Where does an earthworm live in what environment? Details about the plum. Cultivation, beneficial properties and choice of variety. How do earthworms reproduce?

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, tactile and 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 the summer, worms prefer to stay in the upper layers of the soil, and in the 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 it contains the 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 blood flow of the worm 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.

The common earthworm is of great importance for increasing soil fertility, and is also an important part of the diet of many birds and mammals.

   Class - Oligochaetes
   Family - Lumbricidae
   Genus/Species - Lumbricus terrestris

   Basic data:
DIMENSIONS
Length: usually up to 30 cm, sometimes more.

REPRODUCTION
Puberty: from 6-18 months.
Mating season: humid, warm summer nights.
Number of eggs: 20 in a cocoon.
Incubation period: 1-5 months.

LIFESTYLE
Habits: singles; on cold or dry days they lie motionless in the ground.
Food: earth that contains remains of organic matter, sometimes small carrion.
Lifespan: in captivity up to 6 years.

RELATED SPECIES
There are about 300 species of the true earthworm family. 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 been formed over millions of years. In rainy weather, these animals can be seen on the surface of the earth, but catching a worm is not easy, since thanks to its developed muscles it instantly disappears underground.

REPRODUCTION

   Each earthworm has male and female genital organs in its body, that is, it is a hermaphrodite. However, 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 part of one is pressed against the rear end of the other. Earthworms are covered with a mucous membrane, under which sperm exchange occurs. Having separated from each other, earthworms take part of the shell, which gradually becomes denser, 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. Very rarely more than one earthworm hatches from a cocoon.

ENEMIES

   At any time of the day on the lawn or in the clearing you can see a starling or a blackbird and a songbird, who, bowing their heads, listen to see if there is a worm somewhere nearby underground. However, a caught earthworm can defend itself. The bristles on its body and powerful circular and longitudinal muscles help the rain worm stay in the ground.
   Especially large and strong earthworms sometimes manage to escape from the beak of a bird. Sometimes only a piece of an earthworm remains in the bird's beak. If this is the back part of the worm's body, then the animal usually survives and grows back the lost part of the body. Ordinary worms become prey for hedgehogs, badgers, foxes and even wolves. However, their main enemy is the mole, which also lives underground.

LIFESTYLE

   An earthworm spends most of its life underground. It digs a network of underground corridors that can reach a depth of 2-3 m. The earthworm's body consists of segments. Beneath the skin are two layers of muscle. Some stretch along the inside of the body, while others cover the body of the worm in rings. During movement, the muscles pull the body or compress and thicken it.
   The earthworm, straining the annular muscles in the front of the body, moves forward. A wave of muscle contractions then passes through the body to move the back part 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 mucus secreted, the earthworm can move in very hard soil. Sunlight is a serious danger for earthworms, since they are covered only with a thin layer of skin. Worms are not protected from exposure to ultraviolet radiation, so they appear on the surface only in rainy weather. Very often they go out on rainy nights to collect pieces of straw, paper, feathers, leaves on the ground and pull them into their burrow.

FOOD

   Many species of animals look for food in the ground, but the earthworm eats the ground itself. It feeds on organic matter found in the soil. The worm kneads the earth in the muscular stomach, digests some of it, and excretes the remainder in the form of stool. Some species excrete their feces on the surface of the ground in small piles visible to the naked eye, others excrete undigested remains underground.
   Most of all, earthworms love the soil under lawns - about 500 worms can live there in 1 cubic meter of soil. The result of their activity is dry, well-ventilated soil. Such soil is rich in plant remains that decompose. A large concentration of earthworms in the soil is a guarantee of its productivity. Earthworms live in neutral and alkaline soils. In acidic soil, for example, near peat bogs, there are few of them. Earthworms also feed on the surface of the earth. In the forest they collect leaves, pull them into their underground corridors and eat them there.
  

DID YOU KNOW THAT...

• In 1982, an earthworm 1.5 m long was found in England. However, it is significantly smaller than the Australian and South American species (their length is 3 m).
• Fossil worms resembling modern earthworms have been found in geological strata that are approximately 600 million years old.
• If an ordinary earthworm loses the end of its body, it often grows a new one. However, two parts will never produce two earthworms. An ordinary earthworm that is cut in half dies.
• Based on weighing the waste of ordinary earthworms over an area of ​​1 m2 over the course of a year, we can conclude that an earthworm carries 6 kg of excrement to the surface of the earth during this time.

