CATDOLL : CATDOLL: Can you tell me about breeding good fish?

Can you tell me some knowledge about breeding good fish?

1. Eel cage farming

The use of cage culture to culture eels is still in the technical development stage. Cage culture is suitable for large water bodies. The main advantage is that water flows through the mesh, forming a living water environment in the box, so the water quality is fresh and rich in dissolved oxygen, and high-density intensive culture can be implemented. The main breeding technologies are as follows:

The area of ​​the cage is preferably about 20 square meters, with a length of 5m, a width of 4m, and a height of 1m. The above-water part is 40cm, and the underwater part is 60cm. The quality of the net should be good, the mesh should be dense, and the strips should be tight to prevent the eels from escaping due to being bitten by water rats. The cage is set in a pond with a water depth of more than 0.8m. The newly made cage should be placed in the water for 35 days until the harmful substances emitted by it disappear before the eels can be released. A few days before the release of the eels, the water quality should be properly cultivated to make the water color thicker and the transparency about 15cm, so as to control or reduce the damage of mites in the pond to the eels. The cages can be set side by side in the pond, and bamboo frames can be set between the two rows of cages for people to walk and feed. The area of ​​the cage should not exceed 50% of the total area of ​​the pond, otherwise it will easily cause the water quality to deteriorate. Aquatic plants, preferably water peanuts, are placed in the cages, and their coverage area should account for 90-95% of the cage area, providing a good environment for the growth and habitat of eels.

Eels have the habit of cannibalizing each other, so it is better to keep them in the same size. Generally, 20kg of eels can be stocked per square meter, and 400kg can be stocked in each cage.

Once the eel is used to one kind of feed, it is difficult to change its habit and eat another kind of feed, so its feed should be fixed with several varieties, such as earthworms, small fish, mussel meat or animal offal, to increase its growth rate. If conditions permit, live bait can be put in, because it has a high utilization rate, does not need to remove the leftover bait, and has less pollution to the cage, which is conducive to the growth of the eel.

The most critical period of yellow field eel cage culture is within one month after stocking. This period is the process of yellow field eel changing its original living habits and adapting to the new environment. If the method is appropriate, the survival rate of eel species can reach more than 90%, but if the method is inappropriate, the survival rate is sometimes less than 30% or even all of them die. This month is the key to the success or failure of yellow field eel cage culture. In addition to disinfecting and domesticating the eel species, the occurrence of diseases should also be effectively controlled. The specific method is to use strong water disinfectants and quicklime for disinfection alternately to prevent the generation of pathogens.

2. Eel farming in plastic greenhouse without soil and flowing water

Conventional pond farming is prone to disease and the hibernation of eels affects year-round farming. Using plastic greenhouses to farm eels allows for continuous production all year round. Soilless and flowing water farming can effectively control diseases and increase benefits exponentially.

The most suitable growth temperature for eels is 27℃～30℃. With plastic greenhouses, there is no need for special heating equipment, and the temperature in the greenhouse can be easily maintained at this temperature in spring, summer and autumn. Even in the cold winter, the average temperature in the greenhouse can reach 20℃.

Keep the water in the breeding pond slightly flowing so that the water quality will not deteriorate.

There are two main ways to cultivate soilless water in plastic greenhouses:

(1) Open. Suitable for building ponds in places with warm water all year round. The advantage is that the flow is stable and suitable for large-scale operations. The breeding pond is made of bricks and cement. The area of ​​each pond is 10 to 20 square meters, the depth of the pond is 40 cm, the width is 1 to 2 meters, and the width of the pond bank is 20 to 40 cm. Two water inlet pipes and two drainage pipes with a diameter of 3 to 4 cm are installed at opposite positions of the pond. The water inlet pipe is at the same height as the bottom of the pond; one drainage pipe is at the same height as the bottom of the pond, and the other is 5 cm higher than the bottom of the pond. Metal mesh is installed at the inlet and drainage pipe openings to prevent escape. Arrange several breeding ponds side by side to form a unit. The area of ​​each unit should not exceed 500 square meters.

(2) Closed loop filtration type. Suitable for use in large cities or places where water is scarce. Its advantages are that the water used for breeding can be reused, the water consumption is low, and the temperature is easy to control, but the investment is slightly larger. The construction method of the breeding pond is the same as that of the open one. In addition, an aeration tank and a sedimentation tank need to be built, and some water purification equipment, pumping equipment and heating equipment need to be added.

