Observations on the Nutrition of Monogenetic Trematodes

Halton, D W; Jennings, J. B.

doi:10.2307/1539843

Cited by 70 publications

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“…The gastrodermis of A. heterodus is quite similar to the pattern described for other Polyopisthocotylea, with two cell types: hematin cell and connecting syncytium (Llewelyn 1954, Halton & Jennings 1965, Halton et al 1968, Tinsley 1973, Halton 1975.…”

Section: Discussionsupporting

confidence: 59%

The Ultrastructure of the Gastrodermis and the Nutrition of the Gill Parasitic Atriaster heterodus Lebedev and Paruchin, 1969 (Platyhelminthes: Monogenea)

Santos

Souto-Padrón

Lanfredi

1998

Mem. Inst. Oswaldo Cruz

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The gastrodermis of Atriaster heterodus Lebedev & Paruchin, 1969 (Polyopisthocotylea), a gill parasite from Diplodus argenteus (Valenciennes, 1830) The functional morphology of the digestive system has been studied for different Monogenea (Smyth & Halton 1983, Bogitsh 1993 and the feeding in polyopisthocotyleans and monopisthocotyleans is generally distinct with the former ingesting blood (Llewelyn 1954, Halton 1982 and the latter, mucus and epithelial cells. However, blood pigments were observed in a few monopisthocotyleans (Uspenskaya 1962, Kearn 1963, Fournier 1978, Buchmann et al. 1987) while Allen and Tinsley (1989) demonstrated blood and epithelial cells at the same time in the gut lumen of a polyopisthocotylean species.Atriaster heterodus Lebedev & Paruchin, 1969 (Polyopisthocotylea) was recently reported from Rio de Janeiro coast (Santos et al. 1996). Surface topography and ultrastructural aspects of the spermatogenesis of this species have been described by Santos et al. (1997). The ultrastructure of the gastrodermis and the nutrition of this species are described herein. This paper represents the first ultrastructural study of gut caeca and nutrition of a marine monogenean from Brazil. MATERIALS AND METHODSParasites -Sixty five specimens of A. heterodus were obtained from the gills of 25 Diplodus argenteus (Valenciennes, 1830) Sparidae, collected in Copacabana beach, Rio de Janeiro, Brazil.Histochemistry -Monogeneans and gill filaments were fixed in 5% buffered formalin or 70% ethanol. Samples were embedded in paraffin and cut in 5 mM sections which were deparaffinized with xylene and prior to staining, hydrated in decreasing concentrations of ethanol to water. Histochemical reactions are indicated with the references and color of positive reactions as follows. Lilly and Fullmer (1976) were tested Perls (+=blue-green), Okajima (+=or-ange-red) and Dunn-Thompson (+= emerald green). The picric alcohol solubility test (Llewelyn 1954) was tested for hematin (+=solve).Ultrastructure -For ultrastructural studies, parasites were fixed for 2 hr at 4°C in a solution containing 4% paraformaldehyde, 2.5% glutaraldehyde and 0.3M sucrose in 0.1M cacodylate buffer in sea water, pH 7.2. After being washed in the same solution, they were post-fixed for 1 hr in dark conditions in a solution containing 1% OsO 4 , 0.8% potassium ferricyanide, and 5mM CaCl 2 in

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Section: Discussionsupporting

confidence: 59%

The Ultrastructure of the Gastrodermis and the Nutrition of the Gill Parasitic Atriaster heterodus Lebedev and Paruchin, 1969 (Platyhelminthes: Monogenea)

Santos

Souto-Padrón

Lanfredi

1998

Mem. Inst. Oswaldo Cruz

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“…Monopisthocotyleans are known to feed on host epidermal cells and mucus, which is digested by single, columnar shaped digestive cells present in the gut caeca (Kearn 1963;Halton and Jennings 1965;Halton and Stranock 1976a, b), whereas the gastrodermis of polyopisthocotyleans, which feed principally on the host blood, consists of pigmented digestive cells known as haematin cells interconnected by a non-pigmented syncytium (Llewellyn 1954;Halton et al 1968;Rohde 1975;Tinsley 1973;Halton 1975Halton , 1976. Exceptions to these generalisations have also been observed, for example, Euzetrema, a monopisthocotylean, is a known bloodfeeder (Fournier 1978), whereas some of the polyopisthocotyleans, such as Polystomoides, Polystomoidella and Neopolystoma, feed on host epithelial cells and mucus (Tinsley 1974;Allen and Tinsley 1989).…”

