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Micrasterias pinnatifida (KÃTZ.) RALFS The cells are only a little wider than long. The cell halves form three lobes, the lateral lobes are tapered peripherally and have a few denticles at the blunted ends. The lateral lobes are short and are strongly widened with straight ends. The central cut ist deep and strongly widened peripherally. Dimension: Length 60 - 70 µm, width 65 â 75 µm Ecology: Common in moderate acidic to neutral waters of fens and litoral zones. Occurrence: Ubiquitous
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Docidium undulatum BAIL. The cells are 15-25 times longer than wide with truncated ends. The sides are repeatedly flatly undulated. The central cut is little formed. On both sides around the cut runs a ring with tiny, broadly rounded nipples. Dimension: Length 200 â 250 µm, width 12 â 17 µm Ecology: Acidophilic alga, in acidic fens together with Micrasterias jenneri, Micrasterias truncata und Euastrum armatum. Occurrence: Ubiquitous
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Filemaoentous desmids, cells located within a thick mucus sheath. A green alga, with cellulosic cell walls and bright green chloroplasts. Two forms are shown here. Phase contrast micrograph.
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Micrasterias pinnatifida (KÃTZ.) RALFS The cells are only a little wider than long. The cell halves form three lobes, the lateral lobes are tapered peripherally and have a few denticles at the blunted ends. The lateral lobes are short and are strongly widened with straight ends. The central cut ist deep and strongly widened peripherally. Dimension: Length 60 - 70 µm, width 65 â 75 µm Ecology: Common in moderate acidic to neutral waters of fens and litoral zones. Occurrence: Ubiquitous
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Euastrum crassum (BREB.) KÃTZ. The cells are almost two times longer than wide and rounded rectangular in shape. The lateral lobes are broad and rounded off flat concave. The vertex lobes are short and strongly broadened towards the flat recessed ends. They are separated form the lateral lobes only by shallow cuts. The central cuts arenât broadened towards the periphery. At the base of the cell halves there are three swellings with a big pore at their center. Dimension: Length 150 â 200 µm, width 75 â 90 µm Ecology: Acidophilic alga (pH 4 â 6.5), common in shallow sphagnum ponds. Occurrence: Probably ubiquitous
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FIlaments (unhappy) observed in freshwater sediments in the vicinity of Broome, Western Australia in September 2003. This image was taken using differential interference contrast optics. Â Â This work was supported by the Australian Biological Resources Study.
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Micrasterias(mike-raz-tear-ee-ass) is a genus of unicellular algae in the family Desmidiaceae. The cells are flattened and disc-like. The cells of the genus Micrasterias are organized in two semi-cells that are mirror images of each other. The semicells have a distinctive shape with an intricate lobes and indentation. At the end of the lobes the cell wall may sometimes form notches or short spines. The nucleus is located in the centre between the semicells. Each semicell has a chloroplast with some pyrenoids. Usually found in oligotrophic, acid waters. This specimen of Micrasterias rotata collected in the Salzburger Land, Austria. Differential interference contrast.
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Euastrum crassum (BREB.) KÃTZ. The cells are almost two times longer than wide and rounded rectangular in shape. The lateral lobes are broad and rounded off flat concave. The vertex lobes are short and strongly broadened towards the flat recessed ends. They are separated form the lateral lobes only by shallow cuts. The central cuts arenât broadened towards the periphery. At the base of the cell halves there are three swellings with a big pore at their center. Dimension: Length 150 â 200 µm, width 75 â 90 µm Ecology: Acidophilic alga (pH 4 â 6.5), common in shallow sphagnum ponds. Occurrence: Probably ubiquitous
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This image of filamentous desmids shows the mucus layer in which the cells are embedded.
