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searched word: Aphanizomenon
Found 1 match(es) in the Formal Descriptions | Aphanizomenon - Aphanizomenon is a filamentous blue-green alga (cyanobacterium). The filaments may be free-floating, solitary or in some species bound together as colonies up to an inch in length. The filaments (trichomes) are usually straight or slightly curved, rounded or narrowing at the tips, with crosswalls, no firm sheaths but sometimes a surrounding mucilagenous layer; cells may be vacuolized; sometimes with heterocysts, Gas vacuoles may be present. May cause blooms, the type species (A. flos-aquae) may cause problems in water supply reservoirs and aquaculture.
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| Found 11 match(es) in the Image Captions | | Aphanizomenon - The cyanobacteria genus Aphanizomenon is well known as an ingredient of health food providing lots of vitamins and trace elements.
Collected from littoral region (stand of Phragmites) of a rain storage reservoir in Kiel (Schleswig-Holstein, Germany). This image was taken using Zeiss Universal with Olympus C7070 CCD camera.
| Aphanizomenon - Aphanizomenon is a cyanobacterium that often occurs in large aggregates. This was isolated on 4th April in a 20 micron plankton net haul at Sällvik (sample 4). Phase contrast micrograph.
| Aphanizomenon - Aphanizomenon is a cyanobacterium that often occurs in large aggregates. This was isolated on 4th April in a 20 micron plankton net haul at Sällvik (sample 4). Phase contrast micrograph.
| Aphanizomenon - Aphanizomenon is a cyanobacterium that often occurs in large aggregates. This was isolated on 4th April in a 20 micron plankton net haul at Sällvik (sample 4). These DIC images show the vacuolate character of the cell contents.
| Aphanizomenon flosaquae - Portrait of the cyanophyte, Aphanizomenon flosaquae. Collected from freshwater pond near Boise, Idaho. Brightfield optics.
| Aphanizomenon flosaquae - Aphanizomenon flosaquae
| Aphanizomenon ovalisporum - Aphanizomenon ovalisporum (Cyanobacteria, Nostocales), showing atypical long cells in a filament grown in culture.
| Aphanizomenon ovalisporum - The specialized cells of Aphanizomenon ovalisporum: an akinete (large, thick-walled, egg-shaped cell in the upper filament) and a hetetocyte (egg-shaped, transparent cells in the middle and bottom filaments).
The akinetes are much larger than regular cells and can be mid-filament or terminal, at times a few in a single filament, sometimes several in a row. Akinetes function as asexual resting stage and are resistant to harsh conditions. Akinete formation is induced by P-limitation. The akinetes separate from the filament and sink to the sediments, where they remain until conditions are suitable for germination.
| Aphanizomenon ovalisporum - Aphanizomenon ovalisporum (Cyanobacteria, Nostocales) was the first N2-fixing filamentous cyanobacterium that ever bloomed in Lake Kinneret. It happened in 1994 when this species formed an unprecedented autumn bloom. Since then Cylindrospermosis cuspis, another N2 fixer, invaded the lake and now dominates the summer-fall phytoplankton assemblages. A. ovalisporum produces the toxin cylindrospermopsin, which makes it an undesirable species in this important source of drinking water. Aphanizomenon ovalisporum is abundant during summer and fall, being evenly distributed with depth throughout the epilimnion. The filaments are 2 – 5 µm thick and 20 – 500 µm long. Heterocytes (seen as 3 distinct oval cells dispersed along the filament) appear when N-deficient conditions prevail. Akinete formation is induced by P-deficiency. The akinetes (not seen here) are much larger than regular cells and can be mid-filament or terminal, at times a few in a single filament, sometimes several in a row. This specimen was sampled from shallow water near the Kinneret Limnological Laboratory in June 2006.
| Aphanizomenon ovalisporum - This photo shows the typical terminal cells of Aphanizomenon ovalisproum from Lake Kinneret. The filaments, 2 – 5 µm thick and 20 – 500 µm long, are terminated by an elongated hyaline cell, as seen in this picture.
| Cylindrospermopsis cuspis - Cylindrospermopsis cuspis (Cyanobacteria, Hormogonales) is seen here between 2 filaments of Aphanizomenon ovalisporum from Lake Kinneret, showing the differences between those species. C. cuspis typically has gas vacuoles at the end cell, while the end cell of A. ovalisporum is mostly empty and often thinner than the rest of the cells in the trichome.
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