Biological habits and artificial culture techniques of leeches

Leech, also known as leech, meat drill, turtle, is a kind of valuable traditional Chinese medicine, its saliva contains a kind of blood coagulation substance, called hirudin, in addition, it also contains heparin, antithrombotic hormone and so on. it can treat stroke, amenorrhea, paraplegia, angina pectoris, nameless swelling pain, tumor, cervical lymphoid tuberculosis and so on. Hirudin can keep the veins unobstructed after transplantation. In addition, Sinonovacula honey extract can treat corneal ulcer and corneal nebula, which is mainly used for clinical and export foreign exchange earnings, which is needed 5000 tons a year in China alone. However, due to the extensive use of chemical fertilizers and pesticides, and the predatory capture of leeches in recent years, wild resources are decreasing day by day, which is far from being able to meet the needs of medicine and export, so artificial breeding is imperative. 1. Biological habits 1. Most of the leeches live in freshwater ditches, rice fields and lakes, especially in organic matter-rich ponds, slow-flowing streams and courtyard potholes. two。 The species of leeches belong to the bdelloid class of annelid phylum in zoology. there are hundreds of species in the world and nearly 100 in China, and many species live in fresh water. The main clinical applications are Japanese medical leeches, wide-body golden leeches, brown leeches, fine-toothed golden leeches, artificial cultivation of golden leeches and brown leeches are better. 3. Leech is a variable temperature animal, hibernating in the soil in winter, stinging in March to April, when the temperature is low (the water temperature is less than 10 ℃), often hiding in the water edge by withered grass and silt wound into a mud mass, when the temperature is high (water temperature is higher than 15 ℃), often drilling out of the mud mass, activity stretching, static floating in the water, swimming in the water often by wave swimming, and crawling forward by ruler after leaving the water. 4. Feeding leeches make a living by sucking blood or body fluid, and have strong resistance to hunger. They can live for more than half a year by sucking blood once. They mainly feed on plankton, small insects, molluscs and noodle rot residues in water. 5. Breeding leeches are hermaphroditic, allogeneic mating, in vivo fertilization, and leeches have both male and female reproductive organs. # mating: the mating of leeches is similar to that of earthworms. During mating, the head ends are in the opposite direction, with each male genitalia facing each other's female reproductive foramen to complete fertilization and mating. # formation of egg cocoons: about 1 month after mating, the reproductive belt secretes a thin mucus, which is mixed with air to form a soap foam, and then secretes another kind of mucus to form a layer of cocoon wall around the reproductive belt. The eggs are laid from the reproductive pore, fall into the cavity between the cocoon wall and the body, and secrete a protein into the cocoon, and the parent gradually wriggles out to the rear. The whole spawning process takes 30 minutes. Each leech lays 6090 eggs at a time, the eggs harden in the soil for several hours, the cocoon wall foams dry, the wall breaks, leaving only a pentagonal or hexagonal honeycomb or sponge protective layer. # hatching: if the temperature is suitable after the cocoon is produced, the fertilized egg develops directly in the cocoon, hatches after about 16 to 25 days, and can live independently. # Development: the growth period of leeches is longer, and it takes half a year to 3 years from larva to adult.

II. Artificial culture technology

1. Water condition: for artificial culture, the water body can be large or small, generally 0.5 to 5.0 mu, the pond depth is more than 1.5 meters, the water depth is about 1 meter, the bottom silt is 10 centimeters, and the branches, stones, bricks and scrapped tires are placed, 200 million pieces per mu, set into the drainage ditch, the pond is equipped with 20 cm mound above the water surface, 5 mu 8, each mound area 1 square meter 2. In order to prevent leeches from escaping as a result of Rain Water flooding the pool, escape ditches or anti-escape nets are generally set around. The anti-escape ditches are 12 cm wide and 8 cm high, half of which are embedded in the soil, and when it rains, quicklime is sprinkled in the ditch to prevent leeches from escaping because of the current. 15 days before releasing leeches, 100 kilograms of quicklime per mu with a water depth of 20 to 30 centimeters, thoroughly disinfected.