Leeches(lat. Hirudinea) – subclass annelids from the class Clitellata. Most representatives live in fresh water bodies. Some species have mastered terrestrial and marine biotopes. About 500 species of leeches are known, 62 species are found in Russia. Russian word“leech” goes back to the Proto-Slavic *pьjavka (cf. Czech pijavka, Polish pijawka), formed from the verb *pьjati, a multiple verb from *piti “to drink”.
general information
Leeches can move both in water and on land using contraction of body muscles. In water it swims, making wave-like movements, on land it moves with the help of suction cups and crawling, like other worms. Both suction cups are used to move along the substrate and attach to it. Due to the strong muscular body, active leeches can, freely held by the rear suction cup, lift the body and make prowling searching movements with the front end of the body. When resting, it prefers to climb under stones and snags and lie down, partially hanging out of the water.
Leeches are able to respond to light, as well as temperature, humidity and water fluctuations. They have a reflexive reaction to shadows, which may indicate the approach of potential food. The sensitivity of leeches sharply decreases during sucking and mating, to the point that when the rear end of the body is cut off, the leech does not react and continues its behavior.
Nutrition
On average, a hungry leech weighing 1.5–2 g is capable of sucking up to 15 ml of blood at a time, increasing in weight by 7–9 times.
IN natural conditions hungry leeches await their prey, attaching themselves to plants or other substrate with both suckers. When signs of approaching prey appear (ripples, shadows, water vibrations), they detach and swim in a straight line towards the source of the vibrations. Having found an object, the leech fixates on it with its rear suction cup, while the front one makes prowling movements in search of a suitable place to bite. This is usually the place with the thinnest skin and superficially located vessels.
The duration of blood sucking varies depending on the activity of the leech, the properties of the animal’s blood and other conditions. On average, a leech that has been starving for 6 months becomes satiated in 40 minutes – 1.5 hours.
Reproduction and development
Wild leeches reach sexual maturity in 3–4 years, feeding only 5–6 times until this age. In captivity, maturation occurs faster, in 1–2 years.
Reproduction occurs once a year in the summer from June to August. Copulation occurs on land, two leeches wrap around each other and stick together. Despite the fact that leeches are hermaphrodites, and cross-fertilization is possible, each individual, as a rule, acts in only one capacity. Fertilization is internal; immediately after it, leeches look for a place on the shore near the coastline to lay a cocoon.
Leech cocoon
One leech can lay up to 4–5 cocoons; they are oval in shape and covered on the outside with a spongy shell. Inside the cocoon there is a protein mass to feed the embryos, the number of which can be up to 20–30; their development until hatching takes 2–4 weeks. The hatched little leeches are miniature versions of the adults and are ready to feed on blood. They feed mainly on frogs, since they cannot yet bite through the skin of mammals.
History of the use of leeches in medicine
Hirudotherapy(Latin hirūdō - “leech”, ancient Greek θεραπεία - “treatment”) - a method of alternative medicine, one of the areas of naturopathy, treatment various diseases human using a medicinal leech. Treatment with leeches was previously used in conventional medicine, but fell out of use in the 20th century due to the advent of synthetic anticoagulants, including hirudin.
The hiruda is a medicinal leech originating from Europe and has been used for bloodletting for many hundreds of years. Hippocrates, Galen, and Avicenna wrote about treatment with leeches. Drawings of the use of leeches were found on the walls of Egyptian tombs. Medicinal properties Medical leeches have been known to people for thousands of years. Descriptions of methods for treating various diseases with the help of leeches can be found in the medical collections of most ancient civilizations: Ancient Egypt, India, Greece. The use of leeches was described by Hippocrates (IV–V centuries BC) and Avicenna (Ibn Sina, 980–1037).
Medical leeches were most widely used in the 17th–18th centuries in Europe for bloodletting in connection with the concept of “bad blood” that dominated medicine at that time. In order to release bad blood, doctors sometimes applied up to 40 leeches to one patient at a time. Preference was given to vein bloodletting if bloodletting was necessary from hard-to-reach or tender places (for example, gums). In the period from 1829 to 1836, 33 million leeches per year were used for treatment in France, in London - up to 7 million with a population of 2.3 million inhabitants. Russia supplied Europe with about 70 million leeches per year. After a paradigm shift in the mid-19th century, bloodletting was abandoned, and the use of leeches in Europe practically ceased.
Scientific research into the mechanisms of action of leech on humans began in late XIX- the beginning of the 20th century with the work of John Haycraft, who discovered the anticoagulant effect of leech extract. In 1884, he discovered an enzyme from leech saliva - hirudin, and in 1902 preparations from hirudin were obtained. These studies marked the beginning of the scientific use of leeches in medicine. Nowadays, treatment with medicinal leeches is experiencing a rebirth.
