Academic Thesis

Basic information

Name Takeyama Tomohiro
Belonging department
Occupation name
researchmap researcher code 6000026214
researchmap agency Okayama University of Science

Title

Resolution of cryptic species complexes within the genus Metagonimus (Trematoda: Heterophyidae) in Japan, with descriptions of four new species

Bibliography Type

Joint Author

Author

Minoru Nakao, Takanori Ishikawa, Yusuke Hibino, Yuma Ohari, Rintaro Taniguchi  Tomohiro Takeyama, Shingo Nakamura, Wataru Kakino, Hiromi Ikadai, Mizuki Sasaki

Summary

A nationwide fish survey was conducted in Japan to detect metacercariae of the genus Metagonimus (Trematoda: Heterophyidae). The metacercariae were subjected to DNA barcoding for molecular species identification. A phylogeny inferred from the sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) prompted us to recognize three cryptic species complexes (i.e., the M. miyatai complex, the M. takahashii complex, and the M. katsuradai complex). Each complex included one or two undescribed species. For morphological description, adult flukes of each species were raised through the experimental infections of immunosuppressed mice. We propose M. saitoi n. sp., M. kogain. sp., M. shimazui n. sp., and M. kinoi n. sp., based on their phylogeny, morphology, biogeography, and ecology (host-parasite relationships). The originally described species, M. miyatai, was split into M. miyatai sensu stricto and M. saitoi n. sp. The former is distributed mainly in eastern Japan and uses the sweetfish (Plecoglossus altivelis) and daces (Pseudaspius hakonensis and Ps. sachalinensis) as principal second intermediate hosts, while the latter is in western Japan and its principal fish hosts are the dark chub (Nipponocypris temminckii) and the pale chub (Opsariichthys platypus). The present survey resolves a long-standing controversy on the microtaxonomy of Metagonimus in Japan since the first discovery of Metagonimus yokogawai in 1912, and shows that 10 species of Metagonimus are still distributed in Japan, although human metagonimiasis is almost eradicated.

Magazine(name)

Parasitology International

Publisher

Elsevier

Volume

90

Number Of Pages

StartingPage

102605

EndingPage

Date of Issue

2022/10

Referee

Exist

Invited

Not exist

Language

English

Thesis Type

Research papers (academic journals)

ISSN

DOI

https://doi.org/10.1016/j.parint.2022.102605

NAID

PMID

URL

J-GLOBAL ID

arXiv ID

ORCID Put Code

DBLP ID