The structure of an earthworm: digestive, nervous and circulatory systems. Earthworm (lifestyle, structure and movement)

Earthworms, they are earthworms , this is far from being one species, but an entire suborder of the class Oligochaete worms, which belongs to the phylum Annelids. For earthworm most of the structural features of its type and class are characteristic.

Earthworms are ubiquitous. Our area is home to more than a dozen similar friends on another species (European earthworms), the body length of which 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 crawling 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 the edge of the hole with its rear end.

The body of an earthworm, as a representative of annelids, is divided into segments by ring constrictions. As in all oligochaetes, the parapodia are reduced, only tufts of bristles are 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 and 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 and also contains many mucous cells. Under the epithelium there are circular and longitudinal muscles. The body of an earthworm can contract and elongate. Circular muscles make the body of the worm thin and long, longitudinal muscles shorten and thicken. The longitudinal layer of muscles is more powerful. Alternate contraction of these muscles ensures movement. Each segment can change its shape separately.

The coelomic sacs of adjacent segments communicate with each other, thus the liquid in them mixes.

An earthworm often swallows soil, eating its way through. Nutrient particles are absorbed from the soil in the intestines. If the soil is soft, then it drills it with the front end. First, the front end is stretched and thinned, inserted between lumps of soil. Then the front end thickens, causing the soil to move apart. Next, the worm pulls up the back of the body.

They feed on rotting plant debris. In addition, they can drag fallen leaves from the surface. By dragging plant debris into the soil, worms contribute to their decomposition and the formation of fertile soil.

The digestive system consists of the mouth, pharynx, esophagus, crop, gizzard, midgut, hindgut, and anus. Swallowing food is done through the muscular pharynx. The stomach grinds food; in addition to the muscles of the walls, swallowed grains of sand are involved in this. On the dorsal side, the wall of the midgut forms an invagination, increasing the absorption surface. The midgut is lined with ciliated epithelium, in which there are many unicellular glands. It breaks down complex organic matter, simpler substances are absorbed into the blood. In the walls of the earthworm's midgut there is a dense network of blood vessels. The hindgut is small and ends at the anus.

A special feature of earthworms are calcareous glands, whose ducts flow into the esophagus. The substances they release neutralize the acids contained in the soil.

Breathing occurs over 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 crawl to the surface due to lack of air in the soil.

The circulatory, nervous and excretory systems are similar to polychaetes. However, in the circulatory system there are so-called “hearts” - annular vessels capable of muscular contraction. Located in segments 7-13. In a number of species, ring vessels are present only in the anterior part of the body.

There are no metanephridia (excretory organs of annelids) in the anterior three segments.

Sense organs are poorly developed. The skin contains sensitive cells - organs of touch. There are also cells in the skin 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 testes are located in front of the ovaries.

Mutual cross fertilization. Each of the mating worms transfers sperm 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 muff. Unfertilized eggs are laid in it. After mating, spermatozoa enter from the seminal receptacles. Fertilization occurs. After this, the sleeve slides off the worm's body and turns into a cocoon. Small worms develop from the eggs.

Capable of regeneration. If a predator tears off part of the worm's body, the other half completes the missing part. If the worm is divided into two parts, the result is two individuals, which can be considered asexual reproduction. However, the earthworm itself does not reproduce this way.

The body of the earthworm is round in shape; the length of most representatives of this genus is no more than 15 centimeters, occasionally more than twenty, and the length of the largest is slightly more than thirty centimeters.

Consists of 100-180 segments. The segments have small, fairly elastic bristles that are practically invisible, but if you run your finger from the rear tip to the front, you can immediately feel it. The worm needs bristles so that it can cling to uneven ground surfaces while moving.

On the front of the worm's body there is a small thickening that serves as the place where the genital organs are located. The cells located in this thickening are activated during reproduction to lay eggs. If you look closely, you will notice that the belly of the earthworm is somewhat lighter than the rest of the parts. The worm has not only a circulatory system, but also a nervous and tactile system. digestive system.

What environment do earthworms live in?

