In what water are leeches found. Leeches - Life. Reproductive system, reproduction and development
The medical leech has a powerful, well-developed musculature. Muscles lie under the outer layer of integumentary tissue, the cells of which reliably protect them from the harmful effects of the environment. The muscles, which make up 70% of the total body volume of the leech, are heterogeneous in structure. It is represented by several layers of specialized muscle bundles.
Immediately under the skin are circular muscles. Their contraction in response to nerve impulses causes an increase in the length of the body of the leech: it is extended. Benches of longitudinal muscles pass under the annular layer, which are best developed in leeches. The activity of these muscles causes a decrease in the length of the body of the leech, causing it to shrink. The medicinal leech also has developed dorsal-abdominal muscles.
Of greatest interest to medicine and zoology are the digestive organs of the medical leech, since it is the features of this physiological system that allow the use of the leech as a therapeutic agent. The leech is defined by scientists as a true hematophagus (from the Greek haima - blood and phagos - devouring).
This definition is absolutely correct, since the medicinal leech does not feed on anything other than blood. At the same time, it is able to absorb exclusively the blood of vertebrates than. differs from other hirudini, adapted to eating all kinds of aquatic and terrestrial invertebrates. The medicinal leech is adapted to the consumption of the blood of any vertebrates, however, only a large mammal, including humans, can become its main host.
The digestive tract of a leech opens at the anterior end of the body with a mouth opening. In the depths of the oral cavity, immediately in front of the pharynx, there are three small white bodies in the form of a half lens. This is the jaw apparatus of a leech. Two jaws are lateral, and the third is dorsal. Each of the jaws bears from 80 to 90 small teeth. The teeth of a medical leech are very sharp, which allows it to quickly bite through the thick skin of warm-blooded animals.
The throat of a leech is short, it is surrounded by thick bundles of powerful muscles. This musculature compresses the pharyngeal walls and contributes to the active swallowing of blood from the wound cut by the teeth. Following the pharynx is the esophagus, which passes into a multi-chambered stomach, also called the gastric intestine. An intensive process of blood accumulation takes place here, which is served by 10 pairs of segments that can expand.
The stomach is the largest part of the medicinal leech's digestive system. The segments of the stomach, called chambers, were formed by narrowing in several places the originally straight tube of the alimentary canal. The constrictions divided the tube into a number of partially isolated sections, the walls of each of which subsequently began to protrude. Lateral protrusions of the chambers led to the appearance of sac-like processes that increase the volume of the gastric segments.
Throughout this part of the digestive canal, the size of the departments is different, because. bag-like protrusions are developed unequally. The largest segments are located at the end of the stomach, closer to the pharynx they become smaller. This structure of the stomach, together with its ability to stretch, gives the leech the ability to suck out (take away, as they say) the host's blood.
The reserves of the stomach provide a full existence of the leech for several months. At the same time, if we take into account the total volume of blood circulating in the body of a mammal, the leech does not take so much from the owner. A medium-sized leech, reaching a mass of 2 g, sucks out no more than 8 ml of blood, although in principle it is capable of absorbing up to 10-15 ml, i.e., almost 8 times its own weight. The segments of the stomach of a healthy leech serve as a reliable repository of blood, which does not coagulate in them, does not become infected with microbes, and does not deteriorate for any other reason.
Doctors used to make leeches regurgitate sucked blood to empty their stomach and force them to suck blood again. This allowed the use of leeches a second time. Belching occurs when a leech is immersed in vinegar, wine, or saline. Artificial belching is also caused by squeezing the leech with your fingers. Now such techniques are not used, doctors do not force leeches to burp, because with repeated burping, the healing qualities of leeches are significantly reduced, their delicate digestive system is injured. Under natural conditions, healthy leeches never regurgitate.
The digestive system of a medical leech: 1 - jaws and pharynx; 2 - stomach; 3 - terminal intestine; 4 - anal intestine
If the accumulation of blood occurs in the stomach of a leech, then the process of digestion is carried out in the terminal intestine. It is very short, less than 1/4 of the body length of the leech and resembles a thin straight tube. Blood enters this tube in small portions for digestion. The shortest section of the alimentary canal is the anus. Digested blood remnants enter here, forming feces, which are then evacuated through the anus (powder).
Bowel movements in leeches are carried out regularly, up to several times a day. Therefore, the water in the vessel where the used leeches are stored is periodically stained. Frequent staining of water should not cause any concern, since it only indicates the health of leeches and the normality of their physiological functions. The clogging of water that occurs from time to time does not cause any harm to leeches if the water is systematically changed.
Leech care is essential. It consists not only in periodically renewing the water in the vessel. When keeping leeches, it is important to maintain normal light and temperature conditions. Leeches, however, are strictly forbidden to be fed. For therapeutic use, only hungry leeches are suitable, capable of greedily sucking blood.
In addition to sharp teeth and a powerful pharynx, the salivary glands are the most important device for sucking blood in a leech. Strictly speaking, it is the function of these glands that determines the interest of physicians in the leech. The salivary glands of the leech are located around the pharynx, forming a large accumulation of negligible whitish balls.
Each such ball is a body of the gland, consisting of a single cell. Inside this cell is a large nucleus, which has a small nucleolus with chromosomes and is filled with chromatin grains. The rest of the inner space of the cell is filled with a special liquid - the cytoplasm, in which grains are suspended, producing the secret of the salivary glands. This secret, i.e. the end product of biochemical synthesis, goes through the excretory duct and mixes with the water present in the body of the leech. As a result, saliva containing biologically active substances is formed.
Each glandular cell is supplied with a duct, thus connecting with the jaws. The ducts gradually, as they approach the jaws, unite into bundles. These bundles run inside the jaws, ending on their surface and opening with small holes between the teeth. From these holes, saliva enters the wound bitten by a leech.
The secretion of saliva, as shown by the experiments of L. Shapovalenko, occurs continuously during the entire act of sucking. The active components of the secretion of the salivary glands determine its biological and pharmacological properties.
In living cells, it is impossible for biochemical reactions to occur, which require high temperatures or strong acids and alkalis. In order to cause the transformation of various substances, the human body has a stock of some specific compounds called enzymes. They are active at normal body temperature and act as regulators of intra- and extracellular transformations of organic substances.
Since the process of digestion begins already when chewing, during the processing of food with saliva, it is here that enzymes first enter into the reaction, breaking down and converting the nutrients contained in food. We see the same thing in leeches. The main enzyme of the salivary glands of the leech is hirudin, but some other enzymes also play an important role: hyaluronidase, destabilase, orgelase, antistasin, decorine, viburnum, eglin. In total, there are up to 20 active proteins in leech saliva.
