Search

Start Over Subject ultrastructure Type model:internalpart

1. Bacillary band ultrastructure of the fish parasite Capillaria pterophylli (Nematoda: Capillariidae)

Creator:
Žďárská, Zdeňka and Nebesářová, Jana
Format:
print
Type:
model:internalpart and TEXT
Subject:
Nematoda, ultrastructure, bacillary band, and Capillaria pterophylli
Language:
English
Description:
In Capillaria pterophylli Heinze, 1933, two lateral bacillary bands extend along the whole body in female and male worms. A ventral bacillary band is present in females only. The bacillary bands consist of glandular and non-glandular cells, and in the region between the nerve ring and the end of the sticliosome, ciliated sense receptors in tight connection with gland cells are present.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Comparative ultrastructural study of the posterior suckers of four species of symbiotic Platyhelminthes, Temnocephala sp. (Temnocephalida), Udonella caligorum (Udonellidea), Anoplodiscus cirrusspiralis (Monogenea: Monopisthocotylea), and Philophthalmus sp. (Trematoda: Digenea)

Creator:
Rohde, K. and Watson, N.A.
Format:
print
Type:
model:internalpart and TEXT
Subject:
Temnocephala sp., Udonella caligorum, Anoplodiscus cirrusspiralis, Philophthalmus sp., ultrastructure, sucker, haptor, phytogeny, and homology
Language:
English
Description:
The posterior attachment organ (sucker) of Temnocephala sp. is located ventrally attached to the posterior end of the body by a well defined stalk; those of Udonella caligorum Johnston and Anoplodiscus cirrusspiralis Roubal, Armitage et Rohde are extensions of the posterior end facing posteriorly. In Philophthalmus, the sucker is ventrally embedded in the main body. The sucker of Temnocephala is lined by an epidermis, its ventral part separated from the adjacent epidermis by a septate junction. The epidermis resembles that of the body proper, containing nuclei and numerous dense bodies, its surface enlarged by short microvilli, traversed by glandular ducts of two types and by sensory receptors, and based on a basal lamina with a thick underlying fibrous matrix. The stalk of the sucker contains many muscle fibres extending from the main body into the sucker. The posterior surface of the sucker of Udonella is separated from the adjacent tegument by a septate junction; it consists of numerous microvilli arising from the basal lamina and does not represent a tegument; glandular ducts of two types open through it, and muscle fibres extend from the body proper into the sucker. The posterior surface of the sucker of Anoplodiscus consists of a thin tegument not separated from the adjacent tegument by a septate junction, drawn out into a very large number of densely packed, long microvilli, some branching from a thick cross-striated base; large glandular ducts open postero-laterally. The ventral sucker of Philophthalmus is embedded in the body proper but clearly bounded by a “capsule” of basal lamina; it is lined by a tegument continuous with that of the main body and lacking microvilli except in a small band around the ventral sucker opening. There is no evidence from ultrastructure that the stickers of the four taxa are homologous. Since there is no convincing other evidence for the homology of the posterior attachment organs of the major groups of parasitic Platyhelminthes (Neodermata) and the Temnocephalida, a “cercomer theory” assuming such homology cannot be accepted as proven.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Description of a new flagellate protist Desmomonas prorhynchi gen. et sp. n. associated with problematical cell masses, parasitic in the turbellarian Prorhynchus sp. (Lecithoepitheliata)

