Key Points and Methods of Giant Salamander Breeding Technology Explained

   The giant salamander is the common name for the Chinese giant salamander (Andrias davidianus), a national second-class key protected wild animal. In China, the giant salamander is distributed in all provinces and autonomous regions except **, Tibet, Inner Mongolia, Heilongjiang, Jilin, Liaoning, and Taiwan, China, where it has not been reported. It is mainly found in the mountain streams and rivers of the middle and upper tributaries of the Yangtze, Yellow, and Pearl Rivers, especially in Sichuan, Hubei, Hunan, Guizhou, Shaanxi and other provinces. The giant salamander prefers shade and fears light, and grows slowly. Under wild conditions it takes 5 to 6 years to reach sexual maturity and a body weight of over 500 grams, while under artificial conditions it takes at least 3 years to reach commercial size. Moreover, artificial breeding of the giant salamander is relatively difficult. Therefore, breeding is not very widespread, limited to a few farms in Jiangsu, Hubei, Guangdong and other places. However, in recent years, giant salamander breeding has received widespread attention and is a famous, special and high-quality breeding variety with great potential.   
    I. Design and Construction of the Breeding Site   
    Based on the unique ecological habits of the giant salamander, the design of the breeding pond must take into account an ecological environment suitable for the giant salamander's living habits and growth and development.   
    (1) Breeding pond structure. There are two types of giant salamander breeding sites: one is an open-air breeding pond, and the other is a breeding pond in civil air defense works and basements. The structure is made of brick, cement, stone, or concrete. The specific structural requirements are:   
    1. Pond wall structure. The requirements for the giant salamander breeding pond wall are: ① watertight, so that it does not leak; ② safe and firm, able to withstand the pressure of the soil around the pond wall and the pressure of the pond water, with the pond wall not sinking; ③ must have escape-prevention facilities; ④ inexpensive.   
    The giant salamander breeding pond wall is generally built with square stones, bricks or concrete, with cement filling the seams, and the pond wall should be smoothed with cement slurry or tiled.   
⟧    The top of the pond wall should protrude inward by 10 cm to prevent the giant salamander from escaping.   
    2. Pond bottom structure. The bottom of the giant salamander pond is generally first compacted with stones to a thickness of 20 to 30 cm, then filled with small stone gravel, and finally leveled with concrete. To facilitate drainage, the pond bottom slopes from all sides toward the center at a gradient of about 2%, and then slopes from the center toward the drainage outlet at one corner at a gradient of about 1% to 1.5%.   
    3. Water inlet. The position of the water inlet depends on the water supply channel and is set at the corner of the pond opposite the drainage outlet. The water inlet should be higher than the pond wall, preferably 60 cm above the water surface in the pond, and should protrude 20 cm into the pond. The water inlet material can be cement pipe or concrete square, or cast iron pipe or plastic pipe. No matter what material is used for the water inlet, a control facility and a filter screen must be installed. The control facility uses a straight-through stop valve, and the pipe diameter can be determined according to the water demand of each type of giant salamander pond and the water inlet pressure. For juvenile ponds, 100-300 mm can be selected; for adult ponds, 300 to 500 mm can be selected. The filter screen material for the water inlet should be stainless steel, and the mesh should also be determined according to the size of the giant salamander pond.   
    (2) Construction of the breeding site. The adult giant salamander breeding pond is an important environmental condition for giant salamander breeding and is the key period in the commercial breeding stage of the giant salamander. At the adult stage, the giant salamander's resistance and adaptability increase, while escape and the weak being preyed upon by the strong among the same species also reach a peak. Therefore, the adult site must be based on the physiological characteristics of this stage. More than 5 should be built so that they can be bred separately according to individual size.   
    According to actual local conditions, adult ponds can be built indoors or inside civil air defense works, or outdoors. The pond area can reach 100 to 2,000 sq m. The area of artificial arcs or burrows in the pond accounts for 2/3 of the adult pond area, and the size of the arcs or burrows depends on the size of the adult individuals. For outdoor pond construction, in addition to the requirements and facilities of indoor adult sites, shading facilities must be installed. Shading materials can be installed according to actual local conditions, and it is required that the top and all surrounding sides of the pond be fully shaded.   
    II. Adult Breeding   
    China has already gained successful experience and technology in adult breeding. Its main breeding methods include outdoor breeding, basement and civil air defense works breeding, and the factory-based temperature-controlled breeding developed by our research. In summary, they are mainly divided into still-water breeding and flowing-water breeding.   
    Wild giant salamanders rely on natural food in the natural environment as their nutritional basis, so they grow slowly and generally need 5 years of age to reach adulthood. Artificial breeding of giant salamanders creates a good ecological environment and provides nutritionally rich feed. Generally, only 2 to 3 years of age are needed to reach the adult stage.