Before it was said mainly about enzymes that accelerate chemical transformations. These are catalysts, i.e. reaction activators. However, there are also reverse action regulators, also contained in the secretion of the salivary glands of the leech. They are inhibitors, that is, they suppress the activity of other enzymes and drown out certain reactions.
Hirudin and many other substances of the secretion of the salivary glands of the medicinal leech are both inhibitors that suppress the blood coagulation reaction and catalysts that break down many proteins in our plasma. A chemical analysis of the tissues of a medical leech revealed a reduced content of hirudin in all parts of its digestive system.
In the terminal gut, hirudin is cleaved by another type of enzyme. Thanks to this, blood clotting is possible here, the clots of which are immediately broken down by digestive juices into amino acids. This is how the digestion of the blood mass occurs in the intestines of the leech.
The medicinal leech has a nervous system built according to a completely special pattern, different from the nervous organization of the lower or, conversely, the higher representatives of the animal kingdom. More primitive jellyfish and hydras instead of the nervous system have a dense network of neurons (nerve cells) that control the reactions of these creatures.
Of the special sense organs in a leech, only eyes are present, although they are represented in large numbers. Remember that a leech has 10 eyes. They are spherical chambers that do not have a lens and carry 50 photoreceptors each. Judging by the structure of the eyes, the leech does not perceive a complete image. But she responds well to many external influences, although she lacks the organs of smell and touch. Irritations are captured by sensitive skin cells, which are either elements of the sensory kidneys (receptors) or nerve endings. Most of the sensory kidneys and nerves are concentrated at the anterior end of the body of the leech.
Nerve fibers extend from the kidneys and other nerve cells of the skin, gathering as they unite into nodes of the nerve chain. Almost every segment of the leech has such a knot on the ventral side. The nodes are interconnected, providing the reception and transmission of impulses in the nervous system.
Collectively, all this formation is called the abdominal nerve chain, which performs the same functions in a leech as the central nervous system (brain and spinal cord) in humans. The largest nodes of the chain are the supraglottic and subpharyngeal nodes located at the head end of the body. The supraesophageal node is the largest. It is connected to the subpharyngeal by special bridges, so that a ring is formed around the pharynx of the leech, which zoologists call the peripharyngeal ganglion.
In significance, it is similar to the human brain, although, of course, it is not equivalent to it and differs in structure. The "brain" of a leech is relatively simple. Its two constituent elements (supraglottic and subpharyngeal nodes) mutually complement each other, since the action of one compensates and partially neutralizes the action of the other.
Despite the seeming primitiveness of the sensory perception of leeches, they perfectly orient themselves in space. Their sense of smell, taste and touch, in the absence of the corresponding sense organs, are unusually developed, which contributes to their success in finding a victim. First of all, leeches respond well to odors emanating from objects immersed in water. Irritating odors make the leech hastily move to another place. Leeches do not tolerate foul-smelling water.
Of the many different odors - pleasant and unpleasant - animals recognize with high accuracy those that come from people and large mammals, that is, potential hosts. This is proved by simple but cunningly set experiments that are easy to repeat at home. For example, 2 clean plugs are lowered into the water. At the same time, one of them must be lowered with a gloved hand, the other - with a "bare" hand. As a result, most leeches invariably stick to corks that have been in contact with human skin rather than the glove. Leeches will become much more active if the smell of a person on the cork is increased (for example, hold it under the armpit for a while).
Of course, the smell of blood is most attractive to leeches. Their reaction to this stimulus is instantaneous. It is worth adding a few drops of blood of a mammal to a vessel with leeches, like leeches, if they are hungry and healthy, they quickly take a trapping "stance". They rise at the rear ends of the body, stretching into a string, and begin to sway vigorously. At the same time, the front end of the body makes movements that demonstrate the attempts of leeches to stick to a potential victim.
Among other things, it is necessary to mention the presence of the so-called leeches. thermal feeling. Thermoreceptors are present in a great variety of living beings, but only in some highly organized bloodsuckers they are specialized. Temperature-sensitive human skin receptors are adapted to distinguish between the degree of heating of the surfaces of various objects in a wide range of temperatures. Our skin, therefore, can only signal the danger of thermal damage to the skin - due to burns or frostbite.
Leeches, like the South American vampires (bats), catch a slight difference in the heating of surfaces. This makes some biological sense, since some worms have evolved thermotropism (the desire to move to an area with temperatures slightly higher than normal).
Sticking to the skin, the leech does not immediately begin to bite. She persistently searches for the warmest patch of skin around her. The same instinct that governs blood-sucking New World bats tells the medicinal leech that the warmest areas of the skin are the richest in blood. The capillaries are full here, intensive microcirculation in the tissues contributes to their greater warming and increases the power of the infrared (thermal) radiation flux.
If for a vampire an error in determining the temperature of the body parts of the victim is completely indifferent, then it is undesirable for a leech to make mistakes. After all, in all warm-blooded creatures, when they enter cool water, capillaries constrict, as a result of which blood microcirculation becomes slow. That is why the amount of blood taken by a leech strictly depends on the point of the skin where it sticks. To take more blood, the leech must find a zone with increased microcirculation, where the capillaries are slightly narrowed.
The reactions of leeches to smells, water fluctuations and human skin temperature have been thoroughly studied by zoologists over the past two centuries, and even earlier people managed to superficially study the smell, touch and other senses of a leech, based on personal observations. The conclusions obtained at the same time form the basis of leech breeding, leech breeding and bdellotechnique, and in particular the technique of setting medical leeches for patients.
At the same time, for the practical needs of leech breeding, studies of the reproductive system of the leech and the characteristics of its reproduction are no less important. As mentioned in the previous section, leeches are hermaphrodites, that is, they have a dual reproductive system, including both male and female genitalia.
Only 3-year-old leeches reach puberty, since they have already gained the necessary mass for the body to produce reproductive products - eggs and sperm. The leech, breeding once a year, in the summer, brings from 3 to 4 offspring during its life.
As laboratory studies have shown, the average life expectancy of a leech is 6 years. How long wild individuals live, scientists do not know for certain, although it is possible that there are long-livers among leeches.
