“…Because an understanding of the infraciliature in the trophont or non-dividing ciliate is an essential prerequisite to study of its role in morphogenesis, the present study on the enigmatic species Cyathodinium piriforme was undertaken. Reports on the morphology of this small parasitic ciliate already exist in the older literature (eg., 9,10,[17][18][19], but our findings either do not agree in several important respects or have added new data of significance. The study was further stimulated by the fact that to date no wholly satisfactory taxonomic allocation has been made for the organism.…”
SYNOPSIS. The unusual patterns of infraciliary kinetosomes on the body and in the large anterior depression of the trophont stage of this difficult‐to‐classify ciliate have been examined by use of the Chatton‐Lwoff silver impregnation technique. In our material there are nine rows of somatic cilia, arranged more or less concentrically around the oral cavity at the anterior end of the pyriform‐shaped body; in the cavity itself there are eight quite separate rows of “vestibular” ciliature. Erratically distributed on posterior areas of the body are argentophilic “granules” which may be non‐cilia‐bearing kinetosomes. A contractile vacuole pore, described for the first time, is located on the ventral surface in the posterior third of the body to the right of the midline.
Still more information is needed to be able to establish the most appropriate taxonomic allocation for Cyathodinium. It is suggested that a combination of fine structural (electron microscopical) and morphogenetic (fission, stomatogenesis, reorganization) studies is required to elucidate both the form and the function of the several unique features of Cyathodinium and that a new understanding of these will permit resolution of the problem of the systematic status of the ciliate.
“…Because an understanding of the infraciliature in the trophont or non-dividing ciliate is an essential prerequisite to study of its role in morphogenesis, the present study on the enigmatic species Cyathodinium piriforme was undertaken. Reports on the morphology of this small parasitic ciliate already exist in the older literature (eg., 9,10,[17][18][19], but our findings either do not agree in several important respects or have added new data of significance. The study was further stimulated by the fact that to date no wholly satisfactory taxonomic allocation has been made for the organism.…”
SYNOPSIS. The unusual patterns of infraciliary kinetosomes on the body and in the large anterior depression of the trophont stage of this difficult‐to‐classify ciliate have been examined by use of the Chatton‐Lwoff silver impregnation technique. In our material there are nine rows of somatic cilia, arranged more or less concentrically around the oral cavity at the anterior end of the pyriform‐shaped body; in the cavity itself there are eight quite separate rows of “vestibular” ciliature. Erratically distributed on posterior areas of the body are argentophilic “granules” which may be non‐cilia‐bearing kinetosomes. A contractile vacuole pore, described for the first time, is located on the ventral surface in the posterior third of the body to the right of the midline.
Still more information is needed to be able to establish the most appropriate taxonomic allocation for Cyathodinium. It is suggested that a combination of fine structural (electron microscopical) and morphogenetic (fission, stomatogenesis, reorganization) studies is required to elucidate both the form and the function of the several unique features of Cyathodinium and that a new understanding of these will permit resolution of the problem of the systematic status of the ciliate.
“…From the outside, the plasma membrane (PM) is encountered first, then the outer alveolar membrane (OAM), and finally the inner alveolar membrane (IAM) (Figs. 3,8). The space between the alveolar membranes is narrow (ca.…”
Section: Methodsmentioning
confidence: 99%
“…The axoneme of the tentacle consists of two files of microtubules, running parallel to each other, and, when viewed in cross-section, its five distinct lobes resemble a daisy (Figs. [7][8][9]. Each microtubule of the inner file has a small arm directed toward the lumen of the tentacle (arrows, Fig.…”
Section: Methodsmentioning
confidence: 99%
“…Cyathodinium spp. were reported from the caeca of domestic and wild guinea pigs by da Cunha (8) and later redescribed by Lucas (21), Nie (27), Paulin (28), and Paulin & Corliss (30). These organisms do not have a recognizable adult stage but possess cilia, haptocysts, and modified tentacles and undergo a type of evaginative budding (29).…”
Allantosoma intestinalis, a suctorian ciliate isolated from the intestine of the horse, was studied utilizing light and electron optical methods. These small sausage-shaped organisms have a varying number of tentacles (between one and 12) located at each extremity of the body. The microtubular axoneme of each tentacle in cross-section consists of two files of microtubules arranged in a daisy-like configuration. Haptocysts occur in the tentacle shaft, abutted to the plasma membrane of the knob of the tentacle, and in the cell body. The haptocysts are bottle-shaped, with prominent annular striations around their midportion. The cell is covered by three membranes, an outer plasma membrane, an outer alveolar, and an inner alveolar membrane. A thin epiplasmic layer is found beneath the inner alveolar membrane, and a single row of microtubules underlies the epiplasm. The subpellicular microtubules are arranged parallel to each other forming a corset around the cell along the long axis: such a system is not characteristic of suctorians. A field of diminutive kinetosomes (each 180 nm long, max. of 15 per field), lacking cilia, was found below the cortex. The function of these prokinetosomes is unknown. A ciliated swarmer has not been observed, only the nonciliated adult. The characteristics of Allantosoma are compared with those of other suctorian genera.UCTORIA are members of the class Kinetofragminophora
“…of Cyathodinium show an arrangement of microtubules not unlike that known for several suctorians, especially Acineta and Tokophrya. Haptocysts or mis-VER 50 years ago the Brazilian protozoologist da 0 Cunha (22) erected the genus Cyathodinium, placing it among holotrich ciliates of that time, for a rather curious group of parasitic organisms which seemed quite unlike other kinds of ciliates. Since that time it has commonly been considered a trichostome (see textbooks of protozoology), altho suggestions ranging from astome (23, 39) to heterotrich (33) to oligotrich (19) have been made.…”
SYNOPSIS. Two species of the taxonomically enigmatic genus Cyathodinium, C. piriforme and C. cunhai, were studied in some detail at both light and electron microscopic levels. Data obtained strongly suggest suctorian affinities for the genus, since a number of structures or features are strikingly reminiscent of similar (if not homologous) structures recently discovered in ciliates belonging to the order Suctorida.
Endosprits (suctorial tentacles?) of Cyathodinium show an arrangement of microtubules not unlike that known for several suctorians, especially Acineta and Tokophrya. Haptocysts or missile‐like bodies, ca. 600 mμ long, have been observed within endosprits and free in the cytoplasm; again this is reminiscent of the complex organelles recently described from several suctorian groups. Mouthlessness, coupled with the presence of a ventral depression (functioning in gathering prey at distal ends of endosprits?) and the presence of food vacuoles in the cytoplasm, further support a suctorian mode of feeding. Finally, stages in the curious life cycle of Cyathodinium suggest neoteny and a basic similarity to endogenous budding processes in certain suctorians.
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