The structure of an earthworm. Earthworm
The earthworm is known to everyone and everyone, probably since childhood. Everyone remembers the pink creatures that appear out of nowhere after the rain. But not everyone knows that the earthworm is a real treasure for the earth, they play a big role in the ecosystem, enrich the earth with nutrients, and are food for many birds and animals. There are many interesting facts, revealing all the secrets of the "extraordinary" inhabitant of the earth's interior, which does not look attractive at all, but is of great importance in nature and human life.
The structure and description of worms
Earthworms are a type of annelids. They live mainly in moist soil rich in humus. Interestingly, the habitat is 5 continents - all except Australia. Features them appearance these are:
And also on each segment there are bristles that help move underground. In the tubular body, bones and cartilage are completely absent, the body cavities are filled with fluid. An earthworm is perhaps the most amazing creature that lives in the soil, it has no eyes, no lungs, no ears. Breathing is done through the skin. The worm has several hearts, the digestive system runs along the entire length of the body.
The mucous glands located between the segments secrete mucus, which protects against overdrying, helps in moving underground, and prevents the earth from sticking to the body. And it scares off predators because it tastes very bad.
The average life expectancy is from 4 to 8 years. However, there are cases when the age of the worm reached even 10 years. It is difficult to meet such centenarians in nature, since any bird or rodent and, of course, a person are dangerous for them. The greatest threat currently posed by chemicals - fertilizers, generously added to the soil, most of them are deadly to worms.
Favorite food
The question of what earthworms eat is very interesting. Their “menu” is rather modest, the basis of the diet is fallen rotting leaves, as well as other organic residues - roots, rotten pieces of wood. The teeth of worms are in the stomach. Liquid-like soft food is absorbed through the pharynx, then muscularly pushed further - into the goiter, and then into the stomach, where it is crushed and ground with the help of the so-called teeth - hard growths similar to the incisors we are used to. With the contraction of the gastric muscles, these hard tooth-like processes come into motion. Digestion takes place in the intestines.
Undigested food residues are deposited in the soil. In one day, an adult earthworm is able to process a pound of earth!
Lifestyle
As you know, earthworms are underground inhabitants. They spend most of their lives digging underground passages and burrows, the network of such corridors can reach a depth of 2-3 meters. Worms are nocturnal animals by way of life. Their body is not at all protected from ultraviolet radiation, so the peak of activity comes in the evening and at night. As a "home" they prefer moist soil rich in humus. Animals do not like both sandy and too wetlands. It has to do with breathing patterns.
They take in oxygen with their skin, and there is very little air in the excessively moist earth, which causes inconvenience, the animal begins to suffocate. This explains their behavior after the rain. The ground becomes so wet that the worms are forced to crawl to the surface in order not to suffocate.
In dry land, the mucus that covers the skin dries up, making it impossible for the worms to both breathe and move comfortably. With the advent of cold weather, earthworms go into the deep layers of the soil.
Reproduction of worms
A small soil inhabitant has the specifics of the reproduction of offspring. Reproduction of earthworms occurs mainly in the warm season and stops during drought and cold snap, when they go into the deep layers of the soil to winter.
Everyone knows that earthworms are hermaphrodites. In the body of the worm there are both male and female genital organs. However, this is not enough for reproduction. Invertebrates need another individual with which the mating process will take place - the exchange of genetic material. Worms find a partner by smell, as the bodies produce pheromones that other earthworms sense. Reproduction occurs as follows.
They mate on the surface of the earth in wet weather. In the process, the worms are pressed against each other so that the back end of one worm is pressed against the front end of the other, in other words, with a jack. The mucous membrane provides for the exchange of spermatozoa. After separation from each other, each worm retains a part of the shell saturated with spermatozoa, which gradually hardens and thickens and passes to the anterior end of the worm, where fertilization occurs. Then the shell slides off the body and closes, a kind of cocoon is formed, very dense in structure.
It reliably stores about 20-25 eggs. This cocoon is able to protect eggs even in drought or extreme cold conditions. However, as a rule, only one worm hatches from one cocoon, the rest die.
