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In this article, we will find out where the name "earthworms" came from, what they eat and what are their features. We all have noticed more than once that after a good rain on the roads, in parks one can observe creeping creatures that have a reddish tint and risk being trampled by people or animals. In appearance, they are not very pleasant, small children, as a rule, are frightened of them. But, besides fear, it is still interesting for children and adults to find out what earthworms eat. We will try to answer this question in detail in our article.

What are these creatures?

Biology classifies these representatives of the animal world as annelids. If you look closely at them, then on their thin body (50 mm in diameter, 15-30 cm long) you can see rings, the number of which can sometimes reach 300. There are also very small worms about 2 cm. Few people know that there are giant worms reaching up to 2 meters in length. But they, like the rest, are completely harmless and harmless to humans.

What are the benefits?

To begin with, let's find out what the earthworm eats in nature, and what benefits these creatures provide. The role of these individuals in nature is very large - they are engaged in the processing of all kinds of organic waste, turning them into humus. They swallow particles of biomass along with the earth and meticulously mix them during digestion.

Humus is the organic basis of the soil, consuming it, plants acquire the necessary and nutrients. 90% of all humus are products for the existence of worms.

What do earthworms eat in the soil?

Just want to note that earthworms are omnivores. Since they feed on what is on the surface of the earth, at the same time they swallow a large amount of earth, which gives them the organic elements that they so need. In addition, the worms eat a large number of half-decayed leaves. It is important to note that earthworms do not have teeth directly in the mouth - they are located in the stomach. In order to receive food, the worm sucks it in with its special organ - the throat.

Thanks to the muscles of the body, food goes further, pushing first into the crop, and then into the stomach. And already inside the food is rubbing with tooth-like protrusions into small particles. After that, the food is digested in the intestines by enzymes, useful substances are absorbed, and waste products are eliminated from the body. Since worms have small mouths, this explains why they eat rotten leaves and plant debris. Fresh sprouts can damage the delicate and small body of the worm. Usually such worms live under last year's foliage, where the soil is rich in humus. In such places, they are provided with delicious food - pieces of plants, rotted organic matter.

How is the process of eating?

Earthworms drag half-rotten or fresh foliage into their hole and eat it there. Usually they try to tear off small pieces, grabbing the edge of the leaf between the protruding upper and lower jaws. At such a moment, his pharynx, protruding, creates a reference point for the upper lip. But if the worm has stumbled upon a wide plane of the leaf, it will behave a little differently. The front rings are slightly tightened into others, thereby expanding the body. At this time, the pharynx is pressed against the plane of the leaflet, then it stretches back and becomes a little wider. As a result, a kind of "vacuum" is created in the dimple on the front of the body. The work of the pharynx at this moment is comparable to a piston, and the worm sticks very tightly to the leaf.

In addition to using leaves in food, these creatures cover the entrance to their hole. To do this, they bring there pieces of stems, dried flowers, paper, feathers, and what else they find. When a worm has swallowed the earth for food or making passages, it comes to the surface to free its insides. The earth that the worm throws out of the body contains a lot of secretions from the intestinal tract and therefore becomes viscous.

Where do they live?

It is a great honor for worms to choose humus-rich soil under last year's leaves as their habitat. They feed on rotten fragments of vegetation. The food that is not digested in their stomach is deposited by them on the surface of the soil. On one hectare, the number of earthworms can reach up to four million. In a day, one worm can process about half a gram of earth.

What to feed the worm at home?

If you are not aware of what earthworms eat at home and what diet they need, then the following information is just for you. After all, it is necessary not only to create optimal conditions for life, but also to provide the necessary nutrition for these individuals. Consider the food that can be used for an earthworm:

• Food waste (shells, peelings).
• Horse or goat dung.
• Tea brew, coffee grounds, leaves, grass.

It is worth paying attention to what earthworms eat and what is unacceptable for them. You need to know that manure for feeding should not be fresh, but rotted, otherwise the worm will simply die. All this is due to the large amount of ammonia that is found in fresh manure and is very harmful to your pets. There is no oxygen in the ammonia environment, so sometimes individuals die.

