Extrusomes are membrane bound structures in some eukaryote s 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 trichocyst s, which discharge a fibrous rod. The stinging nematocyst s found in Cnidaria n animals may be regarded as extrusomes as well. Extrusomes found in dinoflagellate s are important in the formation of red and black tides. External links http parasitology.informatik.uni wuerzburg.de login b me14047.jpg.php Image extrusome labeled EX Category Organelles Cell biology stub cs Extruzom es Extrusoma it Estrusoma pt Extrussoma ... more details
Unreferenced date December 2009 Taxobox domain Eukaryote Eukaryota regnum Chromalveolata superphylum Alveolata phylum Ciliate Ciliophora classis Nassophorea classis authority Eugene Small Small & Denis Lynn Lynn 1981 subdivision ranks Typical orders subdivision Synhymeniida br Nassulida br Microthoracida The Nassophorea are a class of ciliate protozoa. Members are free living, usually in freshwater but also in marine and soil environments. The mouth is anterior ventral and leads to a curved cytopharynx supported by a prominent palisade of rods or nematodesmata , forming a structure called a cyrtos or nasse , typical of this and a few other classes. When present, extrusome s take the form of fibrous trichocysts. Cilia are usually monokinetids, but vary from order to order. The Synhymeniida and Nassulida have mostly uniform cilia arising from monokinetids. Among the former, and a few members of the latter, there is a series of small polykinetids running from below the mouth to the left side of the body and sometimes almost circling the cell, called a frange or synhymenium . Other forms only have three oral membranelle s, sometimes extending out of the oral cavity, with or without a paroral membrane. These are usually medium in size, sometimes larger, and cylinder shaped. The Microthoracida typically have three or more oral membranelles, with at least a vestige of the paroral membrane occurring during cell division. The body cilia are sparse, and often arise from dikinetids, with cirrus like polykinetids occurring in the marine genus Discotricha . These are usually small and ellipsoid or crescent shaped, with the right side of the body curved outward, and generally have a rigid pellicle. As first defined by Eugene Small and Denis Lynn in 1981, the Nassophorea also included the peniculid s and, in a separate subclass, the hypotrich s. More recent schemes restore these to their earlier positions, leaving this group a relatively small collection of less well known forms. ... more details
Unreferenced date July 2007 Taxobox name Phyllopharyngea domain Eukaryote Eukaryota regnum Chromalveolata superphylum Alveolata phylum Ciliate Ciliophora classis Phyllopharyngea classis authority de Puytorac et al. 1974 small subdivision ranks Typical orders subdivision Subclass Phyllopharyngia br Chlamydodontida br Dysteriida br Subclass Chonotrich ia br Exogemmida br Cryptogemmida br Subclass Rhynchodia br Rhynchodida br Hypocomatida br Subclass Suctoria br Exogenida br Endogenida br Evaginogenida The Phyllopharyngea are a class of ciliate protozoa, including some 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 chonotrich s 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 crustacean s, 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 extrusome s at the tip. These are especially characteristic of the suctoria, which feed upon other ciliates, and are unique among them in having multiple mouths on each cell. They are also found in many rhynchodids, which are mostly parasites of bivalve s. Alveolata Category Ciliates chromalveolate stub es Phyllopharyngea ... more details
Taxobox domain Eukaryote Eukaryota regnum Rhizaria phylum Cercozoa classis Proteomyxidea ? ordo Reticulosida familia Gymnophryidae familia authority Mikrjukov & Mylnikov, 1996 small Gymnophryidae is a small family biology family of amoeboid s that lack shells and produce thin, reticulose pseudopods. These contain microtubule s and have a granular appearance, owing to the presence of extrusome s, but are distinct from the pseudopods of Foraminifera . They are included among the Cercozoa along with Lecythium , ref cite journal author Nikolaev, S.I., et al. title Gymnophrys cometa and Lecythium sp. are Core Cercozoa Evolutionary Implications journal Acta Protozoologica year 2003 volume 42 pages 183 190 url http www.nencki.gov.pl pdf ap ap696.pdf ref ref name pmid18952499 cite journal author Bass D, Chao EE, Nikolaev S, et al. title Phylogeny of novel naked Filose and Reticulose Cercozoa Granofilosea cl. n. and Proteomyxidea revised journal Protist volume 160 issue 1 pages 75 109 year 2009 month February pmid 18952499 doi 10.1016 j.protis.2008.07.002 url http linkinghub.elsevier.com retrieve pii ref but differ from other cercozoans in having mitochondrion mitochondria with flat crista e, rather than tubular cristae. Gymnophrys cometa , found in freshwater and soil, is representative of the group. The cell body is under 10 &mu m in size, and has a pair of reduced flagellum flagella , which are smooth and insert parallel to one another. It may also produce motile zoospore s and cyst s. Gymnophrys and Borkovia are the only confirmed genera, but other naked reticulose amoebae such as Biomyxa may be close relatives. References reflist Category Cercozoa Category Amoeboids Rhizaria es Gymnophryidae ... more details