Role in nature
Some gardeners mistakenly consider earthworms to be harmful "insects" that eat young shoots and gnaw on the roots of plants. This opinion is absolutely wrong. On the contrary, they play a crucial role in creating fertile soil. Worms are a kind of factory, a system for the production of humus. And also worms dig passages and holes, enriching the soil with oxygen and moisture. They improve fertility, mineral composition and soil structure. This process is gradual and occurs in stages.:
Such is the role of invertebrates in soil formation.
In nature, everything is interconnected, so worms are little helpers not only in agriculture, but also have their own function in the entire ecosystem. They are the cleaners of the earth help in the decomposition of organic remains. And finally, the presence of worms is a good indicator of soil fertility.
Increasing quantity
Undoubtedly, the earthworm is a good friend of the gardener and gardener. Therefore, you should not be too lazy and create favorable conditions for them to live and reproduce, for which useful invertebrates will pay back handsomely. The main factor their vital activity is moisture (that is why, having lifted an old stump or garden bricks from the ground, one can observe wriggling pink tails under them). They do not live in dry land, but go to the depths.
Mulching is the best way to keep the soil moist. This is covering the beds with a small layer of straw, leaves or humus. And also do not be too zealous with chemical fertilizers.
Self-breeding
You can breed worms at home to use them for fishing, feeding pets - hedgehogs, bats, birds, as well as to obtain vermicompost - a universal and environmentally friendly fertilizer. Vermicompost is a unique product made from recycled earthworm waste.
Breeding worms is available to everyone, simply and without investment. What for this it is necessary:
These simple rules will allow you to make a home vermifarm. These representatives of the class "girdle worms" are unpretentious in care and nutrition, so it will not be difficult to breed the required number of them. An unusual farm will help show children the life cycle of familiar invertebrates.
The story of Charles Darwin is very instructive. earthworm ka. The great scientist is known to everyone since the school bench as the founder of the theory of evolution. But few people know that this researcher was very interested in the study of ordinary worms. He devoted much time to studying them, even writing scholarly works on this topic. As an experiment, Darwin placed several individuals in pots of earth and watched them. During the experiments, it turned out that the worms are able to eat even meat. The scientist fixed small pieces of meat on the surface of the pots and checked after a few days - the product was eaten almost completely.
And they could also eat pieces of dead brothers, for which the biologist even called the worms the bloodthirsty nickname "cannibals".
Decaying leaves are used by worms not only for food. They can drag and plug the entrances to their minks with leaves, old grass, tufts of wool. Sometimes you can find a mink clogged with bunches of leaves and grass. Darwin assumed that this was warming before the cold season.
According to the scientist, it is the worms that help in the preservation of historical values and treasures. Over the course of several years, stone tools and gold jewelry are gradually covered with worm excrement, which reliably preserves them from the influence of time.
Currently, 11 species of earthworms are listed in the Red Book.
82 percent of invertebrates are made up of pure protein, therefore they are a nutritious food for some peoples the globe. It is not uncommon for stranded travelers or military men who find themselves in the jungle to survive by eating worms. In addition, such a diet is good for health! Scientists have found that eating worms lowers cholesterol levels.
The largest earthworm was found in South Africa, its length was 670 cm. This is a real giant!
Many people believe that if a worm is cut or torn in half, both parts can survive. But it's not. Only the front part, the head, survives, since the worm feeds on the front part, and for life it needs to eat, like all living creatures. A new tail will grow at the front, the back, unfortunately, is doomed to death.
The earthworm is a special inhabitant of our planet. It brings her great benefits. Therefore, one should not forget about its significance in the natural system. Surprisingly, Charles Darwin considered earthworms even somewhat similar to humans and suspected the presence of the rudiments of intelligence in them.
earthworms, they are earthworms, this is far from one species, but a whole suborder of the class Small-bristle worms, belonging to the type Annelids. The earthworm is characterized by most of the structural features of its type and class.
Earthworms are ubiquitous. More than a dozen live in our area. similar friend on another species (European earthworms), whose body length is 10-20 cm, the number of segments is 100-180. At the same time, the Australian earthworm can reach a length of 3 meters.
