Culture technique of Loach

Misgurnus anguillicaudatus is a small omnivorous freshwater fish, which is widely distributed in China, Japan, Korea, Southeast Asia and other countries and regions. Misgurnus anguillicaudatus is light, delicate, delicious and nutritious. It is known as "ginseng in water". It is one of the important aquatic products exported by China and has good economic value. However, due to the increasing demand, wild Loach is far from meeting the needs of the market. Therefore, artificial breeding has become the main channel of market supply. Now, let's go to Weishan Lake in Shandong Province to see how Loach is raised.

Construction of breeding ground for Loach

1. The correct location of the farm

If you want to raise Loach well, it is very important to choose a suitable location. First of all, we should choose places with adequate water sources and good water quality. Because Loach is also a kind of fish, it is inseparable from water, so there must be a clean and pollution-free source of water to cultivate Loach. Secondly, to choose a place with convenient transportation, it is necessary to transport feed and Loach in the process of breeding, so we have to choose a place with convenient transportation. Just choose a good site is not enough, in the construction of the farm, we must consider carefully, now, let's look at the layout of the farm.

2. The overall layout of the farm

The Loach farm must take the pond as the main body, the area of the pond can be large or small, but the east-west is long, the north-south is short for the best, such a pond is exposed to the sun for a long time, which is conducive to the growth of Loach. On both sides of the pond are intake canals and drains, so that the ponds are arranged in turn along the channels on both sides, forming a parallel structure, the purpose of which is to manage separately. If the water quality of one pond is not good, it will not affect other ponds. A walking road is set aside in the middle of each pond and between ponds and canals, which can be used as a passage for daily management. In the construction of Misgurnus anguillicaudatus farm, the location of the drying pool should be set aside. In the management of Misgurnus anguillicaudatus, the stability of water temperature is very important, so it is best to use water with the same temperature as the pond, which is why a drying pool is needed. So far, the main body of the farm has been completed, but we also need to have a separate management area. The management area is generally located on one side of the pond, where the staff's office, feed workshop and feed warehouse are all located. In addition to routine facilities, a temporary pond needs to be built in the management area. Like many fish, Loach has to be temporarily reared for three days before sale to remove the mud smell of fish meat and empty its intestinal feces. This can not only improve the edible value of Misgurnus anguillicaudatus, but also maintain good water quality in the process of transportation and improve the survival rate. When the farm is well built, the necessary protective measures are also indispensable. It is necessary to surround the farm with a purse seine. The purpose of using the purse seine is to prevent animals such as cats and dogs from entering the farm and cause pollution and harm to the farm.

So far, you can understand the layout of the whole farm. Next, let's talk about the construction requirements of the aquaculture pond. As we said just now, the length and width of the pond can be designed according to different ground conditions, but it is better to be longer than 100 meters and not more than 80 meters wide, because the area is too large for management. Misgurnus anguillicaudatus culture pond has strict requirements on the depth, the pond depth of 1 to 1.2 meters is the most suitable.

Misgurnus anguillicaudatus has a characteristic, that is, its evasion. Because of its small size, as long as there is a small gap, it can get out. If there is a loophole in the pond, the Loach can even escape completely within a day. Therefore, special attention should be paid to this when building a pond for Loach.

① treatment of the bottom of the pond: after the excavator has dug out the pond, the bottom of the pond should be rammed solid.

② deals with the edge of the pond: dig a ditch nearly 1 meter deep along the edge of the pond, and then spread the thick plastic sheet from the bottom of the ditch to the ground, and the interfaces of the plastic sheet must be tightly connected. After covering the plastic sheet along the edge of the pond, the plastic sheet is compacted with the excavated soil so that the plastic sheet is integrated with the pond. The upper end of the plastic sheet is fixed with wooden stakes every 1 meter or so to ensure that the plastic sheet will not be blown off by the strong wind.

③ deals with the inlet and outlet of the pond: because the current PVC pipeline is relatively cheap, the farm can consider using the PVC pipe as the intake pipe of the pond, one end of which comes from the water lifting equipment at the edge of the reservoir, and the other directly passes through one side of the pond.