Creator:
Williams, Joan B.
Format:
print
Type:
model:internalpart and TEXT
Subject:
parasitic flagellate, ultrastructure, Desmomonas prorhynchi sp. n., Lecithoepitheliata, Prorhynchus, desmosome, epicuticular projections, and mitochondrial derivative
Language:
English
Description:
The fine structure is described of a new nonphotosynthctic flagellate, named Desmomonas prorhynchi gen. et sp. n„ cndoparasitic in the lecilhoepilheliate turbellarian Prorhynchus sp. The flagellates surround cell masses enveloped by a protective wall, to which adhere many small, regularly arranged cylindroid bodies; these structures are reminiscent of epicuticular projections characterising the body walls of some oligochaetes and polychaetes. The cells of a cell mass arc joined to the enveloping wall by spot hemidesmosomes. Their cytoplasm contains Golgi systems, mitochondria, fibrillar dense bodies, paired centrioles, and rod-shaped bacteria. Certain cells possess four ccntrioles. Ü. prorhynchi bears two flagella, and is attached temporarily to a cell mass by an anterior process ending at a highly organised desmosome. The flagellate plasma membrane has a fuzzy coating. Hair-like plasmalcmmal extensions project from the base of the anterior process. A mitochondrial derivative containing dense spheres lies some distance from the flagellar basal bodies. There is no Golgi apparatus. Other cytoplasmic constituents of the flagellate morphology are vacuoles, and microneme-like bodies. The two flagella, similar and without paraxial rods, arise from a flagellar pocket; neither is recurrent. The new protist cannot at present be assigned to any existing zoomastigophorean order.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Development of a myxozoan parasite Tetracapsula bryozoides gen. n. et sp. n. in Cristatella mucedo (Bryozoa: Phylactolaemata)

Creator:
Canning, Elizabeth U., Okamura, Beth, and Curry, Alan
Format:
print
Type:
model:internalpart and TEXT
Subject:
Tetracapsula bryozoides gen. n. et sp. n., Myxozoa, Cristatella mucedo, Bryozoa, and ultrastructure
Language:
English
Description:
Development of a new myxozoan parasite Tetracapsula bryozoides gen. n. et sp. n. in the coelomic cavities of Cris-latella mucedo Cuvier is described. Uninucleate proliferative cells are formed within well-defined sacs, the wall of which is one cell thick. The sacs, of different sizes according to age, are free floating and are conspicuously moved about within the coelomic fluid by the ciliary movements of the host. Division of the proliferative cells produces spherical cells of different sizes with nuclei of commensurate size. The largest cells enter sporogony by dividing into ten cells. Four of these become capsulogenic cells arranged as an anterior group, each giving rise to a spherical polar capsule containing a polar filament, possibly without prior formation of an external tube or, at most, very transient formation of these. Four valvogenic cells enclose the two sporoplasms and overlie the capsulogenic cells except at the points of exit of the polar filaments from the polar capsules. The two uninucleate sporoplasms are packed with endoplasmic reticulum, numerous mitochondria with tubular cristae and sporoplasmosomes which are distributed peripherally. Both sporoplasms produce secondary cells. Typical myxosporean features of the wall cells of the sac and all stages within the sac are: nuclei with granular nucleoplasm and prominent nucleolus, gap junctions between cells consisting of thickened membranes with cross connections, and haplosporosomes. A new genus is established for the parasite, defined as having development limited to uninucleate pseudoplasmodia within a sac of parasite origin, each uninucleate sporogonie stage giving rise to one spore with tetraradial symmetry, composed of four shell valves, four anterior polar capsules and two uninucleate sporoplasms with secondary cells. No plasmodia are formed. The genus is placed within the order Multivalvuli-da, in a new family Saccosporidae, defined as having development within a sac of parasite origin and sporogony without external tube or microtubules during polar capsule formation.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Early generation merogonies of Sarcocystis muriviperae in liver and muscles of white mice

Creator:
Paperna, Ilan and Finkelman, Simcha
Format:
print
Type:
model:internalpart and TEXT
Subject:
Sarcocystis muriviperae, white mouse, Vipera palaestinae, Coluber jugularis, merogony, young sarcocysts, liver, muscles, and ultrastructure
Language:
English
Description:
Early development of the coccidium Sarcocystis muriviperae Matuschka, Heydom, Mehlhom, Abd-Al-Aal, Diesing et Bichler, 1987 is described from experimentally infected white mice fed sporocysts from naturally infected Vipera palaestinae and Coluber jugularis. Although the course of infection was similar, mice infected with the sporocysts from the first host survived an inoculum of up to 200,000 sporocysts, while others infected with the second, succumbed to inocula exceeding 40,000 sporocysts in 7-10 days post infection (p,i,). Histological and ultrastructural studies revealed merogony in the hepatocytes during days 7-10 p.i. and onset of sarcocyst development by days 19-21 p.i. The livers of infected mice are grossly enlarged and of a mottled whitish colour due to severe neutrophil inflammatory infiltration, apparently stimulated by host cell residues or from defunct disaggregating meronts at the end of the merogony cycle. Early sarcocysts undergo a further division by endopolygeny before proceeding to division by endodyogeny.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Electron microscopic study of a new microsporean Microsporidium epithelialis sp. n. infecting Tubifex sp. (Oligochaeta)