During the day, earthworms crawl in the soil. At night and after rain they can come to the surface. With the onset of cold weather, they go underground, to a depth of 2 m. The back of the body is slightly flattened. When crawling out of the soil, the worm holds on to the edge of the mink with its hind end.
The body of an earthworm, as a representative of annelids, is divided into segments by annular constrictions. As in all oligochaetes, the parapodia are reduced, only tufts of setae have been preserved from them, which allow the worm to cling, rest against the ground and facilitate pushing the body forward. In other words, the bristles provide adhesion to the substrate.
The surface of the body is moist, covered with mucus, which facilitates movement in the soil, and also facilitates the penetration of oxygen into the body.
The epithelium secretes a layer of transparent cuticle, it also contains many mucous cells. Under the epithelium are circular and longitudinal muscles. The body of an earthworm can contract and lengthen. The circular muscles make the body of the worm thin and long, the longitudinal muscles shorten and thicken. The longitudinal layer of muscles is more powerful. Alternate contraction of these muscles provides locomotion. Each segment can change its shape separately.
The coelomic sacs of neighboring segments communicate with each other, thus, the liquid in them is mixed.
An earthworm often swallows the soil, eating its own way. Nutrient particles are absorbed from the soil in the intestines. If the soil is soft, then it drills with its front end. First, the front end is stretched and thinned, pushed between the lumps of soil. After the front end thickens, as a result, the soil moves apart. Next, the worm pulls up the back of the body.
They feed on decaying plant debris. In addition, fallen leaves can be dragged from the surface. By dragging plant residues into the soil, worms contribute to their decomposition and the formation of fertile soil.
Digestive system consists of their mouth, pharynx, esophagus, goiter, muscular stomach, middle and hindgut, anus. Swallowing food is produced by the muscular pharynx. The stomach grinds food, in addition to the muscles of the walls, swallowed grains of sand participate in this. From the side of the back, the wall of the middle intestine forms an invagination that increases the suction surface. The midgut is lined with ciliated epithelium, in which there are many unicellular glands. It breaks down complex organic substances, and simpler substances are absorbed into the blood. In the walls of the midgut of the earthworm there is a dense network of blood vessels. The hindgut is small, ending in the anus.
A feature of earthworms are calcareous glands, whose ducts empty into the esophagus. Substances released by them neutralize the acids contained in the soil.
Breathing is carried out by the entire surface of the skin. In the superficial layers of the body wall there is a dense network of blood vessels. When it rains, earthworms come to the surface due to lack of air in the soil.
The circulatory, nervous, and excretory systems are similar to polychaete. However, in the circulatory system there are so-called "hearts" - annular vessels capable of muscular contraction. Located in 7-13 segments. A number of species have annular vessels only in the anterior part of the body.
In the anterior three segments, there are no metanephridia (organs of excretion of annelids).
The sense organs are poorly developed. In the skin there are sensitive cells - organs of touch. Also in the skin there are cells that perceive the degree of illumination.
Earthworms are hermaphrodites. The reproductive system is located in several segments of the anterior part of the body. The testicles are in front of the ovaries.
Fertilization is mutual cross. Each of the mating worms transfers spermatozoa to the partner's seminal receptacle.
In the first third of the body of earthworms there is a special belt, its glandular cells secrete mucus, which, when dried, forms a clutch. Unfertilized eggs are laid in it. After mating, spermatozoa enter here from the spermatozoa. Fertilization takes place. After that, the clutch slips off the body of the worm and turns into a cocoon. The eggs develop into small worms.
Capable of regeneration. If a predator tears off part of the worm's body, then the other half completes the missing part. If the worm is divided into two parts, then two individuals will be obtained, which can be considered asexual reproduction. However, the earthworm itself does not reproduce in this way.
Who hasn't seen earthworms? Yes, probably everything. However, many do not even realize what benefits they have brought and are bringing to us, it is very difficult to overestimate it. This voluminous article is devoted to earthworms. The reader can learn for himself about the structure, types, and lifestyle of worms underground. If you do not know anything about these animals, then after reading the article, your attitude towards them will radically change. At the end of the publication, several videos will be shown for review. The text will be accompanied by pictures and photos.
