CATDOLL : CATDOLL: How to better farm white eels

White eel is also known as white eel, river eel, eel, green eel, wind bun, Japanese eel. Eel refers to the general term for species under the order Anguilla. Also known as eel, it is a fish that looks like a long snake and has the basic characteristics of fish. In addition, eels have migratory characteristics similar to salmon. Eels are fish, similar to snakes, but without scales, and are generally found in the sea area where salt water and fresh water meet.

White eel farming

The cultivation of white eel fry is the production process of growing white eel fry into white eel fry weighing more than 10 grams. This stage requires cultivation in three different types of ponds: primary pond, secondary pond, and tertiary pond. White eel fry is the basis of adult white eel farming. The quantity and quality of white eel fry directly affect the quality of adult white eel farming. Therefore, to develop white eel production, we must first do a good job in the cultivation of white eel fry.

Key points of white eel breeding technology

⑴ Cultivation of white eel

The cultivation of white eel is the process of raising white eels weighing 0.1-0.2 grams to small white eels weighing 10-20 grams. In the second year, most white eels can be raised to be edible white eels for sale (150-200 grams/tail). The cultivation of white eels is generally divided into three levels. The stocking specifications and densities of each level of white eel pond are as follows: 0.1-0.2 grams of white eel seedlings are stocked per square meter in the first-level pond; 0.3-1 kilograms of white eel seedlings are stocked per square meter in the second-level pond; 0.5-2 kilograms of 2-20 grams of white eel seedlings are stocked per square meter in the third-level pond.

Selection of white eel seedlings: High-quality white eel seedlings should have a broad head and blunt snout, uniform size, active swimming, no body trauma, smooth jade white body color, plump skin, strong body, and no pathogens. The specification is about 6,000 per kilogram.

Stocking of white eel fry: Stocking time is March to April, and it is more suitable when the water temperature is above 20℃. Before stocking, the breeding pond and white eel fry should be disinfected with drugs. The disinfection method of the breeding pond is the same as that of the domestic fish fry breeding pond. The stocking density is carried out according to the requirements of the first-level pond.

Feeding training: Feeding training is the key technology for the success of raising white eels, and it takes about one month of training. In the first week after the white eels are put into the pond, efforts should be made to make the white eels change from scattered feeding to concentrated feeding. Generally, starting from the evening, silk earthworms are used as bait, and the clean silk earthworms are scattered on the feeding table. Feed 4 to 5 times a day, and the daily feeding amount accounts for 20 to 40% of the total weight of the white eel seedlings. At the same time, a 15W electric light is hung above the feeding table to lead the white eel seedlings around the feeding table for concentrated feeding. You can also set up a tent above the feeding table during the day to shade it, creating a dark environment, which also induces the white eel seedlings to feed. After a week, if most of the white eel seedlings are led to the feeding table to feed, it means that the concentrated feeding training has been successful. Then gradually postpone the feeding time, and finally change it to daytime completely. Starting from the second week, the amount of silkworms fed should be gradually reduced, and the amount of minced meat of fresh feed such as clam meat, pig spleen or fresh fish should be increased. It should be fed 4 times a day, and the daily feeding amount should account for 10-15% of the total weight of the white eel fry. After 15 days, the silkworms or minced meat should be gradually mixed with compound feeds and fed, and the proportion of compound feeds should be gradually increased. After 1 month, all eel fry compound feeds can be used instead, feeding twice a day, and the daily feeding amount accounts for 5-8% of the total weight of the white eel fry. The compound feed should be fully kneaded with water, and an appropriate amount of oil should be added if conditions permit. Feed the feed immediately after mixing to prevent the cracking of α-starch and affect the adhesion.

Grading and rearing: During the rearing of white eels, due to the different strengths of the individuals' ability to compete for food, the size of the individuals varies greatly. Therefore, white eels of different sizes should be separated and reared every 20 to 30 days, and they should stop feeding for one day before separation. Because the white eel seedlings are still small, they can be caught under the feeding table with a dense-eye scoop for the first few times of separation, and the strong seedlings that are on the feeding table first will be separated first; later, as the individuals grow up gradually, they can be sorted with Guangdong fish sieves or knotless nets of different mesh sizes. After sorting, they can be bathed in sulfamethoxazole and reared according to grades. The stocking specifications and density of seedling ponds at all levels are as described above. After the white eel is separated and reared, the daily amount of compound feed is 3 to 5% of the total weight of the fish. When the white eel seedlings are reared to mid-to-late November, most individuals can grow to about 20 grams and can be placed in adult white eel ponds as white eel species.

Water quality regulation: Cultivating and managing the water quality of the white eel pond is a reliable guarantee for high yields of white eels.

