Detection and molecular characteristics of Rhytidodoides sp. (Digenea: Rhytidodidae) from the gall bladder of green sea turtles (Chelonia mydas) in the Ogasawara Islands, Japan

Chiyo Kitayama; Kei Hayashi; Kaoru Hayashi; Hitomi Igarashi; Satomi Kondo; Ryuta Ogawa; Tomoaki Hashimoto; Saki Okubo; Yasuhiro Takashima; Tadashi Itagaki; Toshiro Kuroki; Toshiyuki Shibahara

doi:10.1016/j.parint.2021.102377

Detection and molecular characteristics of Rhytidodoides sp. (Digenea: Rhytidodidae) from the gall bladder of green sea turtles (Chelonia mydas) in the Ogasawara Islands, Japan

Parasitol Int. 2021 Aug:83:102377. doi: 10.1016/j.parint.2021.102377. Epub 2021 May 7.

Authors

Affiliations

¹ Everlasting Nature of Asia (ELNA), Ogasawara Marine Center, Ogasawara, Tokyo 100-2101, Japan.
² Laboratory of Parasitology, Faculty of Veterinary medicine, Okayama University of Science, 1-3 Ikoinooka, Imabari 794-8555, Japan. Electronic address: k-hayashi@vet.ous.ac.jp.
³ Laboratory of Parasitology, Faculty of Veterinary medicine, Okayama University of Science, 1-3 Ikoinooka, Imabari 794-8555, Japan.
⁴ Laboratory of Veterinary Anatomy, Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoinooka, Imabari 794-8555, Japan.
⁵ Department of Veterinary Parasitology, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; The United Graduate School of Veterinary Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan; Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan.
⁶ Laboratory of Veterinary Parasitology, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka 020-8550, Japan.

PMID: 33971309
DOI: 10.1016/j.parint.2021.102377

Abstract

Trematodes of the genus Rhytidodoides are parasitic in marine turtles. Of the already known species, Rhytidodoides similis Price, 1939, occurs especially in the gall bladder. In this study, we surveyed 73 green sea turtles (Chelonia mydas) in the Ogasawara Islands, Japan, and detected Rhytidodoides sp. from the gall bladders of 18 turtles. A detailed morphological analysis revealed that the forebody of Rhytidodoides sp. differed slightly in shape from that of R. similis. There has been no information on DNA sequences of the family Rhytidodidae. A molecular phylogeny based on 28S rDNA sequences of Rhytidodoides sp. and related taxa suggested that the Rhytidodidae is sister to the other families of Echinostomatoidea. The intraspecific diversity of Rhytidodoides sp. was examined by using DNA sequences of mitochondrial cytochrome c oxidase subunit 1 gene (COI). The population genetic features of the COI haplotypes demonstrated that Rhytidodoides sp. is highly diverse in the Ogasawara Islands. The DNA sequences determined in this study will contribute to the species identification of congeners and the taxonomic reconsideration of the Echinostomatoidea.

Keywords: 28S; COI; Chelonia mydas; ITS2; Ogasawara Islands; Rhytidodoides sp..

MeSH terms

Animals
DNA, Helminth / analysis
DNA, Ribosomal / analysis
Gallbladder Diseases / parasitology
Gallbladder Diseases / veterinary*
Japan / epidemiology
Phylogeny
Prevalence
Trematoda / anatomy & histology
Trematoda / genetics
Trematoda / isolation & purification*
Trematode Infections / parasitology
Trematode Infections / veterinary*
Turtles*

Substances

DNA, Helminth
DNA, Ribosomal