A method for co-cultivating large-scale loach and mandarin fish seedlings

Abstract

The invention discloses a co-cultivation method of large-scaled paraloach and mandarin fish seedlings, and belongs to the field of freshwater fish seedling cultivation. The operation steps are as follows: 1. preparing a cultivation pond, 2. inducing spawning and hatching of mandarin fish, 3. matching breeding of large-scaled paraloach, and 4. co-cultivation of large-scaled paraloach seedlings and mandarin fish seedlings. The invention utilizes the characteristics of large-scaled paraloach that the breeding cycle is long, high-density cultivation is possible, and it is rich in nutrition to co-cultivate large-scaled paraloach seedlings and mandarin fish seedlings; the unique horizontal swimming period and morphological characteristics of large-scaled paraloach seedlings are easy to be preyed on and digested by mandarin fish seedlings, which can improve the survival rate of mandarin fish seedlings during the opening period; large-scaled paraloach seedlings are rich in nutrition and high in protein content, which promotes the rapid growth of mandarin fish seedlings, and are high-quality bait fish for mandarin fish fry to open. The invention supplies a sufficient amount of palatable bait fish when the mandarin fish opens its mouth, avoids daily catching of silver carp, bream and other fry to feed the mandarin fish fry, saves the heavy workload of manually catching bait fish fry, creatively prolongs the breeding cycle of the mandarin fish fry, and greatly increases the annual output of the mandarin fish fry.

Description

Technical Field

[0001] The invention belongs to the field of freshwater fish seedling cultivation, and particularly relates to a method for co-cultivating large-scale loach and mandarin fish seedlings. Background Art

[0002] Mandarin fish is a precious freshwater farmed fish, but its seedling production and adult fish production are relatively low in the country. In 2023, the annual production of mandarin fish was only 400,000 tons, and its price has been rising year by year. At present, the price of commercial mandarin fish has reached more than 120 yuan / kg, and the price of 5-centimeter mandarin fish seedlings has reached more than 6-7 yuan / fish, and the supply is in short supply.

[0003] The cultivation of mandarin fish fry requires the use of live bait, which is expensive and difficult to store and transport; the cultivation of mandarin fish fry during the opening period is arduous, and the existing technology requires a large amount of manpower to carry out artificial breeding of silver carp and bream for a month. The supply of bait fish is often not timely, resulting in the mandarin fish fry being weak and having poor disease resistance. In severe cases, the mandarin fish cannibalize each other; the normal germination rate of 3 cm mandarin fish in aquaculture production can only reach 30%, which is extremely low, seriously affecting the market value of mandarin fish.

[0004] The cultivation of seedlings is a crucial link in the cultivation of mandarin fish. It is necessary to solve the problem of shortage of mandarin fish seedlings so that the mandarin fish farming industry can develop healthily, stably and sustainably. Low-cost and high-yield mandarin fish seedling cultivation technology can greatly improve the survival rate of mandarin fish seedlings, reduce pollution emissions, increase production and efficiency, and increase the supply of seedlings to a greater extent, providing more high-quality mandarin fish seedlings for the cultivation of finished mandarin fish. Summary of the invention

[0005] In order to solve the serious shortage problem of mandarin fish seedlings and realize efficient cultivation of mandarin fish seedlings, the present invention provides a co-cultivation method of large-scale loach and mandarin fish seedlings.

[0006] A method for co-cultivation of large-scale paraloach and mandarin fish fry, comprising the following steps: (1) preparing a mandarin fish fry cultivation pond, (2) inducing spawning and hatching of mandarin fish, (3) co-breeding large-scale paraloach;

[0007] The method further comprises the step (4) co-cultivating the seedlings of Paraloach dasyphylla and Siniperca chuatsi;

[0008] Co-cultivation environment: The cultivation water temperature of the cultivation pond was 28±0.25℃, the dissolved oxygen was 5 mg / L, and the water level was 0.8 m;

[0009] (4.1) In the culture pond, the density is 6,500 to 7,000 fish / m 3 Three-day-old mandarin fish fry were released, and one-day-old bait fish were released at a ratio of 1:50;

