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Litostomatea
The Litostomatea are a class of ciliates. The group consists of three subclasses: Haptoria, Trichostomatia and Rhynchostomatia. Haptoria includes mostly carnivorous forms such as '' Didinium'', a species of which preys primarily on the ciliate ''Paramecium''. Trichostomatia (trichostomes) are mostly endosymbionts in the digestive tracts of vertebrates. These include the species ''Balantidium coli'', which is the only ciliate parasitic in humans. The group Rhynchostomatia includes two free-living orders previously included among the Haptoria, but now known to be genetically distinct from them, the Dileptida and the Tracheliida. Morphology In litostomes, the body cilia arise from structures in the cell cortex called monokinetids, which are made up of a single cilium and its associated structures, such as basal bodies and microtubular fibres. These have an ultrastructural arrangement characteristic to the group. The cell "mouth" (cytostome) is apical or subapical. In trichostome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Litostomatea
The Litostomatea are a class of ciliates. The group consists of three subclasses: Haptoria, Trichostomatia and Rhynchostomatia. Haptoria includes mostly carnivorous forms such as '' Didinium'', a species of which preys primarily on the ciliate ''Paramecium''. Trichostomatia (trichostomes) are mostly endosymbionts in the digestive tracts of vertebrates. These include the species ''Balantidium coli'', which is the only ciliate parasitic in humans. The group Rhynchostomatia includes two free-living orders previously included among the Haptoria, but now known to be genetically distinct from them, the Dileptida and the Tracheliida. Morphology In litostomes, the body cilia arise from structures in the cell cortex called monokinetids, which are made up of a single cilium and its associated structures, such as basal bodies and microtubular fibres. These have an ultrastructural arrangement characteristic to the group. The cell "mouth" (cytostome) is apical or subapical. In trichostome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Didinium
''Didinium'' is a genus of unicellular ciliates with at least ten accepted species. All are free-living carnivores. Most are found in fresh and brackish water, but three marine species are known. Their diet consists largely of ''Paramecium'', although they will also attack and consume other ciliates. Some species, such as ''D. gargantua'', also feed on non-ciliate protists, including dinoflagellates, cryptomonads, and green algae. Appearance and reproduction ''Didinia'' are rounded, oval or barrel-shaped and range in length from 50 to 150 micrometres. The cell body is encircled by two ciliary bands, or ''pectinelles'', an upper band and a lower band just below the midline. This distinguishes them from the related genus '' Monodinium'', which have only a single band, except during cell division. The pectinelles are used to move ''Didinium'' through water by rotating the cell around its axis. At the anterior end, a cone-shaped structure protrudes, supported by a palisade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliates
The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to eukaryotic flagella, but are in general shorter and present in much larger numbers, with a different undulating pattern than flagella. Cilia occur in all members of the group (although the peculiar Suctoria only have them for part of their life cycle) and are variously used in swimming, crawling, attachment, feeding, and sensation. Ciliates are an important group of protists, common almost anywhere there is water—in lakes, ponds, oceans, rivers, and soils. About 4,500 unique free-living species have been described, and the potential number of extant species is estimated at 27,000–40,000. Included in this number are many ectosymbiotic and endosymbiotic species, as well as some obligate and opportunistic parasites. Ciliate species range in size from as little as 10 µm in some colpodeans to as much as 4 mm in length in some ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balantidium
''Balantidium'' is a genus of ciliates. It contains the parasitic species ''Balantidium coli'', the only known cause of balantidiasis. History The first-described species of ''Balantidium'', ''B. entozoon'', was described in 1838 by Ehrenberg as a member of the genus '' Bursaria''. ''Balantidium coli'' observed in patients with dysentery was originally described as ''Paramecium coli'' by Malmstein in 1857. In 1858, Edouard Claparède and Johannes Lachmann created the genus ''Balantidium'' and reclassified ''B. entozoon'' as its type species. Stein in 1863 reclassified ''Paramecium coli'' into the genus ''Balantidium''. Transcriptomics Transcriptome data for ''Balantidium ctenopharyngodoni'', from single-cell transcriptome sequencing, were published in 2017 and were the first omics data within the subclass Trichostomatia. Taxonomy A separate genus – '' Neobalantidium'' – has been created for several of these species. ''Balantidium coli'' is one of the species that has been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrymaria Olor