- These are rather large invertebrates, having a size of up to 3 meters in length. Green worms that live in Russia belong to the Haplotaxida order (representatives of this order live throughout the Earth, with the exception of Antarctica) and to the Lumbricidae family, which includes about 200 species. About 97 representatives of this family live in Russia. The importance of earthworms for the earth's biosphere is very difficult to overestimate. They eat dead plant tissues and animal waste products, then they digest it all and mix the resulting mass with the soil. People have learned to use this feature for their own purposes to obtain the most valuable fertilizer - biohumus or vermicompost.
These protozoa got their name because when it rains, they crawl out of their burrows and stay on the surface of the soil. This happens because rainwater fills their holes and they have nothing to breathe and, in order to save themselves, they get out.
Biohumus is a hydrophilic structure that has the ability to accumulate moisture. That is, when there is not enough water in the soil, humus releases moisture, and when it is in excess, it accumulates. The phenomenon of humus excretion by worms is explained by studying their structure. The fact is that in the intestines of worms, after the breakdown of organic compounds, molecules of humic acids are formed, and they, in turn, come into contact with various mineral compounds.
Earthworms are very great importance in the formation of fertile soil, this fact was noticed by Charles Darwin. They dig holes for themselves with a depth of 60-80 centimeters, thereby loosening the soil.
To date, worms are very widely used by people for their own purposes. First of all, to obtain vermicompost. Worms are actively used in poultry and livestock for feeding. Worms are also widely used by amateur anglers as a good bait.
The structure of earthworms
The structure of earthworms simple enough. The length of individuals that are common in Russia varies from 2 to 30 centimeters. The whole body is divided into segments, they can be from 80 to 300. The earthworm moves with the help of very small setae, which are located on each segment of the body, with the exception of the very first. Setae on one segment can be from 8 to 20.
Picture: the structure of the earthworm In the attached picture you can visually observe the structure of the worm. You can determine the front of the worm, where the mouth is, the back, where the anus is located. You can also see segments.
Are characterized by a closed circulatory system which is fairly well developed. It contains one artery and one vein. The worm breathes thanks to very sensitive skin cells. The skin contains protective mucus, it contains a large number of antiseptic enzymes. The brain is poorly developed. It consists of only two nerve nodes. It is very characteristic of worms to show the possibility of regeneration. For example, if you cut off his tail, then after a while it will grow back.
Earthworms are hermaphrodites, each having both male and female reproductive organs. Reproduction occurs due to the mating of two individuals. The genital organ of worms is a girdle, in size it occupies several anterior segments. The genital girdle stands out well on the body of the worm, it looks like a thickening. In this organ, a cocoon matures from which, after 2-3 weeks, small worms hatch.
Types of earthworms
Earthworms that live in our country can be divided into two types, which differ in biological characteristics. The first species includes those worms that feed on the surface of the soil (litter), and the second one includes those that live and feed in the soil layers (burrows). The first species lives constantly on the soil surface, its representatives do not descend into soil layers that are below 10-20 centimeters.
Representatives of worms that belong to the second species deploy their activities exclusively at a depth of 1 or more meters. If necessary, they stick out of the ground only the front part of the body.
The second species, in turn, can be divided into burrowing and burrowing worms. Burrowers live in deep layers of soil, but do not have permanent burrows. And burrow worms constantly live in the same minks.
Earthworms of litter and burrowing species live exclusively in moist soils, for example, in places near water bodies. Burrowing worms can live in drier soils.
Lifestyle of worms underground
Worms are nocturnal. At this time of the day, you can observe their most active activity. At night they eat most of the food. Many crawl out to consume food, but rarely get out of their holes completely - the tails always remain underground. During the day, the worms plug their burrows with various objects, such as tree leaves. They can drag small particles of food into their holes.