Features of therapeutic action
Live leeches are applied directly to the human body according to specially designed patterns. The choice of attachment location is determined by many factors: disease, severity of the process, and patient’s condition. The sucking process lasts from 10–15 minutes to an hour, after which the leeches are removed with alcohol, iodine or, in the case of feeding to satiety, they are released on their own. Fed leeches must be destroyed by placing them in a chloramine solution; their reuse is not allowed. The therapeutic effect of live leeches is due to several factors:
- Dosed bloodletting (from 5 to 15 ml of blood for each leech, depending on the mass of the leech and the duration of the attachment). Used to treat arterial hypertension, glaucoma, congestion in the liver, and general intoxication of the body.
- The action of biologically active substances in leech saliva, the main of which is the anticoagulant hirudin, which reduces blood clotting. Used to treat angina and myocardial infarction, thrombophlebitis, vein thrombosis, hemorrhoids.
- A complex of body responses to a bite, biologically active substances in leech saliva and subsequent blood loss.
A reliable guarantee of protection against the transfer of infectious agents by leeches is the use of artificial conditions and animals that have starved for a sufficient time and have no pathogenic flora in their intestines. The use of leeches in therapy was revived in the 1970s: in microsurgery they are used to stimulate blood circulation to save grafted skin and other tissues from postoperative venous stasis.
Other clinical uses of medicinal leeches include the treatment of varicose veins, muscle spasms, thrombophlebitis and arthrosis. The therapeutic effect occurs not only from the flow of blood through the tissue while feeding on the leeches, but from the further and steady bleeding from the wound left after the leeches are detached. Leech saliva has analgesic, anti-inflammatory and vasodilating properties.
What leeches can treat?
Of the several dozen medicinal types, there are only three:
- pharmacy;
- medicinal;
- eastern
We hasten to disappoint those who like to self-medicate with leeches. Caught in a local reservoir, at best they will be useless, at worst they will cause irreparable harm, giving a person a number of unpleasant diseases that they can carry. Leeches intended for hirudotherapy are grown in completely sterile special laboratories and are used only once.
Indications for use
There are a number of diseases in which treatment with leeches significantly improves the patient’s condition:
- Problems with blood vessels, blood formation, tendency to form blood clots, blood stagnation.
- Diseases of connective tissues and joints.
- Dysfunction of the genitourinary system.
- Diseases of a neurological nature.
- Menstrual irregularities, genital inflammation, ovarian dysfunction, endometriosis.
- Neuroses, epilepsy, migraines, sleep disorders.
- diseases associated with disorders of the thyroid gland.
The benefits of leeches in the treatment of blood vessels and blood
For varicose veins, treatment with leeches stimulates blood formation and helps strengthen the walls of blood vessels. Hirudin, secreted by the leech in saliva, is a natural biologically active substance that helps improve metabolism and prevent the formation of blood clots. In the early stages of the disease, it is possible to completely cure or stop its development with the help of hirudotherapy.
Treatment for arthrosis and osteochondrosis
Non-inflammatory lesions of joints and cartilage tissue caused by circulatory or metabolic disorders, large or improperly distributed loads, and injuries are successfully treated with leeches. Treatment is aimed at reducing pain, increasing joint movement and stopping progression. The secretion that leeches secrete when they bite contains a natural analgesic enzyme that helps improve the patient’s condition. It’s not for nothing that a couple of centuries ago, military doctors placed these bloodsuckers in the area of soldiers’ wounds to prevent painful shock.
Treatment of spinal diseases
Hirudotherapy plays an important role in the complex treatment of spinal diseases. It helps restore normal physiological processes occurring in the deep tissues surrounding the spinal column. As effective remedy, complementing the main one, is treatment with leeches for spinal hernia. If there is no desired result from conservative treatment, you have to resort to surgery. During postoperative rehabilitation, leeches can bring a lot of benefits to the patient. Their use helps prevent postoperative complications. Thanks to hirudotherapy sessions, scar-adhesive processes in ligaments and tendons are reduced, the likelihood of the formation of new hernias due to load redistribution is reduced, and congestion in the vertebral veins disappears.
Treatment with leeches is also effective for osteochondrosis. The cause of this pathology is degeneration of intervertebral discs and ligaments that lose water, become thinner, and become covered with microcracks. As a result, the distance between the vertebrae decreases, pressure occurs on the nerve roots, causing pinching, spasms and inflammation in the paravertebral muscles.
