Key techniques of close Culture in small Pond of Monopterus Albus

Because the yellow eel is a carnivorous fish, it has the habit of eating each other in the case of serious lack of feed. Therefore, in order to carry out high-density intensive culture of Monopterus Albus, it is necessary to use a single cement pond, soil pond and cage with an area of less than 30 square meters to raise Monopterus Albus by size and classification (referred to as small pond close culture). Our practice for many years has proved that the close culture of ricefield eel in small ponds has many advantages, such as convenient management, high survival rate, fast growth, small land occupation, remarkable benefit per unit area and so on.

Design and Construction of small Pool

At present, the commonly used culture methods of Monopterus Albus are net cage, cement pond and soil pond, which can be adopted according to the specific conditions of the local area and the breeders: if there are fish ponds or reservoirs, they can be used to carry out the cage culture of Monopterus Albus; if there are rice fields with good water storage conditions, they can be slightly converted into soil ponds to raise Monopterus Albus. It is necessary to build cement ponds for raising rice field eel in dry land or rice fields where water storage conditions are not very good.

1. The setting of the cage. The cage for raising ricefield eel is generally made of durable polyethylene mesh cloth (also known as "sieve cloth" and "bottom cloth"). It generally costs 10 yuan per square meter and can be used for about 3 years. The shape of the cage is rectangular, with a bottom area of 6 mi 30 square meters and a depth of 1 mi 1.5 m. It can be stitched with nylon thread. If a cage is set up in a pond with a water depth of less than 1.5 meters, the cage can be fixed by piling directly to the bottom of the pond; if a cage is set up in a deep-water pond or reservoir, a floating cage can be set up by using waste oil barrels, tires, etc.

2. The construction of earthen pond. The construction of the soil pond is actually to transform the rice field into a small soil pool with a width of 3 meters and a length of no more than 10 meters by piling mud ridges. Generally, it takes only about 3000 yuan to rebuild one mu of rice field, which is the most economical way to raise eel at present. It is required that the water storage depth of each pool can be more than 50 cm, and a row of ditches should be set up between each two rows of pools, so that the water of a single small pool can be drained separately when needed. Polyethylene mesh cloth is used around each earth pool to prevent escape: use polyethylene mesh cloth with a width of more than 1 meter, bury it 20mur30cm under the soil, sew the interface with nylon thread, and the pool mouth is supported by bamboo pole, so that the net wall around it is upright to prevent ricefield eel from leaping away.

3. The construction of cement pool. The one-time investment of cement pool construction is relatively large, generally 30 per square meter of 50 yuan, but the use cycle is long (generally up to more than 20 years), and the management is more convenient, water-saving performance is good, it is also a way that eel farmers are happy to adopt at present. The size of the cement pool is generally 10 mi 30 square meters, with a depth of 60 mi 80 cm. The mouth of the pool is covered with probe brick (as a reverse string), and the four corners are made into an arc to prevent the rice field eel from escaping. The bottom of the pool is made of concrete so that the bottom is tilted slightly to one side of the outlet. Set up an overflow pipe on the lower side of the bottom of the pool: take two plastic water pipe elbows with a diameter of more than 5 cm, connect them with a section of water pipe which is longer than the thickness of the pool wall, and bury it in the position of the water outlet so that one elbow is in the pool and one is outside the pool. The mouth of the elbow in the pool is level with the lowest place of the bottom, and the elbow outside the pool is inserted with a water pipe corresponding to its size. the length of the water pipe depends on the depth of the pool water, which is generally 30ml / 40cm. Buckle a small plastic basket with a small hole and press two bricks on the elbow in the pool to prevent Monopterus Albus from getting into the overflow pipe and escape. A corresponding drainage ditch should be set up between every two rows of cement ponds, and a block should be set at the lowest point of each ditch in case Monopterus Albus escapes from the eel pond.

Treatment of newly built eel pond (box) and laying disinfection of aquatic plants

1. De-alkali treatment of cement pool. The newly built cement pool should be filled with water and soaked for more than 7 days, and then the wall and bottom of the pool should be scrubbed with a brush to prevent the floating ash from causing harm to Monopterus Albus. In case of emergency, an appropriate amount of acetic acid and other acid can be added to the water to shorten the soaking time.

2. Soaking and softening of mesh cloth. The new cage should be put into the water ahead of time, so that its surface is covered with some algae and become smooth, so as not to scratch the eel. The soil pool that uses the net cloth to prevent escape should also add the pool water to the deepest to soak.

3. The laying of aquatic plants. After the cement pool is washed, the water in the pool should be drained and re-injected with new water, and water plants can be laid in the pool. Soil ponds can be directly laid with water plants. The laying method of water plants in cement ponds and soil ponds is to select fresh water floating lotus (scientific name "water hyacinth", also known as "water hyacinth"). If there are dead old seedlings, they should be removed so as not to rot and pollute the pool water. The selected aquatic plants are closely spread into the pool (without leaving gaps), and are blocked by bamboo poles around, so that there are no aquatic plants within 40 cm from the pool wall, so as to prevent the aquatic plants from growing on the edge of the pool and bring convenience to the escape of Monopterus Albus. Water peanuts (also known as "revolutionary grass", "cross-river vine", etc.) or water lotus can be laid in the cage. If the growth of aquatic plants is not luxuriant enough, you can first sprinkle some rotten human and animal dung water for cultivation.