[0010] The body length of the mandarin fish fry was 3.93±0.54 mm, and the body weight was 0.001±0.00082 g;

[0011] The bait fish has a body length of 3.38±0.14 mm and a body height of 0.63±0.05 cm;

[0012] (4.2) On the 1st to 5th day of cultivation, feed the bait fish at 6:00, 14:00 and 18:00 every day, with 3-4 grams of Artemia per 10,000 fry each time, and 9 grams per m 3 Feed the fish with Dongwan open-mouthed fish feed F0 in large quantities, and each feeding time is 15 minutes;

[0013] (4.3) On the 6th to 10th day of cultivation, feed the bait fish at 6:00, 10:00, 14:00 and 18:00 every day, with 4-5 grams of Artemia per 10,000 fry each time, and 12 grams of Artemia per m 3 Feed the fish with Dongwan fish feed F1 in large quantities, and each feeding time is 18 minutes;

[0014] (4.4) On the 11th to 14th day of cultivation, feed the bait fish at 6:00, 10:00, 14:00, 18:00 and 22:00 every day, with 5-6 grams of Artemia per 10,000 fry each time, and 15 grams of Artemia per m 3 Feed the fish with Dongwan fish feed F2 in large quantities, and each feeding time is 20 minutes;

[0015] In steps (4.2) to (4.4), the feeding is carried out using a biological feed feeding machine, which rotates and sprinkles microcapsule feed with a particle size of less than 1.8 mm;

[0016] During steps (4.1) to (4.4), the aquaculture management measures are as follows: Spray the entire pond with a 100 cfu / L concentration of nitrifying bacteria stock solution every other day to degrade the humus at the bottom of the pond;

[0017] The mandarin fish seedlings can germinate after 14 days of cultivation. The germination specifications are: the length of the mandarin fish seedlings reaches 3.0 cm.

[0018] The technical solution is further defined as follows:

[0019] In step (3), the induction of spawning of the mandarin fish parent is started 72 hours after the induction of spawning of the mandarin fish parent.

[0020] In step (4), the co-cultivated mandarin fish seedlings are hatched in the hatching bucket and cultured at high density for 3 days. At 28°C, the mandarin fish seedlings have completely absorbed the yolk 3 days after hatching and are placed in a cultivation pond. The mandarin fish seedlings begin to ingest the one-day-old large-scale loach seedlings for the first time from the outside world, entering the exogenous nutrition period.

[0021] During steps (4.1) to (4.4), the protein content of the Dongwan fish feed F0 is 52%, and the particle size is less than 0.2 mm, the protein content of the Dongwan fish feed F1 is 52%, and the particle size is 0.25 mm, and the protein content of the Dongwan fish feed F2 is 52%, and the particle size is 0.35 mm.

[0022] During steps (4.1) to (4.4), regarding the control of the mandarin fish worm and wheel worm: half an hour after the first feeding in the morning, lower the water level of the culture pond to 0.5 m, and use a 37% formaldehyde aqueous solution in each culture pond at a concentration of 10 g / m 3 Spray the entire pond with a concentration of , bathe for 1.5 hours, pour in new water and raise the water level to 0.8m.

[0023] During steps (4.1) to (4.4), for the control of large-scale loach bellworms: half an hour after the first feeding in the morning, use 1 g / m 3 Spray the entire pond with a concentration of , aerate for 1 hour, and leave one day between two applications.

[0024] The beneficial technical effects of the present invention are embodied in the following aspects:

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. Through the method of the present invention, 3 cm mandarin fish seedlings can be produced in 14 days, which shortens the seedling cultivation cycle and increases economic benefits.

