Artificial Breeding Technique of Giant Salamander

The realization of artificial breeding technology of giant salamander indicates that the breeding of giant salamander has entered the era of artificial control, and has created extremely favorable conditions for its industrial commercial breeding. □ / Guangdong Aquatic Technology Promotion Station Zhong Xiaoqing Yi, biological attribute giant salamander, scientific name: andrias, in biological taxonomy, it belongs to amphibia, cauda, Cryptobranchidae and Genus. The genus giant salamander is mainly composed of Chinese giant salamander, Japanese giant salamander and American giant salamander. Except for American giant salamander, the rest are distributed in Asia and can be found in streams and ponds in China and Japan. As an amphibian, giant salamander is a typical cold-blooded variable temperature animal, the highest adaptive temperature is 24 ℃, and the best growth temperature is 15-20 ℃. When the temperature is lower than 10 ℃, the giant salamander will be in a state of hibernation. Under natural conditions, the life span of giant salamander is as long as 50-60 years, in which the longest length of Chinese giant salamander is 1.8 meters, that of Japanese giant salamander is 1.5 meters, and that of American giant salamander is only 0.75 meters. What they have in common is a long, flat body, short limbs, 4 fingers of the forelimb and 5 fingers of the hindlimb, webbed between the toes, and a short, flattened tail. People who do not know it often mistakenly think that it is a fish, but in fact, it is an amphibian, that is, its physiological structure can help it survive in water and on land. In water, it breathes through its gills, on land, it breathes through its lungs and skin, and its skin is only covered with mucous membranes and no scales. Chinese giant salamander is commonly known as "baby fish" because its cry is similar to that of a baby, while Japanese giant salamander is known as "mountain pepper fish" because its body tastes like mountain pepper. Giant salamander especially like to live in inconvenient transportation, remote and quiet, inaccessible deep mountains and forests, and live in mountain streams with fresh water quality and fast current all the year round. They are used to sleeping during the day, foraging at night, and feed mainly on fish and crustaceans, but because they live in the dark for a long time and have poor eyesight, they can only use the head and body perception areas to detect changes in water pressure to prey. During the mating and breeding season, they swim upstream, and after the eggs are fertilized, the males protect their young salamanders for six months until they are able to feed on their own. Social and economic value the giant salamander has a very long history of living on the earth, which can be traced back to 200 million years ago. at that time, it flourished for a time, because it was in the transitional stage from aquatic to terrestrial, and it had a special status in biological taxonomy. up to now, it has high academic research value in physiology, genetics, evolution, ecology and other disciplines. in addition, the living environment is deteriorating, and the number is getting smaller and smaller. Therefore, it is listed as second-class aquatic wild animals by the state. At the same time, the giant salamander also has certain medicinal and edible functions, and has a certain commercial development value. According to the theory of traditional Chinese medicine, the medicinal value of giant salamander is shown in helping the human body to ventilate and activate blood, moisturize the skin and nourish the beauty, and can comprehensively nourish the human body both internally and externally; in terms of edible value, as a precious and precious meat, giant salamander has the characteristics of cool skin, fine meat, crisp bones, delicious taste and so on. Although the giant salamander is a national second-class aquatic wild protection animal, the purpose of protection is for better development and utilization, according to the relevant laws of the country, its parents are the second generation of artificially bred offspring or adult giant salamanders who have lost reproductive ability or abnormal body shape or abnormal growth have obtained the administrative license of the relevant state departments for commercial purposes. Things are precious when they are rare. At present, the market price of giant salamander reaching commodity specifications has reached 1200 yuan / 500g. Some high-end restaurants in Guangzhou and even some big cities in the Pearl River Delta use giant salamander as the main ingredient to make a series of dishes through traditional fine processing technology. attract customers, and business is booming. Third, the test and demonstration base is driven by the demand of all aspects of society, the fishery departments, scientific research institutions and aquaculture enterprises of the origin