Green vegetation in the aquarium is an element necessary to maintain the chemical composition of the water and give it a natural design. However, not all "greens" are the same. An example of an "aquarium negative" is blue-green algae. – microorganisms, which have another name - cyanobacteria.
Features of the structure of blue-green algae
Blue green algae are large bacteria that can be found singly, in groups, or in filaments. Their feature is the ability to carry out true photosynthesis (in the light to release oxygen into the aquatic environment). They, unlike euglena and pyrophytic algae, do not have flagella and a characteristic mucous membrane, grow rapidly and cover dense layer the surface on which they are attached. In addition, this cell is a typical prokaryote. It does not have a nucleus and internal organelles.
In nature, it is part of the natural phytoplankton, a participant in many symbioses in the water element.
Depending on the growing conditions, they can change their color: from light green to dark purple. Such staining is obtained due to the prevalence of one of the main participants in photosynthesis: chlorophyll and phycocyanin. Hue depends on their percentage.
Dense colonization of aquarium water by such microorganisms leads to the loss of transparency, the acquisition of an unpleasant musty smell, the death of cultivated plants and algae, as well as the existing fauna.
Due to their structure, they quickly grow on hard surfaces, forming dense thick layers. Mucus is almost always formed around such organisms. This is the protective property of cyanobacteria to resist adverse environmental factors. So, in nature, during the drying of the reservoir, mucus does not allow bacteria to die quickly. And when they get back into the water, they quickly restore their viability.
What options exist
Over the 3 billion years of its existence, blue-green algae have formed many modifications. Today, more than 2.5 thousand of their species are known. Among them:
- gleotrichia;
- anabena;
- oscillatory.
For gleothrichia, the natural habitat is reservoirs with salty moving water, in which they can live on obsolete parts of vegetation.
Anabaena can be found in swamps and ponds with a clay bottom, and even in puddles after rain.
Oscillators prefer stagnant water, often envelop the surface of drowned objects, but are also found on the surface of water bodies.
Numerous photos of "blooming" reservoirs reflect the result of the colonization of cyanobacteria. In this case, the ecological balance is violated. Plants stop growing and are poorly strengthened, fish practically suffocate from the presence of harmful chemicals in the water - the waste products of the pest.
Biological characteristics
Nutrition of all species is carried out in a phototrophic way, similar to kelp. However, there is evidence that the bacterium can also feed mixotrophically, i.e. mixed. She practically absorbs ready-made organic matter the entire surface, thanks to which it grows.
Algae are unable to reproduce sexually. They are characterized by a filamentous way of growth, known as vegetative. From several initial elements, whole thickets quickly form, often entangling cultivated plants, like a web.
All types of cyanobacteria are united by high survivability and the ability to quickly recover.
The pest is also resistant to some methods of disinfection. Salting, popular among the people, adding a few drops of brilliant green to the water, or other similar effects, he will be able to resist. To fight, natural antibiotics and special means for disinfecting water and aquarium surfaces are needed.
How to understand that there is cyanobacteria in the aquarium?
Blue-green algae, belonging to the realm of pre-nuclear (or pellets), have gone through such a long historical path of development that they have learned to adapt to the most negative conditions of existence. Many of them are unacceptable for other plants. They can grow in water:
- contaminated with chemicals;
- heated up to 93 about C;
- with signs of decay;
- contaminated with organic matter to levels exceeding the standards acceptable for life.
Bacteria are able to survive in ice and overgrow completely lifeless surfaces.
If blue green algae appeared in the aquarium , this can be seen initially when changing the water. After draining a few liters, you notice an unpleasant smell coming from the inside. The leaves of large plants become slightly slippery and soft, gradually changing their color to a duller one.
Later, you pay attention to a strange slime, which eventually reduces transparency and chemical composition aquatic environment. At the same time, a green coating appears on the surfaces of stones, grottoes, various supports and decor items. It tends to turn into a dense crust of algae. You can verify its presence if you scratch it slightly with your fingernail: it should be removed in large flakes.
Measures not taken in time are a guarantee of the complete death of the existing biocenosis. Plaque will cover the walls, the bottom of the aquarium, settle on the surface of the soil and turn into a dense, air-tight coating. 
What contributes to such a process?
A bacterium brought from outside into a prosperous water home requires:
- intense sunlight or artificial light;
- temperature increase above 24 about C;
- rare change of water;
- low level of aeration;
- extended lighting period;
- the presence of accompanying (bacterial) flora: various microbes, protozoa or viruses.
A factor contributing to overgrowth is the regular sediment from uneaten food, especially of a biological nature.
How to try to get rid of an unwanted guest?
