Folia Parasitologica 72:028 (2025) | DOI: 10.14411/fp.2025.028

A new species of Pseudoacanthocephalus (Acanthocephala: Pseudoacanthocephalidae) from Sado Island, Japan, with a report of its accidental occurrence in a marine elasmobranch

Yuki Kita ORCID...1, Masato Nitta ORCID...2, Harue Abe ORCID...3, Shigen Kaburagi3, Takeshi Fujita3, Kenji Toyota4, 5, 6, Yusuke Kondo7, Hiroshi Kajihara ORCID...8
1 Graduate School of Science, Hokkaido University, Sapporo, Japan;
2 Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie, Japan;
3 Center for Sustainable Agriculture and Forestry, Faculty of Agriculture, Niigata University, Niigata, Japan;
4 Department of Bioresource Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan;
5 Biology Course, Department of Science, Faculty of Science, Kanagawa University, Kanagawa, Japan;
6 Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, Tokyo, Japan;
7 Faculty of Environmental Studies, Hiroshima Institute of Technology, Hiroshima, Japan;
8 Faculty of Science, Hokkaido University, Sapporo, Japan

Three species of amphibian-parasitic acanthocephalans belonging to the genus Pseudoacanthocephalus Petrochenko, 1958 have been recorded in Japan. However, only a limited number of localities have been surveyed, and the distribution of these congeners across other regions of Japan remains unclear. In this study, acanthocephalans of the genus Pseudoacanthocephalus were recovered from both definitive (Rana ornativentris Werner - type host, and Zhangixalus arboreus [Okada et Kawano]) and accidental hosts (Scyliorhinus torazame [Tanaka]) from Sado Island, Japan. Morphological analyses indicate that those specimens represent a new species, Pseudoacanthocephalus sadoensis sp. n., which may be endemic to the island. Additionally, our report of the incidental occurrence of this species in a marine elasmobranch represents the first documented case of a Pseudoacanthocephalus species found in a marine host.

Keywords: stomach contents, molecular phylogeny, endemic species, Sea of Japan, amphibian parasites

Received: April 6, 2025; Revised: June 14, 2025; Accepted: July 6, 2025; Published online: September 10, 2025  Show citation

ACS AIP APA ASA Harvard Chicago Chicago Notes IEEE ISO690 MLA NLM Turabian Vancouver
Kita, Y., Nitta, M., Abe, H., Kaburagi, S., Fujita, T., Toyota, K., Kondo, Y., & Kajihara, H. (2025). A new species of Pseudoacanthocephalus (Acanthocephala: Pseudoacanthocephalidae) from Sado Island, Japan, with a report of its accidental occurrence in a marine elasmobranch. Folia Parasitologica, 72, Article 2025.028. https://doi.org/10.14411/fp.2025.028
Share...
Download citation
  • BibTeX (.bib)
  • Bookends (.ris)
  • EasyBib (.ris)
  • EndNote (.enw)
  • EndNote 8 (.xml)
  • ISI WoS (.isi)
  • Medlars (.medlars)
  • Mendeley (.ris)
  • MODS (.xml)
  • Papers (.ris)
  • RefWorks (.txt)
  • RefManager (.ris)
  • RIS (.ris)
  • MS Word (.xml)
  • Zotero (.ris)
    • Open full article