During the daytime, worms prefer to stay in the soil of the swarm, with passages in it. Light soil, the worm drills with its front tip. To do this, he first compresses the front part so that it becomes thinner, and tries to push it forward between the soil lumps. Subsequently, the front tip becomes thicker, the lumps move apart, and the worm pulls up the back part. In hard soil, raincoats make passages for themselves, passing them through the intestinal tract. Earthen heaps are often visible on the surface of the earth - these are traces of the night activity of worms. They emerge from their burrows after heavy rainfall (that’s why they are called rainfall). IN summer time worms prefer to stay in the upper layers of the soil, and in winter, to escape the cold, they dig holes, the depth of which can be more than two meters.

As the temperature drops, they become less active and their circulatory system circulates more slowly.

Taking a worm in your hands, you will find that its skin is moist, and it itself is covered with mucus, which makes it easier to move in the ground. Apart from this, only through the moist skin does the oxygen required for respiration find its way into his body. This is how the worm breathes.

Directly under the skin there are circular muscles fused with it, and underneath them are longitudinal muscles. Those. An earthworm is a kind of skin-muscular sac. Thanks to the circular muscles, the body of the worm becomes thinner and longer, and thanks to the longitudinal muscles, it shortens and thickens. Due to the alternate functioning of these data, the muscle and the worm move.

How does an earthworm work?

The structure of an earthworm, when compared with the organisms of other animals, is quite primitive, but it has quite interesting features. Under the skin-muscular pouch there is a fluid-filled cavity of the body, and in it there are internal organs. When compared with roundworms, the body cavity of a roundworm is divided by septa, the number of which is equal to the number of segments. They have their own separate walls and are located under the skin-muscular pouch.

Now let's take a closer look at all the available organs of the worm.

Digestive system

The earthworm's mouth is located at the front. The puffball prefers rotting vegetation, swallowing it with soil. Likewise, he often drags fallen leaves into his hole. Swallowing is accomplished through the pharynx. Next, the food ends up in the intestines. Food that has not had time to be digested comes out through the anus located at the back. This is how the digestive system works in almost all types of worms. The worm also needs its mouth in order to drag various small objects to which it simply sticks. As you can see, the digestive system is quite primitive and lacks the organs that higher beings have.

The earthworm has a closed circulatory system, but there are some peculiarities. It is based on two main vessels, the dorsal and the abdominal, which are connected to each other using ring vessels, in some ways very similar to arteries and veins. Depending on the species, the blood of worms can be colorless, red or even green.

Speaking about the circulatory system of the earthworm, the dorsal vessel, which pulsates blood throughout the body, deserves special attention.

Special vessels that cover the intestines and are located in all segments, distill blood into the cavity of the abdominal vessel, which cannot pulsate on its own. The worm's blood flow is from front to back. In addition to these blood flows, there are also vessels that carry blood from the dorsal to the parapodial vessels. In them, the blood oxidizes when it comes into contact with environmental oxygen.

The skin of an annelid worm also has its own vessels, which are connected to the general circulatory system. Those. The circulatory system of worms is quite complex, but it is thanks to it that worms survive in rather difficult conditions.

Nervous system

The nervous system of annelids consists of two nerve trunks. Nerve nodes are formed in the segments on them. those. a kind of nerve chain emerges. In front, two nodules are connected to each other by circular bridges - a perioral nerve ring is formed. Nerves go from the nodules to various organs.

Organs of touch

Worms do not have special organs of touch, but sensitive cells in the skin allow it to feel touch and distinguish when it is light and when it is dark.

Reproductive system

As you know, and we have already talked about this, worms are hermaphrodites, that is, they can do without mating. But most often, reproduction occurs after contact between two individuals and the exchange of sperm between them. Then they spread out, and mucus begins to secrete from a kind of coupling located in front. Into which the eggs subsequently arrive. Then the lump of mucus slides off the worm's body, forming a cocoon. From which small worms are subsequently obtained.

This video talks about the structural features of earthworms.

Earthworms are the family of large soil oligochaete worms Lumbricidae, which phylogenetically belong to the class of oligochaetes (Oligochaete), subtype of worms (Clitellata), type of annelids (Annelida). The type of annelids, or annelids, covers a significant number of species (about 9000) of higher worms .