[0027] 2. The invention improves the emergence rate of mandarin fish seedlings to more than 82.5% by selecting suitable bait fry, preventing and controlling special diseases of co-cultivation, and setting the feeding mode of the automatic feeding device; it changes the disadvantage of only 30% emergence rate of soil pond cultivation in the past. Compared with the previous large pond cultivation, the advantages are that seedlings within 3 cm grow fast, have less disease, save manpower, have strong stability, can improve the survival rate of mandarin fish seedlings, and have high unit yield; accelerate the growth of mandarin fish seedlings, the cultivation cycle of 3 cm mandarin fish seedlings is short, the operation efficiency is high, the manual operation is simple, and it can be promoted on a large scale.

[0028] 3. The breeding period of large-scaled paraloach is as long as 9 months, and it is a bait fish that is highly suitable for the cultivation of mandarin fish fry. In the past, the fertilization rate of large-scaled paraloach artificial breeding technology was below 70%, but our team has now reached more than 95%, with a high fertilization rate and a large number of bait fish fry. The high-protein characteristics of large-scaled paraloach fry are used to meet the protein needs of mandarin fish fry for rapid growth. The unique horizontal swimming period and morphological characteristics of large-scaled paraloach are easily preyed on and digested by mandarin fish fry. The breeding nodes of bait fish are mastered, and the breeding of large-scaled paraloach is started 120 hours after the breeding of mandarin fish, so as to supply the starter bait with high adaptability to mandarin fish fry in time.

[0029] 4. Through the method of the present invention, the bait fish are fed regularly in the cultivation pond in a mode of eating small meals frequently every day, so as to promote the adaptation of the bait seedlings to the growth of the mandarin fish seedlings; the bait seedlings are fed by an automatic feeding machine, creatively solving the disadvantage of uneven artificial bait spraying in the past; the nitrifying bacteria stock solution is sprayed throughout the pond, which can decompose fish feces and feed residues, remove toxic substances such as ammonia nitrogen and nitrite, purify water quality from the source, and realize the healthy cultivation of mandarin fish seedlings. The defects of low emergence rate and unstable seedling quality of mandarin fish seedlings cultivated in soil ponds are overcome. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a picture of a mandarin fish fry opening its mouth to eat a large-scale loach fry for the first time.

[0031] Figure 2 This is a picture showing the body length measurement of mandarin fish fry.

[0032] Figure 3 This is a diagram showing the weight measurement of mandarin fish fry.

[0033] Figure 4 This is the growth curve diagram for the adaptation of the large-scale loach and the mandarin fish. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with embodiments.

[0035] This experiment was conducted at the Industry-University-Research Cooperation Base of Anhui Agricultural University and Anhui Dawei Aquaculture Co., Ltd.

[0036] Example 1

[0037] (1) Prepare a mandarin fish seedling cultivation pond

[0038] The diameter of the culture pond is 6m, the depth is 0.9m, and the volume of the culture pond is 28m 3 , an aeration pipe is set on the side wall of the cultivation pool, which surrounds the side wall of the cultivation pool. The diameter of the aeration pipe is 3cm, and a brushing ladder is set in the center of the cultivation pool. The water source of the cultivation pool comes from the high-level pool, and enters the cultivation pool after being treated by a constant temperature machine and a protein filter. The water inlet is set in the middle and upper part of the pool wall, and is filtered with an iron mesh. The height of the mesh is higher than the pool water, and the top is closed to prevent the escape of fry. The cultivation pool is disinfected before the mandarin fish seedlings are released. After disinfection, a large amount of clean water is needed to clean the cultivation pool; an automatic biological bait feeder is set above the center of the cultivation pool. The water outlet aperture of the automatic feeder nozzle is 1.8mm, and the spraying range is 4 / 5 of the area of ​​the cultivation pool. The nozzle can rotate 360° for spraying.

