Culture techniques of Misgurnus anguillicaudatus

Taiwan Loach belongs to Cyprinidae, Cyprinidae, Loach and Loach in taxonomy. It is a small omnivorous freshwater fish, which is widely distributed in rivers, ditches, paddy fields, ponds, lakes and reservoirs except the Qinghai-Tibet Plateau. In order to increase effective supply, it is particularly important to develop large-scale culture of Misgurnus anguillicaudatus in Taiwan. This paper briefly introduces the artificial propagation of Loach in Taiwan and the technology of large-scale culture in ponds.

Artificial propagation of Misgurnus anguillicaudatus

The main results are as follows: 1. Selection of parent Loach and identification of male and female parent Loach is generally not suitable for long-term storage, it is best to collect natural Taiwan Loach near the spawning period and use it for artificial reproduction after intensive cultivation. Mature Taiwan Loach with more than 2 years old, good shape, strong physique, more mucus and no harm must be selected when collecting parent Loach. Female Misgurnus anguillicaudatus requires body length 18cm, body weight more than 30g, abdomen dilated, soft and elastic, male Loach requires body length 12cm, body weight more than 15g, star pursuit on the pectoral fin is obvious. In the identification of male and female, the mature female Loach is obviously larger than the male, the width of the pectoral fin is short, the end is obtusely round, the fan-shaped, the abdomen is obviously protruding, the body is cylindrical, and the reproductive foramen is turned out and red; the male is small, the pectoral fin is narrow and long, the end is pointed and upwarped, there is a bone sheet at the base of the second fin, and there is a star on the fin.

2. Common utensils must be prepared for artificial labor and prenatal induction, including 2 6cm mortar for grinding pituitary gland and testis, several medical syringes with 1mL~2mL capacity and several No. 4 injection needles for pro-Loach injection, 2 dissecting scissors, 2 knives and tweezers each for testicular extraction, and several water basins or buckets for prenatal care of Loach. Several towels, several hard feathers on poultry wings, 1 1000mL bottle, 2 20mL or 50mL straws, and several white enamel bowls. The artificial spawning time of Misgurnus anguillicaudatus is later than that of natural reproduction, and the water temperature is required to be more than 20 ℃. The drugs for inducing labor are generally chorionic gonadotropin (HCG), pituitary and luteinizing hormone-releasing hormone analogues (LRH~A), and each female Loach is injected with HCG about 300IU ~ 400IU, or 1 carp pituitary, or LRH-An about 5 μ g ~ 10 μ g, the dose of male Loach is halved. The injection site is back muscle injection, or body cavity injection, female Loach injection dose is 0.2mL, male Loach injection dose is 0.1mL, injection depth is 2mm, injection time is Taiwan Loach reached the best part of estrus in the early morning of the next day as the standard. After injection, the parent Loach was placed in a cage with a size of 2m × 1m × 0.5m. 50 groups of parent Loach were reared in each cage, with a female-to-male ratio of 1 ∶ 1.2 to 1.5, and several fish nests were placed in the cage at the same time.

3. When artificial insemination is close to the effect time, it is found that the parent Loach pursues gradually, and the male Loach curls up the female Loach and the female Loach is short of breath, indicating that the most wonderful part of estrus is coming. at this time, golden eggs flow out and free from the belly of the female Loach, indicating that artificial insemination can be carried out. Artificial insemination should be carried out indoors, one person will wrap the mature female Loach in a towel, expose the belly, and gently squeeze the mature egg into the dry white enamel plate; the other person will pour the prepared semen on the egg; the third person shakes the porcelain plate with his hand and gently stirs it with feathers for a few seconds, then add a small amount of water to enhance sperm motility and improve the fertilization rate, then rinse the fertilized egg several times and put it into the incubator to hatch.