The features of their structure are as follows (Fig. 1): The body of annelids consists of a head lobe, a segmented body and a posterior anal lobe. Most of the sensory organs are located on the head lobe.
The skin-muscle sac is well developed.

The animal has a secondary body cavity, or coelom, with each segment corresponding to a pair of coelomic sacs. The cephalic and anal lobes do not have a coelom.
Rice. 1. The front end of the earthworm's body:
A - right side;
B - ventral side;
1- head blade;
2 - lateral bristles;
3 - female genital opening;
4 - male genital opening;
5 - seminal groove;
6 - belt;
7 - ventral setae

The oral opening is located on the ventral side of the first segment of the body. The digestive system generally consists of oral cavity, pharynx, midgut and hindgut, opening with the anus at the end of the anal lobe.

Most ringlets have a well-developed closed circulatory system.
The excretory function is performed by segmental organs - metanephridia. Usually there is one pair of metanephridia in each segment.

The nervous system consists of a paired brain, a pair of peripharyngeal nerve trunks that go around the pharynx from the sides and connect the brain with the abdominal nerve cord. The latter is a pair of more or less close, and sometimes fused together longitudinal nerve cords, on which paired nerve nodes - ganglia (with the exception of the most primitive forms) are located in each segment.

The most primitive annelids dioecious; Some annelids have pronounced hermaphroditism. Oligochaetes also have reduced fingers, parapodia and gills. They live in fresh waters and in the soil.

The body of oligochaetes is highly elongated, more or less cylindrical. The length of small oligochaetes barely reaches 0.5 mm, most major representatives- up to 3 m. At the anterior end there is a small movable head lobe (prostomium), devoid of eyes, antennae and palps. The segments of the body are externally identical, their number is usually large (from 30... 40 to 600), in rare cases there are few segments (7... 9). Each segment, except the anterior one, which bears the mouth opening, is equipped with small bristles protruding directly from the body wall. These are the remains of disappeared paralodia, usually located in four bundles (a pair of lateral and a pair of ventral).

The number of bristles in a tuft varies. At the end of the body there is a small anal lobe (pigi-dium) with powder (Fig. 2).
Rice. 2. Appearance of the anal lobe (pygidium) of an earthworm:
a, b - Eisenia phoetida (a hybrid and an ordinary dung worm, respectively);
c - Lumbricus rubellus

The integumentary epithelium, which forms a thin elastic cuticle on the surface, is rich in mucous glandular cells. Mucous and protein unicellular glands are especially numerous in the girdle area, which is clearly visible during the breeding season of worms. Under the epithelium lie developed layers of the skin-muscular sac - the outer circular one and the more powerful inner longitudinal one.

The digestive system consists of the pharynx, esophagus, sometimes crop, gizzard, midgut and hindgut (Fig. 3). On the side wall of the esophagus there are three pairs of special calcareous glands. They are densely permeated with blood vessels and serve to remove carbopathates that accumulate in the blood.
Rice. 3. Anatomy of an earthworm:
1 - prostomium;
2 - cerebral ganglia;
3 - pharynx;
4 - esophagus;
5 - lateral hearts;
6 - dorsal blood vessel;
7 - seed sacs;
8 - testes;
9 - seed funnels;
10 - seed tube;
11- dissepiments;
12 - metanephridium;
13 - dorso-subneval vessels;
14 - midgut;
15 - muscular stomach;
16 - goiter;
17 - oviduct;
18 - egg funnels;
19 - ovary;
20 - seminal receptacles.
Roman numerals indicate body segments

Excess lime comes from the glands into the esophagus and serves to neutralize humic acids contained in rotting leaves eaten by worms. The invagination of the dorsal wall of the intestine into the cavity of the midgut (typhlosol) helps to increase the absorptive surface of the intestine.

The circulatory system is of the same type as that of polychaete worms. In addition to the pulsation of the dorsal blood vessel, the circulation is maintained by the contractions of certain annular vessels in the front of the body, called the lateral or annular hearts. Since there are no gills and breathing occurs over the entire surface of the body, a dense network of capillary vessels usually develops in the skin.

The excretory organs are represented by numerous segmentally located metanephridia. Chloragogenic cells, also involved in excretion, cover the surface of the midgut and many blood vessels.