The benefits of leeches for weight loss
Medical leeches are actively used in aesthetic medicine for weight loss and cellulite treatment. This effect occurs due to the influence of substances in the saliva of annelids on metabolism and blood circulation. The biologically active substances of leeches have a lipolytic effect - they burn fat. In addition, the process of microcirculation is improved and the supply of oxygen to cells is enhanced, and stagnation of lymphatic fluid in adipose tissue is eliminated. All this contributes to the reverse development of pathological changes in cellulite and a decrease in body volume.
The effect of using leeches for weight loss will be even more noticeable if you combine hirudotherapy with a balanced diet and regular exercise.
Treating acne with leeches
Treating acne with medicinal leeches is very effective. After just a few sessions of applying leeches to the face, the rash is significantly reduced, and after the entire course it completely disappears. The result of this treatment is the amazing and varied properties of these animals on the skin.
Firstly, leech saliva has a powerful bacteriological and antiseptic effect. It destroys all pathological pyogenic microorganisms, which cause the formation of acne. Secondly, the substances that leeches transmit with their bite have a pronounced anti-inflammatory effect, due to which the inflamed areas heal quickly. Thirdly, thanks to the mechanical and biological action of animals, the blood supply to the skin increases, which plays an important role in establishing the normal functioning of the sebaceous glands.
As you can see, hirudotherapy in cosmetology has a wide range of applications. Do not refuse this treatment just because you are disgusted by leeches. You just have to be patient a little and, perhaps, you will get rid of the cosmetic problem that has tormented you for many years forever.
Contraindications
Contraindications are:
- diseases accompanied by bleeding due to decreased blood clotting;
- hemolysis;
- anemia (anemia);
- weakening or exhaustion of the body;
- intolerance by the body to leech enzymes (allergic reactions);
- tuberculosis of various localizations;
- oncological diseases.
Harm of leeches
Due to the specific structure and feeding methods, the use of leeches for medicinal purposes may be associated with the following risks:
- The digestive tract of a medicinal leech constantly contains the bacterium Aeromonas hydrophila, which protects it from infections when feeding on the blood of sick animals and promotes proper absorption of nutrients. In humans, it can cause gastrointestinal disorders, poisoning and even diseases of the mucous membranes. Although hirudotherapists deny the possibility of bacteria getting into the leech’s jaws, this hypothesis has not been completely refuted.
- With the blood of infected animals, pathogens of various dangerous diseases enter the leech’s body. Once settled on the jaws, they can be transmitted through a bite to other people and animals. The use of leeches grown under artificial conditions has eliminated this problem.
- Leech saliva contains substances that thin the blood, and after removing it, the wound may bleed for a long time. In addition, in some cases these substances can be very irritating to the skin.
The process of breeding leeches is simple and accessible to anyone. In order to organize a leech farm, you need to find a room with several rooms, since leeches at different stages of their growth: cocoon, fry, adult, must be kept separately. As an option, you can adapt one room by dividing it into sectors. The main conditions for breeding leeches are maintaining a favorable microclimate for them: air temperature from 25 to 27º C.
Although wild leeches naturally live in colder waters, the reproduction and development of their medical relatives in warm conditions occurs much better. The temperature of the water in which the leeches are located should be room temperature, that is, the same 25-27º C. The air humidity in the room should be at least 80%.
Containers for leeches are ordinary 3-liter jars filled with water purified through special filters. Aquariums can also work, but it will cost much more. It is necessary to carefully monitor all stages of growth of leeches and promptly “transfer” the animals to other rooms (sectors) when they reach the next “age”.
By the way, all work on feeding leeches, purifying water in containers, replanting leeches, etc., is carried out only by hand. Even on large leech farms. Leeches feed on blood, which can be obtained from livestock farms, private farmers, or slaughterhouses by concluding appropriate agreements with them.
Special biofactories are engaged in breeding leeches on an industrial scale. Currently, there are only four such factories in Russia: two in the Moscow region, one in St. Petersburg and one in the city of Balakovo, Saratov region. In total, they grow 5–5.5 million leeches per year, which makes Russia the leader in the production of leeches in the world: only 0.5 million per year are grown in France and the USA.
A leech is a worm that has a kind of “brain”. Nietzsche's Zarathustra tried to claim that he was familiar with the mental, or rather mental, activity of the leeches of these interesting worms. Researchers, of course, have not yet found the “brain” of leeches, but it is quite possible to say that the leech has a fairly branched nervous system, consisting of the peripheral department and the sympathetic autonomic system.
There is an opinion that a leech “loves” a person. Researchers of this “crawling world” have long been interested in whether leeches or any other worms have any feelings. Well, animals, of course, cannot love like people. But some species of mammals are characterized by certain emotional experiences associated with devotion, friendliness, and affection.