Creator:
Oumouna, Mustapha, El-Matbouli, Mansour, Rudolf W., and Bouix, Georges
Format:
print
Type:
model:internalpart and TEXT
Subject:
Microsporea, Actinosporea, ultrastructure, Oligochaeta, and Tubificidae
Language:
English
Description:
The cytology of a new microsporean parasite Microsporidium epithelialis sp. n. from the intestinal epithelial cells of the freshwater oligochaete Tubifex sp. (Tubificidae) is described. The microsporean occurred together with an actinosporean of the genus Triactinomyxon, which was found between the epithelial cells. The merogonic and sporogonie stages (mature spores included) of the microsporean parasite are monokaryotic. An individual sporophorous vesicle surrounds each spore. The fixed and stained spore has an average dimension of 1.9-2.5 x 0.9-1.2 pm. The spores are oval with a characteristic surface layer, showing ornamentation-like projections, which are in close contact to the exosporc. A short polar filament forming three to four coils traverses the polaroplast with two lamellar layers. The ultrastructure and other characteristic features of this microsporean parasite are distinct from those of the microsporean species described so far from oligochaetes.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

7. Life cycles and host-parasite relationships of Microsporidia in culicine mosquitoes

Creator:
Becnel, J.
Format:
print
Type:
model:internalpart and TEXT
Subject:
Taxonomy, transmission, and ultrastructure
Language:
English
Description:
Ileterosporous (polymorphic) microsporidia in mosquitoes are characterized by intricate life cycles involving multiple spore types responsible for horizontal (per os) and vertical (transovarial) transmission. They affect two generations of the mosquito and some involve an obligate intermediate host. Heterosporous microsporidia are generally very host and tissue specific with complex developmental sequences comprised of unique stages and events. Full details on the intricate relationships between heterosporous microsporidia and their mosquito hosts have only recently been elucidated. Edhazardia aedis (Kudo, 1930) and Culicospora magna (Kudo, 1920) have developmental sequences in larvae that involve gametogony followed by plasmogatny and nuclear association to form diplokarya. These diplokaryotic stages then undergo karyogamy and form binucleate spores responsible for transovarial transmission. In the filial generation, haplosis occurs as a result of nuclear dissociation to produce uninucleate spores infectious to larval mosquitoes. Amblyospora cali-fornica (Kellen et Lipa, 1960) has similar sequences except that haplosis is by meiosis to produce spores infectious for a copepod intermediate host. A third spore type is formed in the intermediate host responsible for infection in a new generation of the mosquito host.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

8. Margolisiella kabatai gen. et sp. n. (Apicomplexa: Eimeriidae), a parasite of native littleneck clams, Protothaca staminea, from British Columbia, Canada, with a taxonomie revision of the coccidian parasites of bivalves (Mollusca: Bivalvia)