of giant salamander in China, such as the Yangtze River and Pearl River basins, have set up projects one after another. a large amount of human, material and financial resources have been invested in the artificial breeding and high-yield and efficient breeding technology of giant salamander, including the positive efforts made by Shaoguan Fisheries Administration. Recently, at the invitation of Shaoguan Aquatic products Administration Bureau, the Guangdong Aquatic Technology Promotion Station sent the author to the city to investigate on the spot, and now sort out the relevant situation for those who are interested in it for reference, study and reference. In October 2004, with the strong support of the Department of Finance of Guangdong Province, the Provincial Marine and Fisheries Bureau and the relevant departments of the municipal government, Shaoguan Fisheries Administration invested 4 million yuan at the foot of Chaisang Mountain and Huangshi Mountain in Longgui Town of the city. relying on the infrastructure and technical strength of the Municipal Aquatic Farm and the Municipal Fisheries Research Institute, a municipal aquatic conservation base (hereinafter referred to as "base") was established, and at the same time, in order to increase its functions, a municipal aquatic conservation base was established. Add "Municipal Special Aquatic products Test and demonstration Base". The base covers an area of 60 acres, with a lease term of 30 years, surrounded by green hills on three sides, luxuriant vegetation on the mountains, from which springs and streams flow, especially rich in groundwater resources, and good water quality, constant temperature (20-22 ℃), flow of about 720 cubic meters per hour, relatively less in winter, but does not affect aquaculture production and domestic water. Various conditions are very similar to the natural living environment of amphibians, turtles and other reptiles such as giant salamander, tortoises and soft-shelled turtles, and it is an ideal place for artificial culture of giant salamander and turtles. At present, the base is divided into three relatively independent communities according to their functions: 1. The breeding area has a 600m2 indoor domestication pool of giant salamander, a 1200 sq m turtle conservation pool, a 5000 sq m fish conservation pond and a 1000 sq m management and breeding room. 2, the office area has a 500m2 office and conference room, which can accommodate 3040 people. 3. The living area, with 120 square meters of kitchen and dining room, has built relatively perfect living facilities for the staff of the base. The base, no matter the construction of facilities such as traffic roads, hydropower facilities or flood control, as well as purification, greening and beautification, has reached a new level, and it is a relatively rare standard garden-style aquatic product test and demonstration base. IV. Introduction, domestication and breeding experiment during the five years from 2004 to now, the base has introduced several batches of giant salamander from Shanxi, Shaanxi, Hunan and Huadu, Guangdong, and there are wild and artificial breeding giant salamanders of different sizes and specifications. The technical staff of the base put the breakthrough of the artificial breeding technology of giant salamander on domestication, through artificial domestication for a long time to help them adapt to the artificial breeding environment and conditions, so as to select parents and reproduce the next generation. Through long-term artificial domestication, the base technicians gradually mastered the theoretical knowledge and technical requirements of physiology, pathology and ecology of giant salamander. First, due to long-term evolution, some functions of the giant salamander are seriously degraded, especially eyesight, high myopia, fear of light, requiring a dark and quiet living environment; because its respiratory system is underdeveloped, it is necessary to ensure adequate water quality and good water quality. strong mobility, high dissolved oxygen, convenient for its need for oxygen intake. Second, the giant salamander takes fish as the main food source, and it is best to feed the moderate-sized silver carp, bighead carp and crucian carp, as well as the wild miscellaneous fish caught from Shantang reservoir. Compared with other amphibians such as frogs and toads, the metabolism of giant salamander is very slow. It is shown in action that it is motionless for a long time, so it is fed every two days. When feeding, the giant salamander uses static braking to launch an attack so fast that it will not let go easily after a bite, until the prey dies, and then slowly digest and absorb it. Due to low energy consumption, complete digestion and absorption, high feed conversion rate, the growth rate of giant salamander is very fast, the body weight can be doubled in one year, in other words, the input and output rate of artificial culture of giant