''Pseudorhabdosynochus justinella'' 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 are ...

s of the red grouper, ''

Epinephelus morio The red grouper (''Epinephelus morio'') 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 the western Atlanti ...

''. It has been described by

Kritsky ''Kritsky'' is a genus of digeneans in the family Aporocotylidae or blood flukes.WoRMS (2018). Kritsky Orelis-Ribeiro & Bullard, 2016. Accessed at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=871002 on 2018-09-23 The name of the genus ...

, Bakenhaster and Adams in 2015. The specific name ''justinella'' is in honor of

parasitologist Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question but by their way of life. This means it f ...

Jean-Lou Justine Jean-Lou Justine (born 1955), French parasitologist and zoologist, is a professor at the National Museum of Natural History in Paris, France, and a specialist of fish parasites and invasive land planarians. Higher education and career Justine w ...

from National Museum of Natural History in France.

Description

''Pseudorhabdosynochus justinella'' is a small monogenean. 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 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

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 ''

''.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 description by

, Bakenhaster & Adams in 2015 includes the following:

Diagnosis

, Bakenhaster & Adams (2015) wrote that "examination of the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

, three paratypes, and voucher specimens from red grouper off Florida and Mississippi indicated that the original description of '' P. yucatanensis'' Vidal-Martínez, Aguirre-Macedo & Mendoza-Franco, 1997Vidal-Martínez, V. M., Aguirre-Macedo, L. & Mendoza-Franco, E. F. 1997: ''Pseudorhabdosynochus yucatanensis'' sp. n. (Monogenea: Diplectanidae) from the gills of the red grouper ''Epinephelus morio'' (Pisces: Serranidae) of the Yucatan Peninsula, Mexico" ''Folia Parasitologica'' 44, 274-278
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was based on specimens representing two distinct species of ''

''", namely ''P. yucatanensis'' ''sensu stricto'' and a new species, ''P. justinella''

, Bakenhaster & Adams, 2015. According to

, Bakenhaster & Adams (2015), ''P. justinella'' is most similar to '' P. woodi''

, Bakenhaster & Adams, 2015 based on the comparative morphology of the vaginal sclerite, the ventral bar, and the ventral and dorsal anchors. In both species, the vaginal sclerite possesses an elongate sigmoid distal tube attached to the distal end of the chamber, the ventral bar is short and robust, the deep root of the ventral anchor is shorter than the superficial root, and the dorsal anchors of the two species are morphologically indistinguishable. ''P. justinella'' differs from ''P. woodi'' by having a vaginal sclerite with a larger (~20 μm in diameter) subspherical chamber (vaginal sclerite with a small 10 μm in lengthovate chamber in ''P. woodi'').

Hosts and localities

The type-host and only recorded host is the Red grouper, ''

'' (Serranidae: Epinephelinae). The type-locality is

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

Middle Grounds, Gulf of Mexico. Other localities are Gulf of Mexico (an area off Mississippi with numerous

artificial reef An artificial reef is a human-created underwater structure, typically built to promote marine life in areas with a generally featureless bottom, to control erosion, block ship passage, block the use of trawling nets, or improve surfing. Many re ...

s) and Progreso, Yucatan State, Mexico (as ''P. yucatanensis'').

References

This article incorporates CC-BY-4.0 text from the reference {{Taxonbar, from=Q22285100 Diplectanidae Animals described in 2015