[0039] (2) Induced spawning and hatching of mandarin fish

[0040] On April 10, the mandarin fish were caught from a special breeding pond. 4 / 5 of the pond water was pumped out and the fish were caught manually in the pond. 20 groups of parents were caught at a time. The average body length of the captured mandarin fish parents was 42.4±6.9cm and the average weight was 2021±680g. They were placed in an indoor temporary holding pond, and the first batch of mandarin fish breeding was carried out on April 11, 2023. The female mandarin fish was given a one-shot induction of labor according to DOM: 5mg / kg, A2: 100ug / kg, HCG: 2000IU / kg, and the drug concentration of the male mandarin fish was halved. After induction of labor, they were placed in an indoor mandarin fish temporary holding pond to observe the estrus time of the mandarin fish, keep the water temperature constant at 25-26℃, and use running water stimulation for 25h. The total weight of the fertilized eggs obtained after induction of labor was 3.5kg. The fertilized mandarin fish eggs were incubated in an incubation bucket independently developed by the base with 400,000 eggs / m 3 High-density incubation, incubation water temperature is constant at 28℃, hatching time is 36h, endogenous nutrition time is 72h, average egg weight is 10% of body weight, fertilization rate is 75%, hatching rate is 85%, and a total of 890,000 mandarin fish fry are hatched; after hatching, continue to incubate in the incubator for 3 days, and transfer to the pond for cultivation after 95% of the yolk is consumed; see Figure 2 and Figure 3 , the weight, body length, mouth fissure and gastrointestinal growth of the mandarin fish fry were recorded daily after they emerged from the membrane.

[0041] (3) Supporting breeding of large-scale loach

[0042] 3.1 The adaptation of the large-scale loach to the reproduction node of the mandarin fish

[0043] Combined with actual production, the induced spawning effect time of mandarin fish is 24h, the hatching water temperature is 28℃, the hatching time is 36h, the endogenous nutrition time is 72h, and then it is placed in a cultivation pond at 28℃ for opening cultivation. It takes 132h from induced spawning to the first feeding of mandarin fish seedlings with large-scaled paraloach seedlings; while the induced spawning effect time of large-scaled paraloach is 14h, the hatching water temperature is 28℃, the hatching time is 22h, and the hatching to horizontal swimming period is 24h, and it takes 60h from induced spawning to horizontal swimming of large-scaled paraloach seedlings; therefore, large-scaled paraloach starts to reproduce 72h after the mandarin fish is injected with the induced spawning injection, which just meets the mandarin fish's demand for suitable bait to start feeding.

[0044] 3.2 Reproduction of Paraloach sphaeroides

[0045] On April 14, 2023, 72 hours after the injection of oxytocin, the breeding of large-scaled paraloach was carried out. 0.1 mg / kg of loach oxytocin mixture was injected into the dorsal fin, with an effective time of 14 hours. After the injection of the oxytocin, the fish were placed in a temporary holding pond for water flow stimulation; the incubation water temperature was 28°C, the hatching time was 22 hours, and the time to reach horizontal swimming after hatching was 24 hours. The breeding female loach parents weighed 460 kg, the male loach parents weighed 100 kg, the average egg weight was 15% of the body weight, the total weight of the fertilized eggs was 67.5 kg, the fertilization rate was 95%, the hatching rate was 85%, the opening rate was 85%, and the germination rate was 82.5%. A total of 150 million large-scaled paraloach seedlings were obtained, of which 1 / 2 were cultivated in soil ponds in advance as bait fish for mandarin fish seedlings over 3 cm in height.

[0046] (4) Cultivation of large-scale loach fry and mandarin fish fry in the cultivation pond

[0047] 4.1 Mandarin fish fry cultivation environment:

[0048] On April 17, 2023, 72 hours after the mandarin fish hatched, the yolk of the mandarin fish was consumed by 95%, ending the endogenous nutrition stage. At this time, the mandarin fish were put into the breeding pond for co-cultivation. The mandarin fish were evenly placed along the edge of the pond into the outdoor hatching and breeding pond with fertilized water quality. The daily water level of the breeding pond was 0.8m, and the water temperature was constant at 28℃. The stocking density was 6,800 fish / m 3 , one breeding pond breeds 140,000 mandarin fish fry, and bait fish are stocked at a bait density of 1:50; see Figure 1 The mandarin fish fry open their mouths for the first time and are eating the large-scale loach that has just emerged from the membrane for one day and can already swim horizontally. The mandarin fish fry begin to eat bait fish from the outside world for the first time, entering the period of exogenous nutrition.