What should not be done?

Also, when breeding pets at home, it is not recommended to feed them with fish, meat and dairy products. Also eliminate salty foods from your diet. In addition, neither canned cucumbers, nor tomatoes, cabbage will bring benefits. It must be remembered that feeding the worm is enough once a week. To do this, crush the food and put it on the ground. A layer of feed is allowed up to 10 cm.

On the question of what earthworms eat, you need to know that they usually get used to the same food, and it will take them some time to switch to a different diet. If you decide to change their diet, then you need to do this gradually, adding new food to the usual in small portions.

As a rule, the feed mass is placed in boxes 5-7 cm thick once every 3 weeks, depending on the number, size and appetite of the worms. When they process one layer, they soon leave it and rise higher to a new one. After processing, humus remains in the lower layer, which can be used as a fertilizer.

It is not only important for us to know what earthworms eat, but we should also remember that these individuals are inconspicuous, quiet workers who make the soil fertile. They are the most important friends and helpers for gardeners and gardeners. They need to be protected and helped in every possible way.

Annelids have the highest organization compared to other types of worms; for the first time they have a secondary body cavity, a circulatory system, a more highly organized nervous system. In annelids, another, secondary cavity was formed inside the primary cavity with its own elastic walls from mesoderm cells. It can be compared to airbags, a pair in each segment of the body. They "swollen", filled the space between the organs and support them. Now each segment has received its own support from the bags of the secondary cavity filled with liquid, and the primary cavity has lost this function.

They live in soil, fresh and sea water.

External structure

The earthworm has an almost round body in cross section, up to 30 cm long; have 100-180 segments, or segments. In the anterior third of the body there is a thickening - a girdle (its cells function during the period of sexual reproduction and oviposition). On the sides of each segment, two pairs of short elastic bristles are developed, which help the animal when moving in the soil. The body is reddish-brown in color, lighter on the flat ventral side and darker on the convex dorsal side.

Internal structure

A characteristic feature of the internal structure is that earthworms have developed real tissues. Outside, the body is covered with a layer of ectoderm, the cells of which form the integumentary tissue. The skin epithelium is rich in mucous glandular cells.

muscles

Under the cells of the skin epithelium there is a well-developed musculature, consisting of a layer of annular and a more powerful layer of longitudinal muscles located under it. Powerful longitudinal and annular muscles change the shape of each segment separately.

The earthworm alternately compresses and lengthens them, then expands and shortens them. Wave-like contractions of the body allow not only to crawl along the mink, but also to push the soil apart, expanding the course.

Digestive system

The digestive system begins at the front end of the body with a mouth opening, from which food enters sequentially into the pharynx, esophagus (in earthworms, three pairs of calcareous glands flow into it, the lime coming from them into the esophagus serves to neutralize the acids of rotting leaves that animals feed on). Then the food passes into an enlarged goiter and a small muscular stomach (the muscles in its walls contribute to the grinding of food).

From the stomach almost to the rear end of the body stretches the middle intestine, in which, under the action of enzymes, food is digested and absorbed. Undigested residues enter the short hindgut and are thrown out through the anus. Earthworms feed on half-decayed plant remains, which they swallow along with the earth. When passing through the intestines, the soil mixes well with organic matter. Earthworm excrement contains five times more nitrogen, seven times more phosphorus and eleven times more potassium than ordinary soil.

Circulatory system

The circulatory system is closed and consists of blood vessels. The dorsal vessel stretches along the entire body above the intestines, and under it the abdominal vessel.

In each segment, they are united by an annular vessel. In the anterior segments, some annular vessels are thickened, their walls contract and pulsate rhythmically, due to which blood is distilled from the dorsal vessel to the abdominal one.

The red color of blood is due to the presence of hemoglobin in the plasma. It plays the same role as in humans - the nutrients dissolved in the blood are carried throughout the body.

Breath

Most annelids, including earthworms, are characterized by skin respiration, almost all gas exchange is provided by the surface of the body, so the worms are very sensitive to wet soil and are not found in dry sandy soils, where their skin dries out quickly, and after rains, when in the soil a lot of water, crawl to the surface.