4. Hatching in an incubator should put relatively concentrated fertilized eggs obtained at the same time. The water for hatching should be fresh and pollution-free, the content of dissolved oxygen should be between 6mg/L~7mg/L and pH between 7 and 8, and 2 ~ 3 fertilized eggs should be released per 1mL. The water flow in the incubator should be controlled when the fertilized egg can be filled to the middle of the water surface, and then gradually spread around when it is close to the water surface, and then gradually sink. The optimum water temperature for hatching is 20 ℃ ~ 28 ℃, and the optimum water temperature is 25 ℃. The larvae can be hatched when the water temperature is 24 ℃ ~ 25 ℃ for 30 ~ 35 hours. The newly hatched larvae should continue to be temporarily reared in the original tank. After most of the yolk sac of the larvae basically disappeared, the cooked yolk was fed into the incubator, and one yolk was fed for every 200000 larvae. After continuous feeding for 2 ~ 3 days, the pond could be transferred to the seedling stage.

Large-scale culture in pond

The so-called large-scale farming refers to the concentrated cultivation and production of Taiwan Loach in the same place (100 mu, hundreds of mu or even thousands of mu), which requires an average yield of more than 500kg/ mu, and integrates seedling cultivation, commercial Misgurnus anguillicaudatus production, feed supply, commercial fish centralized sales as one of the "one-stop" production, to provide the market with a large number of and sufficient commodities of Taiwan Loach.

1. The site selection of Taiwan Loach breeding farm should be as far as possible that the water source is sufficient and reliable, the water quality is fresh and pollution-free, the pond is easy to enter and drain (can be irrigated and drained by itself), the soil is neutral or slightly acidic clay soil, and the sun is sufficient. The transportation is convenient and the electricity is guaranteed.

2. The construction area of the adult Loach pond is 100m2 ~ 300m2. The unique habits of submersible mud and escape of the Loach in Taiwan should be fully taken into account in the construction. The pond must be surrounded by 40cm, which can be made of cement board, brick, hard plastic board or compacted with concrete, or the screen cloth can be used to fence around the pond. The lower end of the screen cloth is buried in the hard soil, and the upper end of the screen cloth is higher than the water surface 15cm~20cm. The pond is deep 80cm~100cm, the bottom silt is thick 20cm~30cm, and the water depth is kept at 30cm / 50cm; the pond inlet is 20cm higher than the water surface, the drainage outlet is located at the level of the normal water level of the pond, the bottom outlet is set at the bottom of the pond, and the inlet and outlet are covered with a dense net to prevent the Taiwan Loach from escaping. In order to facilitate fishing, the pond should be equipped with fish slips connected to the drainage bottom, whose area is about 5% of the total area of the pool bottom and 30cm~35cm deeper than the bottom of the pond. The fish slips are surrounded by boards or made of cement and masonry.

3. 10 days before stocking, clean up the Loach pond, plug the loophole, dredge the drainage pipe, plough the silt at the bottom of the pond, and then clean the pond with quicklime, that is, apply quicklime of 100g/ square meters when the water depth is 10cm, and sprinkle quicklime into the whole pond immediately after hydration slurry. Three days after clearing the pond, water 30cm was added to the pond and base fertilizer was applied. The base fertilizer could be 300g/ square meters of fermented chicken manure or 500g/ square meters of fermented human manure, pig manure and cow manure to cultivate plankton in the pond water, so that Loach species could ingest palatable basic food organisms after entering the pond.

4. Beetles were sterilized with 8ppm~10ppm bleach solution before stocking, and washed for 20 ~ 30 minutes when the water temperature was 10 ℃ ~ 15 ℃. The size of the Loach species is body length 3cm~4cm, and the stocking density is 50 / m2 ~ 60 / m2. When the water source condition and technical strength are good, the stocking quantity can be increased appropriately. In the Misgurnus anguillicaudatus culture pond in Taiwan, some fish living in the middle and upper layers of the water, such as grass carp, silver carp and bighead carp, can also be properly stocked, but not tilapia, carp, crucian carp and other species.