How to deal with such a problem? After all, one often hears that water has sufficient cleansing power to cope with its own pollution. To a certain extent this is true, but it concerns large natural reservoirs. Artificial conditions, and, most importantly, a small amount of water, will not make it possible to defeat such an uninvited guest.
After all, he does not need food, he is an autotroph, and reproduction occurs quickly and easily.
You can try to defeat the newly appeared blue-green algae, including Oscillatoria , with the help of orderlies of the bottom - ancistrus. These beloved by many creatures belong to the catfish, which are characterized by a natural way to clean surfaces in a common water home. They are not only funny, but also useful.
Blue green algae are bacteria , which should be dealt with in several directions at once:
- create conditions contrary to the algal world;
- determine and implement a method of water disinfection;
- thoroughly rinse the soil and clean all affected surfaces;
- disinfect plants and rinse them thoroughly in cold running water;
- take measures so that the blue or greenish representative of unicellular algae does not reappear.
Step by step, the essence of these actions of the aquarist is as follows.
- Remove its inhabitants from the affected aquarium as much as possible;
- If possible, remove items that are important for the growth of cyanobacteria;
- Change at least half of the water volume, replacing it with fresh, oxygenated water;
- Well-rooted plants can not be touched, and it is better to take out small and floating ones and sanitize them in an accessible way;
- Add an antibiotic to the water, for example, erythromycin at the rate of 3-5 mg per 1 liter;
- Make a complete shading of the aquarium and leave it without light for 72 hours;
- At the end of the exposure, once again change a third of the water and open it to the light.
Before repopulating the fish, it is worth observing how effective the sanitation was. If there are traces of cyanobacteria, it is better to repeat the procedure in time.
Such actions can simultaneously fight not only with blue-green algae , but also other harmful phenomena in the aquarium, such as xenococus.
For aquariums of small size, general recommendations cannot be considered optimal. Their main difference is that it will not be enough to change part of the water, the amount of which is already limited. For such a case, it is proposed to get rid of a plant pest using hydrogen peroxide. It is necessary to determine its dose based on the volume of the aquarium: 20-25 ml of peroxide is proportionally added per 100 liters. Most likely, the treatment from oscillatoria will not end at once, but after 24 hours it is advisable to repeat it.
Further tactics are determined by the intensity of development of cyanobacteria. If necessary, after a few days, the treatment is carried out again.
Disinfection with hydrogen peroxide is more difficult, since in this case the presence of fish and plants is completely excluded. For them it is Chemical substance represents a danger to life.
How to protect the aquarium from such a problem?
Blue green algae - plants , which in their structure belong to the kingdom of bacteria, although they are not eukaryotes. Therefore, you can bring them into the aquarium with:
- new equipment;
- contaminated soil;
- plant bushes;
- water.
There is evidence that even tap water can serve as a carrier for microscopic pieces of algae. In this case, immediately from the first days of the aquarium equipment, a dark green film will appear on its surface, which has a sharp nasty smell. The water will not be transparent and safe, and the settlement of living creatures in it can lead to death.
If plants are taken for transplantation from an aquarium in which the glass is covered with a slippery dark green coating, most likely ecological system it is disturbed and the probability of the presence of cyanobacteria is high. Such a plant does not grow well, because it does not absorb minerals, looks painful and withers quickly.
The soil with growing cyanobacteria is poorly ventilated, has a low rate of oxidation, releases into water poisonous gases are the waste products of blue-green algae.
It is very important that the water does not contain residues of such organic substances as amino acids, carbohydrates, formed during the decomposition of food residues. Therefore, it is necessary to strictly observe the feeding regimen and the amount of this feed. Mechanical impurities suspended in water are well removed by means of special devices - filters.
A third of the water in the aquarium should be changed regularly (at least once every 10 days). The coefficient of its saturation with oxygen is important, i.e. aeration. The power of the air pump must necessarily correspond to the available volume of liquid.
Another an important factor risk is in excess of regulatory coverage. According to many biologists, fish do not need long daylight hours. Lighting, rather, is a characteristic necessary for the growth of plants and the solution of design ideas. But along with cultivated underwater plants, blue-green algae grow, especially if the water temperature is unreasonably high. Therefore, the number of hours when direct light is directed into the aquarium must be balanced.
The tasks of the aquarist include such unpleasant moments as the fight against blue-green algae. And on this path, you can achieve good results if you follow the generally accepted rules of hygienic care for fish and their habitat.
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The division of organisms considered here as algae is very diverse and does not represent a single taxon. These organisms are heterogeneous in their structure and origin.
Algae are autotrophic plants; their cells contain various modifications of chlorophyll and other pigments that provide photosynthesis. Algae live in fresh and marine, as well as on land, on the surface and in the thickness of the soil, on the bark of trees, stones and other substrates.