Nervous system

In the anterior segment of the worm there is a peripharyngeal ring - the largest accumulation of nerve cells. From it begins the abdominal nerve chain with nodes of nerve cells in each segment.

Such a nervous system of a knotty type was formed by the fusion of the nerve cords of the right and left sides of the body. It ensures the independence of the segments and the coordinated work of all organs.

excretory organs

The excretory organs look like thin loop-shaped curved tubes, which open at one end into the body cavity, and at the other outward. New, simpler funnel-shaped excretory organs - metanephridia - remove harmful substances into the external environment as they accumulate.

Reproduction and development

Reproduction occurs only sexually. Earthworms are hermaphrodites. Their reproductive system is located in several segments of the anterior part. The testicles lie in front of the ovaries. When mating, the spermatozoa of each of the two worms are transferred to the spermatozoa (special cavities) of the other. Worms are cross fertilized.

During copulation (mating) and oviposition, the cells of the girdle on the 32-37th segment secrete mucus, which serves to form an egg cocoon, and a protein liquid to feed the developing embryo. The secretions of the girdle form a kind of mucous sleeve (1).

The worm crawls out of it with its rear end forward, laying eggs in the mucus. The edges of the muff stick together and a cocoon is formed, which remains in the earthen burrow (2). Embryonic development of eggs occurs in a cocoon, young worms emerge from it (3).

sense organs

The sense organs are very poorly developed. The earthworm does not have real organs of vision, their role is performed by individual light-sensitive cells located in the skin. The receptors for touch, taste, and smell are also located there. Earthworms are capable of regeneration (easily restores the back).

germ layers

The germ layers are the basis of all organs. In annelids, the ectoderm (outer layer of cells), endoderm (inner layer of cells) and mesoderm (intermediate layer of cells) appear at the beginning of development as three germ layers. They give rise to all major organ systems, including the secondary cavity and the circulatory system.

These same organ systems are preserved in the future in all higher animals, and they are formed from the same three germ layers. Thus the higher animals in their development repeat the evolutionary development of their ancestors.

Since ancient times, humanity has paid special attention to such unsightly creatures as the earthworm. And scientific minds, in the person of Charles Darwin, decades later, for many years studied their structure and significance in agriculture. And for good reason. Indeed, with the onset of spring warmth, earthworms begin painstaking work and work, without knowing it, for the benefit of people.

Features and habitat

Earthworm , he is ringed - a well-known resident on any personal plot. And it would seem, absolutely imperceptible, useless creation.

However, any person, at least somehow connected with the earth, will be very happy with such inhabitants of his garden. In the Russian Federation, there are no more than a hundred species of earthworm. But all over the world there are one and a half thousand varieties of them.

It belongs to the family of annelid worms, low-bristle class. Its entire long body consists of many rings. There may be seventy, or there may be three hundred. Since in length it grows more than twenty-five centimeters.

But there are also the smallest, two or three centimeters. The Australian earthworms reach two and a half meters in size. Its color is literally gray-brown - raspberry.

Also, on each ring, or it is also called a segment, there are bristles. In our ordinary garden worms, as a rule, eight bristles grow. They are classified as low-bristle.

However, there are also tropical, polychaete species of worms, in which the villi grow in dozens. The bristles help the worms crawl along absolutely all soil tubercles or burrow into holes.

You can find them by taking the worm in your hands and swiping your finger from back to front. But since it is difficult for an inexperienced person to determine where his butt is, you can simply lightly run your hand along the body and back. You can immediately feel it. In one direction, the worm will be absolutely smooth, and in the opposite direction, it will be rough.

Anyone who has ever taken a worm in his hands knows that he is covered with not very pleasant mucus, which is vital for him. Firstly, mucus helps the invertebrate to move freely in the ground. Secondly, since the worm does not have lungs, it breathes through the skin. And thanks to the moisture on the mucus, the body is saturated with oxygen.

Samo earthworm body, consists of two groups of muscle tissue. They are longitudinal and transverse. The transverse muscles are located under the protective top layer of the skin of the worm.

