Vol. 62, 2023
Molecular and Morphological
Characterizations of the Fish Parasitic Isopod Mothocya parvostis
(Crustacea: Cymothoidae) Parasitizing Optional Intermediate Hosts:
Juveniles of the Cobaltcap Silverside Hypoatherina
Yellowfin Seabream Acanthopagrus
Fujita1,*, Kentaro Kawai1,
Diego Deville1, and Tetsuya Umino1
School of Integrated Sciences for Life, Hiroshima University, 1-4-4
Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8528, Japan.
*Correspondence: E-mail: email@example.com (Fujita).
E-mail: firstname.lastname@example.org (Kawai); email@example.com
(Deville); firstname.lastname@example.org (Umino)
(Received 16 June 2022 / Accepted 10
February 2023 / Published 22 May 2023)
Communicated by Benny K.K. Chan
(Isopoda: Cymothoidae) is a parasitic crustacean that infests the
opercular cavities of fishes. Its main final host is the Japanese
halfbeak, Hyporhamphus sajori.
However, M. parvostis also
infests the black sea bream, Acanthopagrus
as an optional intermediate host. Understanding the use of optional
intermediate hosts is important for understanding the life history of
Cymothoidae, and further information should be obtained. In this study,
we aim to investigate the life cycle of M. parvostis. We collected and
examined 20 mancae and 144 juveniles of M. parvostis from 129 cobaltcap
silversides, Hypoatherina tsurugae,
and 494 yellowfin seabreams, Acanthopagrus
latus. Molecular analysis of the cytochrome c oxidase
subunit I gene and 16S rRNA genes revealed that cymothoid mancae and
juveniles from the two fish species were identified to be M. parvostis. All M. parvostis on H. tsurugae and A. latus might be mancae or
juveniles, with no adult parasites; thus, H. tsurugae and A. latus juveniles were optional
intermediate hosts of M. parvostis.
In the results of morphological description, M. parvostis juveniles infesting
the final host H. sajori
lacked swimming setae, while juveniles parasitizing the two optional
intermediate hosts had them. Mothocya
mancae infested juveniles of both species just after metamorphosis,
grew with the host. As the fish grows further, the parasite detached
from the fish. The parasitic status of M. parvostis in the three optional
intermediate hosts indicated that M.
likely reproduced from June to December, and different optional
intermediate hosts were used depending on the time of year in Hiroshima
Bay. Therefore, a parasitic strategy involving optional intermediate
hosts might increase the infestation success of M. parvostis to H. sajori.
Key words: Life cycle, Manca, New host record,
Parasitic cymothoid, Prevalence.
Fujita H, Kawai K, Deville D, Umino T. 2023. Molecular and morphological characterizations of the fish parasitic isopod Mothocya
parvostis (Crustacea: Cymothoidae) parasitizing optional intermediate
hosts: juveniles of the cobaltcap silverside Hypoatherina tsurugae and
yellowfin seabream Acanthopagrus latus. Zool Stud 62:21. doi:10.6620/ZS.2023.62-21.
materials: Table S1