Can leeches be eaten

Leech, commonly known as leech, is a dried body of leech, leech and leech. Leech has a long history of being used as medicine, which was recorded in Shennong Herbal Classic in China. It has the effects of anticoagulation and blood stasis. Traditional Chinese medicine is mainly used to treat thrombosis, vascular disease, glaucoma, blood stasis, nameless swelling, lymphoid tuberculosis and other diseases. Taxonomically, it belongs to annelids, leeches, and its medicinal value is dentigerons, which are divided into leeches and leeches. Leech is a traditional Chinese medicine in the treasure house of traditional Chinese medicine, and its pharmacological characteristics have long been recorded in Shennong Herbal Classic. In traditional Chinese medicine, leeches are mainly used as medicine after drying. Flat in nature, salty and bitter in taste, slightly toxic. Function to break blood stasis and dredge channels, mainly used for blood stasis amenorrhea and stasis. First, the importance of leeches in medicine In the 1950s, a British chemist named McWatt overcame all difficulties and finally discovered a mysterious substance-hirudin. The content of hirudin in leeches is very small, but it has a miraculous effect. Just a few micrograms will prevent blood from clotting. Leech can continue to suck human blood after biting human body, which is the reason why hirudin is released in leech mouth. At present, hirudin extracted from leeches has played an important role in medicine. According to clinical trials, it has the functions of relieving arterial arm spasm, reducing blood viscosity, dilating blood vessels, increasing blood circulation and promoting exudate absorption. Therefore, hirudin is widely used to treat intractable diseases such as hypertension and myocardial infarction. Hirudin can be used for quantitative analysis of human thrombin in biochemistry. With the deepening and development of research on leeches in modern medicine, the demand for leeches at home and abroad is gradually increasing, while the wild resources are increasingly exhausted, and the contradiction between supply and demand is very prominent. In recent years, it has become one of the most popular Chinese herbal medicines in the world. Therefore, Britain, Russia and many other countries are devoted to the research of artificial propagation and breeding technology. In the 1980s, Britain established the Leech Scientists Association, and at the same time established a biological products company. The International Medical Leech Research Center in Moscow, Russia raises more than 6.5438+0.5 million leeches every year, which has formed a unique industry. It has been found that in addition to drugs made from live leeches and leeches, leech extracts can also be made into beauty drugs with excellent curative effects. At present, the center sells a large number of related products and live leeches to the United States, Spain and other countries every year. In China, the research on leeches has also started for many years, and the research on the natural development law and growth habits of leeches, the natural and industrial cultivation of leeches, and the efficient cultivation mode of leeches and aquatic plants have achieved initial results. Second, the urgency of protecting the wild resources of leeches In China, leeches, as a traditional Chinese medicine, have never been in short supply. Leech is a creature, and its growth and reproduction are closely related to natural climate and human activities. Leech, as a wild medicinal resource, is a renewable resource, but its growth intensity and reproduction rate are not unlimited. For example, Jiangsu province is a major province for leech production. Among them, Hongze Lake and gaoyou lake, Jinhu, Sheyang, Yancheng and Ganyu were developed earlier. In the early 1990s, they were the main commodity supply bases of leeches in China, and the annual output in Jiangsu was generally between 50-100t. However, in recent years, it is generally reported that the goods cannot be received, and the output is about 15 tons. Due to the great demand for leeches at home and abroad, the contradiction between supply and demand has become increasingly prominent, and many biopharmaceuticals have emerged in China, resulting in a sharp decline in wild resources. Due to the decrease in quantity and the increase in demand, the purchase price of leeches has risen again and again. At present, the market price has reached 180-200 yuan/kg, sometimes even to the point where there is no market. Therefore, it is urgent to protect the existing wild leech resources. Third, the necessity of artificial cultivation of leeches In recent years, leech resources have become increasingly exhausted. First, because of the rising purchase price, people are driven to fish indiscriminately. Second, the weak awareness of environmental protection has destroyed and polluted the living environment of leeches. Artificial propagation is to create the best living conditions, meet the biological requirements of leeches, make them gain weight as soon as possible and breed more offspring. With the development of social economy, people's requirements for quality of life are higher than before. With the improvement of material life, especially the misunderstanding of health care, cardiovascular disease is rising to be the first killer of human death. Hirudin extracted from leeches is expected to be the bane of this stubborn disease. Medical science reveals that hirudin plays an increasingly important role in human health care, and the demand for hirudin in medicine is also increasing. At present, it is impossible to solve this contradiction through the regeneration of natural