The outlet of the pond needs to be carefully designed. We hope that the water pumped out is the bottom water of the pond. The bottom water of the pond is polluted by Loach faeces and the remaining feed, so the water quality is relatively poor. When changing water, it is necessary to discharge this layer of water with poor water quality. Let's take a look at an ingenious design of the outlet: this outlet is composed of two sleeves inside and outside, and the large casing on the outside, that is, the white pipe, can protrude from the surface of the water; the bottom, that is, at the bottom of the pond, has a gap to drain the bottom water, and this gap is very small, so the Loach can not escape. Inside the white casing is a slightly thin plastic pipe. When the water is pumped out, the water flows out of the gap. When the water is not released, it is put down to block the gap in the drainage, which acts as a switch. Only these two sleeves are not enough, in order to deal with the naughty Loach, but also add a layer of screen, this square fine screen deeply inserted into the pond, Loach want to pass through these blockades, it is not so easy.

Artificial breeding of Misgurnus anguillicaudatus

1. The time and mode of artificial breeding of Misgurnus anguillicaudatus: when the water temperature reaches 18 ℃ ~ 20 ℃, the sexually mature Misgurnus anguillicaudatus begins to reproduce naturally. In northern China, spawning usually begins in mid-April, and the peak spawning period is from mid-late May to late June, and the spawning period can be maintained until August. The artificial breeding of Misgurnus anguillicaudatus is to create a natural environment for natural fertilization. There are three aspects that need to be paid attention to in artificial reproduction: the first is to choose a good parent Loach, the second is to build a suitable breeding pond, and the third is the scientific management during hatching.

2. Choose a robust parent Loach: the parent Loach used for breeding can be fished from ditches and ponds, or can be purchased at the market. Parents of Misgurnus anguillicaudatus are required to be physically strong, disease-free and injury-free, second-year-old Loach with a body length of more than 10 cm, large female Loach with large number of eggs, male Loach with more semen, good fry quality and fast growth. The belly of the female Loach in estrus is big and round, and the color of the whole abdomen is white and shiny. It feels soft and protruding genitals by pressing gently with the hands.

3. Preparation of breeding ponds: breeding ponds can be built according to local conditions. Generally, in places where access and drainage are convenient and close to breeding farms, bricks can be used to build a pool temporarily, and then covered with clean plastic sheeting, or rectangular stainless steel iron boxes can be used as breeding ponds. The area depends on the number of hatches. The depth of the pool is about 1 meter to 1.5 meters, not too deep. The breeding pond should be cleaned before use, and the wall and bottom of the pool should be cleaned with clean water. Fresh water is injected into the breeding pond three days before use, with a depth of no more than 50 centimeters. In order to improve the survival rate of hatching, the parent fish can only be put in the fresh water after three days of drying. The water temperature needs to be measured before releasing the fish. The appropriate water temperature is 18 degrees Celsius to 30 degrees Celsius. After the water temperature is stable, collect the naturally growing aquatic plants on the edge of the pond, rinse the aquatic plants with clean water, carefully examine the aquatic plants, remove the insects attached to the aquatic plants, and then put the aquatic plants into the breeding pond. this creates a good environment for the natural mating of Loach. Two male Loach and one female Loach are generally placed in a breeding pond. Misgurnus anguillicaudatus usually lays eggs in the evening or early morning, so breeders should be diligent in observing. After the female Loach ovulates, the fertilized egg adheres to the aquatic grass. Because the fertilized egg adhesion is very poor, it is easy to fall off from the aquatic plant and be swallowed by the Loach. So after the fertilized egg is formed, the parent Loach should be fished out from the breeding pond.

4. Incubation and feeding of Loach seedlings: Loach seedlings can be hatched in 3 days when the water temperature is between 18 and 25 degrees Celsius. The newly hatched loach seedlings were about 5 mm in length, changed gradually from yellow to black, and began to feed actively 3 days later. From day 3 to day 8, hard-boiled egg yolk can be fed every three to five hours. The amount of feed should not be too large and should be finished within 1 hour. The breeding time of Loach seedlings is from April to May, when the river or lake gradually turns green and zooplankton multiply in large numbers, providing natural bait for the growth of Loach seedlings. Misgurnus anguillicaudatus likes animal bait, so from the 5th day, it is necessary to add nutritious bait such as migratory water. Water migration refers to the water body rich in paramecium in lakes and ponds in nature. Because paramecium propagates in large numbers, it floats in groups like gray clouds in the water layer, so it is called "migratory water". After the fish and insects are salvaged, they are filtered with a 200-mesh sieve. After filtering, these tiny plankton are the favorite feed for Loach seedlings. About 10 days after hatching, the Loach gradually grew up and could feed on larger fish and insects, so the feed gradually increased from 200 mesh sieve to 100 mesh sieve and 80 mesh sieve. With the increase of Loach seedling feeding, the feeding times should be adjusted to twice a day, once in the morning and once in the evening until 30 days. Loach's growth rate is very fast, 30 days after hatching, it can grow to about 3 centimeters, if it is large-scale breeding, then it can be crushed and soaked formula feed. As the Loach seedlings are cultured in still water, the water should be changed frequently during the culture period, twice a day, and the temperature difference between the water in the breeding pond and that in the breeding pond should not exceed 1-2 ℃.

