Who eats leeches in nature. Treatment with leeches (medical leech), we understand the features of hirudotherapy. Indications and contraindications for treatment with leeches
In Latin hirūdō find the same suffix as in testūdō"tortoise", however, the etymologization of the root causes difficulties. As possible relatives are called hīra"small intestine" and haruspex"haruspex".
Structure
The body length of different representatives varies from a few millimeters to tens of centimeters. The largest representative Haementeria ghilianii(up to 45 cm).
The anterior and posterior ends of the body of leeches bear suckers. At the bottom of the anterior there is a mouth opening leading to the pharynx. Proboscis leeches (detachment Rhynchobdellida) the pharynx is able to move outward. In jaw leeches (for example, medicinal leeches), the oral cavity is armed with three movable chitinous jaws that serve to cut through the skin.
Nutrition
Biology of the body
The body is elongated or oval, more or less flattened in the dorsal-abdominal direction, clearly divided into small rings, which in number 3-5 correspond to one segment of the body; numerous glands in the skin that secrete mucus; at the posterior end of the body there is usually a large sucker, often at the anterior end there is a well-developed sucker, in the center of which the mouth is placed; more often, the mouth is used for suction. At the anterior end of the body there are 1-5 pairs of eyes arranged in an arc or in pairs one after the other. Powder on the dorsal side above the rear suction cup. The nervous system consists of a two-lobed supraesophageal ganglion, or brain, connected to it by short commissures of the subpharyngeal ganglion (derived from several merged nodes of the abdominal chain) and the abdominal chain itself, located in the abdominal blood sinus and having about 20 nodes. The head node innervates the sense organs and the pharynx, and 2 pairs of nerves depart from each node of the abdominal chain, innervating the body segments corresponding to them; the lower wall of the intestine is equipped with a special longitudinal nerve that gives branches to the blind sacs of the intestine. The digestive organs begin with a mouth armed with either three chitinous toothed plates (maxillary P. - Gnathobdellidae), which serve to cut through the skin when sucking blood in animals, or a proboscis capable of protruding (in proboscis P. - Rhynchobdellidae); numerous salivary glands open into the oral cavity, sometimes secreting a poisonous secret; the pharynx, which plays the role of a pump during sucking, is followed by an extensive, highly extensible stomach, equipped with lateral sacs (up to 11 pairs), of which the posterior ones are the longest; the hindgut is thin and short. The circulatory system consists partly of real, pulsating vessels, partly of cavities - sinuses, representing the remainder of the cavity (secondary) of the body and interconnected by annular channels; blood in proboscis P. is colorless, in jawed - red due to hemoglobin dissolved in the lymph. Special respiratory organs are available only in the river. Branchellion, in the form of leaf-like appendages on the sides of the body. The excretory organs are arranged according to the type of metanephridia, or segmental organs of annelids, and most P. have a pair of them in each of the middle segments of the body. P. - hermaphrodites: the male genital organs consist of most of the vesicles (testes), a pair in 6-12 middle segments of the body, connected on each side of the body by a common excretory duct; these ducts open outwards with one opening lying on the ventral side of one of the anterior rings of the body; the female genital opening lies one segment behind the male and leads into two separate oviducts with saccular ovaries. Two individuals copulate, each simultaneously playing the role of a female and a male. P. during laying of eggs allocates with glands lying in the genital area, thick mucus surrounding the middle part of P.'s body in the form of a cover; eggs are laid in this sheath, after which P. crawls out of it, and the edges of its holes come together, stick together and thus form a capsule with eggs inside, usually attached to the lower surface of the algae leaf; the embryos, leaving the facial membrane, sometimes (Clepsine) keep for some time on the underside of the mother's body. All P. are predators, feeding on the blood of mostly warm-blooded animals or mollusks, worms, etc.; they live mainly in fresh water or in wet grass, but there are also marine forms (Pontobdella), just like terrestrial forms (in Ceylon). Hirudo medicinalis - medical P. up to 10 cm long and 2 cm wide, black-brown, black-green, with a longitudinal patterned reddish pattern on the back; the belly is light grey, with 5 pairs of eyes on the 3rd, 5th and 8th rings and strong jaws; distributed in the swamps of the South. Europe, South. Russia and the Caucasus. In Mexico, Haementaria officinalis is used in medicine; another species, H. mexicana, is poisonous; in tropical Asia, Hirudo ceylonica and other related species living in humid forests and in the grass are common, causing painful bleeding bites to humans and animals. Aulostomum gul o - horse P., black-green in color, with a lighter bottom, has a weaker armament of the mouth and therefore unsuitable for therapeutic purposes; the most common species in the north. and central Russia. Nephelis vulgaris is a small P. with a thin narrow body, gray in color, sometimes with a brown pattern on the back; equipped with 8 eyes located in an arc at the head end of the body; related to her original Archaeobdella Esmonti, pink, without posterior sucker; lives on the silt bottom in the Caspian and Azov seas. Clepsine tessel ata - Tatar P., with a wide oval body, greenish-brown in color, with several rows of warts on the back and 6 pairs of triangular eyes, located one after the other; lives in the Caucasus and Crimea, where it is used by the Tatars for medicinal purposes; the transitional place to the order of bristle-legged (Chaetopoda Oligochaeta) worms is occupied by Acanthobdella peledina, found in Lake Onega.