The body is flattened in the dorsal-abdominal direction, bears two suckers. The anterior or oral sucker is formed as a result of the fusion of four segments; at its bottom there is a mouth opening. The posterior sucker is formed by the fusion of seven segments. The total number of body segments is 30-33, including segments that form suckers. Parapodia are absent. True leeches lack bristles, bristle-bearing ones have. Leeches living in water swim, bending their body in waves, land leeches "walk" on the ground or leaves, alternately sticking to the substrate with either the front or the back suction cup.
rice. one. Diagram of the structure of the front
end of the body of a medical leech:
1 - ganglion, 2 - longitudinal muscles,
3 - pharynx, 4 - muscles of the pharynx,
5 - jaws, 6 - wall
front sucker.
The composition of the skin-muscle sac includes a dense cuticle, a single-layer epithelium, annular and longitudinal muscles. The epithelium contains pigment and glandular cells. The cuticle is divided into small rings; the outer segmentation does not correspond to the larger inner segmentation.
In general, in bristle-bearing leeches it is preserved, in real leeches it is reduced to one degree or another. In most species of true leeches, the secondary cavity is filled with parenchyma, and longitudinal lacunar canals remain from the coelom.
rice. 2. Structure diagram
medicinal leech:
1 - head ganglia,
2 - oral sucker,
3 - pockets of the stomach,
4 - midgut,
5 - hindgut,
6 - anus,
7 - rear suction cup,
8 - abdominal nervous
chain, 9 - metanephridia,
10 - testes, 11 - egg
bag, 12 - vagina,
13 - copulatory organ.
A real closed-type circulatory system, similar to that of oligochaetes or polychaetes, is found only in some species of leeches (bristle-bearing leeches). In jawed leeches, the circulatory system is reduced, and its role is played by lacunae of coelomic origin: dorsal, ventral, and two lateral.
Gas exchange occurs through the integument of the body, some sea leeches have gills.
Excretory organs - metanephridia.
The nervous system is represented by the ventral nerve chain, which is characterized by a partial fusion of the ganglia. The subpharyngeal ganglion consists of four pairs of merged ganglia, the last ganglion of seven pairs. The sense organs of leeches are goblet organs and eyes. Goblet organs - chemoreception organs - are located in transverse rows on each segment, with their help, leeches learn about the approach of the victim, identify each other. The eyes are transformed goblet organs of the anterior segments, they have only a photosensitive value. The number of eyes in different species is from one to five pairs.
Leeches are hermaphrodites. Fertilization is usually internal. The eggs are laid in cocoons. Postembryonic development is direct.
The Leech class is subdivided into subclasses: 1) Ancient, or Bristle-bearing leeches (Archihirudinea), 2) True leeches (Euhiridinea). The subclass Real leeches is divided into two orders: 1) Proboscis (Rhynchobdellea), 2) Proboscis (Arhynchobdellea).
rice. 3. Appearance
medicinal leech
Detachment Beskhobotnye (Arhynchobdellea)
Medical leech (Hirudo medicinalis)(Fig. 3) is bred in the laboratory for medical purposes. The body length is on average 120 mm, width 10 mm, the maximum values can be much higher. Each of the three jaws has 70-100 sharp "teeth". After a leech bite, a trace in the form of an equilateral triangle remains on the skin.
Under laboratory conditions, they reach sexual maturity in 12-18 months and breed at any time of the year. The reproductive system consists of nine pairs of testes and one pair of ovaries enclosed in egg sacs. The vas deferens merge into the ejaculatory canal, which ends with the copulatory organ. The oviducts leave the ovaries, which flow into the convoluted uterus, which opens into the vagina. Fertilization is internal. Cocoons are oval in shape and reddish-gray in color, average length 20 mm, width 16 mm. In one cocoon from 15 to 20 eggs. The egg diameter is about 100 microns. After 30-45 days, small leeches, 7-8 mm long, emerge from the cocoons. In laboratory conditions, they are fed on blood clots of mammals.
Adult leeches are used for hypertension, strokes, for resorption of subcutaneous hemorrhages. Hirudin, contained in the saliva of leeches, prevents the development of blood clots that clog blood vessels.
In nature, medicinal leeches live in small fresh water bodies and feed on mammals and amphibians.
rice. 4. Big
false horse leech
Large false horse leech (Haemopis sanguisuga)(Fig. 4) lives in fresh water bodies. It leads a predatory lifestyle, feeds on invertebrates and small vertebrates, swallowing them whole or in part. The mouth and pharynx can be greatly stretched. The number of blunt "teeth" on each jaw is 7-18. Stomach - with one pair of pockets.
The false horse leech is often confused with the medical one, although they are quite easily distinguished by the color of the dorsal side of the body. The dorsal surface of the body of the false horse leech is black, uniform, sometimes with randomly scattered dark spots. On the dorsal side of the body of a medical leech there is a characteristic pattern in the form of longitudinal stripes. False horse leeches should not be kept together with medical ones, as they eat them.
The long-awaited report from the leech farm. You will learn how leeches live in captivity,
what they eat, how they reproduce. For the first time we managed to shoot unique shots
birth of leeches in natural conditions and in captivity.
Five pairs of eyes were intensely watching the water column, all the senses were aimed at finding the victim. For more than three weeks, in search of food, one has to move from one corner of the reservoir to another. Even repeated attacks on land did not bring the desired result. Sad thoughts overcame the vampire. Blood and only blood... “Well, you can hold out for another three months, but if happiness does not smile, you will have to emigrate to a nearby reservoir; they say that cattle come there to drink...” A splash was heard somewhere, another, a third - the steel muscles tensed. The vampire determined the source of the vibrations and directed his body towards the victim with smooth wave-like movements. Here she is! Light, warm body, and how little wool, if only not to miss. The vampire spread his huge mouth, bared three terrible jaws with the sharpest teeth, and dug into the victim... A heartbreaking cry resounded the water surface of the reservoir.
01.
02. Today we will tell you about the International Center for Medicinal Leeches, created on the basis of the Medpiyavka association formed in 1937, which was engaged in keeping leeches in artificial ponds of the summer cottage village of Udelnaya (Moscow Region). 
03. At 2500 sq. m. there are production facilities for growing more than 3,500,000 medicinal leeches and the production of cosmetic products. 
04. In total, 400 species of leeches are known to science, which look approximately the same and differ mainly in color. Leeches are black, greenish or brownish. The Russian name for these nimble worms indicates their ability to "bite" into the victim's body and suck out blood. 
05. Leeches live in three-liter jars. Nothing better as a house for them came up with. The leech breeder must ensure that the vessel with leeches is constantly closed with a thick white cloth, which is tightly tied. 