The construction of a plastic greenhouse is the same as that of an ordinary greenhouse. It is best to place each unit in the same greenhouse for easy management.

The breeding method of plastic greenhouse soilless water flow breeding is adopted. As long as there is enough feed, the eels will generally not escape due to the clear water quality. However, it is necessary to prevent natural enemies such as rats and snakes from harming. After a period of breeding, the eels in the same pond will be uneven in size and should be separated and raised in time.

3. Eel farming in rice fields

Using rice fields to breed eels is low-cost, easy to manage, and produces both rice and fish. It is an effective way for farmers to get rich and increase their income.

Selection and requirements of rice fields

Rice fields for raising eels should be selected with good water retention properties, low terrain, and convenient water supply and drainage.

The first is to raise and reinforce the ridges to prevent water seepage and leakage; the second is to dig a set of ditches inside and outside the fields, which are 5m wide and 1m deep, and dig a "+" or "井" shaped ditch in the middle of the field, which is 50 cm wide and 30 cm deep and connected to the surrounding ditches; the third is to improve the drainage system and install sturdy fish-blocking facilities at the inlet and outlet to prevent fish from escaping.

Release seedlings

The time is concentrated in mid-to-late April, and the fish should be released all at once. When releasing the fish, they should be soaked in 3% - 4% salt water for 10 minutes to prevent skin abrasions and kill water molds and surface parasites.

Feeding and management

First, feed well. Rice field eels are omnivorous fish that mainly feed on animal bait. While they prey on natural bait in rice fields, they should be fed with pig blood, small fish and shrimps to meet their feeding and growth needs. Second, water quality management should be done well. The water level in rice fields should be kept at about 10 cm normally, and new water should be added regularly. In the early stage, new water should be added once every 3 to 5 days, and once a day in the hot summer. The water depth should be increased by 3 to 5 cm each time water is added to prevent hypoxia. Third, prevent and treat diseases regularly. Use quicklime or bleaching powder to sprinkle the surrounding ditches once every half a month, and use internal medicines such as sulfamethoxazole or fish blood powder to mix feed and feed regularly to prevent diseases such as enteritis.

How should we choose the breeding site for eels? How about the fields?

1. The cement pool area should be 30 to 50 square meters. The pool surface and bottom should be polished smooth to prevent eels from scratching their skin and causing infection with various bacteria and viruses. The top of the pool should be about 30 centimeters above the water level, and a natural overflow outlet should be set. The outlet should be fixed with a mesh to prevent the eels from escaping. There are two ways to raise eels in cement pools: with soil and without soil. Both methods require planting water peanuts or water hyacinths to regulate the water temperature and provide a rest area for eels in hot seasons. The entire pool can be planted with only a small portion of the feeding port. If it is soil breeding, it is advisable to lay 20 cm to 30 cm of soil, and the water level above the mud layer should be maintained at 20 cm to 25 cm. If the water is too deep, the eels will consume too much energy in the activities, and if it is too shallow, the water body will easily become turbid and the water temperature will change greatly. If it is soilless breeding, the water level should be maintained at 30 cm to 40 cm. The advantage of this breeding model lies in its good water disinfection effect, while in soil breeding, it is difficult for the disinfection drug to act on the soil and the bottom, and it is easy to breed various parasites and their intermediate hosts, such as leeches, flat leaf snails, and lymna snails.

2. Paddy field farming: First dig up the soil in the paddy field, bury the net cage, then put the soil back into the net cage, fix the four corners of the net cage, plant water peanuts or water hyacinths, and the area should be 20 square meters to 30 square meters. It is not suitable to plant crops with rough and developed root systems such as rice in the net cage, because eels have the habit of drilling soil and easily scratch the skin.

3. All kinds of ponds, lakes, and reservoirs are used for net culture, that is, soilless culture in cages. The area should be 15 to 20 square meters, which is convenient for disinfection and treatment. When the disease occurs, the cage and the fish can be directly placed in a large disinfection container. Aquatic plants such as water peanuts or water hyacinths should also be cultivated in the cage for the eels to rest.