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Micrasterias(mike-raz-tear-ee-ass) is a genus of unicellular algae in the family Desmidiaceae. The cells are flattened and disc-like. The cells of the genus Micrasterias are organized in two semi-cells that are mirror images of each other. The semicells have a distinctive shape with an intricate lobes and indentation. At the end of the lobes the cell wall may sometimes form notches or short spines. The nucleus is located in the centre between the semicells. Each semicell has a chloroplast with some pyrenoids. Usually found in oligotrophic, acid waters. This specimen of Micrasterias rotata collected in the Salzburger Land, Austria. Dark ground illumination.
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Median optical section through Euastrum crassum using high resolution optics (Planapochromate 40/1.0) and DIC. Sample from sphagnum pond situated in the northern alpine region of Austria near Salzburg. Images were taken using Zeiss Universal with Olympus C7070 CCD camera
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This filamentous desmid with its charcteristic outline has a delicate textured cell wall. Each cell holds two chloroplasts with nucleus between them. Multi layer image using 7 high resolution DIC frames with manual stacking technique using Corel Photopaint. The scale bar indicates 25 µm. Sample from sphagnum pond Dosenmoor near Neumuenster (Schleswig-Holstein, Germany). Images were taken using Zeiss Universal with Olympus C7070 CCD camera.
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Micrasterias rotata (GREV.) RALFS. Length 200 - 300 µm, width 200 - 270 µm. This species is very tolerant concerning living conditions. Therefore the species is widely spread in all altitudes, in forestal ditches and fens of lowlands sometimes abundant.
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The picture shows the cell wall structure with pores. It is developed using 30 high resolution frames combined with manual stacking technique. Sample from sphagnum pond situated in the northern alpine region of Austria near Salzburg. Images were taken using Zeiss Universal with Olympus C7070 CCD camera.
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A developing filament with only 3 cells is shown. Mulit layer image using 3 high resolution DIC frames with manual stacking technique using Corel Photopaint. Sample from sphagnum pond Dosenmoor near Neumuenster (Schleswig-Holstein, Germany). Images were taken using Zeiss Universal with Olympus C7070 CCD camera.
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Micrasterias rotata (GREV.) RALFS. Length 200 - 300 µm, width 200 - 270 µm. This species is very tolerant concerning living conditions. Therefore the species is widely spread in all altitudes, in forestal ditches and fens of lowlands sometimes abundant.
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Euastrum germanicum (SCHMIDLE) WILLI KRIEG. he cells are only a little longer then wide. The cell halves constist of five broadly rounded lobes. The vertex lobes which are outward somewhat widened are separated from the lobes by extended, inside rounded recessings. Each center of the cell halves showes a hemispheric bump. The cellwall is covered with parallel rows of spines. The central cuts are slender and broadly opened towards the periphery. Dimension: Length 50 â 60 µm, width 40 â 50 µm Ecology: Especially in medium acidic to weakly alcaline waters of ponds and alluvial areas (Danube meadows) Occurrence: Mainly in Europe, but probably ubiquitous
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Cosmarium (cos-may-ree-um) caelatum. Cosmarium is a very common and large genus of alga found usually in oligotrophic, acid waters. The cells of this genus are composed of two semi-cells, constricted in the middle. This region is termed the isthmus and is where the nucleus is found. The outer portions of each semi-cell contain a single, large chloroplast. The outer cell wall of each semi-cell is covered with pores and can be very ornate with the pattern being useful in distinguishing among species. The cells move slowly using mucilage secretion to create the force for movement. Both asexual and sexual reproduction occurs. The asexual reproduction is by cell division and the sexual reproduction involves the formation of zygospores. The gametes migrate from the parental cells, passing through pores to fuse in a region midway between the parental walls. The zygote can form a very ornate wall. This specimen was collected in a moor located in the Salzburger Land, Austria. This image emphasizes the ornate cell wall of Cosmarium ornatum. This specimen measures 49 microns long and 38 microns wide.