For reference. The body of the worms is very much stretched, thanks to the numerous segments. In addition, worms have very tenacious bristles. In this regard, forcibly pulling him out of the mink is a rather difficult undertaking.
They are omnivorous. They have very characteristic food. First, they swallow a large amount of soil, and then they absorb only useful organic substances from it.
Worms are even capable of in large numbers digest food of animal origin, such as meat.
Eating food takes place in burrows. First, the worm outside gropes for a tidbit and drags it into its hole, where the meal takes place. In order to capture the food object, the worm clings to it very strongly, then pulls back with all its might.
Moreover, the worms make a supply of food for themselves. They fold it very neatly into their burrows. Worms can also purposely dig another hole just to store food. They clog such a mink with moist earth and open it only if necessary.
Occurs in the following order. First, the soil is swallowed, then the organic matter is digested inside the worm. After that, the worm crawls out and excretes excrement. Moreover, he puts the products of vital activity in one specific place. Thus, before entering the hole, a kind of pile of worm excrement is formed.
Worms life
Life of earthworms has a very long history. They played a huge role in soil formation. It is thanks to them that we see the land as it is today.
Worms are constantly engaged in burrowing activities, as a result of which the earth layer is always in motion. Worms have a very large appetite. In just one day, he can eat a volume of food that is comparable to him in weight, that is, 3-5 grams.
As a result of their activity, the worms contribute to the best growth of plants. Let's not even take into account the fertilizer they produce. Worms loosen the soil and contribute to a better ingress of oxygen and water into it. The roots of plants grow much better along the holes of worms.
As a result of the constant loosening of the soil, large objects gradually sink into the depths of the earth. Small foreign particles are gradually rubbed by the stomachs of worms and turn into sand.
Unfortunately, the number of earthworms in our country is declining. This is facilitated by the irrational use of chemicals to "fertilize" the soil. To date, 11 species of earthworms have already been included in the Red Book of Russia. Why use chemicals to fertilize the soil when there is such a miracle of nature as vermicompost?!
The role of earthworms in nature very large and hardly something overestimated. A huge role in the decomposition of organic matter belongs to worms. enrich the soil 
the most valuable fertilizer - humus. They can serve as an indicator: if there are a lot of them in the soil, then the land is fertile.
A complete understanding of the role of earthworms came to man relatively recently. Up to this point, they mainly resorted to the use of chemical mineral fertilizers, which destroyed the soil and all life in it. Unfortunately, many modern farmers are also in this delusion. Biohumus or vermicompost is a real magic wand for the soil. It contains a very large amount of potassium, phosphorus and nitrogen - substances that are primarily necessary for plant growth.
We've gone off topic a bit. In wildlife, worms keep to places where there is a large amount of organic waste. IN good example you can bring the forest. When the foliage falls in the fall, it will need to be put somewhere. Soil bacteria and, of course, earthworms will come to the rescue here. Immediately after the leaves fall, soil bacteria will take over and decompose it to the compost stage. Then the worms will take over the work and process the compost to the stage of vermicompost and introduce this most valuable fertilizer into the soil. Basically, this is how soil formation works.
The benefits of earthworms
At times Soviet Union in the Russian open spaces, they began to actively use chemical mineral fertilizers, which eventually destroy entire layers of soil. Today we have just come to the moment when the soil begins to rapidly collapse. Chernozem soils no longer give such good results as before. Unscrupulous farmers who think only about their income use fertilizers that are dangerous for the soil on their plots of land, thereby destroying it. But the restoration of the soil takes a very long period of time, about 1 centimeter in 100 years.
The benefits of earthworms is to quickly restore the earth from chemical burns and other adverse effects. restore the very structure of the soil due to the introduction and distribution of vermicompost in it. Even if the land does not need to be restored, adding vermicompost to it will in any case be beneficial. It is impossible to pollute or burn with humus, unlike any other fertilizer. And this is due to the fact that vermicompost has a very similar structure to black soil. You can even say that humus is concentrated black soil.