History of medical use
Medical leech ( Hirudo officinalis) - found in the north of Russia, so especially in the south, in the Caucasus and Transcaucasia, in Poti, Lankaran. In the 19th century, leeches were a profitable export item: Greeks, Turks, Italians, and others came to the Caucasus for them. In addition, artificial breeding of leeches was carried out in special pools or parks according to the Sale system in Moscow, St. Petersburg, Pyatigorsk and Nizhny Tagil. Based on the laws in force, catching leeches during their breeding season - in May, June and July - is prohibited; when fishing, only those suitable for medical use should be selected, that is, not less than 1 1/2 inches in length; leeches are small, as well as too thick, should be thrown back into the water when catching. To supervise the observance of these rules, the provincial medical departments are entrusted with the duty to testify the stocks of leeches from barbers and other merchants who trade them. Since medicine expelled leeches from use, the leech trade has fallen completely.
Notes
Sources
- Ruppert E.E., Fox R.S., Barnes R.D. Invertebrate zoology. Vol. 2: Lower coelomic animals. M., "Academy", 2008.
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See what "Leech" is in other dictionaries:
- (Hirudinea), a class of annelids. Length from several mm up to 15 cm, rarely more. Descended from small-bristle worms. The body is usually flattened, rarely cylindrical, with two suckers (oral and posterior); consists of a head blade, 33 rings ... ... Biological encyclopedic dictionary
Leeches, a class of worms. Length 0.5-20 cm. Body usually flattened, with 2 suckers. About 400 species live in fresh and marine waters. Most leeches are bloodsuckers, the salivary glands of which secrete the protein substance hirudin, which prevents ... ... Modern Encyclopedia
Class of annelids. Length 0.5-20 cm. They have front and back suction cups. 400 species. In fresh and marine waters. Most leeches are bloodsuckers whose salivary glands secrete hirudin, which prevents blood clotting. Medical leech ... ... Big Encyclopedic Dictionary
- (Hirudinei) detachment of the class of annelids. The body is elongated or oval, more or less flattened in the dorsal-abdominal direction, clearly divided into small rings, which in number 3 5 correspond to one segment of the body; Numerous glands in the skin... Encyclopedia of Brockhaus and Efron
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 consume the blood of any vertebrate, but 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 in leeches are the most important device for sucking blood. 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 in this case 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 sexual maturity, 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.
External structure
Medical leechThe body of leeches is noticeably flattened in the dosoventral direction. At the anterior end there is a muscular anterior sucker, in the center, which fits the mouth opening. At the posterior end there is a second, very strongly developed posterior sucker, above which the anus opens on the dorsal side.
Leeches do not have any appendages or parapodia. The bristles are preserved only in a primitive species - the bristle leech. It has four pairs of setae on five anterior segments.
leeches very mobile, crawling and floating animals . Attached by the posterior oral sucker, the leech pulls the body forward, then attaches with the oral sucker, while the posterior sucker is pulled away from the substrate and the body is pulled to the head end, bending into a loop. Then the leech is sucked again by the back sucker, etc. Thus, the leeches make "walking" movements. Leeches swim, making wave-like movements with their whole body, in which their body bends in a dorsoventral direction.
