Desmidiales

Images Arthur M Scott, from the publication Gronblad and Kallio, 1954, A new genus and a new species among the desmids. Botaniska Notiser, 2: 167-172

End view Staurastrum dilatatum (Ehrenberg,1838) Ralfs, 1848.The four-armed semi-cells are rotated 45 degrees with respect to each other.From freshwater aquaculture tub near Boise, Idaho December 2005. DIC.

Differential interference contrast.

Differential interference contrast.

Colonial desmid in which adjacent cells link together to form elongate filaments. Differential interference contrast image.

Cosmarium, one of the many desmids - most of which have the appearance of mirror imaged cells joined together, but typically with only one nucleus. With cellulose cell wall, bright green chloroplasts. Differential interference contrast.

Differential interference contrast.

Differential interference contrast.

Cosmarium observed in freshwater sediments in the vicinity of Broome, Western Australia in September 2003. This image was taken using differential interference contrast optics.   This work was supported by the Australian Biological Resources Study.

A new desmid, (Cosmarium?) that recently appeared in the plankton of Lake Kinneret. Methylene blue staining shows a “hallow” of thin mucilaginous strands extending out of the cell.

Closterium (claws-tear-ee-um), a common and widespread desmid, a type of green alga. Organisms usually comprised of two mirror image parts. Typically from slightly acidic environments. With a cellulosic cell wall and chlorophyll B containing plastids. Phase contrast.

Closterium (claws-tear-ee-um), a common and widespread desmid, a type of green alga. Organisms usually comprised of two mirror image parts. Typically from slightly acidic environments. With a cellulosic cell wall and chlorophyll B containing plastids. Phase contrast.

Bright field.

Closterium, a common desmid, is very distinctive because of its smile shape. The nucleus is in the central region and the bright green chloroplasts extend into the two sides of the cell. The small circular pyrenoids are located in the chloroplasts. This desmid was collected from Obsidian Creek.

Collected from Cumloden Swamp on October 7, 2002.

Pleurotaenium, one of many desmids - most of which have the appearance of mirror imaged cells joined together, but typically with only one nucleus. With cellulose cell wall, bright green chloroplasts. Phase contrast micrograph.

Pleurotaenium, one of many desmids - most of which have the appearance of mirror imaged cells joined together, but typically with only one nucleus. This is a detail of the ribbon like plastids with nuerous refractile pyrenoids. Differential interference contrast.

Pleurotaenium, one of many desmids - most of which have the appearance of mirror imaged cells joined together, but typically with only one nucleus. With cellulose cell wall, bright green chloroplasts. This is an elongate species. Differential interference contrast.

Differential interference contrast.

Collected from Cumloden Swamp on October 7, 2002.

Differential interference contrast.

Micrasterias (mike-ras-tear-ee-ass), iconic desmid. The desmids are one type of green algae, often associated with slightly acidic freshwater habitats. As with all desmids, they are formed from two mirror imaged cells. Cellulosic wall, plastid, and pyrenoids are evident. The nucleus is in the centre. Differential interference contrast.

Micrasterias (mike-ras-tear-ee-ass), iconic desmid. The desmids are one type of green algae, often associated with slightly acidic freshwater habitats. As with most desmids, they are formed from two mirror imaged cells. Cellulosic wall, plastid, and pyrenoids are evident. Differential interference contrast.

Micrasterias (mike-ras-tear-ee-ass), iconic desmid. The desmids are one type of green algae, often associated with slightly acidic freshwater habitats. As with most desmids, they are formed from two mirror imaged cells. Cellulosic wall, plastid, and pyrenoids are evident. The nucleus is in the centre. Differential interference contrast.