[0049] 4.2 Co-cultivation management measures

[0050] At noon every day, pay attention to the floating situation of mandarin fish on the water surface, add oxygen in time to reduce losses; use a siphon to absorb metabolic waste of mandarin fish in the breeding pond after each feeding; clean the central filter of the breeding pond twice at 10:00 and 18:00 every day; to maintain the steady state of the water environment of the breeding pond, spray nitrifying bacteria in the entire pond at a concentration of 100 cfu / L every other day to decompose fish feces and feed residues to remove toxic substances such as ammonia nitrogen and nitrite, and purify the water quality from the source.

[0051] 4.3 Preparation of Artemia

[0052] On April 16, 2023, the Artemia worms were hatched at night as biological bait in the co-cultivation mode of large-scaled loach. The incubation time in the conical hatching bucket was 18-24 hours. After the hatching, the Artemia worms were collected and filtered and collected with a 200-mesh net. The operation was repeated 3 times to complete the separation of the eggs. Artemia worms can survive in fresh water for about 1.5 hours. They need to be thoroughly cleaned twice when feeding, and then packaged in small containers and frozen for storage.

[0053] 4.4 Cultivation of Paraloach sphaeroides

[0054] By changing the feeding frequency and controlling the growth rate of the large-scale loach seedlings, we can obtain bait fish suitable for the mandarin fish seedlings and meet the palatability and nutritional requirements of the mandarin fish seedlings for bait fish.

[0055] 4.4.1 On the 1st to 5th day of cultivation, feed the 1-5 day old bait fish regularly at 6:00, 14:00 and 18:00 every day, feeding them Artemia at a rate of 3-4g / 10,000 fry each time, and feeding them Artemia at a rate of 9g / m 3 Feed the fish with Dongwan open-starter fish feed F0 in large quantities, and each feeding time is 15 minutes.

[0056] 4.4.2 On the 6th to 10th day of cultivation, feed the 6-10 day old bait fish at 6:00, 10:00, 14:00 and 18:00 every day, feeding 4-5 grams of Artemia per 10,000 fish fry each time, and 12 grams of Artemia per m 3 Feed the fish with Dongwan open-mouth fish feed F1 in large quantities, with each feeding time of 18 minutes.

[0057] 4.4.3 On the 11th to 14th day of cultivation, feed the 11th to 14th day old bait fish at 6:00, 10:00, 14:00, 18:00 and 22:00 every day, feeding 5-6 grams of Artemia per 10,000 fry each time, and 15 grams of Artemia per m 3 Feed the fish with Dongwan open-starter fish feed F2 in large quantities, with each feeding time of 20 minutes.

[0058] 4.5 Co-cultivation disease control

[0059] 4.5.1 On April 22, 2023, on the fifth day of cultivation, five mandarin fish seedlings were examined under a microscope. It was found that two of the mandarin fish seedlings had five wheelworms on their tails under one objective lens, and they were quite active. Half an hour after the first feeding in the morning, the water level in the culture pond was lowered to 0.5m, and a 37% formaldehyde aqueous solution was used in each culture pond at a rate of 10 g / m 3 The concentration was sprayed throughout the pond. After 1.5 hours of medicated bathing, new water was poured in to raise the water level to 0.8m. A microscopic examination the next day found that most of the wheelworms were inactivated, and the prevention and control effect was obvious.

[0060] 4.5.2 On April 28, 2023, on the 11th day of cultivation, five large-scaled loach seedlings were examined under a microscope. It was found that the pectoral fins of three of them had four bell-shaped worms under one objective lens. Half an hour after the first feeding in the morning, the worm net was used at a rate of 1 g / m 3 Spray the entire pond with a concentration of , increase aeration, and observe under a microscope the next day. The prevention and control effect is obvious. There should be a one-day interval between two applications of the drug.