With their help, the worm becomes as long as possible. And the stronger muscles are longitudinal. They shorten, reduce the body. So, sometimes lengthening, sometimes shortening, the animal moves.

The earthworm belongs to the secondary cavity animals. Therefore, it has a complete closed circulatory system. Because they are active.

Muscles contract many times more often than in primary cavity worms. To do this, they need blood to provide the worm with all the nutrients and oxygen.

IN earthworm structure there are a pair of blood vessels, one of them is called the dorsal, the second abdominal. Ring vessels connect them together. Blood flows through them from back to front, and vice versa.

In each ring, or as it is also called, a segment, there is a pair of tubules. The funnels at their ends open and feces are discharged through the bottom. earthworm. This is how the excretory system works.

As for the nervous system, it is nodal. Its components are the ventral nerve chain and the peripharyngeal nerve ring. These endings consist of fibers, and those, in turn, respond to the urges of the contracted muscles of the worm. Thanks to them, the worm can eat, purposefully move, multiply, and develop.

In the building earthworm organs, there are no those responsible for smell, touch, sight, sensation. But there are certain cells, they are located along the entire body of the invertebrate. With their help, the worm navigates in the dark and impenetrable land.

Character and lifestyle

Even Charles Darwin suggested that earthworms have intelligence. Watching them, he noticed that when he dragged a dry leaf into his dwelling, it was turned with its narrow side. This facilitates the passage of the leaf through a dense, earthy hole. But spruce needles, on the contrary, take it as a base so that they do not bifurcate.

All day, all rain life worm scheduled by the minute. He now and then climbs in the ground, makes moves, swallowing it. The worm digs holes in two ways. He or, as already mentioned, swallows the earth, gradually moving forward.

If the ground is too hard. And then leaving their biological waste. Or, he pushes it with his refined end, in different directions, and makes moves for himself. The passages are obliquely vertical.

Tek same, rain worm, hunting in soil, drags into its holes, for insulation, various leaves, veins from leaves, thin pieces of paper and even shreds of wool. Its burrows are up to one meter deep. And the worms are larger in size, and all ten meters. The worm works mainly at night.

A why earthworms come to the surface in great numbers. This means he can't breathe. This usually happens after heavy rains. The earth is clogged with moisture, and there is no oxygen at all. Upon the arrival of cold earthworm goes deep into the soil.

Earthworm food

The food of the worm is quite typical. Swallowing large quantities of earth along with food. For food, they are suitable for wilted and slightly rotten leaves, mushrooms. But it should not have an unpleasant odor, otherwise the worm will not eat it.

It turns out that earthworms even build whole pantries for themselves, and put food there for the winter. They eat it only in case of critical need. For example, in winter, when the ground is completely frozen, and there can be no talk of any terrestrial food.

Having sucked food together with a lump of earth, through the pharynx, with muscular movements, then expanding his body, then narrowing, he pushes it to the back of the esophagus into the goiter. After, it enters the stomach. From the stomach it is sent to be overetched in the intestines, thanks to enzymes, it comes out with the most useful biomass.

Making moves, and at the same time snacking, rainy worm need to crawl out periodically to the surface to throw off the ground. At the same time, he adheres to the hole with his edge of the tail, as if holding on to it.

And after, there are always earthen slides. The soil processed by the worm turns out to be sticky. Notice it dries up, and becomes small, with a match head balls.

These balls are saturated with vitamins, enzymes, organic substances, which, as a result, kill all bacteria in the ground, prevent decay, which is very important for plant roots. And they also act on the composition of the earth as an antiseptic, disinfecting it.

Reproduction and lifespan

Earthworms can be of different sexes, and hermaphrodites. All earthworms have thickenings on the front third of their body. They contain the ovary and testis. Hermaphrodites let the seed into each other. Already mature testicles, within ten pieces, are inseminated. And crawl away in different directions.

When a female is ready for reproduction, she approaches her partner and copulates. Something like a cocoon is formed on it, consisting of several dozen thickened segments.