Sources
- https://ru.wikipedia.org/wiki/Leeches http://www.pijavki.com/o_pijavkah.html http://polzovred.ru/zdorovie/piyavki.html#i-2 http://pomogispine.com /lechenie/girudoterapiya.html http://www.aif.ru/health/life/1188201
– the mention of it causes unpleasant associations for many. And it's true appearance among leeches it is unattractive, one might even say repulsive. But this creation brings great benefits to humans, helping to get rid of many diseases.
Types of leeches
Medical leeches belong to the type of annelids, class belt worms, subclass of leeches, order of proboscis, family Hirudinidae (jawed leeches). Its name is on Latin– Hirudo medicinalis. The medical form is successfully used in the treatment of patients in Europe, Russia, and Ukraine. Asia, Africa, America use other types of leeches.
IN wildlife There are up to 500 varieties of leeches. With such a variety of bloodsuckers, only three main types are used in treatment:
Other types of leeches not only do not bring benefits, but can also cause harm to humans and animals.
Horse (Limnatis nilotica). Also known as Egyptian or Nile. Habitat: Transcaucasia, Central Asia, Mediterranean. This species cannot bite through the skin, so they stick to the mucous membranes. Can penetrate into the oral cavity. The animal, increasing in size while sucking blood, can cause suffocation in humans and lead to death.
Surveyor leech (Piscicola geometra). It has a large rear sucker, although it itself measures no more than 5 cm in length. Feeds on the blood of fish. Having smelled a fish, it begins to move towards it and firmly attaches itself to it. Fish sometimes die due to loss of blood. Can cause harm to fisheries if leeches multiply in large numbers.
Common or false cone (Haemopis sanguisuga). This is a predatory species, reaching 10 cm in length. Lives in rivers, ditches, ponds, crawls ashore. It can swallow the victim whole, or bite off pieces. It attacks those animals that it can easily handle. Doesn't suck blood. Habitat: Ukraine, Russia, Moldova, Belarus.
Eight-eyed (Herpobdella octoculata). Flat, about 6 cm long. Lives in reservoirs with standing water, survives even in very dirty environments. It feeds on both living and dead larvae of insects and small animals.
Pond (Helobdella stagnalis). The smallest representative. Grows no more than 1 cm. Distributed in almost all bodies of water. The main color is brown, but green is also found. Attaches to worms, larvae, snails.
Habitat
The wild animal is very common in Europe, but its numbers are constantly declining due to constant fishing. And also the decline of the species is facilitated by the drainage of swamps and the unfavorable ecological state of the water. Widely distributed in the north, all the way to Scandinavia, and in the south it is also found near Algeria.
Medical species most often live in Transcaucasia and Azerbaijan. But the distribution area of pharmacies is Stavropol and Krasnodar Territory.
Animals can live perfectly well both in water and on land. They can only live in fresh water. Salty bodies of water are unsuitable for them. When moving from one habitat to another, they can cover quite long distances on hard surfaces.
They settle in ponds and reservoirs where the bottom is silted and reeds grow. However, the water must be clean. Gets along well with frogs. The favorite habitat of leeches is stones and driftwood. She hides under them, sometimes not fully protruding from the water.
What does it look like
Medical leech body round shape
, slightly flattened, divided into 33 annular segments. In turn, each of the segments is divided into 3 or 5 parts. Each segment has a central ring in which the sensory papillae are located. They perform the function of a sensor. There are suction cups on the back and front. The front sucker functions as a mouth. The bloodsucker has 270 teeth. Rear sucker much bigger size, since with its help the leech is attached to the surface.
The medical appearance is dark brown, almost black. The back is darker, with distinct stripes along it. The body is without setae and covered with cuticle. The bloodsucker sheds it periodically as the animal grows. As a rule, this happens once every 2–3 days.
The animal moves without any problems and quite quickly. Able to move both through water and on hard surfaces. The leech uses suction cups as a means of movement on the ground, and also helps itself by contracting its body. Once in the water, the animal commits oscillatory movements and floats in waves. She is so strong that with one end of her body she can stick to the surface and lift her body into a vertical position. This way she can search for what she needs.
How a leech works
The choice of the location of the bite remains with the leech. Having decided on the attachment site, it makes a bite no more than 2 mm deep and is saturated with blood. The total volume of blood sucked at one time does not exceed 15 ml. After the bloodsucker detaches, the wound will bleed for 4 to 20 hours. Everything will depend on the individual characteristics of the organism, as well as on how much enzyme the leech releases. It's called hirudin and prevents blood from clotting. There is no need to stop the blood, as this achieves a therapeutic effect.
From the moment the medicinal leech’s saliva penetrates the skin and enters the human blood, the therapeutic effect begins. Beneficial components are carried throughout the body through the bloodstream within 15–20 minutes.