[0061] 4.6 Feeding situation of mandarin fish fry

[0062] When the mandarin fish seedlings are 1-2 days old, they are in the yolk nutrition period and are cultured at high density in the hatching bucket. The yolk of the 3-day-old mandarin fish seedlings has consumed 95%, and they are put into the cultivation pond for co-cultivation. According to the different body lengths of the large-scaled paraloach seedlings, the 3-day-old mandarin fish seedlings only feed on the head and part of the trunk of the large-scaled paraloach, and effectively consume 6 large-scaled paraloach per day; the 6-day-old mandarin fish seedlings consume an average of 5 large-scaled paraloach per day, at this time the mandarin fish seedlings have not been able to completely consume the large-scaled paraloach, but can effectively consume 2 / 3 of the total length of the large-scaled paraloach; the 10-day-old mandarin fish seedlings consume an average of 4 large-scaled paraloach per day, at this time they can completely consume the whole large-scaled paraloach; 12-day-old mandarin fish seedlings consume 3 complete large-scaled paraloach; 14-day-old mandarin fish seedlings consume 3 complete large-scaled paraloach.

[0063] 4.7 Effect of Mandarin Fish Seedling Cultivation

[0064] As can be seen from Table 1, the method of co-cultivation of mandarin fish seedlings in the cultivation pond using large-scale loach as the starter bait in Example 1 has the advantages of fast growth of 3.0 cm seedlings, less disease occurrence, labor saving, and greater stability compared to the previous large pond cultivation. It can improve the survival rate of mandarin fish seedlings and has a high unit yield.

[0065]

[0066] 4.8 Growth of Mandarin Fish Seedlings in Cultivation Ponds

[0067] According to daily production, the adaptive growth conditions of mandarin fish fry and large-scale loach fry were recorded. See Table 2 and Table 3 for details.

[0068] 4.8.1 See Figure 4 , Growth of Mandarin fish seedlings: The body length of Mandarin fish seedlings just out of the membrane is 3.93±0.54mm, the length of the mouth is 0.75±0.13mm, and the length of the gastrointestinal tract is 2.36±0.56mm; the average body length of Mandarin fish seedlings at 6 days old is 15.57±0.42mm, the average weight is 0.250±0.012g, the average mouth is 2.14±0.15 mm, the average gastrointestinal tract length was 6.75±0.63mm, the average body length of 10-day-old mandarin fish fry was 20.98±1.2mm, the average weight was 0.325±0.018g, the average oral fissure was 4.83±0.34mm, the average gastrointestinal tract length was 8.92±0.46mm, and the average body length of 14-day-old mandarin fish fry was 30.6±1.87mm, the average weight was 0.500±0.026g, the average oral fissure was 5.22±0.39mm, and the average gastrointestinal tract length was 13.6±0.82mm.

[0069] 4.8.2 See also Figure 4Growth of large-scaled paraloach: the average body length of large-scaled paraloach seedlings just out of the membrane is 3.38±0.14mm, and the average body height is 0.5±0.02mm; the average body length of large-scaled paraloach seedlings at 6 days old is 11.79±0.43mm, and the average body height is 2.5±0.06mm; the average body length of large-scaled paraloach seedlings at 10 days old is 14.21±0.32mm, and the average body height is 3.0±0.04mm; the average body length of large-scaled paraloach seedlings at 14 days old is 22.50±0.26mm, and the average body height is 3.7±0.12mm.

[0070]

[0071]

[0072] The large-scaled loach seedlings are adapted to the growth of mandarin fish seedlings. In the breeding pond, the bait fish are fed regularly in a pattern of small and frequent meals a day, so that the mandarin fish seedlings can obtain bait fish with strong palatability and high protein content, and obtain healthy mandarin fish seedlings. After 14 consecutive days of cultivation and breeding in outdoor breeding ponds, 140,000 seedlings were released in each breeding pond. Excluding losses, 115,500 mandarin fish seedlings were produced in each pond, with an emergence rate of 82.5%. A total of 734,300 3-centimeter mandarin fish seedlings were obtained in this batch.

