What is the shape of desmids?
Desmids assume a variety of highly symmetrical and generally attractive shapes, among those elongated, star-shaped and rotund configurations, which provide the basis for their classification. The largest among them may be visible to the unaided eye.
Where can you find desmids?
Where can you find Desmids? Desmids need water of specific quality, most species require water with a certain acidity and without too many nutrients. Between sphagnum moss in bogs and marshes you may find many species. An easy way to collect them is to squeeze the water out of sphagnum into a jar.
What is the classification of desmids?
Desmids are sometimes treated as a family (Desmidiaceae) of the order Zygnematales. Desmids are characterized by extensive variation in cell shape and are found worldwide, usually in acid bogsor lakes.
What is the diversity of desmids?
Desmid Diversity : On the left, Netrium, a representative of the homogeneous walled Mesotaeniaceae group of desmids. On the right, Microasterias, a representative of the Desmidiaceae, the other major group which has a cell with two major compartments.
What does desmid look like?
desmid, (order Desmidiales), order of single-celled (sometimes filamentous or colonial) microscopic green algae, comprising some 5,000 species in about 40 genera. Desmids are sometimes treated as a family (Desmidiaceae) of the order Zygnematales.
How many cells does a desmid consist of?
are small forms usually comprised of four cells, but some species may have up to twelve cells. Typically, at least the end cells possess spines. Many species of the genera Cosmarium (left), Euastrum (middle), and Micrasterias (right) have rounded, compressed forms.
What classification is a desmid?
ZygnematophyceaeDesmidiales / ClassZygnematophyceae is a class of green algae in the division Charophyta, consisting of more than 4000 described species. It contains the order Zygnematales. The Desmidiales emerged within the Zygnematales. The Zygnematophyceae are the sister clade of the Mesotaenium, together forming the sister clade of the land plants. Wikipedia
Where could you find a desmid?
Desmids are primarily found in freshwater habitats, such as ponds, rivers, and lakes. There, they may live as phytoplankton, on the bottom as benthic dwellers, or on the submerged portions of plants. They may also be found in saline waters, or in snow or ice.
How do desmids reproduce?
Reproduction. Desmids commonly reproduce by asexual fission, however, in adverse conditions, Desmidiales may reproduce sexually, through a process of conjugation, which are also found among the closely related Zygnematales.
What is Closterium scientific name?
ClosteriumClosterium / Scientific nameClosterium setaceum is a species of unicellular charophyte green algae in the family Closteriaceae. It has a worldwide distribution. Closterium setaceum. Scientific classification.
How do desmids store energy?
Each semi-cell houses a large, often folded chloroplast. One or more pyrenoids can be found. These form carbohydrates for energy storage. Desmids show a wide variety of body shapes and many species are ornamented with all kinds of knobs and spines.
What role do desmids play in the ecosystem?
Like many other algal species, desmids are important indicators of water quality. Their occurrence provides information on environmental conditions such as pH, conductivity and trophic state of a water body. Using desmid species in environmental studies calls for reliable identification.
Is Cosmarium a colonial?
This is one of the few desmid genera that is considered to be colonial.
Do desmids silica?
- The cell membrane of diatoms consists of silica whereas that of desmids consists of cellulose and pectins (like plants) .
Are desmids found in dirty water?
The nutritious content present in the freshwater supports the growth of desmid algae. They are also found in saline waters, snow, ice..etc. But, the polluted water does not have enough nutrients. So, it cannot support the reproduction of mixed desmid.
What is the purpose of oscillatoria?
Oscillatoria uses photosynthesis to survive and reproduce. Each filament of oscillatoria consists of trichome which is made up of rows of cells. The tip of the trichome oscillates like a pendulum....OscillatoriaDomain:BacteriaPhylum:CyanobacteriaClass:CyanophyceaeOrder:Oscillatoriales9 more rows
1. Where Do You Find Desmids?
Ans. Desmids are usually found in freshwaters like ponds, lakes, and rivers. It is a kind of phytoplankton, which lives in the bottom as benthic dw...
2. What Makes Desmid Green?
Ans. Desmids belong to the Desmidiaceae family. The Desmids are single-cell green algae, which can found only in freshwater. The mixed desmids have...
3. Why is Desmid Important?
Ans. As desmids can grow only in freshwater, they act as an important indicator for identifying water quality. It shows the information on aquatic...
What is the cell of a desmid?
The cell of a desmid is often divided into two symmetrical compartments separated by a narrow bridge or isthmus, wherein the spherical nucleus is located. Each semi-cell houses a large, often folded chloroplast for photosynthesizing. One or more pyrenoids can be found.