Creator:
Desser, Sherwin S. and Bower, Susan M.
Format:
print
Type:
model:internalpart and TEXT
Subject:
taxonomy, eimeriorin parasite, bivalve kidney, and ultrastructure
Language:
English
Description:
Two of 98 native littleneck clams, Protothaca staminea Conrad, from Cooper’s Cove, Sooke Basin were infected with an eimeriorin coccidian parasite. Merogonic, gamontogonic and sporogonie development were observed in renal tubular epithelial cells. Sporulation of the oocysts occurred within the host. Mature oocysts were spherical mean 41 pm (range 30-44), and contained about 32 subspherical sporocysts (9 x 10 pm), each of which contained 4 sporozoites. Spherical 19 pm (18-20), cyst-like structures and smaller multinucleate bodies, some of which resembled sporocysts, were also seen.A review of the coccidian parasites of bivalves led to the erection of the new genus, Margolisiella (family Eimeriidae Minchin, 1903) to accommodate M. kabatai sp. n., the parasite in Protothaca staminea described herein. Four previously described monoxenous species (Pseudoklossia patellae Debaisieux, P. chitonis Debaisieux, P. tellinovum Buchanan and P. halintis Friedman, Gardner, Hedrick, Stephenson, Cawthom et Upton) were also transferred to the new genus. The 2 remaining possibly heteroxenous species (P. pelseneeri Léger and P. glomerata Léger et Duboscq) were retained in the genus Pseudoklossia Léger et Duboscq (family Aggregatidae Labbé, 1899).
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

9. Notes on the ultrastructure of two myxosporean (Myxozoa) species, Zschokkella pleomorpha and Ortholinea fluviatilis

Creator:
Lom, Jiří and Dyková, Iva
Format:
print
Type:
model:internalpart and TEXT
Subject:
Myxosporea, ultrastructure, Zschokkella, and Ortholinea
Language:
English
Description:
Two myxosporean species, Zschokkella pleomorpha Lom et Dyková, 1995 (Zp) and Ortholinea fluviatilis Lom et Dyková, 1995 (Of) from the kidney of Tetraodon fluviatilis were studied by transmission electron microscope. Coelozoic sporogonie plasmodia of both species use pseudopodia-like projections for attachment to the epithelial cells of renal tubules. These projections either attach to host microvilli forming an interface reminiscent of septate junction (Zp) or are embedded into the epithelial cell surface (Of) or are inserted into gaps between epithelial cells (Zp, Of). Zp produces spores only by direct division of generative cells while in Of pansporoblasts prevail over direct division of generative cells. Sporogonie plasmodia of Zp greatly differ in size and in the variety of cytoplasmic constituents. A special feature in capsulogenesis is a transient envelope encasing the capsular primordium; there are fine fibres on the surface of the nascent filament spaced at 11 nm. In Of, vegetative nuclei of the plasmodium adhere to generative cells in a way reminding of sporoplasmic plasmodium of actinospores. In Of plasmodia, several unusual cytoplasmic structures were observed (membrane bound bodies with fuzzy radial contents or with a central dense inclusion, and endoplasmic reticulum cistemae forming a scalloped network). Of may also form intracellular coelozoic sporogonie plasmodia in the epithelial cells of renal tubules; these stages do not seem to constitute an important part of the life cycle.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Nybelinia queenslandensis sp. n. (Cestoda: Trypanorhyncha) parasitic in Carcharhinus melanopterus, from Australia, with observations on the fine structure of the scolex including the rhyncheal system

Creator:
Jones, Malcolm K. and Beveridge, Ian
Format:
print
Type:
model:internalpart and TEXT
Subject:
Cestoda, Trypanorhyncha, Tenlaculariidae, Nybelinia, morphology, scolex, ultrastructure, tentacles, and taxonomy
Language:
English
Description:
A new species of Nybelinia Poche, 1926, N. queenslandensis sp. n. (Cestoda: Trypanorhyncha) is described from sharks, Carcharhinus melanopterus (Quoy et Gaimard, 1824) from the coast of northeastern Queensland, Australia. Morphological features of the 46 known species of Nybelinia Poche, 1926 are tabulated and the new species is differentiated from all known taxa that are adequately described on the basis of having a homcomorphous armature, metabasal hooks 20-25 pm long, tentacles 0.07-0.09 mm in diameter, short bulbs (0.38-0.45 mm) and craspedote segments with the testes encircling the female genital complex. The fine structure of the scolex microtriches, frontal and rhynchodeal glands, tentacles and hooks, sheath and retractor muscle is described and compared with that of other trypanorhynchs.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public