Pseudorhabdosynochus americanus

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Pseudorhabdosynochus americanus
Parasite150040-fig1 Pseudorhabdosynochus americanus (Price, 1937) - FIGS 1-8.tif
Pseudorhabdosynochus americanus, body and details of sclerotised parts
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Monogenea
Order: Dactylogyridea
Family: Diplectanidae
Genus: Pseudorhabdosynochus
Species:
P. americanus
Binomial name
Pseudorhabdosynochus americanus
(Price, 1937) Kritsky & Beverley-Burton, 1986
Synonyms

Diplectanum americanumPrice, 1937
Cycloplectanum americanum(Price, 1937) Oliver, 1968 (pro parte)

Contents

Pseudorhabdosynochus americanus is a diplectanid monogenean parasitic on the gills of groupers. It was described as Diplectanum americanum by Price in 1937 [1] and transferred to the genus Pseudorhabdosynochus by Kritsky and Beverley-Burton in 1986. [2] The species was redescribed by Kritsky, Bakenhaster and Adams in 2015. [3]

Description

Pseudorhabdosynochus americanus is a small monogenean. The species has the general characteristics of other species of Pseudorhabdosynochus , 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 squamodiscs, 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 . [2] The vagina includes a sclerotized part, which is a complex structure.

The redescription by Kritsky, Bakenhaster & Adams in 2015 includes the following: Body flattened dorsoventrally. Tegumental scales with rounded anterior margins extending from peduncle anteriorly into posterior trunk. Cephalic region broad, with two terminal and two bilateral poorly developed cephalic lobes, three bilateral pairs of head organs, pair of bilateral groups of cephalic-gland cells at level of pharynx. Posterior pair of eyespots lacking lenses, lying immediately anterior to pharynx (two specimens lacking one member of the pair); anterior pair usually absent, often represented by few poorly associated chromatic granules (one specimen with well-developed anterior eyespots lacking lenses); accessory chromatic granules small, irregular, usually anterior to posterior pair of eyespots. Pharynx with muscular wall; esophagus short to nonexistent; intestinal ceca blind, extending posteriorly to near anterior limit of peduncle. Peduncle broad, tapered posteriorly. Haptor with dorsal and ventral anteromedial lobes containing respective squamodiscs and lateral lobes having hook pairs 2–4, 6, 7. Dorsal and ventral squamodiscs subequal, with 19–23 (usually 21) U-shaped rows of rodlets; 1–3 (usually 2) innermost rows closed. Ventral anchor with well-developed superficial root, long deep root having lateral swelling, slightly curved shaft, and short recurved point extending to just past level of tip of superficial root. Dorsal anchor with subtriangular base, poorly developed roots, arcing shaft, recurved point extending past level of superficial tip of base. Ventral bar with slight medial constriction, tapered ends, longitudinal medioventral groove. Paired dorsal bar with spatulate medial end. Hook with elongate depressed thumb, delicate point, uniform shank; filamentous hook (FH) loop nearly shank length. Testis ovate, lying sinistroposterior to germarium; proximal vas deferens, prostatic reservoir not observed; seminal vesicle an indistinct dilation of distal vas deferens, lying just posterior to MCO; ejaculatory bulb not observed. Male copulatory organ (MCO) reniform, quadriloculate, with short distal cone, elongate tube with comparatively thick walls, delicate apparently retractile distal filament; walls of two distal chambers thick, walls of proximal two chambers thinner but comparatively rigid. Germarium pyriform, shaped as an inverted comma; germarial bulb lying diagonally at body midlength, with elongate dorsoventral distal loop around right intestinal cecum; ootype lying to left of body midline, with well-developed Mehlis’ gland and giving rise to delicate banana-shaped uterus when empty. Common genital pore ventral, dextral to distal chamber of MCO. Vaginal pore sinistroventral at level of seminal vesicle. Vaginal vestibule delicate; vaginal sclerite with distal funnel and two comparatively large juxtaposed thick-walled chambers; seminal receptacle subspherical, immediately proximal to vagina and anterior to ootype. Bilateral and common vitelline ducts at level of ootype; vitellarium absent in regions of other reproductive organs, otherwise dense throughout trunk. [3] [ excessive quote ]

Kritsky, Bakenhaster & Adams concluded that Pseudorhabdosynochus americanus is easily distinguished from its congeners that infect groupers in the western Atlantic region by its unique vaginal sclerite consisting of a distal funnel and two comparatively large juxtaposed thick-walled chambers. [3]

Hosts and localities

The Atlantic goliath grouper (Epinephelus itajira) is the type-host and probably only host of Pseudorhabdosynochus americanus Goliathgrouper1.jpg
The Atlantic goliath grouper (Epinephelus itajira) is the type-host and probably only host of Pseudorhabdosynochus americanus

The type-host of Pseudorhabdosynochus americanus is the Atlantic goliath grouper (Epinephelus itajira). [1] [3] Kritsky, Bakenhaster & Adams in 2015 listed a number of unconfirmed and erroneous host and locality records [3] and concluded that the Atlantic goliath grouper is likely the only natural host for P. americanus.

Related Research Articles

<i>Pseudorhabdosynochus manifestus</i> Species of flatworm

Pseudorhabdosynochus manifestus is a diplectanid monogenean parasite first found in host Epinephelus malabaricus near Nouméa, between its secondary gill lamellae. It can infest its host by the hundreds. It was ascribed that name because it was the most abundant species found while its descriptive study was taking place. As appreciated from studying juvenile specimens, the development of female organs precedes that of male organs in this species and is likely the case in other Pseudorhabdosynochus species.