Section: Introductionmentioning

confidence: 99%

Ultrastructure of the gut caecal epithelium of Pricea multae (Monogenea: Polyopisthocotylea)

Brennan

Ramasamy

1996

Parasitology Research

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Ultrastructural observations of the gut caecal epithelium of Pricea multae revealed the presence of pigmented and non-pigmented digestive cells. The pigmented digestive cells were separated by a connecting syncytium and appeared elongated, with numerous vesicles appearing toward the apical cell surface. They were characterised by granular inclusions in the form of electron-dense pigments, which were eliminated by exocytosis. These cells and their lamellar connecting syncytium were observed projecting into the gut lumen. Transverse sections of the gut epithelium revealed intact portions of digestive cells lying in the lumen. Endocytosis at the apical surface of the pigmented digestive cells gave rise to the formation of granular inclusions, which appeared as electron-dense pigments confined to lysosomal vesicles within the digestive system. Electron X-ray microanalysis indicated these granules were primarily composed of iron, demonstrating that P. multae is a blood-feeder. The connecting syncytium, while probably involved in a structural, supportive role, may additionally function in the absorption of micromolecular nutrients from the host blood meal.

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“…While H. thynni and P. appendiculatus feed on host blood (Halton and Jennings, 1965; Kabata, 1966), E. brachypterus feeds on host mucus. The host response was milder in P. appendiculatus infection than in H. thynni , however there were some similarities, including hyperplastic and inflammatory responses, involving eosinophils at the site of attachment.…”

Section: Discussionmentioning

confidence: 99%

Branchial Pathomorphology of Southern Bluefin Tuna Thunnus maccoyii (Castelnau, 1872) Infected by Helminth and Copepodan Parasites

2017

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Three metazoan parasites, a monogenean Hexostoma thynni and two species of copepods Pseudocycnus appendiculatus and Euryphorus brachypterus are known to parasitize the gills of ranched southern bluefin tuna (SBT) and other tuna species. However, there is no detailed information describing the pathological response to infection by these parasites in this species. Wild southern bluefin tuna Thunnus maccoyii (approximately 3 years of age), captured and towed to a grow-out site in the waters immediately south of Port Lincoln, South Australia were subsequently sampled (n = 10) monthly from March until August 2004 during commercial harvest operations. Longitudinal sections of gill hemibranchs with attached parasites were excised and fixed for routine histology and immunohistochemistry. Reference samples were also collected from fish displaying no signs of parasitism or other grossly observable anomalies. Two morphologically distinct granulocytes were observed and putatively identified as eosinophils and mast cells. Pathology was localized to filaments upon and immediately adjacent to parasite attachment sites. Branchial cellular responses, adjunct to the attachment of H. thynni by its opisthaptoral clamps, included hyperplasia and inflammation resulting in structural remodeling of branchial tissues. Inflammatory infiltrates were often dominated by putative eosinophils and lymphocytes when parasitized by H. thynni and P. appendiculatus. Gill associated lymphoid tissue infiltrated the lamellar regions particularly in response to helminth infection. A variable response ranging from hemorrhage with minor hyperplasia or fibroplasia and eosinophilic inflammation to a barely discernible change was seen for gill sections harboring P. appendiculatus and E. brachypterus. The magnitude of the host response to attachment by the latter was congruent with attachment proximity and parasite load. On the basis of the host responses reported here and the low intensity of infection observed in other associated studies these gill ectoparasites are currently considered a low risk for wild and ranched adult SBT.

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Observations on the Nutrition of Monogenetic Trematodes

Cited by 70 publications

References 0 publications

The Ultrastructure of the Gastrodermis and the Nutrition of the Gill Parasitic Atriaster heterodus Lebedev and Paruchin, 1969 (Platyhelminthes: Monogenea)

The Ultrastructure of the Gastrodermis and the Nutrition of the Gill Parasitic Atriaster heterodus Lebedev and Paruchin, 1969 (Platyhelminthes: Monogenea)

Ultrastructure of the gut caecal epithelium of Pricea multae (Monogenea: Polyopisthocotylea)

Branchial Pathomorphology of Southern Bluefin Tuna Thunnus maccoyii (Castelnau, 1872) Infected by Helminth and Copepodan Parasites

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