With the help of worms, you can bring a very great benefit to your garden, garden or small household plot. To do this, you just need to learn how to breed worms yourself, and this is very simple to do. It is enough to dig a hole in the garden and put all the organic waste there. Over time, the worms will appear there themselves. There is another option - to buy worms. You can also breed worms in separate boxes. As organic waste is eaten, the resulting vermicompost must be collected and scattered around the site.
Worms significantly improve the structure of the soil, improve water and air exchange and water exchange in it. In the garden or garden, it is necessary to create all conditions for the development of worms. It would be most rational to build a special box in which in the summer you can put all the weeds and other organic waste. The next year, with a large number of worms, you can already get ready-made fertilizer from this box, which can be used in different ways (see photo below). Some advise to simply scatter it around the site, while others bury it, and the third is generally prepared on its basis. liquid top dressing. In general, there are a lot of ways to use it.
Earthworms - Vermiculture
A sufficiently large number of farmers and ordinary people who have their own household plots are engaged in breeding earthworms in order to obtain biohumus. And this trend cannot but rejoice. Vermiculture may soon replace harmful chemical fertilizers.
Breeding worms can also be considered as a good business idea. At minimal cost, you can get the most valuable fertilizer and sell it for good money. It is especially beneficial to engage in this business, who has a livestock of poultry or farm animals and does not know where to put their waste products. Farm animal droppings are excellent food for worms that turn into vermicompost.
In this part of the article, one cannot fail to say about the type of worms that is the most productive - the Californian. California worms were bred in 1959 in the USA. These earthworms are most often used in this area due to their enormous productivity. The California worm eats as much as the usual one, but its reproduction rate is 100 times higher, and its lifespan is 4 times longer. However, they will have to provide certain conditions of detention.
Before launching worms into the substrate, it must be prepared. It needs to be turned into compost. It is most convenient to use ordinary metal barrels with a volume of 200 liters.
At home, you can breed worms in various containers. A wooden box with small holes at the bottom to drain excess water is best suited for these purposes, a substrate is laid there and worms are launched. In one summer, a box of organic waste can be turned into vermicompost. See photo:
Compost is laid here, and non-composted organic waste can be placed on top You can use boxes of a different design, such as plastic, in which fruits and vegetables are transported:
The disadvantage of a plastic box is that the holes at the bottom are too large, through which the worm can escape from it. earthworm video
“The appetizing fruits and vegetables that you see are not fake. These beautiful fruits are real, and most importantly - environmentally friendly. And all this is due to the fact that they were obtained with the help of an amazing fertilizer - biohumus. In this video, we will talk about earthworms of the prospector breed. The video is very helpful and educational.
This video was shown on television, this is the Galileo program. The report was prepared about earthworms.
To enlarge an image, simply click on it.
The common earthworm is of great importance for improving soil fertility, and is also an important part of the diet of many birds and mammals.
Class - OligochetesFamily - Lumbricides
Genus/Species - Lumbricus terrestris
Basic data:
DIMENSIONS
Length: usually up to 30 cm, sometimes more.
BREEDING
Puberty: from 6-18 months.
Mating period: damp, warm summer nights.
Number of eggs: 20 in a cocoon.
Incubation period: 1-5 months.
LIFESTYLE
Habits: loners; on cold or dry days lie motionless in the ground.
Food: land that contains the remains of organic matter, sometimes small carrion.
Lifespan: in captivity up to 6 years.
RELATED SPECIES
About 300 species belong to the family of true earthworms. Their closest relatives are leeches and marine polychaete worms.
An ordinary earthworm gnaws its way through the ground. Thanks to the activity of earthworms, a fertile layer of soil has formed over millions of years. In rainy weather, these animals can be seen on the surface of the earth, but it is not easy to catch a worm, because thanks to its developed muscles, it instantly disappears under the ground. BREEDING
Each earthworm has male and female genital organs in its body, that is, it is a hermaphrodite. However, in order to reproduce, the worm needs to find another individual with which it exchanges genetic material, since the worm is not able to fertilize itself. Mating of worms occurs at night on the surface of the earth, in wet weather, for example, after rain. Attracted by pheromones, they lie pressed against each other so that the front of one is pressed against the back end of the other. Earthworms are covered with a mucous membrane, under which sperm exchange takes place. Separated from each other, earthworms take part of the shell, which gradually becomes more and more dense, and then slowly slides off the body to the anterior end, where fertilization occurs.