<i>Pseudorhabdosynochus yucatanensis</i> Species of flatworm

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<i>Pseudorhabdosynochus justinella</i> Species of flatworm

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<i>Pseudorhabdosynochus kritskyi</i> Species of flatworm

Pseudorhabdosynochus kritskyi is a diplectanid monogenean parasitic on the gills of the gag, Mycteroperca microlepis. The species has been described by Dyer, Williams and Bunkley-Williams in 1995 and redescribed successively by Yang, Gibson and Zeng in 2005 and by Kritsky, Bakenhaster and Adams in 2015. The name of the species honours the American parasitologist Delane C. Kritsky.

<i>Pseudorhabdosynochus capurroi</i> Species of flatworm

Pseudorhabdosynochus capurroi is a diplectanid monogenean parasitic on the gills of the Black grouper, Mycteroperca bonaci. It was described by Vidal-Martínez and Mendoza-Franco in 1998 and redescribed successively by Yang, Gibson and Zeng in 2005 and by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus hyphessometochus</i> Species of flatworm

Pseudorhabdosynochus hyphessometochus is a diplectanid monogenean parasitic on the gills of the yellowmouth grouper, Mycteroperca interstitialis. It has been described by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus sulamericanus</i> Species of flatworm

Pseudorhabdosynochus sulamericanus is a diplectanid monogenean parasitic on the gills of the snowy grouper, Epinephelus niveatus, the Warsaw grouper, Epinephelus nigritus and the Haifa grouper, Epinephelus haifensis. It has been described by Santos, Buchmann & Gibson in 2000 , redescribed by Kritsky, Bakenhaster and Adams in 2015. and again redescribed by Chaabane, Justine, Gey, Bakenhaster & Neifar in 2016.

<i>Pseudorhabdosynochus firmicoleatus</i> Species of flatworm

Pseudorhabdosynochus firmicoleatus is a diplectanid monogenean parasite on the gills of the Yellowedge grouper, Epinephelus flavolimbatus and the Snowy grouper, Epinephelus niveatus. It was described by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus mcmichaeli</i> Species of worm

Pseudorhabdosynochus mcmichaeli is a diplectanid monogenean parasitic on the gills of the scamp, Mycteroperca phenax. It has been described by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus meganmarieae</i> Species of flatworm

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<i>Pseudorhabdosynochus vascellum</i> Species of flatworm

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<i>Pseudorhabdosynochus contubernalis</i> Species of flatworm

Pseudorhabdosynochus contubernalis is a diplectanid monogenean parasitic on the gills of the Scamp, Mycteroperca phenax. It has been described by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus monaensis</i> Species of flatworm

Pseudorhabdosynochus monaensis is a diplectanid monogenean parasitic on the gills of the rock hind, Epinephelus adscensionis. It has been described by Dyer, Williams & Bunkley-Williams in 1994 and redescribed by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus mycteropercae</i> Species of flatworm

Pseudorhabdosynochus mycteropercae is a diplectanid monogenean parasitic on the gills of the tiger grouper, Mycteroperca tigris (Serranidae). It has been described by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus williamsi</i> Species of flatworm

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<i>Pseudorhabdosynochus mizellei</i> Species of flatworm

Pseudorhabdosynochus mizellei is a diplectanid monogenean parasitic on the gills of the red hind, Epinephelus guttatus. It has been described by Kritsky, Bakenhaster and Adams in 2015. The species was named Diplectanum epinepheli by Mizelle & Wood but this name was not published and is a nomen nudum according to Kritsky, Bakenhaster & Adams (2015).

<i>Pseudorhabdosynochus bunkleywilliamsae</i> Species of flatworm

Pseudorhabdosynochus bunkleywilliamsae is a diplectanid monogenean parasitic on the gills of the Nassau grouper, Epinephelus striatus. It has been described by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus woodi</i> Species of flatworm

Pseudorhabdosynochus woodi is a diplectanid monogenean parasitic on the gills of the red hind, Epinephelus guttatus. It has been described by Kritsky, Bakenhaster and Adams in 2015.

<i>Pseudorhabdosynochus tumeovagina</i> Species of flatworm

Pseudorhabdosynochus tumeovagina is a diplectanid monogenean parasitic on the gills of the speckled hind, Epinephelus drummondhayi. It has been described by Kritsky, Bakenhaster and Adams in 2015.

Pseudorhabdosynochus hargisi is species of a diplectanid monogenean parasitic on the gills of the White grouper Epinephelus aeneus. It was described in 1984 as Diplectanum hargisi and transferred to the genus Pseudorhabdosynochus by Santos, Buchmann & Gibson in 2000. Its systematic position has been clarified by Kritsky, Bakenhaster & Adams in 2015, who differentiated it from Pseudorhabdosynochus americanus.

References

  1. 1 2 Price, E. W. 1937: North American Monogenetic Trematodes. I. The superfamily Gyrodactyloidea. Journal of the Washington Academy of Sciences, 27, 146-164. PDF Open Access logo PLoS transparent.svg
  2. 1 2 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. PDF Open Access logo PLoS transparent.svg
  3. 1 2 3 4 5 Kritsky, Delane C.; Bakenhaster, Micah D.; Adams, Douglas H. (2015). "Pseudorhabdosynochus species (Monogenoidea, Diplectanidae) parasitizing groupers (Serranidae, Epinephelinae, Epinephelini) in the western Atlantic Ocean and adjacent waters, with descriptions of 13 new species". Parasite. 22: 24. doi:10.1051/parasite/2015024. ISSN   1776-1042. PMC   4536336 . PMID   26272242. Open Access logo PLoS transparent.svg