  

HOW DO EARTHWORMS REPRODUCE?

   Pairing: earthworms are hermaphrodites. They find each other by smell and, connected by a mucous membrane, exchange sperm on the surface of the earth.
   Appearance of mucous membrane: mucus is secreted from the girdle - a light, thickened part at the anterior end of the body, into which numerous glands open. The mucus secreted forms the mucous membrane.
   Fertilization: The mucous membrane moves throughout the body and collects eggs and sperm.
   Mucous membrane: through the head and slides off the body of the worm.
   Cocoon: a slimy container containing up to 20 eggs closes and forms a cocoon that is able to withstand even extremely adverse 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 kill earthworms to remove traces of their activity. By doing this, they harm the entire ecosystem.

The body of an earthworm is divided into segments by ring constrictions. Each segment has eight small bristles, which when the worm moves, rest against uneven soil.

The body wall is covered with a cuticle secreted by a single-layer epithelium. Below it is a layer of circular muscles, and below them are longitudinal muscles. Thanks to the alternating work of these muscles, the worm moves. The movement is facilitated by secreted mucus.

An earthworm is an annelid worm that has a secondary body cavity - as a whole. Its walls are lined with epithelium. The cavity is filled with fluid capable of transporting nutrients and oxygen, which is absorbed by the entire surface of the body. There is no respiratory system. (When it rains, the worms lack oxygen and crawl to the surface of the soil).

The mouth is located on the ventral side of the anterior segment, and the anus is located on the last segment. The worm feeds on fallen leaves and rotting plant debris, swallowing them along with the soil. Nutrients in the intestines are absorbed into the blood. Undigested residues are expelled through the anus.

The circulatory system is closed. The dorsal vessel carries blood from the posterior to the anterior end of the body. Several annular vessels in segments 7–11 play the role of the heart, pumping blood into the abdominal vessel. Blood moves through the abdominal vessel to the posterior end. From the main vessels, thinner ones depart, turning into capillaries. Blood contains hemoglobin, which carries oxygen. A closed circulatory system allows you to significantly increase your metabolic rate.

In each segment, except for the terminal ones, there is a pair of metanephridia - tubes that carry metabolic products out of the coelom (excretory system).

The nervous system consists of the peripharyngeal nerve ring and the ventral nerve cord. There are no sense organs. The worm is able to perceive light and touch due to tactile and light-sensitive cells scattered throughout the surface of the body.

Earthworms are hermaphrodites, but cross-fertilize. On segments 32–37 there is a girdle used for the construction of egg cocoons. The cocoon moves to the anterior end, spermatozoa obtained in advance during copulation with another individual enter it from the seminal receptacles, and fertilization occurs. The cocoon slides off through the head end of the worm. Development is direct, with young worms hatching from the eggs. Earthworms are characterized by the ability to regenerate - to restore a lost body fragment.

The importance of the earthworm in nature

• Earthworms make tunnels in the soil, allowing air and water to penetrate into the soil.
• They improve soil structure by gluing soil particles into small lumps.
• Soil fertility is promoted by worms dragging fallen leaves and other plant debris into burrows, digesting them and decomposing them to form humus.
• Earthworms serve as food for many animals: moles, shrews, hedgehogs, toads, ground beetles.
• They are intermediate hosts of helminths that cause diseases in young pigs, etc.

How long an earthworm lives is of interest to many, especially those who deal with them, fishermen, poultry farmers and, of course, farmers who are underestimating the breeding of these creatures.

According to reliable information, the average life expectancy at home is from five to ten years. The maximum in ideal conditions is about twenty.

In natural conditions, as a rule, the life cycle of a worm is several years, and this is explained by the difficult conditions of their existence.

Enemies of worms

The death of earthworms can be caused either by unfavorable weather conditions (heat or, conversely, a sudden onset of frost), or by their natural enemies. The worm is a tasty food for many animals. It is worth noting that the worms are practically unarmed, they do not know how to defend themselves, their only defense is to immediately hide in their hole.

Moles are the most dangerous enemy of the earthworm, which is its main food. The mole is a very prudent animal that prepares worms for the winter by making chambers. He stores his prey in them, biting the worms so that they do not have the opportunity to hide, but remain alive.