The decay products of chlorogenic cells often stick together and merge with each other into more or less large “brown bodies”, which accumulate in the body cavity and are then expelled through unpaired dorsal pores found in many oligochaetes.

The nervous system is composed of a pair of suprapharyngeal ganglia, parapharyngeal connectives and the ventral nerve cord (see Fig. 3). Only in the most primitive representatives are the abdominal nerve trunks widely spaced.

The sense organs of oligochaetes are extremely poorly developed.

Eyes are almost always absent. It is interesting that earthworms exhibit light sensitivity, despite the fact that they do not have real visual organs - their role is played by individual light-sensitive cells, in large quantities scattered in the skin.

The reproductive system of oligochaetes is hermaphroditic, the sex glands - gonads - are localized in a small number of sexual segments (Fig. 4). In the X and XI segments of the worm's body, the seed capsules contain two pairs of testes, which are covered by three pairs of special seed sacs, the latter developing as protrusions of dissepiments (see Fig. 1).
Rice. 4. Scheme of the structure of the reproductive system of an earthworm (according to Stephenson):
1- nervous system;
2 - testes;
3 - seminal receptacles;
4 - front and rear seed funnels;
5 - ovary;
6 - egg funnel;
7 - oviduct;
5 - seed tube;
IX... XIV - segments

The reproductive cells enter the seed sacs from the seed capsules after being separated from the testes. In the seed sacs, the viper ripen, and the mature sperm return to the seed capsules. Special ducts are used to remove live bait, namely: opposite each testis there is a ciliated funnel, from which an excretory canal extends. Both canals merge into the longitudinal vas deferens, which opens on the ventral side of segment XV.

The female reproductive system is formed by a pair of very small ovaries located in the XIII segment, and a pair of short funnel-shaped oviducts - in the XIV segment. The posterior dissepiment of the female segment forms egg sacs, similar to seminal sacs. In addition, this system includes two more pairs of deep skin invaginations on the abdominal side of segments IX and X. They have no communication with the body cavity and serve as sperm receptacles during cross-fertilization.

Finally, numerous unicellular glands that form a ring-shaped thickening on the surface of the body - a girdle - are indirectly related to the reproductive system. They secrete mucus, which serves to form a facial cocoon and a protein fluid that feeds the developing embryo.

Earthworms undergo cross fertilization. The two animals are in close contact with their ventral sides, their heads facing each other. The belts of both worms secrete mucus, which envelops them in the form of two couplings; the belt of one worm is located opposite the openings of the seminal receptacles of the other. Sperm is released from the male openings of both worms, which, when the abdominal muscles contract, moves along the surface of the body to the girdle, where it enters the mucous membrane. The partner's seminal receptacles perform a sort of swallowing movement and receive the seed entering the coupling. Thus, the spermatheca of both individuals are filled with foreign seed. This is how copulation occurs, after which the worms disperse. Eggs are laid and fertilized much later. The worm secretes a mucous membrane around its body in the girdle area, into which eggs are laid. The coupling slides off the worm through its head end. During the passage of the coupling past the IX and X segments, the spermatic receptacles squeeze out the foreign seed contained in them, which fertilizes the eggs. The ends of the coupling then close together, it becomes compacted and turns into an egg cocoon.

There is no larval stage in the development of oligochaetes. The eggs develop inside an egg cocoon, from which a fully formed worm emerges. In lower oligochaetes, several embryos develop in one cocoon containing a watery liquid. Eggs are rich in yolk, crushing occurs in a spiral type.

In higher oligochaetes, the cocoon contains a nutritious protein liquid, and the eggs are poor in yolk. The resulting embryo is called a "latent" larva

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 at the roots in pots, eat seedlings, sprouts, seeds...”, etc. Therefore, to destroy worms, a wide variety of methods are invented, the most harmless of which - soil freezing. And they say all sorts of nonsense about earthworms. I myself communicated with such people, convincing them of the opposite, namely, what invaluable help and benefit these tireless workers bring.

So, let's start studying the earthworm to understand how its vital functions are maintained.