Eel is the common name for Japanese eel. The southeastern coast of mainland my country has a long coastline, and Japanese eel fry have been abundant over the years. Coupled with the unique natural conditions, it has brought good opportunities for eel production. Since 1973, Zhejiang Freshwater Fisheries Research Institute and Shanghai Fisheries Branch have carried out research on artificial breeding and artificial reproduction of eels in Linghu, Zhejiang, Fujian and Xiamen respectively, and have experienced a process of "three ups and three downs". The rise and fall of the first eel breeding boom (1973-1976) In 1973, the first eel breeding boom in mainland my country was launched. The Central Agriculture, Forestry and Foreign Trade Bureau sent an eel breeding inspection team to Japan, held the first eel breeding conference and technical training courses in the country, and invested tens of thousands of yuan to build ponds. However, due to ignoring the biological characteristics of eels and unilaterally emphasizing saving money, this boom lasted only two years and ended. The rise and fall of the second eel breeding boom (1979-1981) Since 1979, many eel farms have begun to hire Japanese experts, use Japanese feed, fishing machinery, eel medicine, etc., and the total amount has increased. During this period, the resource of water maggots and earthworms in the Huangpu River was developed, research on compound feeds began, eels were raised in flowing water, eels were raised on land in the Pearl River Delta successfully and promoted, and fish disease prevention and control work began. However, due to the copying of Japanese farming methods in terms of technology and the one-sided emphasis on relying on Japanese experts, it failed to form scale advantages. The rise and fall of the third eel farming boom (1988-1997) In the late 1980s, with the deepening of reform and opening up, the growing economic development stimulated the third wave of eel farming in China. The rise of this boom summarized the experience and lessons of the previous two times, developed greenhouse cultivation of eel species, built large-scale high-standard cement steel beam greenhouses, and large-scale eel farming in earthen ponds in the Pearl River Delta. Eel farming has formed a one-stop service from white eel farming to adult eel farming and processing, and a group company has been established, and the advantages of scale operation have been brought into play. In the mid-1990s, it developed into a large industry including seed collection, cultivation, farming and processing, feed, transportation, and export, and the output and production level entered a stable development stage. In 1997, the national eel production reached 170,000 to 180,000 tons. By 1997, the once glorious eel farming industry had become a victim of inflation, high interest rates and foreign exchange markets in importing countries, putting the survival of the eel farming industry on the agenda. How to correctly analyze the eel market; carefully summarize and seize opportunities. The author believes that there are the following points: ① The breeding area and output are out of control, and the carp market is in oversupply; ② The impact and negative effects of the Asian financial crisis; ③ The market prices of seedlings and finished products are not synchronized in the late breeding period, and the blind introduction of foreign seedlings has increased the losses of eels; ④ The market information is lagging, and the expectations of breeders in the later period are too high. In order to enable eels to embark on the road of healthy development, the following countermeasures should be taken: ① The government should increase the formulation of public policies for the eel industry, do a good job in macro-control, and implement a breeding license system; ② Do a good job in advertising and the collection of advertising funds to guide people to consume scientifically and rationally; ③ Strengthen scientific and technological investment and take the road of developing fisheries through science and technology; ④ Strengthen commodity inspection work and increase the consumption of grilled eels. As mankind is about to enter the 21st century, the production of eel fry in 1999 has increased significantly compared with the previous two years, and the price of fry and finished eel is relatively coordinated in the market, and eel production has entered a relatively good recovery and adjustment period. Eel farmers should correctly analyze the situation, strengthen their confidence, improve the scientific and technological content of eel farming, adopt the management mode of agricultural industrialization, increase market competitiveness, improve the overall quality of eel farming, and promote the healthy and sustainable development of eel farming. 1. Requirements for eel ponds The eel pond is the place where eels live and the main building of the eel farm. The construction of eel ponds should focus on the life and physiological characteristics of eels, while considering the convenience of breeding production. Otherwise, it will not only affect the output, increase costs and cause inconvenience, but also make eels susceptible to disease and cause disease transmission and epidemic. Generally speaking, eel seed breeding ponds are built in the main eel fry production areas along the coast; adult eel breeding ponds are built in the Pearl River Delta region of Guangdong with mild climate, abundant rainfall and long sunshine time. (I) Site selection The site selection should be based on the design task, production scale, breeding method, combined with the long-term development plan for field survey and investigation, while considering soil quality, topography, climate, transportation, power supply, seed resources and living conditions. 1. Water source Water source is the first element of breeding. It consists of water quality and water quantity. In addition to the national fishery water quality standards, the following standards should also be noted for eel breeding water (Table 2-1). The water supply should be sufficient. Deep well water is often used in eel breeding. Generally, for a 2,000 square meter breeding field, the deep well water output per hour should not be less than 60 tons; the water temperature should not be less than 24℃ to reduce heat consumption; it is ideal for the water source of the eel breeding pond to be able to irrigate by gravity. 2. Feed should have a reliable source of feed. One is compound feed, and the other is artificial feed. It is necessary to ensure that the feed can be adequately supplied, the quality is guaranteed, and it is economically cost-effective. 3. Geographical environment The environment around the eel farm should avoid noise and industrial pollution; the terrain should be good, the construction cost should be low, and the water should not be dry in the dry season and not flooded in the rainy season. 4. The soil greenhouse is a cement culture pool, and the soil quality has little effect. The eel pond should be loam between sand and clay. 5. Transportation and communication are an important aspect to consider when selecting a site. The eel farm purchases feed and ships adult eels in large quantities and must be timely. The site should be selected in a place with convenient transportation. 6. Power system The power system must ensure sufficient capacity and reliable normal supply of power grid and self-contained power system.