    References

    1. Amin O.M. 2013: Classification of the Acanthocephala. Folia Parasitol. 60: 273-305. Go to original source... Go to PubMed...
    2. Amin O.M., Ha N.V., Heckmann R.A. 2008: New and already known acanthocephalans from amphibians and reptiles in Vietnam, with keys to species of Pseudoacanthocephalus Petrochenko, 1956 (Echinorhynchidae) and Sphaerechinorhynchus Johnston and Deland, 1929 (Plagiorhynchidae). J. Parasitol. 94: 181-189. Go to original source... Go to PubMed...
    3. Amin O.M., Heckmann R.A., Ha N.V. 2014: Acanthocephalans from fishes and amphibians in Vietnam, with descriptions of five new species Parasite 21: 53. Go to original source... Go to PubMed...
    4. Ansai N., Yoshino H., Waki T. 2025: [Cystacanth of the frog acanthocephalan Pseudoacanthocephalus lucidus (Palaeacanthocephala: Echinorhynchidae) in Japan.] Proc. Jpn. Soc. Syst. Zool. 58: 41-46. (In Japanese.)
    5. Arredondo N.J., Gil de Pertierra A.A. 2009: Pseudoacanthocephalus lutzi (Hamann, 1891) comb. n. (Acanthocephala: Echinorhynchidae) for Acanthocephalus lutzi (Hamann, 1891), parasite of South American amphibians. Folia Parasitol. 56: 295-304. Go to original source... Go to PubMed...
    6. Benesh D.P., Hasu T., Suomalainen L.-R., Valtonen E.T., Tiirola M. 2006: Reliability of mitochondrial DNA in an acanthocephalan: the problem of pseudogenes. Int. J. Parasitol. 36: 247-254. Go to original source... Go to PubMed...
    7. Bhattacharya S.B. 2007: Handbook on Indian Acanthocephala. Zoological Survey of India, Kolkata, 225 pp.
    8. Bouchon D., Souty-Grosset C., Raimond R. 1994: Mitochondrial DNA variation and markers of species identity in two penaeid shrimp species: Penaeus monodon Fabricius and P. japonicus Bate. Aquaculture 127: 131-144. Go to original source...
    9. Bush S.E., Duszynski D.W., Nickol B.B. 2009: Acanthocephala from amphibians in China with the description of a new species of Pseudoacanthocephalus (Echinorhynchida). J. Parasitol. 95: 1440-1445. Go to original source... Go to PubMed...
    10. Chernomor O., von Haeselar A., Minh B.Q. 2016: Terrace aware data structure for phylogenomic inference from supermatrices. Syst. Biol. 65: 997-1008. Go to original source... Go to PubMed...
    11. Edmonds S.J. 1971: Australian Acanthocephala No. 13: three new species. Trans. R. Soc. S. Aust. 95: 55-60.
    12. Fernández J.C., Ibarra Vidal H.G. 1992: Acanthocephalus caspanensis n. sp. (Acanthocephala. Echinorhynchidae) parásito de Bufo spinulosus Wiegmann en el Altiplano Chileno. Acta Zool. Lilloana 41: 207-213.
    13. Gibson D.I., Wayland M.T. 2025: World list of marine Acanthocephala. Pseudoacanthocephalus Petrochenko, 1958. World Register of Marine Species, https://www.marinespecies.org, 3/2025.
    14. Golvan Y.J. 1969: Systematique des acanthocephales (Acanthocephala Rudolphi, 1801), l'ordre des Palaeacanthocephala Meyer, 1931, la superfamille des Echinorhynchidea (Cobbold, 1876) Golvan and Houin 1963. Mém. Mus. Nat. Hist. 47: 1-373.
    15. Golvan Y.J. 1994: Nomenclature of the Acanthocephala. Res. Rev. Parasitol. 54: 135-205.
    16. Gupta V., Fatma S. 1986: Three acanthocephalan parasites of amphibian and mammalian hosts from Lucknow. Ind. J. Helminthol. 37: 137-148.
    17. Harada I. 1935: Zur Acanthocephalenfauna von Japan. Mem. Fac. Sci. Agr. Taihoku Imp. Univ. 14: 7-23.
    18. Hoang D.T., Chernomor O., von Haeseler A., Minh B.Q., Vinh L.S. 2018: UFBoot2: improving the ultrafast bootstrap approximation. Mol. Biol. Evol. 35: 518-522. Go to original source... Go to PubMed...
    19. Igawa T., Komaki S., Takahara T., Sumida M. 2015: Development and validation of PCR-RFLP assay to identify three Japanese brown frogs of the true frog genus Rana. Curr. Herpetol. 34: 89-94. Go to original source...
    20. Kita Y., Hiruta S.F., Sasaki M., Kajihara H. 2023: Systematic position of the genus Metacanthocephalus Yamaguti, 1959 (Palaeacanthocephala: Echinorhynchida) inferred from molecular evidence, with a redescription of Metacanthocephalus ovicephalus (Zhukov, 1960). Parasitol. Int. 94: 102731. Go to original source... Go to PubMed...