A person does not feel how a leech sucks blood. A slight unpleasant feeling may occur when the skin is bitten. After this, the blood flows by gravity into the mouth, and then into the stomach of the bloodsucker. It doesn't curl up there. As the animal becomes saturated, it increases in size. When the limit of filling her stomach comes, it falls off on its own.
While waiting for food, leeches attach to the surface with two suckers. As soon as they sense that a potential victim is approaching, they begin to move towards it. Having reached the target, the leech attaches itself to the body with its rear end, and with its front end it looks for the most suitable place to bite. This will either be an area where the skin is thin or where the blood vessels are located closest to the surface.
Having attached itself, the leech does not let go of the victim until it is completely satiated. An animal may not eat for a long time. Therefore, the amount of blood drunk will depend on how long the bloodsucker was fasting. For example, if a leech has not received food for about six months, then it can take up to 1.5 hours to become saturated.
Leeches reproduce in nature once a year, when the animals reach sexual maturity. It occurs at the age of four. To breed offspring, leeches choose the summer period. The mating process in leeches is called copulation. Mating occurs by entwining one individual with another, as if they are glued. Once fertilization has occurred, the female lays cocoons after mating. Usually their number does not exceed 5 pieces.
Leech embryos feed on the protein mass located inside the cocoon. The cocoon itself is covered on top with a dense protective shell. After about two weeks, small leeches hatch and can already drink blood. The number of babies ranges from 20 to 40 pieces.
Benefits of leeches
Medical leeches are successfully used in the treatment of many diseases. They can, if not completely cure, then significantly improve the patient’s condition. The use of leeches in complex treatment speeds up the patient’s recovery.
Treatment with medicinal leech is called hirudotherapy. The highest effect is achieved thanks to several actions of hirudotherapy:
- hirudin– a hormone that prevents blood clotting and thrombus formation;
- eglins – substances that prevent joint damage already cure existing diseases;
- hyaluronidase – an enzyme that promotes the fertilization process is used in the treatment of infertility.
Salivary secretion contains analgesic and antibacterial substances.
The main diseases for which the use of medicinal leech is indicated are.
For hirudotherapy, medical leeches grown artificially should be used. It is strictly forbidden to use leeches caught in open waters for treatment. Wild animals are carriers of dangerous diseases; diseases accumulate on their jaws when bitten by infected animals.
Contraindications to hirudotherapy
Despite the enormous benefits and positive result when treating diseases with medicinal leeches, There are a number of contraindications:
- poor blood clotting;
- oncology;
- hemolysis;
- individual intolerance to enzymes;
- allergic reactions;
- anemia;
- tuberculosis of various forms.
Treatment with a medicinal leech will undoubtedly bring great benefits. However, hirudotherapy must be carried out by a qualified specialist so as not to harm the human body.
Previously, the medicinal leech lived in almost every corner of Europe, but now its numbers have sharply decreased. This happened because active commercial fishing in the past, as well as drainage of swamps, significantly reduced the population.
The body of the medicinal leech is flattened, rounded, with two suckers that grow at the front and rear ends. The anterior sucker is crowned with a mouth opening.
In its natural habitat, the leech attaches itself to various underwater plants, where it waits for prey. The leech is very voracious; with a weight of about 2 g, it can easily suck up to 15 ml of blood in one go, while its body weight increases almost 10 times.
The blood that the leech has sucked from the victim does not clot and can remain in a liquid state for up to several months. The period that she can live from the first meal to the next is about 2 years.
To digest blood and keep it in its original liquid form, special bacteria called Aeromonas hydrophila are found in the leech’s intestines. Leeches have a symbiotic relationship with these microorganisms. This means that both participants in the tandem benefit. In addition, if there are unwanted bacteria in the leech’s stomach, the symbiont destroys them, purifying the blood contained in the worm.
The use of leeches in domestic medicine is aimed against diseases such as varicose veins, bleeding (hemorrhage), and ulcers. In the West and in Europe, with the help of these worms they fight venous stagnation, which is formed during tissue transplantation. Some medicines contain leech extract. Today, technological progress allows attempts to create an artificial leech.
Distribution area of medicinal leeches
Live in large quantities in the north to the border with Scandinavia, in the south – to Algeria and Transcaucasia. There is an assumption that within the boundaries of their habitat, they live in isolated populations, avoiding contact with groups of other leeches. The form of leeches used in medicine lives mainly in Azerbaijan and Transcaucasia. Another form, pharmaceutical, lives in Krasnodar region, Stavropol region.