5. Fertilization Taiwan Loach is an omnivorous fish and likes to eat organic detritus, plankton, benthos and so on. Therefore, fertilization measures should be taken to cultivate the basic food organisms in the pond water during the culture stage of adult Loach. In addition to applying base fertilizer, topdressing should be applied in time according to water color. Farm manure such as fermented pig manure, cow manure, chicken manure and human manure are commonly used, and chemical fertilizers such as calcium superphosphate, urea and ammonium bicarbonate can also be applied. The amount of topdressing depends on the water color, the amount of topdressing is 30%-50% of the base fertilizer, the transparency of the pool water is controlled in 15cm~20cm, and the water color is yellowish green.

6. Misgurnus anguillicaudatus should be fed with compound feed in addition to fertilizer and water. The appetite of Misgurnus anguillicaudatus is related to the water temperature: when the water temperature is below 20 ℃, it mainly eats plant feed, accounting for about 60%-70%; when the water temperature is 21 ℃-23 ℃, the proportion of animal feed and plant feed each accounts for 50%; when the water temperature exceeds 24 ℃, the proportion of plant feed should be reduced to 30%-40%. The animal feed for Taiwan Loach includes fish meal, animal viscera, earthworms, small miscellaneous fish, blood meal, etc., and plant feed includes soybean meal, rapeseed meal, secondary meal, wheat bran, grain, etc., and can also be fed with artificial formula feed twice a day. The daily feeding amount is 4%-10% of the total body weight of Taiwan Loach, and the feeding amount should be flexibly controlled according to water quality, weather, Taiwan Loach intake and so on. The appetite of Misgurnus anguillicaudatus increased gradually when the water temperature was above 15 ℃, and especially exuberant when the water temperature was between 25 ℃ and 27 ℃. Less or even stopped feeding should be given when the water temperature was above 30 ℃ or lower than 12 ℃. Feed feeding requires "timing, fixed point, quality and quantity".

7. Daily management should pay attention to keeping the water quality of the pond fat, lively, tender and cool, and the water color should be yellowish green, and the water should be changed once or twice a week. Keep patrolling the pond three times a day, pay attention to the changes of water color and the activities of Loach in Taiwan, regularly feed bait to prevent fish diseases, clean the feed table frequently and disinfect regularly, and treat diseases in time when diseases are found. Always check the intake, drain and pond ridges to find loopholes and repair them in time; when the weather changes suddenly, such as muggy weather, low air pressure, thundershowers or days of overcast and rain, we should pay attention to observe whether the adult Loach is floating or not. when the floating head is serious, it should be filled with new water in time; make a good breeding record.

Prevention and control of common diseases

The main results are as follows: 1. Water mildew is caused by fungal infection such as water mold and Pythium. Most of the mold spores multiply in the wound and invade the body tissue because of the injury of Loach body. the white or gray cotton flocculent can be seen with the naked eye. The prevention and treatment method is to sprinkle the whole pool with the mixture of 400ppm's baking soda and salt.

2. Red fin disease is caused by Brevibacterium infection. The fin, abdomen, skin and anus of Misgurnus anguillicaudatus are congested and ulcerated, and the caudal fin and pectoral fin are white and rotten. The prevention and control method is to sprinkle the whole pool with 1ppm bleach powder.

3. Printing disease is caused by parasite of Aeromonas aerogenes. The focus of Misgurnus anguillicaudatus is puffy, red, oval and round, and the affected area is mainly concentrated on both sides of the tail stalk, like a seal. The prevention and treatment method is to sprinkle the whole pool with dibromohydantoin of 0.5ppm.

4. Parasitic diseases are mainly caused by rotifers, tongue cup worms and third-generation parasites. Loach is thin, often floating on the surface, anxious, or turning on the water surface, and the body surface mucus is increased. The prevention and control method is to use 0.7ppm copper sulfate and ferrous sulfate mixture (5 ∶ 2) to control rotifer and tongue trichlorfon in the whole pool, and to sprinkle 90% crystal trichlorfon in the whole pool to control the third generation disease.

Fishing, temporary cultivation and transportation of Loach in Taiwan

The main results are as follows: 1. Fish is caught in a net at the bottom of the pond. As the water flows out of the outlet, the Taiwan Loach is slowly concentrated in the fish-collecting pit, and some of it flows into the fish-collecting pit with the water, and then rinses the fish-collecting pit with water to make the Taiwan Loach concentrate in the net.