    21. Kita Y., Kajihara H. 2021: Morphological and molecular characterization of the marine-teleost parasitizing acanthocephalan Echinorhynchus hexagrammi (Syndermata: Palaeacanthocephala) from a new host, Liparis sp. (Actinopterygii: Scorpaeniformes). Parasitol. Int. 85: 102430. Go to original source... Go to PubMed...
    22. Kita Y., Nitta M., Kajihara H. 2024: Morphological and molecular characteristics of two species of the genus Rhadinorhynchus (Palaeacanthocephala: Echinorhynchida) from the western Pacific. Spec. Div. 29: 171-178. Go to original source...
    23. Kumar S., Stecher G., Tamura K. 2016: MEGA7: Molecular Evolutionary Genetic Analysis version 7.0 for bigger datasets. Mol. Biol. Evol. 33: 1870-1874. Go to original source... Go to PubMed...
    24. Matsui M. 2018: [Encyclopedia of Japanese frogs.] Bun-ichi Sogo Shuppan, Tokyo, 272 pp. (In Japanese.)
    25. Minh B.Q., Schmidt H.A., Chernomor O., Schrempf D., Woodhams M.D., von Haeseler A., Lanfear R. 2020: IQ-TREE 2: new models and efficient methods for phylogenetic inference in the genomic era. Mol. Biol. Evol. 37: 1530-1534. Go to original source... Go to PubMed...
    26. Miya M., Sato Y., Fukunaga T., Sado T., Poulsen J.Y., Sato K., Minamoto T., Yamamoto S., Yamanaka H., Araki H., Kondoh M., Iwasaki W. 2015: MiFish, a set of universal PCR primers for metabarcoding environmental DNA from fishes: detection of more than 230 subtropical marine species. Roy. Soc. Open. Sci. 2: 150088. Go to original source... Go to PubMed...
    27. Nagasawa K. 2014: An amphibian acanthocephalan, Acanthocephalus lucidus (Echinorhynchida: Echinorhynchidae), infecting a fish, Salvelinus leucomaenis leucomaenis (Salmoniformes: Salmonidae). Spec. Div. 19: 151-156. Go to original source...
    28. Nagasawa K., Nakamura Y. 2018: Further records of Pseudoacanthocephalus cf. bufonis (Acanthocephala: Echinorhynchidae) infecting anurans in the Ryukyu Islands, southern Japan. Nature of Kagoshima 45: 11-14.
    29. Nagasawa K., Yoshida R. 2017: Host utilization by the anuran acanthocephalan Pseudoacanthocephalus bufonis (Echinorhynchidae) on two subtropical islands, southern Japan. Biogeography 19: 25-30.
    30. Nakao M. 2016: Pseudoacanthocephalus toshimai sp. nov. (Palaeacanthocephala: Echinorhynchidae), a common acanthocephalan of anuran and urodelan amphibians in Hokkaido, Japan, with a finding of its intermediate host. Parasitol. Int. 65: 323-332. Go to original source... Go to PubMed...
    31. Nakao M., Ishigoka C. 2021: The phylogeographic puzzle of Pseudoacanthocephalus toshimai, an amphibian acanthocephalan in northern Japan. Parasitol. Int. 84: 102400. Go to original source... Go to PubMed...
    32. Nakao M., Sasaki M. 2021: Frequent infections of mountain stream fish with the amphibian acanthocephalan, Pseudoacanthocephalus toshimai (Acanthocephala: Echinorhynchidae). Parasitol. Int. 81: 102262. Go to original source... Go to PubMed...
    33. Park J.M., Baeck G.W., Raoult V. 2019: First observation on the diet and feeding strategy of cloudy catshark Scyliorhinus torazame (Tanaka, 1908). Reg. Stud. Mar. Sci. 28: 100596. Go to original source...
    34. Petrochenko V.I. 1956: Acanthocephala of Domestic and Wild Animals. Vol. 1. Izdatel'stvo Akademii Nauk SSSR, Moscow, 465 pp. (English translation by Israel program for scientific translations, Keter Press, Jerusalem, 1971, 465 pp.)
    35. Petrochenko V.I. 1958: Acanthocephala of Domestic and Wild Animals. Vol. 2. Izdatel'stvo Akademii Nauk SSSR, Moscow, 478 pp. (English translation by Israel program for scientific translations, Keter Press, Jerusalem, 1971, 478 pp.)
    36. Ronquist F., Teslenko M., van der Mark P., Ayres D.L., Darling A., Höhna S., Larget B., Liu L., Suchard M.A., Huelsenbeck J.P. 2012: MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Syst. Biol. 61: 539-542. Go to original source... Go to PubMed...
    37. Sado Geopark Promotion Council 2022: [Understanding the Sado Geopark, Nature and Human Life.] Bun-ichi Sogo Shuppan, Tokyo, 176 pp. (In Japanese.)