Typical habitat of leeches
Leeches are adapted to aquatic and air habitats. To pump from one body of water to another, they are able to travel long distances over land. They live only in fresh waters. They do not tolerate salty water sources. The usual place where they live is lakes or ponds, the bottom of which is lined with silt. Prefer clean water, where frogs live and reeds grow thickly.
The International Union for Conservation of Nature (IUCN) classifies medicinal leeches as numerically vulnerable animals. Some habitats that have long been familiar to leeches are no longer areas of their distribution. The reason for the decline in numbers is the massive outflow for medical purposes. Today, the intensity of population depletion has decreased due to the fact that the bloodletting technique has become irrelevant.
Also, biofactories are being created in which leeches are artificially grown, however, this does little to restore the population. Also an obvious factor that leads to death large number of these animals is the reduction in the number of frogs. They are the main source of nutrition for small leeches that are not able to penetrate to larger animals.
Features of the body structure of leeches
As mentioned earlier, the medicinal leech has an elastic body, elongated, with well-developed muscles. It is divided into 33 segments. It has two suckers, the back one is larger than the front one, its function is to attach itself to the substrate. Each segment is divided into a certain number of segments (3 or 5); sensory papillae are located in the central ring of each segment.
The abdomen and back differ in color, the back is dark, with brown stripes. The outside of the body has a cuticle; it is shed repeatedly during growth. By the intensity with which the animal sheds, you can determine the health status of the leech.
The leech has four layers of muscles. The first consists of circular fibers, responsible for swallowing blood, followed by a layer of diagonal and deep longitudinal fibers, they provide contraction of the body, the last layer is the dorso-abdominal muscles, they serve to make the body flat. Connective tissue is very elastic, dense, it covers both muscle fibers and organs.
The nervous system consists of ganglia and segmental nerves extending from them. At the anterior and posterior ends of the body, the ganglia unite and form a pair of synganglia, one pharyngeal and one anal.
The receptors that are located on each segment are divided according to the type of sensitivity into three types: baroreceptors, thermoreceptors and chemoreceptors. All of them serve to search for food and navigate in space. On top of that, on the first five segments there are five pairs of eyes, which include special pigment cells, with the help of which the leech can distinguish light from darkness.
The digestive system includes: the mouth, in the central part of the front sucker, jaws - one upper and two lower, each with 100 chitin teeth, they can damage the skin of the organism to which it is sucked. A special secretion also enters the mouth opening, which prevents the blood from clotting at the moment of absorption. The stomach is presented in the form of an elastic tube, which has 11 paired pockets. The muscular sphincter separates the stomach from the intestines. In the latter, feces accumulate, when excreted, the water becomes colored dark color.
Urine, which is formed in the leech’s body, is released through the nephropores. According to the type of reproduction, she is a hermaphrodite; she cannot fertilize herself alone; she still needs a pair.
Feeding and reproduction of leeches
It feeds mainly on the blood of warm-blooded animals, but can sometimes attack frogs and fish. The duration of blood absorption always varies depending on the state of the leech.
A hungry individual can take blood for 2 hours.
It breeds once a year, in summer. The copulation process occurs on land, the leeches wrap around each other and stick together, after fertilization the leech lays 5 cocoons, from which babies will be born after 2 weeks.
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In previous centuries, leeches were widely used to cleanse human blood. However, in the last century there was a peak in popularity for these worms, as a result of which their collection and intensive destruction of the natural habitat of leeches led to a reduction in their numbers. Today, worms are propagated for medical purposes in specialized laboratories.
Characteristics
The leech's body has a ringed appearance, but is slightly flattened than that of worms. And the stomach is a modified midgut. Most species of these worms have eyes, but all have a closed circulatory system.
Each individual has two suckers:
- back;
- front
With the help of these suckers, the worm attaches itself to the victim, as well as to surrounding objects. With their help, the leech moves.
Diet
What do leeches eat in nature? In most cases, leeches feed on the blood of mollusks, vertebrates and other representatives of the animal world. It is these types (not all) that are used for medical purposes.
Medical leeches have three jaw plates, on which there are a huge number of small and very sharp teeth. The jaws themselves are a collection of thick muscles. First, the leech pierces the skin with its teeth, then tears the tissue and sucks out the blood. After a bite, a protein substance called hirudin is released from the sebaceous glands of the worm's sucker. It prevents blood from clotting, but on the contrary, provokes its flow to the wound. In addition, saliva with anesthetic properties is secreted, so the worm manages to remain undetected for a long time.
One of the representatives of this subspecies is the fish leech, which swims well, unlike the medicinal leech. What do leeches of this species eat? Tissue fluid of fish.
These are quite large worms and can reach 50 centimeters in length. They do not disdain almost any type of fish; more than 100 worms can be found on one.