The external ringing of leeches is false, secondary, it does not coincide with the true internal segmentation. Each real segment in different leeches corresponds to 3 to 5 outer rings. The external ringing of leeches is an adaptive trait that provides body flexibility with a powerful development of the skin-muscle sac.
The body of leeches is formed by 33 segments (with the exception of the bristle leech, which has 30 segments), of which a weakly separated head lobe - the prostomium - and four head segments are part of the anterior sucker. The trunk section is represented by 22 segments. The posterior sucker is formed by the fusion of the last seven segments.
Skin-muscular sac
The skin-muscular sac of leeches is formed by a single-layer epithelium, which secretes a dense layered cuticle, and powerfully developed muscles. The skin of leeches is rich in glandular cells that secrete mucus and is permeated with a network of lacunar capillaries. Under the epithelium there are numerous pigment cells that cause a peculiar pattern of leeches.
Leeches are characterized by the presence of three continuous layers of musculature of the skin-muscular sac, like in flatworms: the outer annular, diagonal, and the most powerful longitudinal. The dorsoventral muscles, which are not part of the skin-muscular sac, are also strongly developed.
Body cavity and circulatory system
In almost all leeches, the entire space between the organs is filled with parenchyma, like in flatworms. Only in leeches does the parenchyma fill the secondary body cavity, while in flatworms it fills the primary.
In another order - proboscis leeches (Rhynchobdellida) - a stronger growth of the parenchyma is observed. This leads to a partial reduction of the coelom. However, the coelomic cavity is preserved as a whole system of lacunae. Four main coelomic lacunae run along the entire body: two on the sides, one above the gut, surrounding the dorsal blood vessel, and one below the gut, containing the ventral blood vessel and the ventral nerve cord. These gaps communicate with each other, forming a network of smaller gaps. Thus, proboscis leeches have both a circulatory system and a lacunar system, which is a modified coelom.
In the third order, the higher jawed leeches (Gnathobdellida), which include the medicinal leech and many other freshwater leeches, the development of the parenchyma goes as far as in the proboscis leeches. The blood vessels lying inside coelomic lacunae in proboscis leeches are reduced in jaw leeches. The function of the circulatory system is performed by the lacunar system, which originates from the coelom. Such a process of functional replacement of one organ by another, different in origin, is called substitution or replacement of organs.
excretory system
The excretory organs of leeches are represented by segmental organs of metanephridial origin. However, the number of pairs of pephrindia does not correspond to the number of segments. The medicinal leech has only 17 pairs. In connection with the transformation of the coelom into a system of lacunae, the structure of the metanephridia of leeches also changed. The funnels of the metanephridia open into the ventral lacuna (coelom), but not directly into the nephridial canal. They are separated from the nephridial canal by a septum, so the secreted substances diffuse from the funnel into the nephridium.
Such a structure of the metanephridia of leeches (separation of the infundibulum from the nephridial canal) is explained by the functional transformation of the lacunae into the main circulatory system, which replaces the circulatory one. The metanephridia of leeches are characterized by the presence of a special expansion - the bladder.
Digestive system
The mouth is placed on the bottom of the front sucker. It leads to the anterior part of the digestive system, lined with ectoderm and consisting of the oral cavity and muscular pharynx. The structure of the oral cavity and pharynx in proboscis and jaw leeches is different.
In proboscis leeches, the oral cavity, growing back, surrounds the pharynx in the form of a vagina. A very muscular pharynx turns into a proboscis, protruding and retracting with the help of special muscles. The proboscis can penetrate into the thin covers of various animals (for example, mollusks), and in this way the leech sucks out blood.
In jawed leeches (medical leeches, etc.) in the oral cavity there are three longitudinal muscular ridges that form jaws directed with their crests towards each other. Muscular rollers are covered with chitin, serrated along the edge. With these jaws, leeches incise the skin of an animal or person. In the throat of blood-sucking jaw leeches, glands open that secrete a special substance - hirudin, which prevents blood clotting.
Next, food enters the endodermic midgut, which consists of the stomach and posterior midgut. The stomach forms paired lateral protrusions, of which the last pair is usually especially developed, extending to the posterior end of the body. The stomach serves as a reservoir for long-term storage of blood. The blood that fills his pockets does not clot for weeks and months.