    38. Sekiya K., Miura I., Ogata M. 2012: A new frog species of the genus Rugosa from Sado Island, Japan (Anura, Ranidae). Zootaxa 3575: 49-62. Go to original source...
    39. Smales L.R. 2005: Acanthocephalans from some frogs and toads (Anura) and chameleons (Squamata) from Tanzania with the description of a new species. J. Parasitol. 91: 1459-1464. Go to original source... Go to PubMed...
    40. Smales L.R., Allain S.J.R., Wilkinson J.W., Harris E. 2020: A new species of Pseudoacanthocephalus (Acanthocephala: Echinorhynchidae) from the guttural toad, Sclerophrys gutturalis (Bufonidae), introduced into Mauritius, with comments on the implications of the introductions of toads and their parasites into the UK. J. Helminthol. 94: e119. Go to original source... Go to PubMed...
    41. Sumida M., Ueda H., Nishioka M. 2003: Reproductive isolating mechanisms and molecular phylogenetic relationships among Palearctic and Oriental brown frogs. Zool. Sci. 20: 567-580. Go to original source... Go to PubMed...
    42. Tamura K., Stecher G., Kumar S. 2021: Molecular Evolutionary Genetics Analysis version 11. Mol. Biol. Evol. 38: 3022-3027. Go to original source... Go to PubMed...
    43. Tkach V.V., Lisitsyna O.I., Crossley J.L., Binh T.T., Bush S.E. 2013: Morphological and molecular differentiation of two new species of Pseudoacanthocephalus Petrochenko, 1958 (Acanthocephala: Echinorhynchidae) from amphibians and reptiles in the Philippines, with identification key for the genus. Syst. Parasitol. 85: 11-26. Go to original source... Go to PubMed...
    44. Toda M., Kusano T. 2013: [Feeding habits of the Japanese treefrog, Rhacophorus arboreus, clarified by palpation and forced-regurgitation methods.] J. Jpn. Wildl. Res. Soc. 38: 13-20. (In Japanese.)
    45. Van Cleave H.J. 1925: Acanthocephala from Japan 1. Parasitology 17: 149-156. Go to original source...
    46. Van Cleave H.J. 1937: Acanthocephala from China. Parasitology 29: 395-398. Go to original source...
    47. Ward R.D., Zemlak T.S., Innes B.H., Last P.R., Hebert P.D.N. 2005: DNA barcoding Australia's fish species. Trans. R. Soc. London, Ser. B. 360: 1847-1851. Go to original source... Go to PubMed...
    48. Wayland M.T., Vainio J.K., Gibson D.I., Herniou E.A., Littlewood D.T., Väinölä R. 2015: The systematics of Echinorhynchus Zoega in Müller, 1776 (Acanthocephala, Echinorhynchidae) elucidated by nuclear and mitochondrial sequence data from eight European taxa. Zookeys 484: 25-52. Go to original source... Go to PubMed...
    49. Yamaguti S. 1939: Studies on the helminth fauna of Japan. Part 29. Acanthocephala, II. Jpn. J. Zool. 8: 317-351.
    50. Yoshino T., Aonuma Y., Yamaguchi A. 2013: [Scyliorhinidae. In: T. Nakabo (Eds.), Fishes of Japan with Pictorial Keys to the Species, Third Edition.] Tokai University Press, Hadano, pp. 162-166, 1759-1760. (In Japanese.)
    51. Yuan Z.-Y., Zhou W.-W., Chen X., Poyarkov N.A. Jr., Chen H.-M., Jang-Liaw N.-H., Chou W.-H., Matzke N.J., Iizuka K., Min M.-S., Kuzmin S.L., Zhang Y.-P., Cannatella D.C., Hilli D.M., Che J. 2016: Spatiotemporal diversification of the true frogs (genus Rana): a historical framework for a widely studied group of model organisms. Syst. Biol. 65: 824-842. Go to original source... Go to PubMed...
    52. Zhao C.-H., Yang R.-J., Lü L., Ru S.-S., Wayland M.T., Chen H.-X., Li Y.-H., Li L. 2013: Phylomitogenomic analyses provided further evidence for the resurrection of the family Pseudoacanthocephalidae (Acanthocephala: Echinorhynchida). Animals 13: 1256. Go to original source... Go to PubMed...
    53. Zhao C.-H., Yang R.-J., Ru S.-S., Chen H.-X., Li D.-X., Li L. 2024: Integrative taxonomy of the genus Pseudoacanthocephalus (Acanthocephala: Echinorhynchida) in China, with the description of two new species and the characterization of the mitochondrial genomes of Pseudoacanthocephalus sichuanensis sp. n. and Pseudoacanthocephalus nguyenthileae. Parasit. Vectors 17: 541. Go to original source... Go to PubMed...

    Return to the content