Algae belong to 10 divisions from two kingdoms: 1) Blue-green, 2) Red, 3) Pyrophytes, 4) Golden, 5) Diatoms, 6) Yellow-green, 7) Brown, 8) Euglenoids, 9) Greens and 10 ) Charovye. The first section belongs to the kingdom of Prokaryotes, the rest - to the kingdom of Plants.
Department of Blue-green algae, or Cyanobacteria (Cyanophyta)
There are about 2 thousand species, united in about 150 genera. These are the oldest organisms, traces of which were found in Precambrian deposits, their age is about 3 billion years.
Among blue-green algae there are unicellular forms, but most species are colonial and filamentous organisms. They differ from other algae in that their cells do not have a formed nucleus. They lack mitochondria, vacuoles with cell sap, no formed plastids, and the pigments with which photosynthesis is carried out are located in photosynthetic plates - lamellae. The pigments of blue-green algae are very diverse: chlorophyll, carotenes, xanthophylls, as well as specific pigments from the phycobilin group - blue phycocyanin and red phycoerythrin, which, in addition to cyanobacteria, are found only in red algae. The color of these organisms is most often blue-green. However, depending on the quantitative ratio of various pigments, the color of these algae can be not only blue-green, but also purple, reddish, yellow, pale blue or almost black.
Blue-green algae are distributed throughout the globe and are found in a wide variety of environments. They are able to exist even in extreme living conditions. These organisms endure prolonged darkening and anaerobiosis, can live in caves, in different soils, in layers of natural silt rich in hydrogen sulfide, in thermal waters, etc.
Mucous sheaths are formed around the cells of colonial and filamentous algae, which serve as a protective wrapper that protects the cells from drying out and is a light filter.
Many filamentous blue-green algae have peculiar cells - heterocysts. These cells have a well-defined two-layer membrane, and they look empty. But these are living cells filled with transparent contents. Blue-green algae with heterocysts are able to fix atmospheric nitrogen. Some types of blue-green algae are components of lichens. They can be found as symbionts in the tissues and organs of higher plants. Their ability to fix atmospheric nitrogen is used by higher plants.
The massive development of blue-green algae in water bodies can have negative consequences. Increased water pollution and organic substances cause the so-called "water bloom". This makes the water unfit for human consumption. Some freshwater cyanobacteria are toxic to humans and animals.
Reproduction of blue-green algae is very primitive. Unicellular and many colonial forms reproduce only by dividing cells in half. Most filamentous forms reproduce by hormogonia (these are short sections that have separated from the maternal filament and grow into adults). Reproduction can also be carried out with the help of spores - overgrown thick-walled cells that can survive adverse conditions and then grow into new threads.
Department Red algae (or Bagryanka) (Rhodophyta)
Red algae () - a large (about 3800 species from more than 600 genera) group of mainly marine life. Their sizes vary from microscopic to 1-2 m. Outwardly, red algae are very diverse: there are filamentous, lamellar, coral-like forms, dissected and branched to varying degrees.
Red algae have a peculiar set of pigments: in addition to chlorophyll a and b, there is chlorophyll d, known only for this group of plants, there are carotenes, xanthophylls, and pigments from the phycobilin group: blue pigment - phycocyanin, red - phycoerythrin. A different combination of these pigments determines the color of algae - from bright red to bluish-green and yellow.
Red algae reproduce vegetatively, asexually and sexually. Vegetative reproduction is typical only for the most poorly organized crimson (unicellular and colonial forms). In highly organized multicellular forms, torn off sections of the thallus die. Various types of spores are used for asexual reproduction.
The sexual process is oogamous. On the gametophyte plant, male and female germ cells (gametes) are formed, devoid of flagella. During fertilization, female gametes are not released into environment, but remain on the plant; male gametes are thrown out and passively carried by currents of water.
Diploid plants - sporophytes - have the same appearance like gametophytes (haploid plants). This is an isomorphic change of generations. Organs of asexual reproduction are formed on sporophytes.
Many red algae are widely used by humans, they are edible and beneficial. In the food and medical industry, it is widely used derived from different types crimson (about 30) polysaccharide agar.
Department Pyrophyta (or Dinophyta) algae (Pyrrophyta (Dinophyta))
The department includes about 1200 species from 120 genera, uniting eukaryotic unicellular (including biflagellate), coccoid and filamentous forms. The group combines the features of plants and animals: some species have tentacles, pseudopodia and stinging cells; some have a type of nutrition characteristic of animals, provided by the pharynx. Many have a stigma, or peephole. Cells are often covered with a hard shell. Chromatophores are brownish and reddish, contain chlorophylls a and c, as well as carotenes, xanthophylls (sometimes phycocyanin and phycoerythrin). Starch is deposited as reserve substances, sometimes oil. Flagellated cells have distinct dorsal and ventral sides. There are grooves on the surface of the cell and in the pharynx.
