orientalis in Japan. Fisheries Science, 76: 981–990.




How to Cite

Nguyen Ngoc, C., & Shirakashi, S. (2024). The first record of \(\textit{Kudoa yasunagai}\) (Hsieh & Chen, 1984) (Myxosporea: Multivalvulida) parasitizing the brain of barhead spinefoot \(\textit{Siganus virgatus}\) (Valenciennes) from Vietnam. Academia Journal of Biology, 46(1), 87–97.