[0073] Example 2

[0074] The mandarin fish seedlings were cultivated according to the method of Example 1, and mandarin fish breeding was carried out on July 7, 2023, 10 groups of parent mandarin fish were induced to lay eggs, the water temperature for incubation of mandarin fish fertilized eggs was 28.5°C, the dissolved oxygen was 5 mg / L, the average egg weight was 10% of the body weight, the fertilization rate was 70%, the membrane rate was 80%, and the opening rate was 88.5%; 230 female loaches were bred on July 10, 2023 kg, 40kg of male loach were induced to lay eggs, the average egg weight was 15% of body weight, the fertilization rate was 90%, the membrane emergence rate was 89%, the opening rate was 88%, the germination rate was 85%, and 50 million large-scaled loach seedlings were obtained; 5-day-old mandarin fish seedlings grew to 1 cm, 10-year-old mandarin fish seedlings grew to 2 cm, 14-day-old mandarin fish seedlings grew to 3 cm, and the germination rate of 3 cm mandarin fish seedlings was 85%. A total of 308,000 3 cm mandarin fish seedlings were cultivated this time.

[0075] Table 4 shows the feeding situation of mandarin fish seedlings in a breeding pond (mandarin fish seedlings start to adapt to the breeding of large-scaled loach 72 hours after breeding, so the age of large-scaled loach seedlings in Table 5 is 3 days younger than that of mandarin fish seedlings). Mandarin fish seedlings are in the yolk nutrition period 1-2 days after hatching, and are cultured at high density in the hatching bucket. After the yolk is consumed by 95%, they are put into the breeding pond for co-cultivation.

[0076] The mandarin fish entering the breeding pond are 3 days old, and the suitable bait fish are 1 day old. According to the different body lengths of the large-scaled paraloach seedlings, the 3-day-old mandarin fish seedlings only feed on the heads of the 1-day-old large-scaled paraloach, and effectively consume 6 large-scaled paraloach per day; the 6-day-old mandarin fish seedlings feed on an average of 5 3-day-old large-scaled paraloach per day. At this time, the mandarin fish seedlings have not completely consumed the large-scaled paraloach, and can effectively consume 2 / 3 of the body length of the large-scaled paraloach; the 10-day-old mandarin fish seedlings feed on an average of 5 7-day-old large-scaled paraloach per day. At this time, the large-scaled loach can be completely fed with the whole large-scaled loach; at the age of 12 days, it feeds 4 large-scaled loaches that are 11 days old; the 14-day-old mandarin fish feed an average of 3 large-scaled loaches that are 11 days old per day, and the 17-day-old mandarin fish feed an average of 3 large-scaled loaches that are 14 days old per day. The number of large-scaled loaches that are fed by the mandarin fish feed is on a downward trend, indicating that the large-scaled loach breeding in the cultivation pond is in good condition, the effective feeding rate of the mandarin fish feed is high, which promotes the rapid and healthy growth of the mandarin fish feed.

[0077]

[0078] The method of the present invention has the advantages of extending the breeding period of mandarin fish, allowing mandarin fish seedlings to enter the market in advance, cultivating bait fish in the cultivation pond to make them suitable for the growth of mandarin fish seedlings, and the mandarin fish seedlings directly prey on the bait fish in the cultivation pond, thereby eliminating the heavy workload of artificially catching bait fish for feeding, timely avoiding the occurrence of diseases, ensuring the emergence rate of mandarin fish seedlings, using large-scaled loach as the bait fish co-cultivated, the mandarin fish seedlings have good physique and strong disease resistance, and high-quality cultivation of mandarin fish seedlings is achieved.