It is separated by a kind of belt. This cocoon receives all the nutrients necessary for the brood. After fertilization, the worm removes this burden from itself, it simply slides off the animal.

The edges on the cocoon, on both sides, are quickly pulled together so that future offspring do not dry out before they are born. Then, for four weeks, small worms mature and hatch.

Once born, they spread in all directions. And already from the first days of their lives, they begin active work, processing the land. And already at the age of three months, grown children reach the size of adults.

Another fact about earthworms is the ability to regenerate. If someone or something divides it into two halves. Over time, each of the halves will become a full-fledged individual. This is one of the ways of reproduction, but not sexually.

The role of the earthworm very important in agriculture. Firstly, they saturate the soil with oxygen, which is so necessary for everything growing on it. With their moves, they help the roots to fully develop.

Moisture is evenly distributed, and the soil is well ventilated, loosened. Due to the constant movement of the earth, with the help of worms, stones are extracted from it.

Also, with their recycled sticky residues, they stick the soil together, preventing it from eroding. Well, of course, they fertilize the earth when they drag leaves, insect larvae into it. It all rots and serves as excellent, natural bio-additives.

And the suborder of earthworms (Haplotaxida). Its body consists of ring-shaped segments, the number of which can reach 320! These animals are widespread in all corners of our planet. They are not found only in Antarctica. Very often, children are interested in how earthworms move. In our article, we will analyze this issue in detail, and at the same time we will learn about their appearance, lifestyle and method of reproduction.

Lifestyle of earthworms

If in the morning or after rain you walk through the garden, then, as a rule, you can see small piles of soil thrown out by worms on the ground, and you can see them in the puddles. Due to the fact that these individuals crawl out to the surface of the earth after rain, such a name was assigned to them. (the photo above shows this invertebrate animal) also creeps out to the earth's surface at night. As a rule, it prefers humus-rich soil, so it is rarely found in sandstones. Dislikes earthworm and swampy soils. These features are explained by the physiological features of the Lumbricidae. The fact is that worms breathe the entire surface of their body, covered with a mucous epidermis. Too little air is dissolved in moisture-saturated soil. As a result, the earthworm suffocates there. By the way, this explains his behavior during the rain. Dry soil is also detrimental to representatives of Haplotaxida: their skin dries up and breathing stops. In wet and warm weather, earthworms (the photo below shows the Lumbricidae in all their "glory") stay closer to the surface of the earth. With a decrease in temperature, as well as with the onset of a dry period, they crawl into the deep layers of the soil.

earthworms

Adults reach 30 centimeters in length, although there are individual specimens of larger sizes. The body of the earthworm is slippery, smooth, has a cylindrical shape, consists of segments - piece rings. Such a constitution is explained by the way of life of Lumbricidae: such a structure facilitates the process of movement in the soil. The number of piece rings reaches two hundred. The surface of the body, which could conditionally be called the back, is convex, the ventral surface is flat and lighter. On the body of an earthworm, where its front part ends, there is a thickening, which is called a girdle. It contains special glands that secrete a sticky liquid. During reproduction, an egg cocoon is formed from the girdle, eggs develop in it.

How do earthworms move?

Representatives of Haplotaxida crawl. First, they stretch the front end of their body and cling to the irregularities of the earth's surface with special bristles, which are located on the ventral side of the rings. After this, muscle contraction occurs, and the back is pulled forward. The movement of the worm in the ground is characterized by the fact that it makes passages in the soil. At the same time, with the pointed end of the body, he pushes the earth apart, and then squeezes between its particles. It is also interesting how earthworms move in denser layers. In the process of movement, they swallow the earth and pass it through the intestines. As a rule, worms swallow the soil at a considerable depth, and throw it out through the anus already at the top, near their own mink. It can often be observed in the summer on the surface of the earth in the form of lumps and elongated "laces".

Earthworm and its biology

Worms have well-developed muscles, thanks to which such a method of movement became possible. Their muscles are located under the epidermis, in fact, together with the skin, they form a kind of skin-muscle bag. Musculature is located in two layers. Directly under the epidermis are the circular muscles, and below them is a second, thicker longitudinal layer (consists of contractile long fibers). When the longitudinal muscles are compressed, the body of the earthworm becomes thicker and shorter. With a contraction of the circular muscles, on the contrary, it is long and thin. Alternate contraction of both layers of muscles, carried out under the influence of the nervous system branching in the muscle tissue, determines the movement of Lumbricidae.