How do Desmids reproduce?
Reproduction. Desmids commonly reproduce by asexual fission , however, in adverse conditions, Desmidiales may reproduce sexually, through a process of conjugation, which are also found among the closely related Zygnematales .
What is the order of desmidiales?
Desmidiales. Desmidiales, commonly called desmids ( Gr. desmos, bond or chain), are an order in the Charophyta, a division of green algae in which the land plants ( Embryophyta) emerged. Or in other words, Desmid, (order Desmidiales), order of single-celled (sometimes filamentous or colonial) microscopic green algae.
Where are desmids grown?
So, the desmids are widely grown in lakes, pits, aquariums. .etc. The development of desmid are based on other systems like climate, nutrient conditions, and geology influence species composition, but in macrophyte plant composition, water level, wetlands, and degree of mixing with other water bodies.
Why are desmids important?
Ans. As desmids can grow only in freshwater, they act as an important indicator for identifying water quality. It shows the information on aquatic environmental conditions like pH, conductivity, and trophic state of the aquatic body. The chlorophyll present in desmid algae absorbs the dissolved carbon dioxide and releases oxygen during photosynthesis. This helps to provide oxygen to aquatic organisms. The desmid acts as food for many aquatic species.
What is the role of desmids in the food web?
The two symmetric semi-cells are joined together by the narrow connections called the isthmus. The desmid algae play an important role in the complex food web of life. As with other plants, the desmid contains chlorophyll. This will helps the desmids to capture sunlight for the generation of photosynthesis.
What is the role of desmids in the aquatic ecosystem?
Desmid is a well-known aquatic species. It plays an important role in aquatic ecosystems. The desmids are the type of unicellular biomass algae. It acts as an important food source for many invertebrates. The desmids are the potential food source for zooplankters like Cladocera and Copepods. The daphnids use planktonic mixed desmids as a food source. The Dplanktonic desmids are a rich potential food source. As the desmid has a low population density, it plays a minor role in the pelagic food web. In particular, where desmids grow in a submerged substrate as a green film that can be view through the naked eye, they are acting as a feed for the large numbers by grazers like rotifers, worms, midge larvae, etc.
How do Desmids reproduce?
Desmids reproduce asexually like amoeba through the simple cell division method. The two semi cells are connected together with a centre called an isthmus. Usually, cell division occurs in the region of the isthmus, each half of the semi cells is divided into two halves and developed into an individual organism.
What does a semi cell look like?
The shape of the semi cells changes. It looks like a disc or spindle shape and ranging from more or less globular. The cell wall of the mixed desmids are smooth and have distinct patterns of tubercles, granules, or spines. The desmids have a rich cell wall and not in combination with deep semicellular incisions.
What is the nucleus of a desmid?
The nucleus present in the middle of the desmids contains a transparent and denser nuclear structure. The globular nucleus turns and develops into a globose, vacuole-like structure. The shape of the semi cells changes.
Overview
Desmidiales, commonly called desmids (Gr. desmos, bond or chain), are an order in the Charophyta, a division of green algae in which the land plants (Embryophyta) emerged. Or in other words, Desmid, (order Desmidiales), order of single-celled (sometimes filamentous or colonial) microscopic green algae. Desmids are sometimes treated as a family (Desmidiaceae) of the order Zygne…
Morphology
The structure of these algae is unicellular, and lacks flagella. Although most desmids are unicellular, the species Desmidium swartzii forms chains of cells resembling the algae genus Spirogyra. However, these filaments are arranged in a helix pattern.
The cell of a desmid is often divided into two symmetrical compartments separated by a narrow bridge or isthmus, wherein the spherical nucleus is located. Each semi-cell houses a large, often …
Reproduction
Desmids commonly reproduce by asexual fission, however, in adverse conditions, Desmidiales may reproduce sexually, through a process of conjugation, which are also found among the closely related Zygnematales.
Classification
Classification of the families and genera in the Desmidiales:
The family Gonatozygaceae is sometimes included within the Peniaceae, reducing the number of families from four to three. A fifth family Mesotaeniaceae was formerly included in the Desmidiales, but analysis of cell wall structure and DNA sequences show that the group is more closely related to the Zygnemataceae, and so is now placed together with that family in the order
Further reading
• Survey of Clare Island 1990 - 2005, noting the Desmidiales recorded. Ed. Guiry, M.D., John, D.M., Rindi, F. and McCarthy, T.K. 2007. New Survey of Clare Island. Volume 6: The Freshwater and Terrestrial Algae. Royal Irish Academy. ISBN 978-1-904890-31-7
External links
• Microphotographs of desmids