The mole searches for its prey by smell. In turn, the worm has a chance to hide by hearing the ground vibrations emitted by the mole while it is making an underground passage for itself. If the worm does not hide in time, it will most likely become prey, and if it is not eaten immediately, then it will go to the storage chamber.

People also often become the cause of death of these creatures, and sometimes massively:

• use by fishermen;
• deforestation;
• plowing the soil;
• soil treatment with chemicals;
• city ​​construction;
• cutting during digging;
• feeding to livestock;
• In some countries, various dishes and medicines are prepared from worms.

How to determine which genus or family a worm belongs to

You can determine a species or family by the following parts of its body:

• head blade shape;
• location of the belt;
• number of rings.

In our country you can find the following types of earthworm:

• Lumbricus;
• Dendrobaena;
• Allolobophora.

Video “Popular about earthworms”

This video popularly talks about the life of worms. What species they belong to, what conditions they live in, and much more.

Lifestyle

Raincoats live in the ground, making passages in it. At night, they come to the surface in search of food, which they then drag into their burrows. The earthworm's diet consists of various organic matter. The excrement of raincoats contains many small earthen particles, which they deposit on the surface of the earth, increasing the fertile layer.

The usual reproduction of worms is in pairs. Semen exchange occurs after two individuals are in close contact with each other. But if there is no partner for mating, the worm can reproduce independently.

The life cycle of worms is almost the same for all species. Therefore, let’s consider it using the example of ordinary rainwater ones.

Earthworms have colonized the top layer of soil, digging holes in it, thereby loosening it. In addition, the earthworm very often has to swallow soil, passing it through its intestines, digesting all the organic matter in it, and then throwing it out in the form of lumps.

If you notice lumps on the ground in spring, this may mean that the worms have already moved away from winter, having risen to the upper layers of the soil and begun an active life. Rainflies eat a lot of remains of various vegetation, pulling them into their burrows.

The body of an earthworm consists of clearly visible segments. The tip at the front is its main spatula and lacks any organs, eyes or tentacles. Each segment of the body contains 4 small bristles. The skin has a cuticle that contains skin glands that moisturize the skin. Such hydration is vital for a raincoat.

If you examine the worm, you will find a small thickening called a girdle, which plays an important role in reproduction.

The skin-muscle pouch is exceptionally developed.

The worm's body can be extended and, conversely, shortened due to the presence of special muscle groups.

Digestive system

The raincoat digestive system consists of the following organs:

• oral cavity;
• pharynx;
• esophagus;
• stomach;
• middle and hindgut.

In the puffball, the stomach is formed from a wide segment of the foregut. Necessary for mechanical processing of food. A well-formed digestive system helps the worm absorb organic matter found in wood, leaves, and other food.

The excretory organs of the raincoat are the same as those of other worms and are arranged quite simply. Other systems are the same as those of any other polychaete worm. As for gas exchange, it occurs not through specific outgrowths on the body, which are absent in the raincoat, but through the entire surface of the body.

Sense organs

The tactile organs of earthworms are primitive. They are only able to distinguish the dark time of the day from the light time with the help of special light-sensitive cells that are located on the surface of its body.

Reproduction

As you know, puffballs are hermaphrodites and can reproduce without mating. The gonads are located in the front part of its body, the testes are in the tenth and eleventh segments, then the ovaries come in the thirteenth and fourteenth, opening outward in the fifteenth.

In the case of pair reproduction, after mating, fertilization occurs inside the body.

Life cycle of worms

The life cycle of worms consists of laying eggs in a special cocoon, and from this cocoon, after a certain time, worms appear.

Varieties of oligochaete worm

Low-bristle worms live mainly in the ground and only a few species lead an aquatic lifestyle, living in fresh water reservoirs.

Video "Structure of worms"

After watching this video you will learn how earthworms work and what they need for normal existence.