The movement of worms is greatly facilitated by the presence of small bristles on the lower part of the body. They can be felt if you run a wet finger along the abdomen of the worm from the back to the front end. Thanks to these bristles, earthworms not only move in the soil, but also “grab” the ground when they are pulled out. They also help to rise and fall along the already made earthen passages. With this, we will finish dealing with the question of how earthworms move, and move on to no less interesting facts about the life of Lumbricidae.

Circulatory system

It consists of two longitudinal vessels - the abdominal and dorsal, as well as the branches connecting them. Due to muscle contraction of the walls, blood moves throughout the body. The blood of earthworms is scarlet. With its help, a connection is established between the internal organs, and metabolism is also carried out. When circulating, the blood carries nutrients from the digestive organs, as well as oxygen from the skin. At the same time, carbon dioxide is removed from the tissues. In addition, the blood removes unnecessary and harmful compounds into the excretory organs.

Earthworm nutrition

The basis of nutrition of representatives of Haplotaxida is half-decayed remains of plants. As a rule, at night, earthworms drag leaves, stems, etc. into their holes. In addition, they can pass humus-rich soil through their intestines.

Irritation of earthworms

Special earthworms do not have. They perceive external stimuli through the nervous system. Worms have a highly developed sense of touch. The nerve cells responsible for this are located over the entire surface of the skin. The sensitivity of earthworms is so great that the slightest vibrations of the soil make them hide in burrows or in deeper layers of the earth as quickly as possible. However, the significance of sensitive nerve endings is not limited to the function of touch. Scientists have found that with the help of these cells, earthworms are able to sense the rays of light. So, if a beam of a flashlight is directed at a worm at night, then it will hide in a safe place with great speed.

The response of animals to any irritation, carried out thanks to the nervous system, is called a reflex. It is customary to distinguish between different kinds of reflexes. Thus, contraction of the body of an earthworm from touching it, as well as its movement in sudden illumination, is a protective function. This is the defensive reflex. Experiments of scientists have shown that earthworms can smell. They use their sense of smell to find food.

reproduction

Earthworms reproduce sexually, although protostomes are generally hermaphrodites. Each member of the Haplotaxida has male organs called testes (they develop sperm) and female organs called ovaries (they produce eggs). The earthworm lays its eggs in a slimy cocoon. It is formed from a substance that is released through the girdle. Further, the cocoon in the form of a clutch slides off the body and is pulled together at the ends. It remains in the ground until the young worms come out of it. The cocoon serves to protect the eggs from moisture and other adverse effects.

What are worms for?

This section will be useful for those who think that earthworms are needed only for fishing. Of course, a fisherman without them has nothing to do without them on the river, but this is not the whole benefit of representatives of Lumbricidae. The role of the earthworm in nature is so great that it is impossible to overestimate it. They contribute to the decomposition of organic matter in the soil. In addition, earthworms enrich the earth with the most valuable fertilizer - humus. They are also a kind of indicator: if the soil contains a lot of worms, then it is fertile.

A complete understanding of the role of Haplotaxida has come to mankind relatively recently. However, even now, many farmers prefer to use chemical fertilizers, despite the fact that they kill all living things. Today, chemicals have found an alternative - vermicompost and biohumus. In fact, this is a magic wand for the earth, because they contain a large amount of phosphorus, potassium, nitrogen, that is, precisely those substances that are vital for plants for their full growth.

Conclusion

Earthworms are the most important link in soil formation. Let's look at the process. In autumn, leaves fall from the trees and cover the entire surface of the earth. Immediately after that, they get down to business and decompose the leaves to the compost stage. And then the baton is picked up by worms, which process the foliage to the stage of vermicompost. Thus, the most valuable fertilizers get into the soil.