Claims

1. A method for co-cultivation of large-scale loach and mandarin fish seedlings, comprising the following steps: (1) preparing a mandarin fish seed cultivation pool, (2) inducing spawning and hatching of mandarin fish, and (3) co-breeding large-scale loach; characterized in that: The method further comprises the step (4) co-cultivating the seedlings of Paraloach dasyphylla and Siniperca chuatsi; Co-cultivation environment: The cultivation water temperature of the cultivation pond was 28±0.25℃, the dissolved oxygen was 5 mg / L, and the water level was 0.8 m; (4.1) In the rearing pond, stock 3-day-old mandarin fish at a density of 6,500 to 7,000 per cubic meter, and stock 1-day-old bait fish at a ratio of 1:50; The body length of stocked Siniperca chuatsi fry was 3.93±0.54mm, and the body weight was 0.001±0.00082g; The body length of the stocked bait fish was 3.38 ± 0.14 mm, and the body height was 0.63 ± 0.05 mm; (4.2) On the 1st to 5th day of cultivation, feed the bait fish at 6:00, 14:00 and 18:00 every day, with 3-4 grams of Artemia per 10,000 fry each time, and 9 grams / m 3 Feed Dongwan fish feed F0 in large quantities, and each feeding time is 15 minutes; (4.3) On the 6th to 10th day of cultivation, feed the bait fish at 6:00, 10:00, 14:00 and 18:00 every day, with 4-5 grams of Artemia per 10,000 fry each time, and 12 grams per m 3 Feed Dongwan fish feed F1 in large quantities, and each feeding time is 18 minutes; (4.4) On the 11th to 14th day of cultivation, feed the bait fish at 6:00, 10:00, 14:00, 18:00 and 22:00 every day, with 5-6 grams of Artemia per 10,000 fry each time, and 15 grams of Artemia per m 3 Feed Dongwan open-mouth fish feed F2 in large quantities, and each feeding time is 20 minutes; In steps (4.2) to (4.4), the feeding is carried out using a biological bait feeding machine; During steps (4.1) to (4.4), the Mandarin fish fry were dissected and their feeding habits were counted; During steps (4.1) to (4.4), the growth of mandarin fish seedlings and large-scale loach seedlings were measured; The mandarin fish seedlings can be germinated after 14 days of cultivation. The germination specifications are: the length of mandarin fish seedlings reaches 3 cm, and the germination rate reaches more than 82.5%; In step (3), the large-scaled loach begins to reproduce 72 hours after the mandarin fish is injected with the oxytocin injection, which just meets the mandarin fish's demand for suitable bait to start eating.

2. The method for co-cultivating seedlings of Paraloach sphaerocephalus and Siniperca chuatsi according to claim 1, characterized in that: In step (4), the co-cultivated mandarin fish seedlings are hatched in an incubation bucket and cultured at a high density for 3 days. At 28°C, the mandarin fish seedlings have completely absorbed the yolk 3 days after hatching, and the endogenous nutrition stage is over. After being placed in a cultivation pond, the mandarin fish seedlings begin to eat bait fish from the outside for the first time, entering the exogenous nutrition stage.

3. The method for co-cultivating seedlings of Paraloach maculatus and Siniperca chuatsi according to claim 1, characterized in that: During steps (4.1) to (4.4), the protein content of the Dongwan fish feed F0 is 52%, and the particle size is less than 0.2 mm, the protein content of the Dongwan fish feed F1 is 52%, and the particle size is 0.25 mm, and the protein content of the Dongwan fish feed F2 is 52%, and the particle size is 0.35 mm.

4. The method for co-cultivating seedlings of Paraloach maculatus and Siniperca chuatsi according to claim 1, characterized in that: During steps (4.1) to (4.4), regarding the control of the mandarin fish worm and wheel worm: half an hour after the first feeding in the morning, lower the water level of the culture pond to 0.5 m, and use a 37% formaldehyde aqueous solution in each culture pond at a concentration of 10 g / m 3 Spray the entire pond with a concentration of , bathe for 1.5 hours, pour in new water and raise the water level to 0.8m.

5. The method for co-cultivating seedlings of Paraloach maculatus and Siniperca chuatsi according to claim 1, characterized in that: During steps (4.1) to (4.4), for the control of large-scale loach bellworms: half an hour after the first feeding in the morning, use 1 g / m 3 Spray the entire pond with a concentration of , aerate for 1 hour, and leave one day between two applications.

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