06. Leeches are unusually mobile and often tend to crawl out of the water. Therefore, they are able to easily leave the container in which they are stored. Escapes occasionally happen. 
07. A leech has 10 eyes, but the leech does not perceive a complete image. Despite the seeming primitiveness of the sensory perception of leeches, they perfectly orient themselves in space. Their sense of smell, taste and touch are extraordinarily developed, which contributes to their success in finding prey. First of all, leeches respond well to odors emanating from objects immersed in water. Leeches do not tolerate foul-smelling water. 
08. Unhurried, devoid of sharp movements allow you to see the entire body of a leech. On the back, against a dark background, bright orange blotches form a fancy pattern in the form of two stripes. On the sides - black piping. The abdomen is delicate, light olive in color with black edging. The body of an ordinary medical leech consists of 102 rings. On the dorsal side, the rings are covered with many small papillae. On the ventral side, the papillae are much smaller and less visible. 
09. But behind the harmless external beauty of a leech lies its secret weapon - the front sucker, outwardly invisible. A large, frightening rear sucker does not cause any physical damage, but in the depths of the front jaws lurk, geometrically located according to the sign of the prestigious company in the automotive world - Mercedes. In each jaw, there are up to 90 teeth, a total of 270. Here it is - deceit. 
10. The record for the largest size of a leech grown in this center is 35 centimeters in length. The leech in the photo still has everything ahead. 
11. Bitten by a leech - like a nettle stung. The bite of the same horsefly or ant is much more painful. Leech saliva contains painkillers (analgesics). The leech feeds exclusively on blood. Hematophagus, that is, a vampire. 
12. The epidermal layer of the leech is covered with a special film - the cuticle. The cuticle is transparent, it performs a protective function and continuously grows, being periodically updated in the process of molting. Normally, molting occurs in leeches every 2-3 days. 
13. Dropped films look like white flakes or small white cases. They clog the bottom of the vessels for storing used leeches, and therefore must be removed regularly, and the water is also periodically stained from digestion products. Water is changed twice a week. 
14. Water is specially prepared: it settles for at least a day, it is purified from harmful impurities and heavy metals. After cleaning and passing control, the water is heated to the desired temperature and enters the common network for leeches. 
15.
16. Leeches poop up to several times a day, so the water in the vessel where the used leeches are stored is periodically stained. The clogging of water that occurs from time to time does not cause any harm to leeches if the water is systematically changed. 
17. The most important condition for the rapid cultivation of full-fledged medicinal leeches is their regular feeding with fresh blood, which is purchased from slaughterhouses. 
18. Large clots are used, formed during the coagulation of the blood mass. For the full feeding of leeches, only the blood of healthy animals, mainly large and small cattle, is taken. Clots are placed at the bottom of special vessels, where leeches are then released. 
19. To make it pleasant for leeches to eat, a film is laid on them, which they bite through and suck blood out of habit. 
20. During growth, the leech feeds every one and a half to two months. 
21. After the leeches have grown and starved for at least three months, they are collected in a batch and sent for certification, and then they go on sale or are used in the production of cosmetics. The Center has an accredited laboratory of the quality control department. But more on that tomorrow. 
22. For one feeding, a leech sucks out five times its weight, after which it may not eat for three to four months, a maximum of a year. After eating, the leech looks like a solid muscle bag filled with blood. In her digestive tract there are special substances that protect the blood from putrefaction, which preserve it in such a way that the blood always remains complete and stored for a long time. 
23. A leech usually eats up in 15-20 minutes. A sign that the leech is full, foam appears. 
24. Well-fed leeches are trying to escape from the "dining room". 
25. Yum-yum! 
26. After feeding, the leeches are washed. 
27. And they put it back in the jar. 
28.
29. And they wash the dishes. 
30.
31. Leeches communicate with each other extremely rarely, only during the mating period. And then, most likely, out of necessity, so as not to die out. Leeches that are suitable for reproduction, that is, carefully fed and have reached a given size, are called queens. 
32. They are placed in pairs in jars filled with water and stored in special rooms where the optimum temperature of the environment is observed, which supports the activity of leeches and their reproductive abilities. Copulation and laying of cocoons with eggs occur in leeches at an environmental temperature of 25 to 27 °C. And although each individual carries both the male and female principles (hermaphrodites), she cannot satisfy herself in this intimate matter and is looking for a partner. 
33. The mating season, during which mating takes place, takes about 1 month, after which the leeches are seated in queen cells - three-liter jars. Moist peat soil is placed at the bottom of the mother liquor, which is a favorable environment for medical leeches and their cocoons. Soft moss sods are lined over the peat, which regulate soil moisture. The queens move freely on the moss, in which they feel comfortable, and gradually dig into the peat. 
34. Leeches practice different positions in which copulation is carried out. There are 2 main positions that make biological sense. First position: the front ends of the bodies of copulating leeches are directed in one direction. The second main position: the ends of the bodies are opposite, that is, they look in different directions. 
35. The peat is thoroughly washed so that the leeches are damp and comfortable. 
36. 
37. By light rings, you can identify a pregnant leech and plant it in a jar of peat. 
38. Breaking through a shallow passage in the soil, the leech lays a cocoon in it, from which the threads are subsequently removed - this is the name of the leech growers of small young leeches. Their mass reaches a force of 0.03 g, and the body length is 7-8 mm. Filaments are fed in the same way as adults. 
39. Each mother leech lays on average 3-5 cocoons, each of which contains 10-15 fry. 
40. After a while, the cocoons become like soft foam balls. 
41. It can be seen through the light that fry are sitting inside the cocoon. 
42. And here are unique birth shots. The leech leaves the cocoon through a hole in the end. 
43. 
44. The first minutes of the life of a small leech. 
45. And this is how they are born in the conditions of the center. The cocoons just burst. 
46. A leech lives in the center for a year and a half, then it is given away for the treatment of people or processed into cosmetics. 
The leech has many amazing qualities. It's hard to imagine, but this little worm has a sense of smell, taste and touch, and also distinguishes between heat and light.
The leech is hermaphrodite by nature, that is, it has the characteristics of both sexes. When they meet, the leeches fertilize each other.
The leech lives only in fresh water. It can be found in large quantities in the waters of Central and Southern Europe and Asia Minor. Under natural conditions, leeches feed on the blood of animals that come to drink.