To absorb food, worms have an organ called pharynx. It works on the principle of a rubber bulb: when compressed and then unclenched, a vacuum is created, thanks to which food is drawn inside. It is clear that there are no teeth in the mouth, therefore, the worm is not able to gnaw or bite anything.

In order to pass through the rather small mouth opening, food must be sufficiently soaked or softened. Therefore, plant food (shoots, leaves) should not be freshly picked (or freshly bitten), but already dried, with softened fibers. That’s why earthworms love to live and feed so much in half-rotted humus, under last year’s fallen leaves, in mowed or cut vegetation that has lain for quite a long time on the surface of the soil.

Goiter- This is a large thin-walled cavity in which swallowed food accumulates. What happens next? What to do without teeth? It turns out that the worm has them too, only they are located... in the stomach!

Stomach- This is a muscular, thick-walled chamber, the inner surface of which consists of hard tooth-like projections. When the walls of the stomach contract, they crush (grind) food into small particles. And already in this state, the food enters the intestines, where it is digested under the action of digestive enzymes, and the nutrients released are absorbed. By the way, the stomach of crocodiles and most birds is constructed in a similar way.

The peculiarities of their digestion make earthworms detritivorous, that is, they eat detritus- decaying plant organic matter located on the surface of the earth or in their underground burrows, as well as in the soil itself, in contact with 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.

If you carefully examine the picture, you will see that the worm has a brain, nerves, and a heart (of which there is not even one, but five!). That is, the earthworm feels and understands everything, but it cannot say. Here’s another tragic secret, still not understood by biologists and not revealed by criminologists: why do they crawl onto footpaths after the rain and then die en masse?

The earthworm has its own "Achilles' heel", its own weakness. the whole point is that worms require energy for normal functioning. And they get it through respiration (and oxygen oxidation), which 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 worms do not have any protective shell, the most common reason for their death is desiccation.

The body of earthworms consists of many ring-shaped segments (from 80 to 300), which can be easily seen. The worm can be both slippery and rough. He resists bristles- they are on each ring and are visible with a regular magnifying glass.

The bristles are the main support in the life of the worm; they are very convenient for gripping tiny unevenness in the soil, which is why it is so difficult to pull the worm out of the burrow - it would rather allow itself to be torn in half. Thanks to the bristles, it is inactive on the surface and deftly evades danger.

If necessary, the body of the worm is covered with abundant mucus, which serves as an excellent lubricant for squeezing through the ground. This same mucus prevents the body from wasting water, which constitutes as much as 80% of the total weight in the worm.

Under certain conditions, worms can restore missing body parts. For example, rear end will grow again if it is torn off in an accident. But this doesn't always happen. So let's take care of our underground architects, the "angels of the earth", and create favorable conditions for them. And they, in turn, will thank us with healthy soil on our plots and a generous harvest.

The earthworm has been known to 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 nutrients, are food for many birds and animals. There are many interesting facts, revealing all the secrets of an “extraordinary” inhabitant of the earth’s bowels, who does not look attractive at all, but has enormous significance in nature and human life.

Structure and description of worms

Earthworms are a type of annelid. They live mainly in moist soil rich in humus. Interestingly, the habitat is 5 continents - all except Australia. Features of them appearance these are:

Each segment also has bristles that help it move underground. The tube-shaped body completely lacks bones and cartilage; the body cavities are filled with liquid. The earthworm is perhaps the most amazing creature that lives in the soil; it has no eyes, no lungs, no ears. Breathing occurs through the skin. The worm has several hearts, and the digestive system runs along the entire length of the body.

The mucous glands located between the segments secrete mucus, which protects against drying out, helps in movement underground, and prevents soil from sticking to the body. And it scares away 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 find such long-livers in nature, since any bird or rodent and, of course, humans pose a danger to them. The greatest threat currently comes from chemical fertilizers generously added to the soil, most of which are lethal to worms.

Favorite food

A very interesting question is what earthworms eat. Their “menu” is quite modest; the basis of the diet is fallen, rotting leaves, as well as other organic remains - roots, rotten wood. Worms have teeth in their 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. When the gastric muscles contract, these hard tooth-like processes come into motion. Digestion occurs in the intestines.