2. After temporary cultivation of Taiwan Loach for capture, whether for domestic sale or outward transportation, it must be temporarily raised in fish baskets, cages, water tanks or cement ponds with clear water (not fed) for several days. The purpose is to remove the feces in the fish body and improve the survival rate of transportation; remove the fishy smell of the Taiwan Loach meat and improve the edible taste; concentrate the Taiwan Loach in one place to facilitate batch transportation.

3. The respiratory function of the skin of transport adult Loach is very strong, and the transportation is convenient. Short-range transport can take dry transport, that is, Taiwan Loach is packed in a container to keep the skin moist for close transport; medium-range transport can be shipped in wooden barrels or fish baskets; generally, 1kg water body can be loaded with 1kg~1.5kg Taiwan Loach, and the temperature can be maintained for 5 hours to 8 hours at 15 ℃; long-distance transport should adopt cooling measures to put the fresh Taiwan Loach in a refrigerated car with a temperature control of about 5 ℃.

Management technique of raising Taiwan Loach in Pond

1, pond construction: the pond should be close to the water source, with an area of 200-400 square meters and a water depth of 0.7-1 m; the wall of the pond is made of brick and stone, or hammered with concrete, and the bottom of the pond is rammed, which is required to be sturdy and durable without leakage; the inlet and outlet is blocked with wire or plastic net; the bottom of the pond is inclined to the outlet for drainage and fishing. Leave 10 cm of water and disinfect the pond with 50 kg of quicklime and 15 kg of bleach per mu.

2. Loach species stocking: it is best to choose Taiwan Loach (also known as True Taiwan Loach) or large scale Paramisgurnus anguillicaudatus. After cleaning the pond for 7 days, the water was injected 20-30 cm deep. Apply enough base fertilizer on the sunny side of the pond and deepen the water to 40-50 cm. Three days later, the Loach species were released, and 100-150 Loach species with a body length of 3-5 cm or 60-70 species with a body length of more than 6 cm were placed on each square meter of water surface.

3. Feed feeding: set up a fixed-point feeding platform, which is usually fed once every morning and once in the afternoon, and the daily feeding amount is 5-10% of the body weight of Taiwan Loach in the pond. The specific amount of feeding depends on the water quality, weather and the feeding situation of Loach in Taiwan. The water temperature is too high and the thunderstorm is not allowed.

4. Water quality regulation: reasonable fertilization according to pool water fertility, pool water transparency should be controlled at 15-20 cm, water color should be yellowish green. When the water temperature exceeds 30 ℃, the Misgurnus anguillicaudatus will drill into the mud to avoid the heat, which is easy to cause anoxia and asphyxiation. At this time, new water should be injected frequently to adjust the water temperature and increase the content of dissolved oxygen in the water. At the same time, shading measures should be taken to shade the sun with aquatic plants such as water hyacinth and duckweed. When the Misgurnus anguillicaudatus swims to the surface to "swallow air", it shows that there is a lack of oxygen in the water and should stop fertilizing and inject new water in time. In winter, it is necessary to deepen the water level and raise the water temperature to ensure that Taiwan Loach can survive the winter safely.

5. prevention of diseases and enemies: disinfect frequently and grasp "Sanxiao", that is, Loach body disinfection, pond disinfection and table disinfection. When it is found that Taiwan Loach is dead, it is immediately removed to prevent infection of other Taiwan Loach, and timely treatment. Remove weeds by the pool, keep the breeding environment hygienic, strictly prevent frogs from invading, catch frogs in time and remove frog eggs; block the water inlet with a sieve net to prevent wild miscellaneous fish from entering the pond with the water; find birds and drive them away in time.

I think we are all very familiar with Loach, but there are many kinds of Loach. Perhaps many people in Taiwan are not particularly familiar with Loach. In fact, no matter what kind of Loach it is, as long as we understand its living habits, it is very helpful to its breeding.