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Suctoria
Suctoria are ciliates that become sessile in their developed stage and then lose their redundant cilia. They feed by extracellular digestion. They were originally thought to feed by suction – hence their name. In fact, they use specialized microtubules to ensnare and manipulate their prey. They live in both freshwater and marine environments, including some that live on the surface of aquatic animals, and typically feed on other ciliates. Instead of a single cytostome, each cell feeds by means of several specialized tentacles. These are supported by microtubules and phyllae, and have toxic extrusomes called haptocysts at the tip, which they attach to prey. They then suck the prey's cytoplasm directly into a food vacuole inside the cell, where they digest and absorb its contents. Most suctoria are around 15-30 μm in size, with a non-contractile stalk and often a lorica or shell. Suctoria reproduce primarily by budding, producing swarmers that lack both tentacles and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phyllopharyngea
The Phyllopharyngea are a class of ciliates, some of which are extremely specialized. Motile cells typically have cilia restricted to the ventral surface, or some part thereof, arising from monokinetids with a characteristic ultrastructure. In both chonotrichs and suctoria, however, only newly formed cells are motile and the sessile adults have undergone considerable modifications of form and appearance. Chonotrichs, found mainly on crustaceans, are vase-shaped, with cilia restricted to a funnel leading down into the mouth. Mature suctorians lack cilia altogether, and initially were not classified as ciliates. The mouths of Phyllopharyngea are characteristically surrounded by microtubular ribbons, called ''phyllae''. Nematodesmata, rods found in several other classes of ciliates, occur among the subclass Phyllopharyngia, most of which are free-living. In others, the mouth is often modified to form an extensible tentacle, with toxic extrusomes at the tip. These are especia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciliate
The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a different wikt:undulating, undulating pattern than flagella. Cilia occur in all members of the group (although the peculiar Suctoria only have them for part of their biological life cycle, 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 Ectosymbiosis, ectosymbiotic and endosymbiotic species, as well as some Obligate parasite, obligate and Facultative parasite, opportunistic parasites. Ciliate species r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
René-Édouard Claparède
René-Édouard Claparède (24 April 1832 in Chancy – 31 May 1871 in Siena) was a Swiss anatomist. The Claparède family was Protestant and originally from Languedoc. They moved to Geneva after Louis XIV:s Edict of Fontainebleau in 1685. He received his education in Geneva and Berlin, where he attended lectures given by Johannes Peter Müller. Later on, he served as an assistant to François Jules Pictet de la Rive at the Geneva Academy, where in 1862 he became a professor of comparative anatomy. He was a regular contributor to th''Archives des sciences physiques et naturelles''Claparède, René-Edouard Historischen Lexikon der Schweiz 
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Lachmann (biologist)
Lachmann (also Lachman, Lachemann, Lackman, or Lackmann) is a family name of German origin and may refer to: Lachmann * Erich Lachmann (1909-1972), Nazi SS officer at Sobibor extermination camp * Esther Lachmann, later Pauline Thérèse Lachmann, later Mme Villoing, later Mme la Marquise de Païva, later Countess Henckel von Donnersmarck, courtesan * Georges Lachmann, World War I flying ace and General officer * Gustav Lachmann, engineer * Hans Lachmann-Mosse, publisher * Karl Lachmann, classic philologist, Germanist * Ludwig Lachmann, Austrian economist * Peter Lachmann, British immunologist and nephew of Robert Lachmann * Richard Lachmann, American political scientist and international relations theorist. * Robert Lachmann, German ethnomusicologist and musicologist Lachman * Darryl Lachman * Dichen Lachman * Harry Lachman * Irwin Lachman * Patrick Lachman * Seymour P. Lachman (born 1933), New York politician and historian * Zvi Lachman * Lachman test (Lachman maneuver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sessility (zoology)
Sessility is the biological property of an organism describing its lack of a means of self-locomotion. Sessile organisms for which natural ''motility'' is absent are normally immobile. This is distinct from the botanical concept of sessility, which refers to an organism or biological structure attached directly by its base without a stalk. Sessile organisms can move via external forces (such as water currents), but are usually permanently attached to something. Organisms such as corals lay down their own substrate from which they grow. Other sessile organisms grow from a solid such as a rock, dead tree trunk, or a man-made object such as a buoy or ship's hull. Mobility Sessile animals typically have a motile phase in their development. Sponges have a motile larval stage and become sessile at maturity. Conversely, many jellyfish develop as sessile polyps early in their life cycle. In the case of the cochineal, it is in the nymph stage (also called the crawler stage) that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytostome
A cytostome (from ''cyto-'', cell and ''stome-'', mouth) or cell mouth is a part of a cell specialized for phagocytosis, usually in the form of a microtubule-supported funnel or groove. Food is directed into the cytostome, and sealed into vacuoles. Only certain groups of protozoa, such as the Ciliophora and Excavata, have cytostomes. An example is '' Balantidium coli'', a ciliate. In other protozoa, and in cells from multicellular organisms, phagocytosis takes place at any point on the cell or feeding takes place by absorption. Structure The cytostome forms an invagination on the cell surface and is typically directed towards the nucleus of the cell.Okuda, Kendi, et al. "The cytostome of Trypanosoma cruzi epimastigotes is associated with the flagellar complex." Experimental parasitology 92.4 (1999): 223-231. The cytostome is often labeled as the entire invagination, but in fact the cytostome only constitutes the opening of the invagination at the surface of the cell. The rest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Vacuole
A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these. The organelle has no basic shape or size; its structure varies according to the requirements of the cell. Discovery Contractile vacuoles ("stars") were first observed by Spallanzani (1776) in protozoa, although mistaken for respiratory organs. Dujardin (1841) named these "stars" as ''vacuoles''. In 1842, Schleiden applied the term for plant cells, to distinguish the structure with cell sap from the rest of the protoplasm. In 1885, de Vries named the vacuole membrane as tonoplast. Function The function and signifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorica (biology)
In biology, a lorica is a shell-like protective outer covering, often reinforced with sand grains and other particles that some protozoans and loriciferan animals secrete. Usually it is tubular or conical in shape, with a loose case that is closed at one end. An example is the protozoan genus ''Stentor'', in which the lorica is trumpet-shaped. In the tintinnids, the lorica is frequently transparent and is used as domicile. ''Halofolliculina corallasia'' has a lorica that is attached as an outer structure, and into which it retracts when disturbed. There are three phases in the formation of lorica: agglomeration in a natural cast; helical extension; and stabilization. The original meaning of the word is: cuirass, a type of chest armor, originally made of leather, afterward of plates of metal or horn sewed on linen or the like. See also * Chitin Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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