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Micrasterias rotata (GREV.) RALFS Length: 200 â 300 µm, width: 200 â 270 µm. This specie is very tolerant concerning living conditions. Therefore the species is widely spread in all altitudes, in forestal ditches and lowland fens sometimes abundant. The cells are 1.08 to 1.15 times longer than wide, the shape seems almost circular or wide elliptical. The cell is devided into lobes due to deep cuts, the terminations of lobes are denticulated. The central lobe is broadened evenly at the end. The termination is formed concavely and is lightly arched upwards at both sides. The lateral angles of the central lobe are little denticulated. The cut in the middle of the cell (sinus) is very deep and peripherally a little widened. The cellwall is densly punctuated by tiny pores. The Chromatophores have several scattered pyrenoids with varying sizes.
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Euastrum germanicum (SCHMIDLE) WILLI KRIEG. The cells are only a little longer then wide. The cell halves constist of five broadly rounded lobes. The vertex lobes which are outward somewhat widened are separated from the lobes by extended, inside rounded recessings. Each center of the cell halves showes a hemispheric bump. The cellwall is covered with parallel rows of spines. The central cuts are slender and broadly opened towards the periphery. Dimension: Length 50 â 60 µm, width 40 â 50 µm Ecology: Especially in medium acidic to weakly alcaline waters of ponds and alluvial areas (Danube meadows) Occurrence: Mainly in Europe, but probably ubiquitous
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Cosmarium (cos-may-ree-um) caelatum. Cosmarium is a very common and large genus of alga found usually in oligotrophic, acid waters. The cells of this genus are composed of two semi-cells, constricted in the middle. This region is termed the isthmus and is where the nucleus is found. The outer portions of each semi-cell contain a single, large chloroplast. The outer cell wall of each semi-cell is covered with pores and can be very ornate with the pattern being useful in distinguishing among species. The cells move slowly using mucilage secretion to create the force for movement. Both asexual and sexual reproduction occurs. The asexual reproduction is by cell division and the sexual reproduction involves the formation of zygospores. The gametes migrate from the parental cells, passing through pores to fuse in a region midway between the parental walls. The zygote can form a very ornate wall. This specimen is 49 microns long and 38 microns wide.
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The picture shows the outline, the texture of the cell wall and some dictyosomes producing mucilage for motion (see also inserted image). This multi layer image was built up using 40 high resolution DIC frames with manual stacking technique using Corel Photopaint. The scale bar indicates 50 µm. Sample from sphagnum pond situated in the northern alpine region of Austria near Salzburg. Images were taken using Zeiss Universal with Olympus C7070 CCD camera.
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Euastrum intermedium CLEVE The celles are almost two times longer than wide. The cell sides are loboid broadly rounded. The vertex lobes are protruding clearly, broadened on the ends and with a cut in the middle. In the center of the cell halves there are pairs of bumps which are covered with small warts. The central cuts are far opened towards the periphery. Dimension: Length 70 â 80 µm, width 35 â 45 µm Ecology: Acidophilic alga, rather rare in shallow waters between sphagnum. Occurrence: Ubiquitous, prefers boreal areas (mountains), rather rare in Central Europe.
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Cosmarium (coz-mare-ee-um) praemorsum is a very common and large genus of phytoplankton alga found usually in oligotrophic, acid waters. The cells of this genus are composed of two semi-cells, constricted in the middle. This region in the middle is called the isthmus and is the site of the nucleus. The outer portions of each semi cell contains a single, large chloroplast. The outer cell wall of each semi-cell are covered with pores and can be very ornate and the appearance can be used to define the species. The cells are move slowly as the result of mucilage secretion. Both asexual and sexual reproduction occurs. The asexual activity is cell division and the sexual reproduction involves the formation of zygospores. The gametes migrate from the parental cell walls through pores and fuse in a region midway between the parental walls. The zygote can form a very ornate wall. Focal plane on the conspicuous ornate of the cell wall. This specimen was collected in a moor located in the Salzburger Land, Austria.