Not every leech can heal a person. Of the more than 400 species of leeches found in nature, only one species is used in medical practice. This is a medical leech. This species has two subspecies - pharmaceutical (Hirudina officinalis) and medicinal (Hirudina medicinalis) leeches. Both subspecies are used for medicinal purposes. In order to understand this issue and distinguish a useful leech from the rest, it is absolutely not necessary to know the characteristics of these animals, and even more so to go to reservoirs with a net. Medicinal leeches must be purchased only in pharmacies, in addition, they must be licensed, like any medicine.
Leeches, which are used for medicinal purposes, have not been caught in swamps and ponds for a long time. They are grown in special biofactories under artificial conditions under the careful supervision of biologists. This is necessary so that the leeches are sterile and cannot become a source of infection for the people who use them.
medical leech
A medical leech is a special, thoroughbred leech, which differs sharply from the pond one. It is grown precisely in order to serve a person only once. The leech is used as a disposable syringe, which is absolutely sterile. After the procedure, the leech is killed. It is believed that now she can be potentially dangerous, as she was dealing with a sick person, which means sick blood. Sterilizing a leech is a very troublesome business.
However, there is one circumstance in defense of the leech. Her saliva contains the strongest bactericidal substance that kills microbes contained in the blood. Therefore, the leech disinfects its food and cannot itself be a source of infection. But you cannot be sure that this substance will cope with any bacteria that can enter the body of a leech, for example, with the blood of infected animals (if it is a pond leech). This is why it is easier to grow a new sterile leech than to risk using an old one. For such economic benefits and our health, this blood-sucking creature pays with its life.
The most valuable thing in a medical leech is its secret, which is excreted with saliva. Leech saliva contains more than a hundred biologically active substances containing the entire periodic table. Therefore, the impact of a leech on a person can replace any medicine prepared chemically and therefore having a lot of side effects. In the process of treatment with leeches, all biologically active substances enter the bloodstream and have a beneficial effect on our organs, systems and well-being. At the same time, the leech secret is completely harmless, because it is used in minimal doses and strictly as needed.
The nature of the action of this healer - leeches - is unique. Medical beer is a very sensitive organism. It recognizes a diseased organ in a special way and unmistakably finds biologically active points corresponding to this organ. Therefore, leeches are not only a therapeutic, but also a diagnostic tool. Many doctors allow leeches to determine the sites of bites themselves, checking their diagnosis against them with the “diagnosis of a leech”. That is why hirudotherapy is successfully used in any field of medicine for a wide range of diseases.
Another interesting characteristic feature of the leech is its cleanliness. The human body must be very clean and without foreign odors, only then the leech will stick to it.
Interestingly, the leech is very sensitive to the bad habits of humans. She will never treat a drunk patient, she ignores a heavy smoker who smells of tobacco. And if the patient has not washed for a long time, the leech will immediately crawl away, no matter how hungry she may be. These natural healers are very picky!
The structure of a leech
The leech is an annelids averaging 12 to 15 cm in length. It has a greenish back with orange stripes and black dots. The medicinal leech lives in fresh water bodies of Central and Southern Europe and Asia Minor. It feeds on the blood of large mammals entering the water during a watering hole.
The leech is a digestive tube covered with sensitive skin. The leech breathes through the skin, and the skin protects it from external irritants. The skin performs another function - it is the sensory organ of the leech. The leech has a very developed muscular system, which consists of ring muscles that cover the entire body of the leech and form its suckers, longitudinal muscles that stretch along the body, and dorsal-abdominal muscles located from the back to the abdomen. This structure of the muscular system allows the leech to be very mobile, to make the most diverse and fast movements.
On the head of a medicinal leech there are five pairs of eyes, and in the mouth there are three jaws with chitinous teeth, of which there are about 260 pieces. With their help, the leech cuts through the skin to a depth of 1.5-2 mm and sucks up blood in a volume of 5-15 ml, the same amount flows out of the bite site over the next 3-24 hours. This is due to the fact that the secret of leech saliva envelops the walls of the affected vessels, as a result, the blood loses its ability to coagulate. But such bleeding is absolutely harmless to human health and is easily tolerated by the patient. 5-7 individuals are usually attached to the session. Even one session of hirudotherapy is very healing, as a whole complex of biologically active substances and enzymes enters the human blood, which cause anti-inflammatory, analgesic, decongestant effects, reduce the likelihood of blood clots, improve blood microcirculation, and also activate the human immune system.
The oral cavity of the leech passes into the pharynx, which has thick muscular walls, they act as a pump when pumping out blood.
The stomach of a leech is a gut with 10 pairs of lateral processes. In length, the stomach occupies 2/3 of the body length of the leech and can hold from 5 to 15 ml of blood. And what is especially important: the intestines of the leech contain special bacteria that disinfect harmful substances, so the saliva of the leech is always sterile. Therefore, the medical leech is actively used for thrombophlebitis, hypertension, in pre-stroke states and other diseases. Due to the fact that the leech stimulates blood circulation in tissues, affects the walls of blood vessels and increases blood oxygen saturation, it has a beneficial effect on the entire body as a whole.
How to distinguish a real medical leech from a fake one?
They are not medical: leeches are one-colored, without stripes on the back. In addition, take a close look at the shape and other external signs of the leech. It should not be covered with hairs, have a cylindrical body and a blunt head. A real medical leech is smooth, almost flat, with a sharp head.
The healing effect of leeches
The mechanism of the therapeutic effect of leeches is very multifaceted, so the effect itself occurs in a complex. Bloodletting gives a kind of impetus to the immune system of the body. Thanks to this, there is an influx of "fresh" blood and renewal of the whole organism, in which the healing processes are launched. In addition, a small loss of blood lowers blood pressure. A special substance hirudin, which prevents blood clotting, stimulates the blood supply to all organs. But this is not all the functions of leech saliva. Consider each type of therapeutic effect of a leech in detail.
So, the therapeutic effect of hirudotherapy consists of several factors: reflex, mechanical and biological.
reflex action
This action lies in the fact that the leech bites through the skin only at biologically active points, which are also called acupuncture points. These points are used in acupuncture. They are inextricably linked with all organs and systems. By acting on certain points, the doctor starts the process of self-healing of the organ, enhancing its energy. The mechanism of the reflex action of leeches is exactly the same as with acupuncture. In addition, the leeches themselves feel the points that need to be acted upon, that is, they choose the bite sites. Thanks to this, even a person who does not know acupuncture can put leeches. But it is better, of course, if this medical manipulation is carried out by a doctor.
mechanical action
It consists in the fact that after a leech bite, lymph continues to ooze with an admixture of capillary blood under the influence of hirudin and destabilase injected with saliva. Due to the long expiration of lymph (from 5 to 24 hours), mechanical irritation of the lymph nodes occurs and the production of natural protective cells - lymphocytes - is stimulated. This leads to an increase in local and general immunity. In addition, local blood flow is unloaded, which contributes to blood renewal and greater blood flow to the diseased organ.