Undigested food remains are deposited in the soil. In one day, an adult earthworm can process half a kilo of soil!

Lifestyle

As you know, earthworms are underground inhabitants. They spend most of their lives digging underground passages and holes; 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 either sandy or overly swampy areas. This is due to breathing patterns.

They take in oxygen through their skin, but in excessively damp soil there is very little air, which causes inconvenience and 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 to avoid suffocation.

In dry soil, the mucus covering the skin dries out, depriving the worms of the ability to both breathe and move comfortably. With the arrival of cold weather, earthworms go into the deeper layers of the soil.

Reproduction of worms

The small soil dweller has the specificity of reproducing offspring. Reproduction of earthworms occurs mainly in the warm season and stops during drought and cold snap, when they go into the deeper layers of the soil to winter.

Everyone knows that earthworms are hermaphrodites. The body of the worm contains both male and female genital organs. However, this is not enough for reproduction. Invertebrates need another individual with whom the mating process will occur - the exchange of genetic material. Worms find a partner by smell, since their bodies produce pheromones that are sensed by another earthworm. Reproduction occurs as follows.

They mate on the surface of the ground 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, a jack. The mucous membrane ensures the exchange of sperm. After separation from each other, each worm remains with a part of the sperm-rich shell, which gradually hardens and becomes denser and passes to the anterior end of the worm, where fertilization occurs. Then the shell slides off the body and closes, forming a kind of cocoon, very dense in structure.

It safely stores about 20-25 eggs. This cocoon is able to protect eggs even in conditions of drought or extreme cold. 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 plant roots. This opinion is absolutely wrong. On the contrary, they play a vital role in creating fertile soil. Worms are a kind of factory, a humus production system. Worms also 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.:

This 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 orderlies-cleaners of the earth, help in the decomposition of organic remains. And finally, the presence of worms is a good indicator of soil fertility.

Increase in quantity

Undoubtedly, the earthworm is a good friend of the gardener and gardener. Therefore, it is worth not being lazy and creating favorable conditions for them to live and reproduce, for which beneficial invertebrates will repay a hundredfold. Main factor their vital activity is moisture (which is why, when you lift an old stump or garden bricks from the ground, you can see wriggling pink tails underneath them). They do not live in dry soil, but go to the depths.

The best way to keep the soil moist is to mulch. This is covering the beds with a small layer of straw, leaves or humus. And also don’t 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 for producing vermicompost - a universal and environmentally friendly fertilizer. Vermicompost is a unique product made from recycled earthworm waste.

Breeding worms is accessible 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 “belt worms” class are unpretentious in care and nutrition, so diluting the required amount of them will not be difficult at all. An unusual farm will help show children what life cycle their familiar invertebrates go through.

The story of Charles Darwin and the earthworm is very instructive. The great scientist has been known to everyone since his school days as the founder of the theory of evolution. But few people know that this researcher was very interested in studying common worms. He devoted a lot of time to studying them, even writing scientific works on this topic. As an experiment, Darwin placed several individuals in pots of soil and observed them. During the experiments it turned out that the worms are able to eat even meat. The scientist attached small pieces of meat to the surface of the pots and checked after a few days - the product was almost completely eaten.

They could also eat pieces of their dead brethren, 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 burrows with leaves, old grass, and scraps of wool. Sometimes you can find a hole filled with bunches of leaves and grass. Darwin assumed that this was insulation before the cold season.

According to the scientist, it is 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 invertebrates are composed of pure protein, so they are nutritious food for some peoples globe. Often travelers or soldiers in difficult situations who find themselves in the jungle survive by eating worms. Plus, this diet is good for your health! Scientists have found that eating worms lowers cholesterol levels.

The largest earthworm was discovered 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 will survive. But that's not true. Only the front part, the head, survives, since the worm feeds using the front part, and to live it needs to eat, like all living creatures. The front part will grow a new tail, the back part, unfortunately, is doomed to death.

The earthworm is a special inhabitant of our planet. It brings her great benefit. Therefore, we should not forget about its significance in the natural system. Surprisingly, Charles Darwin considered earthworms to be somewhat similar to humans and suspected that they contained the rudiments of intelligence.