When the leech is not eating, it calmly swims in a pond or “sits” on aquatic plants. It does not pose any danger to humans. In winter, these worms do not hibernate, and without fish they can live up to 3 months.
Habitat - Eurasia, lakes and large rivers, very rare, but found in wastewater. Prefers fish from the genus carp.
By the way, this worm can appear in an aquarium. What do leeches eat in such cases? All the same tissue fluid. It is quite difficult to deal with such a problem in a closed reservoir; most likely, complete disinfection and disinfection will be required. They can get into the aquarium along with live food.
The snail leech also belongs to the proboscis annelids. This is a very slow creature that does not even move independently, but completely relies on the current. What do leeches eat? Mainly with the blood of pulmonary freshwater mollusks, and these are, first of all, pond snails. After a worm attack, as a rule, the snail dies, since the leech causes blockage of the respiratory tract. Worms are also brought into the aquarium with live food.
The closest relatives of these species include bird leeches - species that “feast” on the blood of Kamchatka crab and shrimp.
These worms are also called Nile or Egyptian worms. They live in Central Asia and in the Mediterranean, Transcaucasia. They prefer small fresh water bodies.
What do leeches eat in a pond? The horse species also prefers blood, but does not have a developed jaw, so it attaches itself to the mucous membranes of the victim when it bathes in a pond. Most often, horses become victims, but the worm does not disdain other artiodactyls, amphibians, and even representatives of the human race. They can even attach to the conjunctiva of the eye. The most dangerous thing about these worms is that once they enter the body, they greatly increase in size and if they enter through the mouth, they can cause blockage of the respiratory tract and, as a result, suffocation.
Predatory leeches
The most common species in Asia and Europe is the small false horse leech. What do leeches eat in bodies of standing water? Oddly enough, they consume invertebrate representatives of the animal world. These are insect larvae - microscopic worms. The small false horse leech itself reaches a maximum length of 6 centimeters, and can itself become a victim of fish or an invertebrate predator.
The Erpobdella leech acts in a similar way. It is quite large and can be seen from afar. This is an excellent swimmer, but the worm does not have a proboscis, but its body is equipped with a powerful mouth. What do leeches eat? All the same invertebrates, these are mollusks, fish fry, crustaceans, insect larvae. This worm does not even disdain carrion.
After a medicinal leech bite, the bleeding may not stop for a whole day. The largest leech is 30 centimeters long.
The cultivation of annelids for medical purposes was first started in Wales, from where leeches are still supplied today. But the most interesting thing is that there are leeches that, in addition to invertebrate fauna, consume vegetation.
The long-awaited report from the leech farm. You will learn how leeches live in captivity, what they eat, and 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 intensely watched the water column, all senses aimed at finding the victim. For more than three weeks now, in search of food, they have had to move from one corner of the reservoir to another. Even repeated forays onto land did not bring the desired result. Sad thoughts overwhelmed the vampire. Blood and only blood... “Okay, you can hold out for another three months, but if luck doesn’t smile, you’ll have to emigrate to a nearby body of water; they say that cattle come there to drink...” There was a splash somewhere, another, a third - the steel muscles tensed. The vampire identified the source of the vibrations and, with smooth wave-like movements, directed his body towards the victim. Here she is! Light, warm body, and so little fur, just not to miss. The vampire straightened his huge mouth, exposed three terrible jaws with sharp teeth and bit into the victim... A heartbreaking cry filled the water surface of the reservoir.
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02. Today we will tell you about the International Center for Medical Leeches, created on the basis of the Medpiyavka association formed in 1937, which was engaged in keeping leeches in artificial ponds in the dacha village of Udelnaya (Moscow region). 
03. At 2500 sq. m. there are production facilities for growing more than 3,500,000 medicinal leeches and producing cosmetic products. 
04. In total, science knows 400 species of leeches, 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. They couldn’t come up with anything better as a house for them. The leechkeeper must ensure that the vessel with leeches is constantly covered with a thick white cloth, which is tied tightly. 
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 occur periodically. 
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 are excellent at orienting themselves in space. Their sense of smell, taste and touch are unusually developed, which contributes to their success in finding prey. First of all, leeches respond well to odors emanating from objects immersed in water. Leeches cannot tolerate foul-smelling water. 
08. Slow, devoid of sharpness movements allow you to see the entire body of the leech. On the back, against a dark background, bright orange inclusions form a bizarre pattern in the form of two stripes. On the sides there is black edging. The abdomen is delicate, light olive in color with a black edging. The body of an ordinary medicinal leech consists of 102 rings. On the dorsal side the rings are covered with many small papillae. On the ventral side there are much fewer papillae and they are less noticeable. 