Biological action
This is the most valuable and most important effect, which is provided by the leech saliva itself, which contains a huge amount of useful substances. The most valuable of them are: hirudin, destabilase complex, bdellins, eglins, hyaluronidase, antibacterial and analgesic substances.
Hirudin- the most studied leech hormone. It slows down blood clotting and flushes blood clots from blood vessels, preventing thrombosis. Hirudin is the best remedy in the treatment and prevention of intravascular coagulation syndrome.
Hyaluronidase- an enzyme that is found in the venoms of snakes, spiders, extracts of human testes and some bacteria. This substance is necessary for the fertilization process, so hirudotherapy successfully copes with such a problem as infertility.
Bdellins trypsin and plasmin inhibitors.
Eglins- substances that the body needs, suffering from rheumatoid arthritis, gout, emphysema. Eglins act in such a way that they prevent further damage to the joints and lungs, curing an existing pathology. Eglins penetrate into the blood and, connecting with other components, prevent the process of tissue degradation. This property allows the use of leeches in the treatment of skin diseases and injuries, surgical treatment.
In addition to the secretion of saliva, the symbiont bacterium Aeromonas hydrophilia contained in the intestinal canal of the medical leech, which provides a bacteriostatic effect, has a healing effect.
So, we list all types of therapeutic effects of leeches on the human body:
Anticoagulant;
thrombolytic;
Anti-ischemic;
Antihypoxic;
Hypotensive (more precisely, normotensive);
Decongestant;
Draining;
Restoration of microcirculation;
Lipolytic;
Restoration of neuromuscular transmission of impulses;
General reflex;
Restoration of the permeability of the vascular wall;
Bacteriostatic;
Immunostimulating;
Analgesic.
A leech bite is often much more effective than a drug injection. The fact is that when the drug is injected, the medicinal substances are distributed evenly throughout the body, and the leech acts only on the diseased organ. In the zone of influence is 70-80% of all biologically active substances introduced by the leech into the patient's blood.
Hirudotherapy session lasts from 40 minutes to one hour. Leeches should not be removed, they themselves determine the end of the session. Depending on the complexity of the disease, treatment requires 5 to 10 sessions 1-3 times a week.
Hirudotherapy can be used as an independent method of treatment, and can be combined with other methods of naturopathy, most often with herbal medicine, as well as with homeopathy and physiotherapy. This combination is determined by the doctor, depending on the nature of the disease, the patient's condition and the characteristics of his body.
How a leech "works"
With the help of sharp jaws, the leech bites through the skin to a depth of 1.5-2 mm and sucks blood in a volume of 5-15 ml. The same amount of blood flows from the bite site subsequently (over the next 3-24 hours). This is because leech saliva contains hirudin, which prevents blood clotting. You don't need to stop the bleeding. In one treatment session, usually 5 to 7 leeches are applied.
The medical leech itself chooses the bite site - the warmest area, the richest in blood. Here it reveals biologically active points through which it acts on blood vessels and internal organs and systems of a person.
Gradually, as it becomes saturated, the leech noticeably increases in size. The volume of blood that she drinks is 3-5 times her own weight, that is, it can be up to 15 ml. Feeding on blood, the leech injects into the bite site, that is, into the bloodstream of the vessel, its healing saliva - a unique balanced complex of biologically active substances. Almost immediately after a leech bite, its therapeutic effect begins. Valuable substances of saliva under the influence of its special enzymes quickly penetrate into the tissues. And already 20 minutes after the removal of the leech, the components of its secret are carried with the bloodstream throughout the body.
A leech bite resembles a mosquito bite or a nettle sting. Then there is a purely mechanical unloading of the blood flow, that is, a person practically does not feel how the leech sucks blood. The blood itself flows to her mouth and stomach. Having sated, the leech itself disappears, and the blood (mainly lymph) continues to flow out in a very thin stream. For a period of 3 to 24 hours, it can flow out as much as the leech drank, that is, about 12-15 ml. And in total, a person loses no more than 30 ml of capillary blood along with lymph from one leech. This process is also healing, so you can not stop it. Such a small loss of blood triggers the mechanism of stimulation of the immune system and eliminates swelling.
The probability of infection of people through leeches during hirudotherapy sessions is practically excluded. Leeches are bred in special biofactories by the canning method, they are kept in sterile conditions. Leeches feed on the tested blood of animals. Ready-to-sell leeches are tested and certified. After treatment, leeches are destroyed and not reused.
Independent use of leeches
You can choose different ways to treat the disease: drink pills, be treated with herbs, use physiotherapy or turn to hirudotherapy. Each method has its pros and cons. But treatment with leeches stands out from the general list of treatment methods in that there are much more pluses than minuses. And the cons themselves are only in the presence of a small number of contraindications, which are quite rare. Therefore, there are more and more adherents of hirudotherapy today. A serious problem is the choice of a qualified hirudotherapist - such specialists can only be found in large cities, in large clinics or specialized hospitals. Leeches are much easier to acquire.
The doctor using this method must know the human anatomy perfectly, find an individual approach to each patient, taking into account his diseases, physical and mental condition. It is the doctor who determines how many sessions the patient will need and how many leeches to put during each session.
However, the procedure for installing a leech is quite simple, so you can use leeches on your own, but subject to certain conditions.
Firstly, before self-treatment with leeches, you should still consult a specialist. Remember the contraindications to hirudotherapy: although there are few of them, they are very serious. In addition, it is necessary to agree on the number of leeches and procedures. And remember that everything is in moderation. Your well-being will tell you when to stop the procedures, which should be no more than ten.
Secondly, only an experienced specialist should install leeches on the mucous membranes and genitals - it is extremely dangerous to do it yourself!
Thirdly, you can put leeches on diseased organs only if you know exactly your diagnosis and the location of the diseased organ. You can go the other way: put the leech on its back and give it the right to choose the right point on its own. Be sure - the leech will not be mistaken.
