''Pseudorhabdosynochus satyui'' is a species of diplectanid

monogenea Monogeneans are a group of ectoparasitic flatworms commonly found on the skin, gills, or fins of fish. They have a direct lifecycle and do not require an intermediate host. Adults are hermaphrodites, meaning they have both male and female reprod ...

n that is parasitic on the

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s of the Hong Kong grouper (''

Epinephelus akaara The Hong Kong grouper (''Epinephelus akaara'') is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in eastern and ...

''). It was described in 2009.

Description

''Pseudorhabdosynochus satyui'' is a small monogenean, 0.5-0.7 mm in length. The species has the general characteristics of other species of ''

Pseudorhabdosynochus ''Pseudorhabdosynochus'' is a genus of monopisthocotylean monogeneans, included in the family Diplectanidae. The type-species of the genus is ''Pseudorhabdosynochus epinepheli'' ( Yamaguti, 1938). The genus includes more than 80 species, which a ...

'', with a flat body and a posterior haptor, which is the organ by which the monogenean attaches itself to the gill of is host. The haptor bears two

squamodisc Squamodiscs are epidermal structures, which are typical of and found only in certain monogeneans of the family Diplectanidae. There are, typically, two squamodiscs, one ventral and one dorsal, located on the haptor of the monogenean. Squamodiscs ...

s, one ventral and one dorsal. The sclerotized male copulatory organ, or "quadriloculate organ", has the shape of a bean with four internal chambers, as in other species of ''Pseudorhabdosynochus''.Kritsky, D. C. & Beverley-Burton, M. 1986: The status of ''Pseudorhabdosynochus'' Yamaguti, 1958, and ''Cycloplectanum'' Oliver, 1968 (Monogenea: Diplectanidae). Proceedings of the Biological Society of Washington, 99, 17-20
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The

vagina In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vestibule to the cervix. The outer vaginal opening is normally partly covered by a thin layer of mucosal tissue called the hymen ...

includes a sclerotized part, which is a complex structure. The species was found in 2009 among specimens of other species of diplectanid monogeneans, on two slides made in 1936 par the Japanese parasitologist Satyu Yamaguti and deposited in the Meguro Parasitological Museum in

Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. Only two specimens of the species were found. Jean-Lou Justine wrote "the author is aware that describing a new species from only two specimens is not optimal. However, ''P. satyui'' has a sclerotised vagina and measurements which enable its differentiation from other species, and the specimens are already deposited on two slides of good quality".

Etymology

The species ''Pseudorhabdosynochus satyui'' was named in honor of " Satyu Yamaguti, a parasitologist of immense reputation, who collected the type-specimens".

Hosts and localities

The type-host and only recorded host of ''P. satyui'' is the Hong Kong grouper (''Epinephelus akaara''). The type-locality and only recorded locality is Off Tarumi, Inland Sea of Japan.

References

{{Taxonbar, from=Q21325932 Diplectanidae Animals described in 2009 Fauna of Japan