09. But behind the harmless external beauty The leech hides its secret weapon - the front sucker, outwardly invisible. The large, intimidating rear sucker does not cause any physical damage, but in the depths of the front jaws are hidden, geometrically located according to the sign of a prestigious company automotive world- Mercedes. There are up to 90 teeth in each jaw, for a total of 270. This is deceit. 
10. The record for the maximum size of a leech grown in this center is 35 centimeters in length. The leech in the photo still has everything ahead. 
11. A leech bit me 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. Hematophage, that is, a vampire. 
12. The epidermal layer of the leech is covered with a special film - cuticle. The cuticle is transparent, it performs a protective function and continuously grows, periodically being renewed during the molting process. Normally, leeches moult every 2-3 days. 
13. Discarded films resemble white flakes or small white covers. They clog the bottom of the vessels for storing used leeches, and therefore must be removed regularly, and the water is also periodically colored from digestion products. The water is changed twice a week. 
14. The water is specially prepared: it sits for at least a day, and is purified from harmful impurities and heavy metals. After cleaning and passing control, the water is heated to the required temperature and enters the common network for leeches. 
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16. Leeches poop up to several times a day, so the water in the vessel where used leeches are stored periodically becomes colored. Clogging of water that occurs from time to time does not cause any harm to leeches if the water is regularly changed. 
17. The most important condition A way to quickly grow full-fledged medicinal leeches is to regularly feed them with fresh blood, which is purchased from slaughterhouses. 
18. Large clots formed during coagulation of blood mass are used. To fully feed leeches, only the blood of healthy animals, mainly large and small livestock, is taken. The clots are placed at the bottom of special vessels, into which the leeches are then released. 
19. To make it pleasant for leeches to eat, a film is laid on them, which they, out of habit, bite through and suck blood. 
20. During growth, the leech feeds every one and a half to two months. 
21. After the leeches have grown and fasted for at least three months, they are collected in series 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 about this tomorrow. 
22. During one feeding, a leech sucks out five times its own weight, after which it may not eat for three to four months, or a maximum of a year. After eating, the leech looks like a solid muscle sac filled with blood. In its digestive tract there are special substances that protect blood from putrefaction, which preserve it in such a way that the blood always remains full and is stored for a long time. 
23. A leech usually eats its fill in 15-20 minutes. A sign that the leech is full is the appearance of foam. 
24. Well-fed leeches are trying to escape from the “dining room”. 
25. Yum-yum! 
26. After feeding, the leeches are washed. 
27. And put it back in the jar. 
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29. And the dishes are washed. 
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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. Suitable for reproduction, that is, carefully fed and reaching a given size, leeches are called queens. 
32. They are placed in pairs in jars filled with water and stored in special rooms where optimal temperature environment that 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 within itself both the male and female principles (hermaphrodites), it cannot satisfy itself in this intimate matter and is looking for a partner. 
33. The mating season, during which mating occurs, takes about 1 month, after which the leeches are placed in queen cells - three-liter jars. Moist peat soil is placed at the bottom of the queen cell, providing a favorable environment for medicinal leeches and their cocoons. On top of the peat are soft moss turfs that regulate soil moisture. The queens move freely on the moss, in which they feel comfortable, and gradually burrow into the peat. 
34. Leeches practice different positions, in which copulation takes place. There are 2 main positions that have a biological meaning. First position: the anterior ends of the bodies of copulating leeches are directed in one direction. The second main position: the ends of the bodies are oppositely directed, that is, they look in different directions. 
35. The peat is thoroughly washed so that the leeches are moist and comfortable. 
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37. You can identify a pregnant leech by the light rings and place it in a jar of peat. 
38. Breaking a shallow hole in the soil, the leech lays a cocoon in it, from which filaments are subsequently hatched - this is what the leech breeders of small young leeches are called. Their mass reaches 0.03 g at most, and their body length is 7-8 mm. The filaments are fed in the same way as adults. 
39. Each mother leech lays an average of 3-5 cocoons, each of which contains 10-15 fry. 
40. After a while, the cocoons become like soft foam balls. 
41. In the light you can see that the fry are sitting inside the cocoon. 
42. And here are unique shots of the birth. The leech leaves the cocoon through a hole in the end. 
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44. The first minutes of life of a small leech. 
45. And this is how they are born in the conditions of the center. The cocoons are simply torn apart. 
47. As laboratory studies have shown, the average life expectancy of a leech is 6 years. Scientists do not know for certain how long wild individuals live, although it is possible that leeches have their own long-livers. 
Tomorrow at this 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:
Book by D.G. Zharov "Secrets of Hirudotherapy"
Book "Vampire's Kiss". Authors: Nikonov G.I. and Titova E.A.
