''Pseudorhabdosynochus regius'' is a diplectanid monogenean 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 ar ...

s of the mottled grouper (''Mycteroperca rubra'').

Description

Parasite140133-fig2 Pseudorhabdosynochus regius (Diplectanidae) Male and female organs 2B 2C

''Pseudorhabdosynochus regius'' is a small monogenean, about 600-1300 µm in length. The species has the general characteristics of other species of '' Pseudorhabdosynochus'', with a flat body and a posterior

haptor The haptor is the attachment organ of the monogeneans, a group of parasitic Platyhelminthes. The haptor is sometimes called opisthaptor (from ''opistho-'': behind) to emphasize that it is located in the posterior part of the body, and to differe ...

, which is the organ by which the monogenean attaches itself to the gill of is host. The haptor bears two squamodiscs, one ventral and one dorsal, which are small, with a length of 20-40 µm, and made up of only 10-11 rows of rodlets. 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, 26-35 µm in length. It exhibits a trumpet in continuity with the primary canal, a straight primary canal, and primary and secondary chambers included in a common sclerotised mass along the primary canal. The sclerotised vagina is the structure used by systematicians to differentiate species of '' Pseudorhabdosynochus''. The closest relatives of ''P. regius'', based on the structure of its sclerotised vagina, are species mostly found in the Mediterranean Sea and parasites on species of ''

Mycteroperca ''Mycteroperca'' is a genus of marine ray-finned fish, groupers from the subfamily Epinephelinae, part of the family Serranidae, which also includes the anthias and sea basses. They are predatory fish, largely associated with reefs and are found ...

''.

Hosts and localities

The type-host of ''Pseudorhabdosynochus regius'' is the grouper mottled grouper (''Mycteroperca rubra'') and the species has not been found in another host. The type-locality if off

Dakar Dakar ( ; ; wo, Ndakaaru) (from daqaar ''tamarind''), is the capital and largest city of Senegal. The city of Dakar proper has a population of 1,030,594, whereas the population of the Dakar metropolitan area is estimated at 3.94 million in 2 ...

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...

. The monogenean has also been found on fish of the same species caught off

Sfax Sfax (; ar, صفاقس, Ṣafāqis ) is a city in Tunisia, located southeast of Tunis. The city, founded in AD849 on the ruins of Berber Taparura, is the capital of the Sfax Governorate (about 955,421 inhabitants in 2014), and a Mediterrane ...

Tunisia ) , image_map = Tunisia location (orthographic projection).svg , map_caption = Location of Tunisia in northern Africa , image_map2 = , capital = Tunis , largest_city = capital , ...

and off

Tripoli, Libya Tripoli (; ar, طرابلس الغرب, translit= Ṭarābulus al-Gharb , translation=Western Tripoli) is the capital and largest city of Libya, with a population of about 1.1 million people in 2019. It is located in the northwest of Libya o ...

. Thus, ''P. regius'' is known from the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

and the Eastern

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. Only 14 species of diplectanids parasitic on

groupers Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" i ...

are known in the

and ''P. regius'' is one of them.

Gallery

Pseudorhabdosynochus regius - with English captions.png, ''Pseudorhabdosynochus regius'' - with captions for parts and organs Parasite140133-fig3 Pseudorhabdosynochus regius (Diplectanidae) Sclerotised vaginae.png, Sclerotised

e of various specimens Parasite140133-fig2 Pseudorhabdosynochus regius (Diplectanidae) Haptor hard parts 2C-2G.png, Hard parts of the

Parasite140133-fig2 Pseudorhabdosynochus regius (Diplectanidae) Squamodisc 2H.png, Ventral squamodisc

References

External links

{{Taxonbar, from=Q19595152 Diplectanidae Animals described in 2015 Fauna of Senegal Fauna of Tunisia Fauna of Libya