Since the leech is a living being, it has its own characteristics. A leech may refuse to treat you, that is, to stick, if there is a change of weather on this day, magnetic storms or other jumps in biorhythms, to which leeches are very sensitive. In addition, leeches do not like to eat at night, so hirudotherapy sessions are held only in the morning and afternoon, at least not late in the evening.
How to put a leech at home
So, you bought leeches in a pharmacy. They should be stored in a jar of tap water, the neck of which is covered with gauze, in a bright place at a temperature of 10–15 °C. Water should be changed daily. Only healthy and hungry leeches, moving quickly in water, are suitable for treatment. Sluggish, with nodules, with a sticky surface, leeches are not suitable for consumption.
Leeches can "work" only once. After using the leech, it is thrown away. Usually put five leeches, at an advanced stage of the disease, you can put seven leeches. To enhance the effect of leeches put on acupuncture points used in reflexology. But if you have never encountered acupuncture, then you can arrange the leeches arbitrarily - they themselves will choose the places of the strongest impact on the body.
They put leeches on the heart area (to cleanse blood vessels), the liver (to cleanse the liver), on the limbs (for thrombophlebitis and varicose veins), behind the ears (for atherosclerosis and heart failure), on the back of the head (for hypertension and for general cleansing of blood vessels), on back (for general cleansing of blood vessels). You can not put leeches on those places where there are distracting veins (eyelids, temples, scrotum).
Do not be afraid of the sensations that may arise during the suction of a leech - this is normal. You may feel a slight burning sensation, like an ant sting, and even severe itching, especially if the leech is placed in a place where the skin is thin. These discomforts pass in a couple of minutes. After a skin puncture, a characteristic trace of small leech teeth remains on it.
In the first ten minutes, the leech lets its saliva into the wound, containing about one hundred and fifty healing substances. At this time, the blood becomes homogeneous, that is, homogeneous, due to the dissolution of small cholesterol plaques and blood clots. Then the leech begins to suck blood, continuing to secrete saliva, but in smaller quantities.
One leech sucks up to 5-10 ml of blood. When the leech fills its stomach, it will fall off on its own. But with incomplete exposure, it is carefully removed.
Rules for setting leeches
Before setting up leeches, you need to stock up on the following supplies:
Healthy, mobile leeches;
Bank with clean water;
Beaker or test tube;
Sterile tray with sterile dressing material;
A bottle of hydrogen peroxide;
Ampoule with glucose or sweetened water;
A jar of salt water to place the leech after removal.
This procedure is best done with an assistant. If you put leeches on another person, do it in this order.
1. Lay the person comfortably on a bed or sofa.
2. Expose the part of the body where the leeches should be placed. If there is hair, it must be shaved off.
3. Rinse the skin well with warm water and dry it dry.
4. Moisten the skin with sweet water or glucose for a better suction of the leech.
5. Grab the tail end of the leech with tweezers and place it in a test tube.
6. Attach the tube to the desired location on the skin.
7. Wait for the leech to suck on. Having sucked, it will fall off the skin itself.
8. Remove the leech and place it in a jar of salted water, then flush it down the drain.
9. Apply a sterile napkin to the places where the leeches are sucked. After the procedure, microbleeding is possible for 6-24 hours, so a volume bandage is necessary, which should be removed only the next day.
10. In the presence of severe bleeding, a pressure bandage should be applied to the wounds.
11. If you need to remove the leech earlier, then the skin under it is moistened with salted water.
12. Leeches can only be used once!
It is necessary to monitor the well-being of a person during the setting of leeches and for some time after the end of the procedure. It is strictly forbidden to tear off a leech by force, as it can cause significant bleeding.
You can re-put leeches only after 5-6 days.
Warning!
After the procedure, itching around the wound may appear at the places where leeches are placed. It is necessary to lubricate the skin around the wound with a mixture of ammonia and vaseline oil in equal amounts. The itch will pass.
Acquisition and storage of leeches
Leeches should be purchased only in specialty stores and pharmacies. They sell certified medical leeches grown in biofactories. These leeches are under control from the moment they are born, so they are a guarantee of effective and safe treatment. In no case should wild leeches be used, because it is impossible to know what the leech fed on and what infections it is a source of. Despite the fact that the leech has a unique set of disinfectants, it cannot be tested for the entire range of infections found in the world. Therefore, one should not take risks, especially since buying a leech is not a problem today.
Leeches are sold in glass jars with clean water in which they live. Such water must be maintained constantly. Water should be well settled and at room temperature, and the jar itself should be in a room with an air temperature of +8 to +20 ° C. Sudden changes in air or water temperature are detrimental to leeches. They do not like leeches and strong odors; upon contact with odorous substances, they get sick and die. They can go without food for half a year, so all this time you only need to change the water and feed the leeches with sugar syrup, which they love very much.
When purchasing leeches, monitor their condition. A healthy leech is active: it swims, resists when it is touched or tried to be placed in a bubble. Watching leeches is extremely interesting, because they are living barometers. In clear weather, leeches crawl out onto the walls of the jar in which they live, and in bad weather they stay under water.
The long-awaited report from the leech farm. You will learn how leeches live in captivity, what they eat, how they reproduce. For the first time, we were able to capture unique footage of the birth of a leech in natural conditions and in captivity.
Five pairs of eyes were intensely watching the water column, all the senses were aimed at finding the victim. For more than three weeks, in search of food, one has to move from one corner of the reservoir to another. Even repeated attacks on land did not bring the desired result. Sad thoughts overcame the vampire. Blood and only blood... “Well, you can hold out for another three months, but if happiness does not smile, you will have to emigrate to a nearby reservoir; they say that cattle come there to drink...” A splash was heard somewhere, another, a third - the steel muscles tensed. The vampire determined the source of the vibrations and directed his body towards the victim with smooth wave-like movements. Here she is! Light, warm body, and how little wool, if only not to miss. The vampire spread his huge mouth, bared three terrible jaws with the sharpest teeth, and dug into the victim... A heartbreaking cry resounded the water surface of the reservoir.
01.
02. Today we will tell you about the International Center for Medicinal Leeches, created on the basis of the Medpiyavka association formed in 1937, which was engaged in keeping leeches in artificial ponds of the summer cottage village of Udelnaya (Moscow Region). 
03. At 2500 sq. m. there are production facilities for growing more than 3,500,000 medicinal leeches and the production of cosmetic products. 
04. In total, 400 species of leeches are known to science, which look approximately the same and differ mainly in color. Leeches are black, greenish or brownish. The Russian name for these nimble worms indicates their ability to "bite" into the victim's body and suck out blood. 