resources. At present, the wild leech resources are decreasing year by year, which will inevitably lead to the increase of raw material prices. The resulting soaring drug prices will make many patients lose the opportunity to treat diseases and cause many social problems. In order to make up for the shortage of this natural resource and protect the precious and limited wild resources, it is imperative to cultivate leeches artificially. The huge market demand has created a broad market prospect for the artificial cultivation of leeches. Artificial cultivation of leeches not only contributes to human health care, but also protects wild provenances and maintains ecological balance. This characteristic aquaculture is of great significance to the prosperity of local economy, the adjustment of agricultural industrial structure and the enrichment of farmers. Feasibility of artificial cultivation of leeches Leeches in wild conditions can survive and reproduce as long as they have a basic living environment. According to the observation and research of domestic experts for many years, the species, habits, feeding habits and feeding methods of leeches have been further understood, and a relatively complete feeding scheme has been explored to ensure the success of artificial feeding of leeches. Leeches are omnivores and grow very fast. Some low-lying farmland and lakeside beaches that meet the requirements can also be cultivated artificially if they are slightly transformed in waste fish ponds. Manual excavation of leech culture pond has lower requirements than fish ponds and less earthwork excavation, which is a rural sideline with less investment and high efficiency. The breeding period of leeches is one and a half years, the largest individual can reach 65g, with an average of about 35g-50g, and the yield per mu can reach more than 100kg. Judging from the current market situation, the output value per mu is not less than 18000 yuan, and the net income can reach more than 10000 yuan. It can be seen that the artificial cultivation of leeches requires little investment and the cultivation technology is not very complicated, but it can get quick results. Its finished products are in great demand in the domestic market, and it is also the fist product to earn foreign exchange through export. V. Natural growth habits and geographical distribution of leeches There are about 500 species of leeches, most of which live in fresh water, a few in salt water and a few on land. Most species of bdelloids live semi-parasitically, and some species prey at an early age and live a blood-sucking life in adulthood. Leeches often eat one host, not one animal. For example, leeches like medical leeches like to suck the blood of all vertebrates. The mouth end of the leech is located in the center of the front sucker, with an everted kiss and muscular. There are three triangular jaws with fine teeth in the mouth, and a Y-shaped incision is left on the skin of the host after blood sucking. Leeches can stop eating for several months after sucking blood, and leeches of medical leeches can even live for one and a half years without eating. The bdelloids have well-developed sensory organs and clusters of sensory cells in the epithelial layer, which have tactile and chemical sensory functions. There are photoreceptor cells in 2- 10 eyes in front of the body, and the nerve endings in the epidermis are free, which has the functions of temperature perception and touch, and can quickly detect the subtle changes of temperature in water, thus quickly finding the host. The existence of biological population is the result of long-term selection in nature. Slow-flowing streams, ditches, pits and ponds, paddy fields, swamps, lakes and warm grasslands are all places where leeches are willing to live, feed and give birth. Acidic water quality and fast-flowing rivers are not distributed. Under certain temperature and humidity conditions, leeches are full of vitality. After the water dries up, some species can dive into the mud at the bottom and make holes, and they can survive 40% weightlessness. Leech can grow into two new individuals from the fracture site after transverse cutting. This is the unique regeneration ability of leeches. Leeches mainly exchange gas on the body surface. Some species have gills, such as Hirudo, which has saccular gills. Because it is an extension of the body wall, it does not have the perfect function of gills. In water, leeches swim in waves by contracting and stretching their bodies. On land, it migrates inchworm-like through the alternate attachment of the front and rear suction cups and the antagonistic contraction of the longitudinal and annular muscles of the body, and it is agile. Young leeches feed on plankton, but when they don't suck blood, they feed on larvae of small insects, worms and snails, and also eat mud humus, so their diets are miscellaneous. When leeches suck human and animal blood, the anticoagulant hirudin is first released from the sucker, and the host blood is successfully sucked. Leeches have strong vitality and can be found in areas that adapt to the environment. In China, leeches are mainly distributed in lakes and tributaries between 32 and 38 north latitude, which is the most suitable range for leeches to grow, such as Taihu Lake, Hongze Lake, gaoyou lake Lake and Weishan Lake in Jiangsu, especially the great rivers and lakes south of Huaihe River. Under field conditions, it takes 4-5 years from hatched larvae to adults. Under the condition of artificial feeding, the growth and development time can be obviously shortened because of the rich bait and suitable temperature and humidity conditions, which generally takes only 2-3 years.