When the shell slides off the body of the worm, it closes tightly at both ends and a dense cocoon is formed, which can contain up to 20-25 eggs. It is very rare for more than one earthworm to hatch from a cocoon.
ENEMIES
At any time of the day, on a lawn or in a clearing, you can see a starling or a black and song thrush, which, with their heads bowed, listen to see if there is a worm somewhere nearby under the ground. However, a captured earthworm can defend itself. The bristles on its body and powerful circular and longitudinal muscles help the rainy worm to refrain in the ground. Especially large and strong earthworms sometimes manage to escape from the beak of a bird. Sometimes only a piece of earthworm remains in the bird's beak. If this rear end the body of the worm, the animal usually survives, and grows back the lost part of the body. Ordinary worms become the prey of hedgehogs, badgers, foxes and even wolves. However, their main enemy is the mole, which also lives underground.
LIFESTYLE
The earthworm spends most of its life underground. He digs a network of underground corridors, which can reach a depth of 2-3 m. The body of an earthworm consists of segments. Under the skin are two layers of muscles. Some stretch along the inside of the body, while others cover the body of the worm with rings. During movement, the muscles pull out the body or compress and thicken it. The earthworm, tensing the circular muscles in the front of the body, moves forward. The wave of muscle contractions then passes through the body to move the back of it. Then comes the turn of the longitudinal muscles, which attract the back of the body. At this time, the front end is pulled forward again. Thanks to the secreted mucus, the earthworm can move in very hard ground. Sunlight is a serious danger for earthworms, since they are covered with only a thin layer of skin. Worms are not protected from ultraviolet radiation, so they appear on the surface only in rainy weather. Very often they go outside on rainy nights to collect pieces of straw, paper, feathers, leaves on the ground and pull them into a mink.
FOOD
Many species of animals look for food in the earth, but the earthworm eats the earth itself. He feeds organic matter located in the soil. The worm kneads the earth in the muscular stomach, digests part of it, and excretes the rest outward in the form of a stool. Some species excrete their feces on the surface of the earth in small piles visible to the naked eye, others excrete undigested remains underground.Most of all, earthworms love the ground under lawns - about 500 worms can live there in 1 cubic meter of soil. The result of their activity is a dry, well-ventilated soil. Such soil is rich in the remains of plants that are laid out. A large concentration of earthworms in the ground is a guarantee of its productivity. Earthworms live in neutral and alkaline soils. In acidic soil, for example, next to peat bogs, there are few of them. Earthworms also feed on the surface of the earth. In the forest, they collect leaves, draw them into their underground corridors and eat there.
DO YOU KNOW WHAT...
- In 1982, an earthworm 1.5 m long was found in England. However, it is much smaller than the Australian and South American species (their length is 3 m).
- Fossil worms resembling modern earthworms have been found in geological strata dating back approximately 600 million years.
- If an ordinary earthworm loses the end of its body, it often grows a new one. However, two earthworms will never appear from two parts. An ordinary earthworm that is cut in half dies.
- Based on the weighing of the waste of ordinary earthworms on an area of 1 m2 during the year, it can be concluded that the earthworm brings 6 kg of excrement to the surface of the earth during this time.
HOW EARTHWORMS REPRODUCE
Pairing: earthworms are hermaphrodites. They find each other by smell and, connected by a mucous membrane, exchange spermatozoa on the surface of the earth.The appearance of the mucous membrane: mucus is secreted from the girdle - a light, thickened part at the front end of the body, where numerous glands open. From the mucus secreted, the mucous membrane is formed.
Fertilization: the mucous membrane moves around the body and collects eggs and sperm.
Mucous membrane: through the head slides off the body of the worm.
Cocoon: the slimy container containing up to 20 eggs closes and forms a cocoon that is able to withstand even extreme unfavourable conditions. Most often, only one earthworm hatches from it.