05. Leeches live in three-liter jars. Nothing better as a house for them came up with. The leech breeder must ensure that the vessel with leeches is constantly closed with a thick white cloth, which is tightly tied. 
06. Leeches are unusually mobile and often tend to crawl out of the water. Therefore, they are able to easily leave the container in which they are stored. Escapes occasionally happen. 
07. A leech has 10 eyes, but the leech does not perceive a complete image. Despite the seeming primitiveness of the sensory perception of leeches, they perfectly orient themselves in space. Their sense of smell, taste and touch are extraordinarily developed, which contributes to their success in finding prey. First of all, leeches respond well to odors emanating from objects immersed in water. Leeches do not tolerate foul-smelling water. 
08. Unhurried, devoid of sharp movements allow you to see the entire body of a leech. On the back, against a dark background, bright orange blotches form a fancy pattern in the form of two stripes. On the sides - black piping. The abdomen is delicate, light olive in color with black edging. The body of an ordinary medical leech consists of 102 rings. On the dorsal side, the rings are covered with many small papillae. On the ventral side, the papillae are much smaller and less visible. 
09. But behind the harmless external beauty of a leech lies its secret weapon - the front sucker, outwardly invisible. A large, frightening rear sucker does not cause any physical damage, but in the depths of the front jaws lurk, geometrically located according to the sign of the prestigious company in the automotive world - Mercedes. In each jaw, there are up to 90 teeth, a total of 270. Here it is - deceit. 
10. The record for the largest size of a leech grown in this center is 35 centimeters in length. The leech in the photo still has everything ahead. 
11. Bitten by a leech - like a nettle stung. The bite of the same horsefly or ant is much more painful. Leech saliva contains painkillers (analgesics). The leech feeds exclusively on blood. Hematophagus, that is, a vampire. 
12. The epidermal layer of the leech is covered with a special film - the cuticle. The cuticle is transparent, it performs a protective function and continuously grows, being periodically updated in the process of molting. Normally, molting occurs in leeches every 2-3 days. 
13. Dropped films look like white flakes or small white cases. They clog the bottom of the vessels for storing used leeches, and therefore must be removed regularly, and the water is also periodically stained from digestion products. Water is changed twice a week. 
14. Water is specially prepared: it settles for at least a day, it is purified from harmful impurities and heavy metals. After cleaning and passing control, the water is heated to the desired temperature and enters the common network for leeches. 
15.
16. Leeches poop up to several times a day, so the water in the vessel where the used leeches are stored is periodically stained. The clogging of water that occurs from time to time does not cause any harm to leeches if the water is systematically changed. 
17. The most important condition for the rapid cultivation of full-fledged medicinal leeches is their regular feeding with fresh blood, which is purchased from slaughterhouses. 
18. Large clots are used, formed during the coagulation of the blood mass. For the full feeding of leeches, only the blood of healthy animals, mainly large and small cattle, is taken. Clots are placed at the bottom of special vessels, where leeches are then released. 
19. To make it pleasant for leeches to eat, a film is laid on them, which they bite through and suck blood out of habit. 
20. During growth, the leech feeds every one and a half to two months. 
21. After the leeches have grown and starved for at least three months, they are collected in a batch and sent for certification, and then they go on sale or are used in the production of cosmetics. The Center has an accredited laboratory of the quality control department. But more on that tomorrow. 
22. For one feeding, a leech sucks out five times its weight, after which it may not eat for three to four months, a maximum of a year. After eating, the leech looks like a solid muscle bag filled with blood. In her digestive tract there are special substances that protect the blood from putrefaction, which preserve it in such a way that the blood always remains complete and stored for a long time. 
23. A leech usually eats up in 15-20 minutes. A sign that the leech is full, foam appears. 
24. Well-fed leeches are trying to escape from the "dining room". 
25. Yum-yum! 
26. After feeding, the leeches are washed. 
27. And they put it back in the jar. 
28. 
29. And they wash the dishes. 
30. 
31. Leeches communicate with each other extremely rarely, only during the mating period. And then, most likely, out of necessity, so as not to die out. Leeches that are suitable for reproduction, that is, carefully fed and have reached a given size, are called queens. 
32. They are placed in pairs in jars filled with water and stored in special rooms where the optimum temperature of the environment is observed, which supports the activity of leeches and their reproductive abilities. Copulation and laying of cocoons with eggs occur in leeches at an environmental temperature of 25 to 27 °C. And although each individual carries both the male and female principles (hermaphrodites), she cannot satisfy herself in this intimate matter and is looking for a partner. 
33. The mating season, during which mating takes place, takes about 1 month, after which the leeches are seated in queen cells - three-liter jars. Moist peat soil is placed at the bottom of the mother liquor, which is a favorable environment for medical leeches and their cocoons. Soft moss sods are lined over the peat, which regulate soil moisture. The queens move freely on the moss, in which they feel comfortable, and gradually dig into the peat. 
34. Leeches practice different positions in which copulation is carried out. There are 2 main positions that make biological sense. First position: the front ends of the bodies of copulating leeches are directed in one direction. The second main position: the ends of the bodies are opposite, that is, they look in different directions.
35. The peat is thoroughly washed so that the leeches are damp and comfortable. 
36. 
37. By light rings, you can identify a pregnant leech and plant it in a jar of peat. 
38. Breaking through a shallow passage in the soil, the leech lays a cocoon in it, from which the threads are subsequently removed - this is the name of the leech growers of small young leeches. Their mass reaches a force of 0.03 g, and the body length is 7-8 mm. Filaments are fed in the same way as adults. 
39. Each mother leech lays on average 3-5 cocoons, each of which contains 10-15 fry. 
40. After a while, the cocoons become like soft foam balls. 
41. It can be seen through the light that fry are sitting inside the cocoon. 
42. And here are unique birth shots. The leech leaves the cocoon through a hole in the end. 
43. 
44. The first minutes of the life of a small leech.
45. And this is how they are born in the conditions of the center. The cocoons just burst. 
47. As shown by laboratory studies, the average life expectancy of a leech is 6 years. How long wild individuals live, scientists do not know for certain, although it is possible that there are long-livers among leeches.
Tomorrow at the same time there will be a story about how leeches are killed to help people. What happens to a leech after it has sucked blood from a person? How are these cute worms tortured? How to make leech powder and much more!
Text:
The book of D.G. Zharov "Secrets of hirudotherapy"
The Kiss of the Vampire book. Authors: Nikonov G.I. and Titova E.A.