Culture of adult Misgurnus anguillicaudatus

From the Loach seedlings hatched, about 60 days, Loach grew to 5 to 8 centimeters, then the Loach seedlings can be put into a large pond for breeding. Before the loach seedlings enter the pond, the pond needs to be carefully treated.

1. Pond exposure and disinfection

① pond exposure: for many years of use of the pond, sunlight exposure is very important, generally 30 days before the loach seedlings into the pond exposure, the bottom of the pond into the shape of a turtle, which is of great benefit to the elimination of pond microorganisms.

② dug out the bottom silt: as the bottom of the pond deposited a lot of feces and remaining feed, so the silt at the bottom of the pond is the habitat of bacteria and microorganisms, and Loach has the habit of drilling mud and likes to move at the bottom of the pond, so for Loach seedlings, the bottom silt must be removed before entering the pond. In general, 40 centimeters of mud at the bottom is dug up with a shovel, gathered together, and then pushed away from the pond by a trolley.

③ quicklime disinfection: in production, about a week in advance, using quicklime disinfection. Quicklime can eliminate a variety of pathogens and pests. After dissolving in water, quicklime turns into a strong alkaline solution, which can kill miscellaneous fish, insects, leeches, clear mud moss, net algae and some weak aquatic plants, as well as parasites and pathogens, so the germicidal effect is particularly good. The dosage of quicklime is 1000 kg per mu, which is sprinkled directly to the bottom of the soup and then filled with fresh water. after a week, the Loach seedlings can be put into the pool.

2. Loach seedlings enter the pool

A pond can only put Loach of the same specification, Loach of 5 to 6 centimeters, 100-150 Loach per square meter, Loach of 7 to 8 centimeters, and 50-80 Loach per square meter. If the condition of the fish pond is better, the stocking quantity can be increased appropriately, otherwise the stocking quantity should be reduced appropriately. During the stocking period of Misgurnus anguillicaudatus, if the density is too low, it will cause a waste of water resources. If the density is too high, the dissolved oxygen content will decrease, which is disadvantageous to the growth of Loach. Next, let's take a look at those aspects that need to be paid attention to in the daily management of Loach.

3. Daily management of adult Loach

Preparation and feeding of ① feed: it is best to use compound feed for artificial breeding Loach, one is because the formula feed is nutritious, and the other is because it is convenient to use and has little pollution to water quality. Loach formula feed is divided into three specifications, 5 to 8 cm Loach seedlings use one specification, 8 to 12 cm medium Loach use one specification, and 12 cm to 20 cm adult Loach use one specification. The three kinds of feed are not only different in particle size, but also different in protein content. Loach seedlings require higher protein content, while adult Loach requires lower protein content. Now let's take a look at the recipes of these three kinds of feed:

No. 1 feed: wheat bran 42%, soybean meal 20%, cottonseed meal 10%, fish meal 15%, blood meal 10%, yeast powder 3%.

No. 2 feed: wheat bran 48%, soybean meal 20%, cottonseed meal 10%, fish meal 12%, blood meal 7%, yeast powder 3%.

No. 3 feed: wheat bran 50%, soybean meal 20%, cottonseed meal 10%, fish meal 10%, blood meal 7%, yeast powder 3%.

When using formula feed, sprinkle it along the edge of the pond, requiring it to be sprinkled very evenly to avoid being too concentrated in a certain place, causing the phenomenon of food grab. Feed twice a day, the amount of feeding Loach in 1 hour to finish. So, the feed is scattered in the pond, how to judge whether it is finished or not can be judged by a simple observation platform. The observation table is a lever structure, with one end fixed on the shore and a round or square sieve at the other end. an hour after feeding, the breeder should raise the sieve to have a look to see if the feed has been eaten. This observatory also plays the role of checking the growth of Loach, through which you can easily see how big the Loach has grown, how its growth state, and so on.

② water temperature management in Loach culture: the most suitable temperature for the growth of Loach is 22 degrees Celsius to 30 degrees Celsius. When the water temperature exceeds 30 degrees Celsius, the Loach's food intake decreases, and even stops feeding and drills into the soil. So breeders should often measure the water temperature, especially in summer, every day around 2: 00 p. M. to measure the water temperature, if the water temperature is too high, to timely add new water.