PLACES OF ACCOMMODATION
Earthworms are found all over the world. Common earthworms live throughout Europe and Asia, wherever they find the right soil and climate conditions.
PRESERVATION
Some gardeners destroy earthworms to get rid of traces of their activity. By doing this, they harm the entire ecosystem.
26.01.2018
Dear colleagues! Today we will continue the topic "earthworms", in which we will consider the structure of an earthworm. Who knows, maybe among those reading these lines there are those who consider earthworms to be harmful such as: "they gnaw roots in pots, eat seedlings, sprouts, seeds ...", etc. Therefore, a variety of methods are invented to destroy worms, the most harmless of which - freezing of the soil. And they talk all sorts of nonsense about earthworms. I myself talked with such people, convincing them of the opposite, namely, of the invaluable help and benefit these tireless workers bring.
So, let's start studying the earthworm in order to figure out how its vital activity is supported.
To absorb food, worms have an organ called pharynx. It works on the principle of a rubber bulb: when squeezing and then unclenching, a vacuum is created, due to which food is drawn inward. It is clear that there are no teeth in the mouth, therefore, the worm is not able to gnaw or bite something.
In order to pass through a rather small mouth opening, the food must be sufficiently soaked or softened. Therefore, plant foods (shoots, leaves) should not be freshly picked (or freshly bitten), but already dried, with softened fibers. Therefore, earthworms so love to live and feed in half-rotted humus, under last year's fallen leaves, in mowed or cut vegetation that has lain on the surface of the soil for a long time.
Goiter- This is a large thin-walled cavity in which swallowed food accumulates. What happens next? How to be without teeth? It turns out that the worm also has them, only they are located ... in the stomach!
Stomach is a muscular, thick-walled chamber, the inner surface of which consists of hard, tooth-like protrusions. When the walls of the stomach contract, they crush (grind) food into small particles. And already in this state, food enters the intestines, where, under the action of digestive enzymes, it is digested, and the resulting nutrients are absorbed. By the way, the stomach is arranged in a similar way in crocodiles and most birds.
Features of digestion make earthworms detritivorous, that is, they feed on detritus- decaying plant organic matter located on the surface of the earth or in their underground burrows, as well as in the soil itself, biting into the soil itself. Therefore, the coprolites that the earthworm leaves behind are lumps of soil enriched with nitrogen, microelements, and having low acidity due to the alkaline environment of its intestines.
Upon careful examination of the picture, you will see that the worm has a brain, and nerves, and a heart (which is not even one, but five!). That is, the earthworm feels and understands everything, but it cannot say. Here is another tragic secret, still not understood by biologists and not revealed by forensic scientists: why do they crawl out onto the footpaths after the rain, and die en masse there?
The earthworm has its own "Achilles heel", its own weakness. the thing is that worms need energy for normal life. And they get it due to respiration (and oxygen oxidation), and it requires gas exchange between the body and the environment.
The structure of the earthworm is such that the worm does not have a special organ for gas exchange (such as lungs or gills), so it breathes skin. To do this, it must be thin and constantly moisturized. Since the worms do not have any protective shell, the most common reason for their death is drying out.
The body of earthworms consists of many annular segments (from 80 to 300) that can be easily seen. A worm can be both slippery and rough at the same time. He rests bristles- they are on each ring and are visible in an ordinary magnifying glass.
The bristles are the main support in the life of the worm, they are very convenient to grab hold of the tiny unevenness of the soil, which is why it is so difficult to pull the worm out of the mink - it will rather let itself be torn in half. Thanks to the bristles, inactive on the surface, it deftly eludes danger.
If necessary, the body of the worm is covered with abundant mucus, which serves as an excellent lubricant for squeezing through the ground. The same mucus does not allow the body to waste water, which in the worm is as much as 80% of the total weight.
Under certain conditions, worms can restore missing parts of the body. For example, the back will grow back if it is torn off in an accident. But this does not always happen. So let's take care of our underground architects, "angels of the earth", and create favorable conditions for them. And they, in turn, will thank us with improved soil on the plots and a generous harvest.
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