Unreferenced date July 2007 Taxobox color greenyellow name Peniculids image Paramecium.jpg image caption Paramecium aurelia domain Eukaryote Eukaryota regnum Chromalveolata superphylum Alveolata phylum Ciliate Ciliophora classis Oligohymenophorea ordo Peniculida ordo authority Faur Fremiet in Corliss 1956 subdivision ranks Typical families subdivision Suborder Frontoniina br Clathrostomatidae br Frontoniidae br Lembadionidae br Maritujidae br Stokesiidae br Suborder Parameciina br Parameciidae br Neobursaridiidae br Urocentridae wikispecies Peniculida The peniculids are an order of ciliate protozoa, including the well known Paramecium and its close relatives. Most are relatively large, freshwater forms that feed on smaller organisms swept into the mouth. They have simple life cycles, and in many cases do not even form resting cysts. Typically the body has uniform, dense cilia, which also cover a vestibule preceding the mouth. Extrusome s are characteristically in the form of spindle trichocysts, which release thread like shafts, and never mucocysts. The oral cilia include peniculi, corresponding to the membranelle s of related groups, arranged parallel to the mouth deep in the oral cavity. Nematodesmata rods arise from the bases of the oral or perioral cilia, but these do not support a cyrtos as in some other classes. Two suborders are recognised The Frontoniina typically have a shallow oral cavity, with a long paroral membrane and denser somatic kineties to the right of the mouth. These are called ophryokineties , and take part in forming the new mouth during cell division. The Parameciina typically have a deeper oral cavity, with peniculi mainly forward of the mouth, and the paroral membrane reduced, though still present throughout interphase. The peniculids were first defined by Faur Fremiet in 1956. Originally they were one of three suborders of the hymenostome s, which are now treated as subclasses of the Oligoh ... more details
Taxobox color khaki name Suctoria image Suctoria wiki.jpg domain Eukaryote Eukaryota regnum Chromalveolata superphylum Alveolata phylum Ciliate Ciliophora classis Phyllopharyngea subclassis Suctoria subclassis authority Clapar de & Lachmann biologist Lachmann 1858 small subdivision ranks Typical orders subdivision Exogenida br Endogenida br Evaginogenida Suctoria are sessile ciliate s which feed by extracellular digestion and lack cilia in the adult phase. ref name Juneja Cite book last1 Juneja first1 Kavita last2 Bhamrah first2 title An Introduction to Protozoa date publisher Anmol Publications Pvt Ltd location isbn 81 261 0679 4 pages 204 207 ref They were originally thought to feed by suction &ndash hence their name. ref name Rudzinska1973 cite jstor 1296568 ref In fact, they use specialized microtubules to ensnare and manipulate their prey. ref name Rudzinska1973 They are found in both freshwater and marine environments, including some which 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 extrusome s called haptocysts at the tip which attach to prey. Its cytoplasm is then sucked directly into a food vacuole inside the cell, where its contents are digested and absorbed. Most suctoria are around 15 30 m in size, with a non contractile stalk and often a Lorica biology lorica or shell. Image Suctoria1 wiki.jpg thumb 400px Suctoria sucking a colpidium. Suctoria reproduce primarily by budding, producing swarmers which lack both tentacles and stalks but have cilia. They may also reproduce through conjugation, which is peculiar in involving cells of different size and often involves total fusion. The way in which buds are formed is the primary way the different orders of suctoria are distinguished. Among the Exogenida , including common genera like Podophrya and Sphaerophrya , they appea ... more details
Refimprove date August 2010 Taxobox name Cryptomonads image Rhodomonas salina CCMP 322.jpg image caption Rhodomonas salina domain Eukaryota regnum Chromalveolata unranked phylum Hacrobia phylum Cryptophyta classis Cryptophyceae subdivision ranks Typical genera subdivision Order Cryptomonadales Campylomonas br Chilomonas br Chroomonas br Cryptomonas br Falcomonas br Geminigera br Guillardia br Hemiselmis br Plagioselmis br Proteomonas br Storeatula br Rhodomonas br Teleaulax br Order Goniomonadales br Goniomonas The cryptomonads or cryptophytes are a group of algae , ref name pmid18397952 cite journal author Khan H, Archibald JM title Lateral transfer of introns in the cryptophyte plastid genome journal Nucleic Acids Res. volume 36 issue 9 pages 3043 53 year 2008 month May pmid 18397952 pmc 2396441 doi 10.1093 nar gkn095 url http nar.oxfordjournals.org cgi pmidlookup?view long&pmid 18397952 ref most of which have chloroplast plastids . They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 1 E 5 m 10 50 m in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagellum flagella . Some may exhibit mixotrophy . ref name urlCryptophyta the cryptomonads cite web url http www.life.umd.edu labs delwiche PSlife lectures Cryptophyta.html wwwtax.cgi?mode Info&id 412159&lvl 1 title Cryptophyta the cryptomonads format work accessdate 2009 06 02 ref Characteristics Cryptomonads are distinguished by the presence of characteristic extrusome s called ejectisomes or ejectosomes, which consist of two connected spiral ribbons held under tension. ref name Graham Graham LE, Graham JM, Wilcox LW 2009 Algae . 2nd Editio ... more details
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