They reproduce by division in a mobile or immobile state (vegetatively), by zoospores and autospores. Sexual reproduction is known in few forms; it takes place in the form of fusion of isogametes.
Pyrophytic algae are common inhabitants of polluted water bodies: ponds, settling ponds, some reservoirs and lakes. Many form phytoplankton in the seas. Under unfavorable conditions, they form cysts with thick cellulose membranes.
The genus Cryptomonad (Cryptomonas) is the most widespread and rich in species.
Division Golden algae (Chrysophyta)
Microscopic or small (up to 2 cm long) golden yellow organisms that live in salt and fresh water bodies around the globe. There are unicellular, colonial and multicellular forms. About 300 species from 70 genera are known in Russia. Chromatophores are usually golden yellow or brown. They contain chlorophylls a and c, as well as carotenoids and fucoxanthin. Chrysolaminarine and oil are deposited as spare substances. Some species are heterotrophic. Most forms have 1-2 flagella and are therefore mobile. They reproduce mainly asexually - by division or zoospores; the sexual process is known only in a few species. Usually found in clean fresh waters(acidic waters of sphagnum bogs), less often - in the seas and in soils. Typical phytoplankton.
Division Diatoms (Bacillariophyta (Diatomea))
Diatoms (diatoms) number about 10 thousand species belonging to about 300 genera. These are microscopic organisms that live mainly in water bodies. diatoms - special group unicellular organisms, different from other algae. Diatomaceous cells are covered with a silica shell. The cell contains vacuoles with cell sap. The nucleus is located in the center. Chromatophores are large. Their color has various shades of yellow-brown, since carotenes and xanthophylls, which have yellow and brown hues, and masking chlorophylls a and c predominate among the pigments.
The shells of diatoms are characterized by geometric regularity of the structure and a wide variety of outlines. The shell consists of two halves. The larger one, the epithecus, covers the smaller one, the hypotheca, just like a lid covers a box.
Most diatoms with bilateral symmetry are able to move on the surface of the substrate. The movement is carried out using the so-called seam. The seam is a gap that cuts through the wall of the sash. The movement of the cytoplasm into the gaps and its friction against the substrate ensure the movement of the cell. Diatom cells with radial symmetry are incapable of locomotion.
Diatoms usually reproduce by dividing the cell into two halves. The protoplast increases in volume, as a result of which the epithecus and hypothecus diverge. The protoplast divides into two equal parts, the nucleus divides mitotically. In each half of the divided cell, the shell plays the role of an epitheca and completes the missing half of the shell, always a hypotheca. As a result of numerous divisions, a gradual decrease in cell size occurs in part of the population. Some cells are about three times smaller than the original ones. Having reached the minimum size, the cells develop auxospores (“growing spores”). The formation of auxospores is associated with the sexual process.
Cells of diatoms in the vegetative state are diploid. Before sexual reproduction, the reduction division of the nucleus (meiosis) occurs. Two diatom cells approach each other, the valves move apart, the haploid (after meiosis) nuclei merge in pairs, and one or two auxospores are formed. The auxospore grows for some time, and then develops a shell and turns into a vegetative individual.
Among diatoms, there are light-loving and shade-loving species; they live in water bodies at different depths. Diatoms can also live in soils, especially wet and swampy ones. Along with other algae, diatoms can cause snow blooms.
Diatoms play a large role in the economy of nature. They serve as a permanent food base and the initial link in the food chain for many aquatic organisms. Many fish feed on them, especially juveniles.
The shells of diatoms, settling to the bottom for millions of years, form a sedimentary geological rock - diatomite. It is widely used as construction material with high heat and sound insulation properties, as filters in the food, chemical, medical industries.
Department of yellow-green algae (Xanthophyta)
This group of algae has about 550 species. They are mainly inhabitants of fresh waters, less often found in the seas and on moist soil. Among them there are unicellular and multicellular forms, flagella, coccoid, filamentous and lamellar, as well as siphonal organisms. These algae are characterized by a yellow-green color, which gave the name to the whole group. Chloroplasts are disc-shaped. Characteristic pigments are chlorophylls a and c, a and b carotenoids, xanthophylls. Spare substances - glucan,. Sexual reproduction is oogamous and isogamous. Vegetatively reproduce by division; asexual reproduction is carried out by specialized mobile or immobile cells - zoo- and aplanospores.
