Ultrastructural observations on the epidermis of the polyopisthocotylinean monogeneans Rajonchocotyle emarginata and Plectanocotyle gurnardi

Lyons, Kathleen M.

doi:10.1007/bf00329145

Cited by 28 publications

(20 citation statements)

References 15 publications

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“…On the haptor, the haptoral appendix and the sucker peduncles, these projections have a regular knob-shape and a uniform distribution. It is also worth noting that, as also shown by Lyons (1972) in the related hexabothriid Rajonchocotyle emarginata (Olsson, 1876), a dense fibrous layer occurs beneath the surface membrane of the syncytial tegumental cytoplasm. This same layer has also been shown by Poddubnaya et al (2013) to occur beneath the surface membrane of the tegument of Chimaericola leptogaster (Leuckart, 1830), a polyopisthocotylean of the family Chimaericolidae, which is also a parasite of holocephalans.…”

Section: Discussionmentioning

confidence: 99%

“…Several of the most recent revisions of the taxonomic status of species of Callorhynchocotyle from chimaeras (both the Callorhinchidae and the Chimaeridae) provided diagnoses for the five known species of the genus Beverley-Burton and Chisholm 1990;Vaughan and Christison 2012). However, studies on the ultrastructural characteristics of hexabothriids are few (Lyons 1972;Agrawal et al 1996;Bullard et al 2001;Bullard and Dippenaar 2003;Poddubnaya et al 2015) and only the latter deals with a species of Callorhynchocotyle.…”

Section: Introductionmentioning

confidence: 97%

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The surface topography of Callorhynchocotyle callorhynchi (Manter, 1955) (Monogenea: Hexabothriidae), a parasite of the holocephalan fish Callorhinchus capensis

2015

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A scanning electron microscopical study, incorporating some transmission electron microscopical observations, was undertaken on the surface topography of the gill parasite Callorhynchocotyle callorhynchi (Manter, 1955) (Monogenea: Hexabothriidae) from the Cape elephant fish Callorhinchus capensis (Holocephali) off the western coast of South Africa. The study revealed the presence of several new characteristics for this species. These include the presence of regularly distributed, knob-shaped projections on the surface of the haptor, haptoral appendix and sucker peduncles measuring 0.2 μm and in concentrations of approximately 100 per 10 μm(2) and the existence of a ridge which bisects each sucker lumen, forming two different loculi. We also report, for the first time for any monogenean, the presence of 'true spines'; these occur on the luminal surface of the haptoral suckers and have all of the characteristics of the tegumental spines of digeneans, i.e. they are situated within the distal syncytial tegumental cytoplasm, rest on the basal plasma membrane, have a uniform structure and are covered apically by the tegumental surface plasma membrane. These spines are simple, straight and single-pointed. Under the scanning electron microscopy (SEM), within an area of 20 μm in diameter, 23 such spines were counted, but their concentration and arrangement varies in different regions of the sucker. At their base, they measure about 1.5 μm in width and reach approximately 2 μm in height above the general level of the tegument, but transmission electron microscopy (TEM) measurements of an entire spine indicate that they may reach 3 μm in total length. The presence of spines, possessing similar morphological characteristics in both basal polyopisthocotylean monogeneans and digeneans, represents another characteristic which may prove useful in understanding the evolutionary relationships within the Neodermata.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

The surface topography of Callorhynchocotyle callorhynchi (Manter, 1955) (Monogenea: Hexabothriidae), a parasite of the holocephalan fish Callorhinchus capensis

2015

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“…Ainsi, le spermatozoïde, l'épithélium intestinal et le syncytium tégumentaire (Lyons, 1972 b ;Rhode, 1975) des Polystomes ont des caractéristiques ultrastructurales qui confirment leur place parmi les Polyopisthocotylea. Tout récemment, Kearn (1978 b) a apporté un nouvel argument en prouvant que la paire d'yeux postérieure des Monopisthocotylea, trouve son homologue dans les nou veaux photorécepteurs non pigmentés, qu'il a découverts chez la larve des Polyopis thocotylea de Téléostéens.…”

Section: A Lambert Phylogénèse Des Monogènes D'après Llewellyn (1970unclassified

“…Bresciani (1973) et Rohde (1975 décrivent la même structure chez des Polystomatidae. Ces pores ne se rencontrent pas chez les Polyopisthocotylea de Téléostéens étudiés jusqu'ici (Morris et Halton, 1971 ;Lyons, 1972 b) qui présentent à l'inverse des microvillosités. Cet argument va dans le sens de nos observations ; il mérite cependant d'être déve loppé sur la base d'exemples plus nombreux.…”

Section: A Lambert Phylogénèse Des Monogènes D'après Llewellyn (1970unclassified

“…Par leur système excréteur, les Gyrodactylidae se rapprochent donc du type Polyopisthocotylea. Lyons (1972Lyons ( b, 1977 propose une distinction entre les Monopisthocotylea et les Polyopisthocotylea, d'après la présence d'une zone dense fibreuse, située sous la mem brane plasmique externe du tégument des Polyopisthocotylea. Sous réserve d'une véri-fication de cette hypothèse, on remarque que Kristky et Kruidenier (1976) retrouvent cette particularité ultrastructurale chez Gyrodactylus eucaliae ; le tégument de ce Gyrodactylidae présente donc un caractère décrit uniquement, jusqu'à présent, chez les Polyopisthocotylea.…”

Section: -Les Gyrodactylidaeunclassified

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