Water quality management of ③ Loach culture: the water quality of the pond is very important to the growth and development of the Loach. The pond water is yellowish green and the transparency is 20 to 25 cm. Misgurnus anguillicaudatus is a very spicy creature, and there is basically no disease, but in high-density culture, it will be due to the high density of Misgurnus anguillicaudatus, more feed, more feces and other reasons, resulting in the change of pH value, dissolved oxygen content and ammonia nitrogen content in the pond. These data affect the growth and development of Misgurnus anguillicaudatus, but it is not possible to rely solely on the eyes of the breeders. The simple way is to use the test paper to correctly judge these data. For the pH test paper, fish farmers are no stranger, pH refers to the pH of the water. Its use is very simple, according to the method of the instructions, and finally compared with the color on the pH test paper, you can easily know whether the pH value in the water meets the requirements. The most suitable pH value for the growth of Misgurnus anguillicaudatus is 7 to 7.5. Due to the growth of algae in the pond, the pH value of Loach culture is often on the high side, which can be adjusted by sprinkling quicklime. The amount of dissolved oxygen in the pond is also very important, which refers to the amount of oxygen in the water. When testing the dissolved oxygen content, add 5 drops of dissolved oxygen reagent to the water sample, and compare it with the color of the color card, the dissolved oxygen content of the water sample can be obtained. When the temperature is too high and there is too much plankton in the water, the amount of dissolved oxygen will be reduced. When the amount of dissolved oxygen in the water is less than 2 milligrams per liter, timely measures should be taken to inject more new water, the new water is added, and the old water is exchanged, and the water in the whole pond will form convection, so that the fresh water can bring in enough dissolved oxygen to increase the oxygen in the water, otherwise the normal growth of Loach will be affected because of the lack of dissolved oxygen in the water. The high content of ammonia nitrogen in water has strong toxicity to Loach, which will gradually reduce the number of red blood cells and hemoglobin of Loach, cause chronic poisoning of Loach and inhibit its growth. The high content of ammonia nitrogen is caused by the decomposition of excreta, residual bait and plankton debris of Loach. The method of measuring the content of ammonia nitrogen is similar to that of measuring dissolved oxygen. The content of ammonia nitrogen in Misgurnus anguillicaudatus culture pond can not exceed 0.03. If the content of ammonia nitrogen is on the high side, photosynthetic bacteria and other microbial preparations can be used according to the instructions. It can significantly reduce the organic content of sediment and water quality, thus reducing the release of ammonia nitrogen, the decomposition product of organic matter.

④ check anti-escape measures: Loach's body is very small, even if the pool wall and embankment cave is very small, it can drill a hole to escape, so every day when the keeper patrol the pool, must check whether the pool edge of the plastic sheet is strong, anti-escape net is strong, pay attention to plug the loophole, prevent escape.

⑤ cleaning every day: the keeper has to clean the pond every day, especially to pull out the weeds on the ridge of the pond to prevent the weeds from falling into the water and become the escape road for Loach. In addition to cleaning, but also salvage the harmful insects in the pond, to salvage the dead Loach, if found Loach abnormal phenomenon, timely analysis and treatment.

Fishing of Loach

Loach from May to June under the pond, November can grow to 15 to 20 centimeters, at this time can be caught and sold. Misgurnus anguillicaudatus is generally caught in the ground cage, which is made of bamboo as a support and a round cage made of a fish net. The Loach swims into the ground cage through a small hole at one end and stays in the cage and cannot be drilled out again. Capturing Misgurnus anguillicaudatus by using cages will not harm the mucous membrane on the surface of Loach and can improve the survival rate in the process of transportation. Misgurnus anguillicaudatus can be caged in the morning, closed in the afternoon, and set up a ground cage every 3 meters along the pond. After thoroughly clearing the pond, there will be sporadic Loach at the bottom of the pond, at this time, you can use a handwritten net to catch once. The captured Loach has to be temporarily reared for 1-3 days before sale to remove the muddy smell of the meat, empty its intestinal feces and improve the survival rate during transportation. Through the above explanation of Misgurnus anguillicaudatus culture, I do not know whether you have some understanding of Loach culture. Wild Misgurnus anguillicaudatus, which lives in shallow water such as rivers and ditches, is a highly adaptable organism, so there are almost no diseases in artificial culture. as long as the water quality is controlled and escape prevention is done, the cultivation of Loach is very simple. Nowadays, Loach is widely sold in the international market, and Loach in China is listed as one of the imported commodities by South Korea and Japan. Therefore, the development of Loach culture is a farming industry with broad development prospects in rural areas.