Division Brown algae (Phaeophyta)
Brown algae are highly organized cellular organisms living in the seas. There are about 1500 species from about 250 genera. The largest of the brown algae reach several tens of meters (up to 60 m) in length. However, microscopic species are also found in this group. The shape of the thalli can be very diverse.
A common feature of all algae belonging to this group is a yellowish-brown color. It is caused by the pigments carotene and xanthophyll (fucoxanthin, etc.), which mask green color chlorophylls a and c. The cell membrane is cellulose with an outer pectin layer capable of strong mucus.
In brown algae, all forms of reproduction are found: vegetative, asexual and sexual. Vegetative propagation occurs by separated parts of the thallus. Asexual reproduction is carried out with the help of zoospores (mobile spores due to flagella). The sexual process in brown algae is represented by isogamy (less often, anisogamy and oogamy).
In many brown algae, the gametophyte and sporophyte differ in shape, size, and structure. In brown algae, there is an alternation of generations, or a change in nuclear phases in the development cycle. Brown algae are found in all seas the globe. In the thickets of brown algae near the coast, numerous coastal animals find shelter, breeding and feeding places. Brown algae are widely used by man. Alginates (salts of alginic acid) are obtained from them, which are used as stabilizers of solutions and suspensions in Food Industry. They are used in the manufacture of plastics, lubricants, etc. Some brown algae (kelp, alaria, etc.) are used in food.
Division Euglenophyta (Euglenophyta)
This group contains about 900 species from about 40 genera. These are unicellular flagellar organisms, mainly inhabitants of fresh waters. Chloroplasts contain chlorophylls a and b and a large group of auxiliary pigments from the group of carotenoids. Photosynthesis occurs in these algae in the light, and in the dark they switch to heterotrophic nutrition.
Reproduction of these algae occurs only due to mitotic cell division. Mitosis in them differs from this process in other groups of organisms.
Division Green algae (Chlorophyta)
Green algae is the largest division of algae, numbering, according to various estimates, from 13 to 20 thousand species from about 400 genera. These algae are characterized by a purely green color, like in higher plants, since chlorophyll predominates among the pigments. In chloroplasts (chromatophores) there are two modifications of chlorophyll a and b, as in higher plants, as well as other pigments - carotenes and xanthophylls.
Rigid cell walls of green algae are formed by cellulose and pectin substances. Spare substances - starch, less often oil. Many features of the structure and life of green algae indicate their relationship with higher plants. Green algae are distinguished by the greatest diversity compared to other departments. They can be unicellular, colonial, multicellular. This group represents the whole variety of morphological body differentiation known for algae - monadic, coccoid, palmelloid, filamentous, lamellar, non-cellular (siphonal). The range of their sizes is great - from microscopic single cells to large multicellular forms tens of centimeters long. Reproduction is vegetative, asexual and sexual. All the main types of change in the forms of development are encountered.
Green algae live more often in fresh water bodies, but there are many brackish and marine forms, as well as out-of-water terrestrial and soil species.
The Volvox class includes the most primitive representatives of green algae. Usually these are unicellular organisms with flagella, sometimes united in colonies. They are mobile throughout life. Distributed in shallow freshwater bodies, swamps, in the soil. From single-celled species of the genus Chlamydomonas are widely represented. Spherical or ellipsoidal cells of chlamydomonas are covered with a membrane consisting of hemicellulose and pectin substances. There are two flagella at the anterior end of the cell. The entire inner part of the cell is occupied by a cup-shaped chloroplast. In the cytoplasm that fills the cup-shaped chloroplast, the nucleus is located. At the base of the flagella there are two pulsating vacuoles.
Asexual reproduction occurs with the help of biflagellate zoospores. During sexual reproduction in the cells of chlamydomonas, biflagellated gametes are formed (after meiosis).
Chlamydomonas species are characterized by iso-, hetero- and oogamy. When unfavorable conditions occur (drying of the reservoir), chlamydomonas cells lose their flagella, become covered with a mucous membrane and multiply by division. When favorable conditions occur, they form flagella and move to a mobile lifestyle.
Along with the autotrophic method of nutrition (photosynthesis), chlamydomonas cells are able to absorb organic substances dissolved in water through the membrane, which contributes to the processes of self-purification of polluted waters.
Cells of colonial forms (pandorina, volvox) are built according to the type of chlamydomonas.
In the Protococcal class, the main form of the vegetative body is immobile cells with a dense membrane and colonies of such cells. Chlorococcus and chlorella are examples of unicellular protococci. Asexual reproduction of Chlorococcus is carried out with the help of biflagellated motile zoospores, and the sexual process is a fusion of mobile biflagellated isogametes (isogamy). Chlorella does not have mobile stages during asexual reproduction, there is no sexual process.