4. Disinfection of eel ponds and aquatic plants. After the laying of aquatic plants, drugs should be used to disinfect and kill insects in eel ponds and aquatic plants. The method is: every cubic meter of water to take "Eel Bao 2" 2 ml or 30 grams of quicklime, sprinkle in the whole pool of water (quicklime clarification liquid), including water plants should be sprinkled. Exchange water as much as possible to prevent burns of water plants. At the same time, every cubic meter of pond water is sprinkled with "Eel Bao No. 1" or crystal trichlorfon 5 grams of water to kill parasites in the water and aquatic plants. After two days of disinfection and disinfestation, the eel can be thrown into the pool.

Selection and release of eel species

The seedling sources of Monopterus Albus can be divided into two ways: breeding and purchasing wild Monopterus Albus. This paper focuses on the acquisition of wild ricefield eel for breeding. At present, the acquisition of wild ricefield eel for artificial breeding is a common method adopted by most eel farmers. It is generally purchased from April to September and listed on the market in winter or around the Spring Festival, which can increase the weight by 1 Mel 5 times (depending on the length of time of acquisition and breeding). Generally, the purchase price in summer is less than 20 yuan / kg, and the selling price in winter is more than 40 yuan / kg, so the breeding benefit is very considerable. Generally used for breeding Monopterus Albus sources are: cage capture, electric catch, hand catch, etc.; for fishing, trapping Monopterus Albus should be selected according to the degree of damage; Drug catch Monopterus Albus should not be used.

The way of purchasing ricefield eel is generally self-catching and self-feeding, ordering from familiar eel catchers, or purchasing from township markets. Monopterus Albus, which has been stored in high density for a long time and in large farmers' markets, cannot be used for breeding. When purchasing in the township market, you should check whether Monopterus Albus has redness or blackening of the cheeks (obvious congestion or congestion blackening), anal redness, valgus, obvious trauma, and so on. If a family of Monopterus Albus has these phenomena, do not purchase; if the first purchase is not very good at identifying, you can look at a few ricefield eels, and it is not difficult to see its parotid color and anus. The rice field eel purchased for breeding should weigh 30Mel 80g, which is too large and expensive, and its growth is slow when it grows to 300g. It is too small and fragile, and the mortality rate is higher after capture injury. The purchased ricefield eel should immediately add pond water and aquatic plants not less than 4 times the body weight of the eel, and will be released immediately. The release density of eel species increases or decreases according to the length of time to prepare for breeding, generally 1ml / m ~ 2. Eel should be fed on the same night when it is put into the pond, using chopped earthworms, pig liver, mussel meat, fish meat, etc. (those with maggots can also use scalded fresh maggots). At the same time, according to the fresh material weight of 1 kg, add the following drugs: electrolytic Duowei 10g, eel Baoxin 4 3g, eel 5 5g, use special adhesive or a small amount of wheat flour to adhere to the feed, the dosage is 0.5% of the body weight of Monopterus Albus. The material can be put directly on the water plant, and the cement pool can also put the feed directly to the place where there is no water plant in the pool, so more feeding points should be set up as much as possible. The next morning, every cubic meter of pool water was sprinkled with eel Baoxin No. 5 5 g / 1 cubic meter water over the whole pool (box). The above medication should be carried out for 3 days in a row.

Domestication and Daily Management of Monopterus Albus

1. Domestication of Monopterus Albus. After Monopterus Albus enters the pond, we should always observe the eating situation of Monopterus Albus, and gradually increase the feeding amount in the pond (box) where the feeding condition is good. When the feed intake reaches more than 2% of the body weight of Monopterus Albus (fresh feed weight), formula feed (carp feed, river ball feed, eel feed, etc.) should be gradually added to the feed until the feeding amount is 510% of the Monopterus Albus body weight (wet weight). If there is any leftover material, it should be picked up every morning.

2. The management of Monopterus Albus just entering the pool. The normal rice field eel should move freely in the aquatic plants and will not climb onto the grass for a long time. If you find Monopterus Albus and other abnormal behaviors such as rolling in the water, you should pick out the eel in time.

3. Cooling management. For raising ricefield eel in the pool, sunshade nets should be set up on the pool in the high temperature season, on the one hand, the water temperature should be reduced, and at the same time, the light intensity should be reduced. In the high temperature weather, the pool water should be deepened to more than 40 cm, and the water temperature should be controlled below 32 ℃ as far as possible.

The initial capture of Monopterus Albus

For cement ponds and cages, it is very convenient to catch Monopterus Albus, which can be caught directly after removing grass. For earthen ponds, the method of gathering grass should be adopted. The method is: leave only about 1 square meter of water plants in a pool and deepen the water to more than 50 centimeters. At this time, Monopterus Albus will generally gather in the aquatic plants, and every morning they will move up from the bottom of the aquatic plants with a copying net of more than 1 square meter, until they come out of the water and pick out the aquatic plants, then the Monopterus Albus will be caught in the net for three times. This method is only effective in the eating season of Monopterus Albus. If it needs to be sold in winter, it should be caught in another pond (box) before stopping feeding.