The posterior midgut is represented by a relatively short straight tube in which the final digestion and absorption of food takes place. It passes into a short, often enlarged posterior ectodermic gut, which opens with an anus above the posterior sucker.
Nervous system and sense organs
The nervous system of leeches consists of a paired supraoesophageal ganglion connected by circumoesophageal connections with the suboesophageal ganglionic mass. The latter is formed by the fusion of the first four pairs of ganglia of the abdominal nerve chain. This is followed by 21 ganglia of the ventral nerve chain and a ganglionic mass (of eight pairs of ganglia) that innervates the posterior sucker.
The sensory organs of leeches are represented by sensitive kidneys, or goblet organs. Each such organ consists of a bundle of spindle-shaped cells located under the epithelium. The outer end of sensitive cells forms a sensitive hair. Nerves from the ventral nerve cord approach the inner ends of these cells.
Some of the goblet organs perform the functions of chemical sense organs, others - tactile. The eyes of leeches have a similar structure to the goblet organs described above. There may be several pairs. The eye consists of vesicle-shaped photosensitive cells with large vacuoles inside, to which the nerves that make up the axial part of the eye approach. The eye is surrounded by dark pigment.
Reproductive system, reproduction and development
According to the structure of the genital organs and the method of reproduction, leeches have much in common with oligochaetal rings. They are hermaphrodites, and their genitals are concentrated mainly in the region of the 10th and 12th body segments. Leeches have a girdle section, which, unlike oligochaetes, coincides in position with the penis. The girdle becomes noticeable only during the breeding season.
The male reproductive apparatus consists of several pairs (4-12 or more) of the testes. The medicinal leech has 9 pairs of testes located inside the seed sacs. Short vas deferens depart from them, opening into longitudinal paired vas deferens. The latter in the area of the 10th segment form dense balls - appendages of the testes, in which sperm accumulates. Then they pass into the ejaculatory (paired) canals that open in the copulatory organ, which can protrude forward through the unpaired male genital opening on the 10th segment. Not everyone has a copulatory organ. In many leeches, spermatozoa are enclosed in spermatophores. Spermatophores are either introduced into the female genital opening or stuck into the skin, and the spermatozoa penetrate the body of the leech and make their way to the female reproductive tract.
The female reproductive apparatus consists of a pair of ovaries located in egg sacs. They pass into short and wide uterus, which are interconnected and form an unpaired oviduct, which flows into a wide vagina, which opens on the 11th segment with the female genital opening.
Fertilized eggs are laid in a cocoon secreted by a girdle. The cocoon is either attached to aquatic plants, or is located at the bottom of the reservoir. Some leeches lay single eggs.
The development of leeches is not direct, since larvae emerge from the eggs, remaining, however, in a cocoon. The larvae have cilia and protonephridia. In the cocoon, the transformation of larvae takes place, and already formed leeches emerge from the cocoon into the water. The laying of eggs in relatively strong cocoons, which protect eggs and larvae well, causes a small number of eggs. It is measured in various leeches in units, in extreme cases, in tens.
Classification
The class of leeches is divided into three orders: 1. Bristle-bearing (Acanthobdellida); 2. Proboscis (Rhynchobdellida); 3. Jaw (Gnathobdellida).
Order Bristle-bearing leeches (Acanthobdellida)
A very primitive relic form bearing four pairs of sharp, curved setae on five anterior segments. The anterior sucker is absent, only the posterior one is present. The parenchyma is poorly developed, there is a coelomic cavity and a circulatory system.
Squad Proboscis leeches (Rhynchobdellida)
Proboscis leeches are remarkable for breeding and caring for offspring. The leech lays eggs that remain attached to the ventral side of its body. At this time, the leech is not very mobile: it sits, attached by suckers, on some plant and makes oscillatory body movements. When the juveniles are hatched from the eggs, the leech does not change its position and the young leeches remain attached to the ventral side of the mother with their suckers, usually for several days, and then spread and begin to lead an independent existence.
Squad Jawed leeches (Gnathobdellida)
Most jaw leeches in the oral cavity have the jaw apparatus described above.