The Ulotrix class combines filamentous and lamellar forms that live in fresh and marine waters. Ulothrix is a thread up to 10 cm long, attached to underwater objects. The filament cells are identical, short-cylindrical with lamellar parietal chloroplasts (chromatophores). Asexual reproduction is carried out by zoospores (mobile cells with four flagella).
The sexual process is isogamous. Gametes are motile due to the presence of two flagella in each gamete.
The class Conjugates (couplings) combines unicellular and filamentous forms with a peculiar type of sexual process - conjugation. Chloroplasts (chromatophores) in the cells of these algae are lamellar and very diverse in shape. In ponds and slow-flowing water bodies, the main mass of green mud is formed by filamentous forms (spirogyra, zignema, etc.).
When conjugated from opposite cells of two adjacent threads, processes grow that form a channel. The contents of the two cells merge, and a zygote is formed, covered with a thick membrane. After a dormant period, the zygote germinates, giving rise to new filamentous organisms.
The Siphon class includes algae with a non-cellular structure of the thallus (thallus), with its rather large size and complex dissection. The siphon seaweed caulerpa outwardly resembles a leafy plant: its size is about 0.5 m, it is attached to the ground by rhizoids, its thalli creep along the ground, and vertical formations resembling leaves contain chloroplasts. It easily reproduces vegetatively by parts of the thallus. There are no cell walls in the body of the alga, it has a continuous protoplasm with numerous nuclei, chloroplasts are located near the walls.
Department Charovye algae (Charophyta)
These are the most complex algae: their body is differentiated into nodes and internodes, in the nodes there are whorls of short branches resembling leaves. The size of plants is from 20-30 cm to 1-2 m. They form continuous thickets in fresh or slightly saline water bodies, attaching to the ground with rhizoids. Outwardly, they resemble higher plants. However, these algae do not have a real division into root, stem, and leaves. There are about 300 species of charophytes belonging to 7 genera. They have similarities with green algae in terms of pigment composition, cell structure, and reproduction characteristics. There is also a similarity with higher plants in the features of reproduction (oogamy), etc. The noted similarity indicates the presence of a common ancestor in characeae and higher plants.
Vegetative reproduction of characeae is carried out by special structures, the so-called nodules, formed on rhizoids and on the lower parts of the stems. Each of the nodules germinates easily, forming a protonema, and then a whole plant.
The whole department of algae, after the first acquaintance with it, is very difficult to grasp mentally and give each department its correct place in the system. The system of algae did not develop in science soon and only after many unsuccessful attempts. At the present time, we impose on any system the basic requirement that it be phylogenetic. At first it was thought that such a system could be very simple; imagined it as a single genealogical tree, albeit with many side branches. Now we are building it in no other way than in the form of many genealogical lines that developed in parallel. The matter is further complicated by the fact that, along with progressive changes, there are also regressive ones, putting on resolution difficult task- in the absence of one or another sign or organ, decide that it has not yet appeared or has already disappeared?
For a long time, the system given to Ville in the 236th issue of the main work on the descriptive taxonomy of plants, published under the editorship of A. Engler, was considered the most perfect. Flagellates or Flagellata are recognized as the main group here.
This scheme covers only the main group of green algae. For the rest, we will take Rosen's scheme, changing only the names of the groups, in accordance with those adopted above when describing them.
LESSON #1
TOPIC: Introduction to systematics. Kingdom of Bacteria.
Kingdom of Algae.
TARGET: Familiarize yourself with the basics of taxonomy and classification flora, explore the features morphological structure bacteria, as well as the systematic position, structural features and reproduction of the main representatives of the departments green, red, diatoms and brown algae, medicinal representatives.
INDEPENDENT WORK.
QUESTIONS FOR SELF-EDUCATION:
1. Systematics as a biological science. System types. taxa.
2. Empire cellular organisms (Cellulata). Pre-nuclear organisms (Procariota). Main systematic features
3. Subkingdom of Oxyphotobacteria. Department of Cyanobacteria (Cyanobacteria). Features of the structure, significance in nature and human life.
4. Kingdom Protoctista, main systematic features, representatives.
5. Protoctists - algae (Algae). general characteristics algae.
6. Systematics of algae. Significance in nature and human life.
7. Department of Bagryanka (Rhodophyta), structural features, reproduction.
8. Division Green algae (Chlorophyta), structural features, reproduction.
9. Division Brown algae (Phaeophyta), structural features, reproduction.
LITERATURE: 1. Yakovlev G.P. etc. Botany. - St. Petersburg: SPFHA Publishing House, 2001. - pp. 232 - 284.