''Lacrymaria olor'' is a species of ciliates, typically long, that is found in freshwater ponds. Its name means "swan tear" in Latin, and refers to its general shape: namely, a teardrop-shaped cell with a small "head" at the end of a long slender "neck". The protist is notable for its ability to extend the anterior end of the cell up to 7 times its body length, and manipulate in many directions — even around obstacles — in order to capture its food. Richard L. Howey, Ken Jones, Roy WinsbLacrymaria Olor: Tear of a Swan Accessed on 2009-12-04. For that reason it is a popular subject for amateur microscopists. The classification has been attributed to Müller (1786). Ward and Whipple, ''Fresh-water Biology''. Cited by Howey. The protist usually has two macronuclei and a single micronucleus. Its entire cell body is covered with cilia arranged in spirals. It has two contractile vacuoles, one at each end of the body. It contains small birefringent crystals. ''Lacrymaria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Body
A basal body (synonymous with basal granule, kinetosome, and in older cytological literature with blepharoplast) is a protein structure found at the base of a eukaryotic undulipodium (cilium or flagellum). The basal body was named by Theodor Wilhelm Engelmann in 1880 It is formed from a centriole and several additional protein structures, and is, essentially, a modified centriole. The basal body serves as a nucleation site for the growth of the axoneme microtubules. Centrioles, from which basal bodies are derived, act as anchoring sites for proteins that in turn anchor microtubules, and are known as the microtubule organizing center (MTOC). These microtubules provide structure and facilitate movement of vesicles and organelles within many eukaryotic cells. Assembly, structure Cilia and basal bodies form during quiescence or the G1 phase of the cell cycle. Before the cell enters G1 phase, i.e. before the formation of the cilium, the mother centriole serves as a component of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyrtos
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Extrusome
Extrusomes are membrane-bound structures in some eukaryotes which, under certain conditions, discharge their contents outside the cell. There are a variety of different types, probably not homologous, and serving various functions. Notable extrusomes include mucocysts, which discharge a mucous mass sometimes used in cyst formation, and trichocysts, which discharge a fibrous rod. The stinging nematocysts found in Cnidarian animals may be regarded as extrusomes as well. Extrusomes found in dinoflagellate The dinoflagellates ( Greek δῖνος ''dinos'' "whirling" and Latin ''flagellum'' "whip, scourge") are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered algae. Dinoflagellates are ...s are important in the formation of red and black tides. References External links Image: extrusome (labeled EX) Organelles {{Protist structures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dikinetid
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Spirotrich
The spirotrichs are a large and diverse group of ciliate protozoa. They typically have prominent oral cilia in the form of a series of polykinetids, called the adoral zone of membranelles, beginning anterior to the oral cavity and running down to the left side of the mouth. There may also be one or two paroral membranes on its right side. The body cilia are fused to form polykinetids called cirri in some, and are sparse to absent in others. Forms with cirri are common throughout soil, freshwater, and marine environments. Individuals tend to be flattened, with cirri confined to the ventral surface. These are variously used for crawling over objects, acting as feet, swimming, or assisting in food capture. They are generally divided into hypotrichs and stichotrichs, but were originally all considered hypotrichs. Forms with sparse or absent body cilia tend to be smaller and are mostly marine, but a few are common in freshwater. Again, they are generally divided into oligot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membranelle
Membranelles (also membranellae) are structures found around the mouth, or cytostome, in ciliates. They are typically arranged in series, to form an "adoral zone of membranelles," or AZM, on the left side of the buccal cavity (peristome). The membranelles are made up of kinetosomes arranged in groups to make up ''polykinetids''. The cilia The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike proje ... which emerge from these structures appear to be fused and to function as a single membrane, which can be used to sweep particles of food into the cytostome, or for locomotion.Kudo, Richard R. Protozoology. 4th ed. Charles C. Thomas, 1954. p. 59. References Organelles Ciliate biology {{cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