EARTHWORMS (earthworms), a group of families of oligochaete worms, including large forms (Megadrili), living in the soil. The group was identified on the basis of the characteristics of their ecology, body size and some morphological characters. They appear in large numbers after rain (hence the name) on the surface of wet soil, on the edges of puddles, and in urban environments - on asphalt near lawns. This phenomenon is associated with the migratory activity of worms, which are able to crawl freely on the soil surface in conditions of high air humidity, or with a lack of oxygen in soil pores filled with water and the toxicity of soil moisture, which dissolves organic acids. The body of an earthworm is cylindrical and consists of several tens or hundreds of segments. Body length varies from 15 mm, for example, in species of the genera Dendrobaena and Eiseniella, to 1 m or more in tropical species of the Megascolecidae family. The earthworm has well-developed body muscles; moving in the soil, they push its particles apart. Each segment bears from 4 to several dozen pairs of short setae, which serve as support during movement. The body is covered with cuticular epithelium with numerous glandular cells that secrete mucus. Surrounding the body, it protects it from mechanical damage and facilitates movement. There are no eyes; the integument contains a large number of photosensitive and tactile cells. The mouth opening leads to the intestine, which runs along the entire length of the body; it is differentiated into the muscular pharynx, esophagus, crop, stomach, midgut and hindgut. Earthworms feed on dead plant debris and play a large role in their decomposition and the formation of soil humus. In the walls of the esophagus there are 3 pairs of calcareous glands, the secretions of which neutralize the acidic reaction of the soil mass ingested along with food. Large grains of sand entering the stomach are involved in grinding coarse plant foods. The circulatory system is represented by dorsal and abdominal vessels, connected by pulsating annular vessels, or “ring hearts”. Breathing is carried out through the integument of the body; Oxygen is carried by hemoglobin, which gives blood its red color. The nervous system consists of a pair of suprapharyngeal ganglia and a ventral nerve cord. Hermaphrodites: Male and female reproductive organs are concentrated in the front of the body. During puberty, a glandular belt develops on the body, covering several segments. Most earthworms are characterized by cross-fertilization with copulation, during which (at the girdle level) an exchange of male reproductive products occurs. The ripening eggs enter the mucous membrane of the girdle, which gradually slides through the head end of the body. When passing past the openings of the sperm receptacles, foreign sperm enters the coupling and fertilizes the eggs. After dropping the muff from the body of the worm, its ends close, the integument becomes denser, and it turns into an egg cocoon, inside which embryonic development takes place. Formed young worms emerge from the cocoon.

Earthworms are widespread in all natural areas except polar deserts. In the temperate zone, they are especially numerous in chernozem soils, where their number reaches 100-500 individuals per square meter. Worms, including the widespread tillage worm (Aporrectodea caliginosa), build and maintain a system of soil tunnels within which they move and feed. They strengthen the walls of the passages with their mucous secretions, which attract abundant microflora, which develops in the lining of the passages and serves as a source of food for the worms. Some species of earthworms, such as the common earthworm (Lumbricus terrestris), feed on fallen leaves, moving them into deeper layers of soil. The activity of earthworms is one of the most important factors in soil formation. They move along the soil profile a huge mass of organic and mineral material, which is many times greater than the mass of the worms themselves, and bring up to 30 t/ha of soil from deep horizons to the surface. It has been established that the thickness of the humus horizon coincides with the depth of earthworm tunnels. By creating a system of passages, they contribute to the aeration of deep soil horizons and the regulation of its water regime.

The world fauna of earthworms has about 1,500 species. More than 60 species are found in Russia, mainly from the family of true earthworms (Lumbricidae). Many species have a wide distribution, for example, the common earthworm, the small red worm (Lumbricus rubellus), the rock worm (Octolasion lacteum), the tillage worm, the compost worm (Eisenia foetida), which are common in temperate climates. A technology has been developed for the introduction of earthworms into marginal lands, in which their activity contributes to the rapid formation of a humus horizon, including in newly irrigated lands in arid regions of Central Asia and Transcaucasia, as well as on saline marshes in the Netherlands. In different countries, the cultivation of earthworms on an industrial scale is widespread for the purpose of processing organic waste (sludge, animal waste, industries operating on plant and animal raw materials, etc.) and obtaining high-quality fertilizer (“vermihumus”) for indoor soil and small farms. Mainly the compost worm and the highly productive hybrid race of this species, bred in the USA, called the “red California worm,” are widely used. In addition, the biomass of earthworms developing in vermiculture (artificial breeding of earthworms) is a valuable product, which, after certain processing, is used as a feed additive in poultry and fish farming, as well as raw materials for the pharmaceutical industry.

Lit.: Animal life. M., 1987. T. 1; Invertebrates: a new generalized approach. M., 1992.

A. V. Chesunov, B. R. Striganova.