Exercise 1. Write down and learn the Latin names of the representatives of the department under study.
brown algae - ________________________________________________________________
Laminaria sugary - ________________________________________________________________
Japanese kelp - _________________________________________________________________
green algae - ______________________________________________________________
Chlamydomonas - _________________________________________________________________________
Chlorella - ___________________________________________________________________________
Ulotrix - _______________________________________________________________________________
Spirogyra - ________________________________________________________________________________
blue green algae - ________________________________________________________
Nostok - _______________________________________________________________________________
Anabena - ____________________________________________________________________________
Oscillatory - _____________________________________________________________________________
Spirulina - _____________________________________________________________________________
Task 2. Select the appropriate additions to characterize the cyanobacteria department.
1. Cyanobacteria, or blue-green algae, include:
A - to the super-kingdom of prokaryotes; B - to the kingdom of eukaryotes; C - to the kingdom of plants, G - to the kingdom of pellets, D - to the sub-kingdom of oxyphotobacteria; E - real algae to the sub-kingdom.
2. Representatives of cyanobacteria are:
A - unicellular organisms inhabiting exclusively fresh water bodies; B - unicellular, multicellular colonial forms that live in fresh water, less often in the seas,
B - settling on the soil, stones, tree trunks, forming lichens; D - autotrophic organisms; D - heterotrophic organisms; E - organisms capable of fixing free nitrogen.
3. Structural features of cyanobacteria cells usually include:
A - morphologically formed core is absent; B - one core or many of them; B - the shell is dense, thick, includes pictin substances, cellulose, murein and other polysaccharides; D - chitinous shell pigments are concentrated in the wall layer of the cytoplasm; E - pigments are localized in chromophores; G - specific pigments - carotenoids; H - specific pigments - phycocyanins and phycoerythrin.
Task 3. Describe the division of Clorophyta by selecting the appropriate additions:
1. Cells of green algae are similar to cells of higher plants, namely:
A - cellulose-pectin cell wall; B - chlorophylls and carotenoids are concentrated in plastids; B - chloroplasts usually with pyrenoids; G - a product of photosynthesis - starch.
2. Thallus - ...
A - always unicellular; B - always multicellular; B - unicellular or multicellular;
G - non-cellular and colonial.
3. They breed ...
A - vegetatively; B - asexually with the help of zoospores, C - asexually with the help of aplanospores; G - sexually.
4. Forms of the sexual process:
A - oogamy; B - heterogamy; B - isogamy; G - conjugation.
5. Representatives of the department:
A - nostoc; B - chlorella; B - ulotrix; G - spirogyra; D - fucus; E - chlamydomonas;
G - volvox.
Task 4. Indicate the names of the depicted algae (A, B, C, D) of the departments to which they belong, and make captions for the digital designations.
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| A | B | IN | G | ||
| 1__________________________________ 2__________________________________ 3__________________________________ 4__________________________________ 5__________________________________ | 6__________________________________ 7__________________________________ 8__________________________________ 9__________________________________ | ||||
Task 5. Describe the department of Phaeophyta, choosing the right one:
1. Brown algae are ...
A - to the super-kingdom of prokaryotes; B - to the kingdom of eukaryotes; B - the kingdom of shotguns; G - the kingdom of the plant; D - real algae to the sub-kingdom; E - to the kingdom of purple.
2. They live ...
A - in cold seas, on rocky bottom substrates; B - in warm seas and fresh water bodies, in the water column.
3. Building level…
A - one and multicellular, B - only multicellular; B - small sizes, no more than 1 m;
G - large sizes, up to 6 m and more.
4. Thallus of sporophyte...
A - filamentous, multi-row or dissected into a "trunk" and leaf-shaped plates;
B - filamentous, not dissected; B - with false tissues; G - with real fabrics.
5. In the development cycle of brown algae ...
A - a change in nuclear phases is observed, alternation of generations is expressed; B - the change of nuclear phases and generations is not expressed.
6. Cells are characterized by ...
A - one nucleus, many vacuoles; B - many nuclei, one vacuole; B - the shells are mucilaginous; D - chloroplasts have pyrenoids and contain the pigment phycoerythrin; D - chloroplasts without pyrenoids, specific pigment - fucoxanthin; E - reserve substances - laminarin, mannitol and fatty oil; G - reserve substance - starch.
7. Representatives of the department are:
A - chlorella; B - fucus; B - ulotrix; G - kelp; D - wash; E - spirogyra.