salamander is very high, and its feed coefficient can reach 1-2, which is of great commercial investment value. Third, due to the short time of artificial domestication and low density, it has not been found that giant salamander is easy to suffer from any kind of epidemic disease, but from the practice of breeding and production in the base, as long as the water supply is guaranteed, the amount of water is large, the water temperature does not fluctuate greatly, and the water quality is good. Giant salamander is not easy to get sick, the survival rate is very high, and the breeding risk is low. However, this conclusion still needs further observation and analysis. In 2009, the base has 201 giant salamanders, including the largest 15 kg and the smaller 0.5 kg, and 400 grass turtles, yellow box turtles and yellow-throated water turtles. In July 2008, after careful study and discussion, the leaders of Shaoguan Fisheries Administration and the technical personnel of the base thought that the conditions for artificial breeding of giant salamander were gradually mature, and decided to carry out the experiment of artificial breeding of giant salamander. The test technical cooperation unit is the Zhangjiajie national giant salamander protection center, and the experiment is successful. The parent of the experiment is the giant salamander introduced and domesticated from other places 4-5 years ago. Base technicians carefully selected 5 males and 10 females adult giant salamander, through artificial injection of hormones to promote their sexual maturity, male ovulation, female ovulation. Because these parents are all through artificial breeding, the gonads are not yet fully mature, and it is the first artificial induced breeding, only 4 female giant salamanders successfully laid 150 eggs through artificial spawning. among them, 2 eggs were absorbed by them due to missing the best time to induce spawning. Like the eggs laid by frogs and toads, the eggs laid by giant salamanders are like black beans, wrapped in egg membranes and floating in the water. Technical points of successful hatching of giant salamander: first of all, it is necessary to grasp the best time for artificial fertilization. The giant salamander is fertilized in vitro, and artificial fertilization must be completed 20 seconds after spawning and ovulation, otherwise semen failure can not be achieved; second, after successful fertilization, the fertilized eggs of the giant salamander are placed in an incubator with a constant temperature of 19 ℃ to ensure good water quality through a circulating filtration system, and the small salamander will break the membrane after 31 days of incubation. Through the above technical links, the base successfully hatched more than 60 small salamanders, and the hatching survival rate was as high as 40%. Newborn salamanders, like tadpoles, are lively and active, swimming around, completely different from their parents, they first digest their own nutritional reserves, begin to eat 4 weeks later, and generally feed red worms and other zooplankton. When it grows to a certain extent, it can be fed to small fish and shrimp. 5. economic benefit analysis in 2009, although Shaoguan Aquatic products Administration and its municipal aquatic biological conservation base successfully hatched 60 giant salamanders after five years and a lot of manpower and material resources, they took a big step forward. Master the source, key and core technology of artificial breeding, and successfully realize the artificial breeding of giant salamander, which indicates that giant salamander farming has entered the era of artificial control. It has created extremely favorable conditions for the development of factory commercial breeding. At present, the market price of giant salamander is 300,400 yuan per tail of young salamander, 500,600 yuan per tail of small salamander, 800 yuan per jin of giant salamander reaching commodity specifications, and the price of restaurants is as high as 1000 yuan per jin. The water used for breeding in the base is high-quality groundwater, with large flow, stable water temperature and excellent water quality, which is very suitable for the growth of giant salamander. In addition, through introduction, domestication and breeding experiments, the base has basically mastered the techniques and methods of artificial breeding, adult salamander breeding, disease prevention and daily management, which can expand the breeding and breeding scale of giant salamander anytime and anywhere, creating considerable economic and social benefits. At present, the base has worked out a short-term development plan, which plans to domesticate and cultivate 400 parents of giant salamander, breed 6000-8000 seedlings of giant salamander annually, and develop commercial giant salamander culture, with an average of 2000-3000 seedlings per tail, with an average of 5000 grams per tail. Its development prospect is very attractive.