An important element of freshwater and marine plankton, harmoniously combining the properties of both plants and animals are diatoms. Examples of these unicellular organisms can be seen in many textbooks.
They are very different from other representatives of the underwater fauna, their main part is considered to be the diatom – a special cell covered with a layer of silicon.
The main feature of diatom algae – diatom – a special cell coated with a layer of silicon
Diatom algae were discovered in the 18th century, when Leeuwenhoek microscopes and new magnifiers with a strong magnification were used for various research works. This group of unicellular algae has received several scientific names, namely: bacillary (Bacillariophyta), silica (Kieselalgae) and diatom (Diatomeaea).
The last name was given to these organisms because of a special way of reproduction – by dividing the shell into 2 parts. The second is explained by the presence of a silica shell found in algae cells. And the bacillary ones began to be called by the name of the first kind, which was described in 1788.
The name formed from the word bacillaria, which translates as “rod-shaped.”
In Russian literature, the second name or its derivative is usually found – diatoms, and the Latin Bacillariophyta is considered to be the modern (scientific).
Diatoms were discovered in the 18th century.
Silica organisms are the main component of plankton-benthos, in the wild waters they can be found at a depth of no more than 100 meters. The habitat for diatoms is a substrate.
They move in it, clinging to the surface, with the help of legs and tubes.
According to the method of feeding, diatoms are classified as phototrophs; however, heterotrophs, mixotrophs, and symbiotrophs are often found among them.
These organisms prefer to dwell in groups with their relatives. Their presence in the aquarium can be recognized by the appearance of a brown, brown-green or gray plaque that covers the glass walls. For the global ecosystem these algae are very important, as produce a large amount of organic matter.
This is what triggered the emergence of interest in single-celled by nature conservationists and manufacturers of various biomaterials.
The habitat for diatoms is a substrate.
However, it should be borne in mind that their appearance in aquariums does not bode well, so you should get rid of such phototrophs as soon as possible. To do this, you need to learn about these algae more, namely, to understand their purpose and device.
Thanks to electron microscopes, the power of which allows you to increase the objects under study thousands of times, experts were able to examine the structure of diatom cells.
The main component is the shell, representing the outer shell of the two halves. Depending on the variety, these valves can be fastened together, slightly shifted to each other or have a separator, which helps the parts of the shell to move apart so that the body can build up the cell mass.
The main component of diatomy is the shell, which is the outer shell of the two halves
The halves have a rough surface, they can be seen many ribs, pores, cells, holes or chambers. The area of this improvised armor is covered with grooves by 75 percent.
And also there are various growths that allow unicellular to form in groups.
The main component of this natural protection is silicon dioxide, in which there are various impurities, for example, iron, organic matter, aluminum and magnesium. The outer side of the shell is decorated with a thin coating of organic matter.
Using a microscope, scientists were able to examine the forms that this cover may have:
The area of this improvised armor is covered with grooves by 75 percent.
Exists many types of valves. These structural elements are capable of forming complex and interesting combinations, although they consist of only one cell.
Forms of armor and sashes are very diverse, fancy and intricate, and their surface is so elegant and unusual that enlarged images of diatoms can be easily taken as works of art.
The protective function of the body is performed by the cytoplasm – it is located inside the cell and covers the entire surface of the silicon walls with a thin layer. The entire internal space of the cell is occupied by a vacuole, and the nucleoli and the diploid nucleus form a specific bridge. Also around the perimeter of the shell are chromatophores, which look like small plates and discs.
The smaller their size, the more they are contained in the cell. Some diatoms belong to heterotrophs and therefore do not have pigments.
Autotrophic species are composed of plastids of various shades.
As a result of photosynthesis, such algae produce not carbohydrates, like all land plants, but lipids. For healthy and active life, these organisms require fats, as well as reserve and additional substances, such as chrysolaminarine, for example.
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