Task 6. Basic terms on the topic (define):
Binary nomenclature - ______________________________________________________________
____________________________________________________________________________________
Artificial systems - _____________________________________________________________
Classification - ________________________________________________________________________
_____________________________________________________________________________________
Systematics - ________________________________________________________________________
_____________________________________________________________________________________
Taxon - _____________________________________________________________________________
Akinetes - _________________________________________________________________________
Heterocysts - ______________________________________________________________________________
Genofor - _________________________________________________________________________
Algology – ____________________________________________________________________________
Benthos – _____________________________________________________________________________
Gametophyte - _________________________________________________________________________
_____________________________________________________________________________________
Hypothesis - ________________________________________________________________________
Karpogon - ________________________________________________________________________________
Pellicle - _____________________________________________________________________________
Pyrenoids - _____________________________________________________________________________
Rhizoids - ___________________________________________________________________________
Sporophyte - ________________________________________________________________________
Undulipodium - _____________________________________________________________________________
Tall – ____________________________________________________________________________
Phytoplankton - ____________________________________________________________________________
Chromatophores - ____________________________________________________________________________
Epithecus - ___________________________________________________________________________
Task 7. Match: Algae Breeding Species - Their Essence
Task 8. For the specified groups of plants, select the appropriate value and application.
Cyanobacteria (blue-green) - a department of the kingdom of prokaryotes (shotguns). Represented by autotrophic phototrophs. Life forms - unicellular, colonial, multicellular organisms. Their cell is covered with a layer of pectin located on top of the cell membrane. The nucleus is not expressed, the chromosomes are located in the central part of the cytoplasm, forming the centroplasm. Of the organelles, there are ribosomes and parachromatophores (photosynthetic membranes) containing chlorophyll, carotenoids, phycocyan and phycoerythrin. Vacuoles are only gas, cell juice does not accumulate. Spare substances are represented by grains of glycogen. Cyanobacteria reproduce only vegetatively - by parts of the thallus or by special sections of the thread - hormogonia. Representatives: oscillatoria, lingbia, anabaena, nostoc. They live in water, on soil, in snow, in hot springs, on the bark of trees, on rocks, and are part of the body of some lichens.
blue green algae, cyanide (Cyanophyta), algae department; belong to prokaryotes. In blue green algae, as in bacteria, the nuclear material is not separated by a membrane from the rest of the cell content, the inner layer of the cell wall consists of murein and is sensitive to the action of the enzyme lysozyme. Blue-green algae are characterized by a blue-green color, but pink and almost black are found, which is associated with the presence of pigments: chlorophyll a, phycobilins (blue - phycocyan and red - phycoerythrin) and carotenoids. Among the blue-green
algae, there are unicellular, colonial and multicellular (filamentous) organisms, usually microscopic, less often forming balls, crusts and bushes up to 10 cm in size. Some filamentous blue-green algae are able to move by sliding. The protoplast of blue-green algae consists of an outer colored layer - chromatoplasm - and a colorless inner part - centroplasm. In the chromatoplasm there are lamellae (plates) that carry out photosynthesis; they are arranged in concentric layers along the shell. The centroplasm contains a nuclear substance, ribosomes, reserve substances (volutin granules, cyanophycin grains with lipoproteins) and bodies consisting of glycoproteins; plantain species have gas vacuoles. Chloroplasts and mitochondria are absent in blue-green algae. The transverse partitions of filamentous blue-green algae are equipped with plasmodesmata. Some filamentous blue-green algae have heterocysts - colorless cells, isolatedfrom vegetative cells by "plugs" in plasmodesmata. Blue-green algae reproduce by division (unicellular) and by hormogonia - sections of filaments (multicellular). In addition, the following are used for reproduction: akinetes - immobile resting spores, formed entirely from vegetative cells; endospores that arise several times in the mother cell; exospores, detached from the outer side of the cells, and nanocytes - small cells that appear in the mass during the rapid division of the contents of the mother cell. There is no sexual process in blue-green algae, however, there are cases of recombination of hereditary traits through transformation. 150 genera uniting about 2000 species; in countries former USSR- 120 genera (over 1000 species). Blue-green algae are part of the plankton and benthos of fresh waters and seas, live on the surface of the soil, in hot springs with water temperatures up to 80 ° C, on snow - in the polar regions and in the mountains; a number of species live in a calcareous substrate (“drilling algae”), some blue-green algae are components of lichens and symbionts of protozoa and terrestrial plants (bryophytes and cycads). IN largest quantities blue-green algae develop in fresh waters, sometimes causing water blooms in reservoirs, which leads to the death of fish. Under certain conditions, the mass development of blue-green algae contributes to the formation of therapeutic mud. In some countries (China, the Republic of Chad), a number of species of blue-green algae (nostoc, spirulina, etc.) are used for food. Attempts are being made to mass-scale cultivation of blue-green algae to obtain fodder and food protein (spirulina). Some blue-green algae absorb molecular nitrogen, enriching the soil with it. In the fossil state, blue-green algae have been known since the Precambrian.