In addition to the medicinal leech (Hirudo medicinalis), common in the southern part of Russia, this order includes the ubiquitous false horse leech (Haemopis sanguisuga). This is a large dark-colored leech, has weak jaws and is not able to bite through the skin of humans and mammals. It feeds on worms, mollusks and other invertebrates. The cocoons of the false-horse leech are buried in the coastal strip, above the water level.
Some jawed leeches (especially those found in southern latitudes) can be human parasites, for example, from the genus Limnatis. One of them - L. turkestanica - is found in Central Asia. When drinking raw water from a reservoir, it can enter the human nasopharynx, where it settles and sucks blood. In addition to severe irritation, it causes bleeding. In the jungles of Sri Lanka, India, Indonesia, land animals from the genus Haemadipsa live. They hide in damp places, in grass and under foliage, and attack animals and humans, causing very sensitive bites.
Leeches belong to the subclass of annelids, which in turn belong to the class of belt worms. In Latin, the leech sounds like "hirudinea" (Hirudinea). Around the world there are about 500 species of leeches, in Russia there are about 62 species.But for treatment, only a medical leech is used. Among medical leeches, there are two subspecies:
Medicinal leech (Hirudina medicinalic)
Apothecary leech (Hirudina officinalic)
Color. May vary from black to reddish-brown. Abdomen motley. The sides are green with an olive tint.
The size. About 3 - 15 cm - length, about 1 cm - width.
Lifespan. Up to 20 years.
Habitat. They are found mainly in Africa, Central and Southern Europe, as well as Asia Minor. In Russia, they are not so numerous, they mainly spread to the south of the European part of the country. Although there is evidence that individual individuals of the species were found in the southern and eastern parts of Siberia.
They love fresh clean water - lakes, ponds, quiet rivers, as well as damp places near water - clay shores, wet moss. Leeches live in stagnant water - running water is unfavorable for them.
Lifestyle and behavior. Most of the time, the medicinal leech spends hiding in thickets of algae, hiding under snags or stones. This is both a cover and an ambush.
Leeches love warm sunny weather and even tolerate heat quite well, it is in these conditions that they are most active. They are also not afraid of drought - they either crawl away from a drying up reservoir, or dig deeper into the coastal silt. Leeches are able to stay on land for a long time in hot and humid weather.
With the deterioration of conditions (lower air temperature, windy weather), medical leeches become lethargic and passive. Leeches overwinter by burrowing into coastal silt or bottom soil. Frosts are detrimental to them.
The body of the leech is greatly flattened and elongated when swimming, and the posterior sucker acts as a fin. With wave-like movements, the leech moves in the water.
For medical leeches, an instant reaction to external stimuli is quite characteristic: smell, temperature, splash.
A hungry leech can be recognized by the characteristic position of the body - it sticks to a plant or stone with its back sucker, while the front one makes circular movements.
Enemies: Desman, water rat, shrews, bugs, dragonfly larvae.
Nutrition. As food, medical leeches use the blood of worms, mollusks and vertebrates, and in their absence they can eat insect larvae, ciliates, and mucus of aquatic plants. The leech bites through the skin of the victim and sucks out a small amount of blood, about 10-15 ml. Having satiated, the leech can remain without food for quite a long time - an average of six months, since the blood in its body is digested slowly. However, a record fasting period was observed, which amounted to 1.5 years.
Reproduction. The medicinal leech is a hermaphrodite. Leeches begin to lay eggs during the warm period, approximately two weeks before the end of August or in mid-September. Under adverse weather conditions, this period comes earlier or is postponed.
In the process of reproduction, the leech crawls out onto land, digs a small depression in the silt, then a special department of medical leeches, buy medical leeches, buy leeches in Perm, buy leeches in Perm, the cover of a leech - a girdle - secretes a foamy cocoon in which eggs are laid. This cocoon contains albumin, a protein that serves as food for embryos. The egg incubation period is about two months.
Newborn medicinal leeches are transparent and resemble adults, they still spend some time in a cocoon, feeding on albumin, but soon crawl out. Small leeches that have not reached puberty attack tadpoles, snails, frogs.
If a leech does not drink the blood of a mammal within three years from the moment it emerges from the cocoon, it will never reach puberty.
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.
Leeches are placed on the heart area (to cleanse the 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 the 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.