In the world of fauna is the earthworm. He can rightly be called an earthworker, because it is thanks to him that the soil on which we walk is fully saturated with oxygen and other minerals. Passing various parts of the earth up and down, this worm makes them loose, which then allows planting cultivated plants there, as well as gardening.

General characteristics of the species

The earthworm belongs to the kingdom Animals, to the sub-kingdom Multicellular. Its type is characterized as ringed, and the class is called Small-bristle. The organization of annelids is very high compared to other types. They possess a secondary body cavity which has its own digestive, circulatory and nervous systems. They are separated by a dense layer of mesoderm cells, which serve as a kind of airbags for the animal. Also, thanks to them, each individual segment of the worm's body can autonomously exist and progress in development. The habitats of these earthly orderlies are moist soil, salty or fresh waters.

The external structure of the earthworm

The body of the worm is round. The length of representatives of this species can be up to 30 centimeters, which can include from 100 to 180 segments. The front part of the body of the worm has a slight thickening, in which the so-called genitals are concentrated. Local cells are activated during the breeding season and perform the function of laying eggs. The lateral outer parts of the body of the worm are equipped with short setae, completely invisible to the human eye. They allow the animal to move in space and touch the ground. It is also worth noting that the tummy of the earthworm is always painted in a lighter tone than its back, which has a maroon, almost brown color.

What is it like from the inside

From all other relatives, the structure of the earthworm is distinguished by the presence of real tissues that form its body. The outer part is covered with ectoderm, which is rich in mucous cells containing iron. This layer is followed by muscles, which fall into two categories: annular and longitudinal. The former are located closer to the surface of the body and are more mobile. The latter are used as auxiliary during movement, and also allow the internal organs to work more fully. The muscles of each individual segment of the worm's body can function autonomously. When moving, the earthworm alternately compresses each annular muscle group, as a result of which its body either stretches or becomes shorter. This allows him to break through new tunnels and fully loosen the earth.

Digestive system

The structure of the worm is extremely simple and clear. It originates from the mouth opening. Through it, food enters the pharynx and then passes through the esophagus. In this segment, products are cleaned from acids released by decay products. Then the food passes through the crop and enters the stomach, which contains many small muscles. Here, the products are literally ground and then enter the intestines. The worm has one middle intestine, which passes into the rear opening. In its cavity, all useful substances from food are absorbed into the walls, after which the waste leaves the body through the anus. It is important to know that earthworm excrement is saturated with potassium, phosphorus and nitrogen. They perfectly nourish the earth and saturate it with minerals.

circulatory system

The circulatory system that the earthworm possesses can be divided into three segments: the abdominal vessel, the dorsal vessel and the annular vessel, which combines the two previous ones. The blood flow in the body is closed, or annular. The annular vessel, which has the shape of a spiral, combines two arteries vital for the worm in each segment. It also branches off capillaries that come close to the outer surface of the body. The walls of the entire annular vessel and its capillaries pulsate and contract, due to which the blood is distilled from the abdominal artery to the spinal one. It is noteworthy that earthworms, like humans, have red blood. This is due to the presence of hemoglobin, which is regularly distributed throughout the body.

Breathing and nervous system

The process of breathing in an earthworm is carried out through the skin. Each cell of the outer surface is very sensitive to moisture, which is absorbed and processed. It is for this reason that worms do not live in dry sandy areas, but live where the soil is always filled with water or in the reservoirs themselves. The nervous system of this animal is much more interesting. The main "lump", in which all the neurons are concentrated in large numbers, is located in the anterior segment of the body, however, its analogues, smaller in size, are in each of them. Therefore, each segment of the worm's body can exist autonomously.

reproduction

We note right away that all earthworms are hermaphrodites, and in each organism the testes are located in front of the ovaries. These seals are located in the front of the body, and during the mating period (and they have a cross), the testes of one of the worms pass into the ovaries of the other. During the mating period, the worm secretes mucus, which is necessary for the formation of a cocoon, as well as a protein substance that the embryo will feed on. As a result of these processes, a mucous membrane is formed in which the embryos develop. After they leave her rear end forward and crawl into the ground to continue their race.