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Portrait of a zoospore (motile reproductive cell capable of transformation into another developmental stage but incapable of sexual fusion) of the filamentous green alga, Oedogonium. The ovoid to elongate zoospore bears a wreath of flagella around an anterior hyaline dome. Reproduction in Oedogonium may be asexual, by means of large flagellated zoospores (motile reproductive cells capable of transformation into another developmental stage but incapable of sexual fusion) or oögamous with fertilization of oögonia by antherozoids (motile male gametes structurally similar to zoospore but smaller). Release of zoospores is followed by a short swarming phase that ends by the zoospore coming to rest with its flagellated hyaline dome at the substratum, shedding its flagella and then forming a holdfast. A new filament then forms by repeated intercalary and distal terminal cell divisions. The zoospores of algae may be confused zoochlorellae bearing ciliates (e.g. Cyclotrichium viride) but are distinguished by the absence of other somatic cilia or somatic kinetosomes. Collected from freshwater pond near Boise, Idaho in October 2003. DIC optics.
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Ribadelago, Castille and Leon, Spain
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Arboli, Catalonia, Spain
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Portrait of antherozoid (motile male gamete structurally similar to the zoospore but smaller) of the aquatic filamentous green alga Oedogonium. Reproduction in Oedogonium may be asexual, by means of large flagellated zoospores (motile reproductive cells capable of transformation into another developmental stage but incapable of sexual fusion) or o?¶gamous with fertilization of o?¶gonia by antherozoids (motile male gametes structurally similar to zoospore but smaller). O?¶gonia appear as large globular cells interposed between the cylindrical vegetative cells of the filament. Fertilization occurs after the antherozoid penetrates a specialized receptive area of the o?¶gonial cell wall. Collected from freshwater pond near Boise, Idaho in October 2003. DIC optics.
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Ribadelago, Castille and Leon, Spain
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Galende, Castille and Leon, Spain
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Portrait of zoospore (motile reproductive cell capable of transformation into another developmental stage but incapable of sexual fusion) of the filamentous green alga, Oedogonium. Reproduction in Oedogonium may be asexual, by means of large flagellated zoospores (motile reproductive cells capable of transformation into another developmental stage but incapable of sexual fusion) or oögamous with fertilization of oögonia by antherozoids (motile male gametes structurally similar to zoospore but smaller). Release of zoospores is followed by a short swarming phase which ends by the zoospore coming to rest with its flagellated hyaline dome at the substratum, shedding its flagella (as seen here) and then forming a holdfast. A new filament then forms by repeated intercalary and distal terminal cell divisions. Collected from freshwater pond near Boise, Idaho in October 2003. DIC optics.
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la Parrilla, Madrid, Spain
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Arboli, Catalonia, Spain
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Detail of vegetative cell of Oedogonium. This aquatic genus includes approximately 400 species. Oedogonium, composed of uninucleate cells, is unbranched. Cell division is intercalary or at the distal terminus and results in formation a series of transverse annulae or caps at the distal end of cells after multiple divisions (seen in this image). Division of the basal cell does not occur. The reticulate chloroplast is peripheral, surrounding the cytoplasm. There are multiple pyrenoids (proteinaceous centers of starch production) associated with each chloroplast. The large nucleus is peripheral, usually at mid-cell. Collected from freshwater pond near Boise, Idaho in October 2003. DIC optics.
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El Rasillo, La Rioja, Spain
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Portrait of a filamentous green alga of the genus Oedogonium. This aquatic genus includes approximately 400 species. Oedogonium, composed of uninucleate cells, is unbranched. The basal (proximal) cell of a filament attaches to the substrate by a holdfast. Cell division is intercalary or at the distal terminus and results in formation a series of transverse annulae or caps at the distal end of cells after multiple divisions. Division of the basal cell does not occur. The reticulate chloroplast is peripheral, surrounding the cytoplasm. The strands of the reticulum are parallel to the long axis of the cell. There are multiple pyrenoids (proteinaceous centers of starch production) associated with each chloroplast. The large nucleus is peripheral, usually at mid-cell. Reproduction may be asexual, by means of large flagellated zoospores (motile reproductive cells capable of transformation into another developmental stage but incapable of sexual fusion) or oögamous with fertilization of oögonia by antherozoids (motile male gametes structurally similar to zoospore but smaller). A zoospore is seen here below the algal filament. Collected from freshwater pond near Boise, Idaho in October 2003. DIC optics.
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One end of each cell accumulates rings when the cells divide. These cell rings help to distinguish oedogonium from other filamentous green algae. Phase contrast.
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Filamentous of Oedogonium do not branch. This image shows one cell with an oogonium inside. Phase contrast optics.
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The chloroplasts are ribbon like and form a layer just under the cell wall. Bright regions are where the pyrenoids are located. The bright green colour is typical of plastids of green algae. Differential interference contrast optics.
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This is the flagellated zoospore that is formed as a result of asexual reproduction, swims around, finds somehwere to settle and starts to change into a filament. The zoospore swims by the flagella that form a wreath around the anterior end of the cell (upper). Phase contrast micrograph.
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A typical section of a filament of Oedogonium. Cell walls have rings at one end. Chloroplasts are bright green. Differential interference contrast optics.
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The wall of a dead filament of Oedogonium acts as the substrate from which other organisms attach. In the case of Oedogonium, male filaments are much thinner than female filaments and often attach to the females. Which may be what is happening here. Phase contrast optics.
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The cell wall of a dead Oedogonium acts as the substrate from which other organisms attach. There is a community of bacteria, blue green algae and maybe even some male filaments of Oedogonium. Differential interference contrast optics.
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The green algal material in this boggy pond of the Beaucamp wetlands is Oedogonium. It forms loose spongy aggregates.
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The green algal material in this boggy pond of the Beaucamp wetlands is Oedogonium. It forms loose spongy aggregates.
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After settling, the zoopsore develops into a filament. This germling is the first stage of development of the filament. Differential interference contrast optics.
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Fixation of an Oedogonium filament showing cell surface with chloroplasts. Depht of focus was gained through stacking of 20 frames Images were taken using Zeiss Universal with Olympus C7070 CCD camera.
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Public Domain, U.S. Government Work 2011 Barry H. Rosen Courtesy of life.nbii.gov
NBII images
Category hierarchy: Microorganisms | AlgaeDescription: Oedogonium germination micrograph. Sample was collected from Silver Springs, Florida.Capture device: Olympus DP71Locality: Latitude: 2.859009900000000e+001; Longitude: -8.119031699999999e+001