Domestication method of wild sal-family pseudosciaena crocea fry

Abstract

The invention provides a domestication method of wild sal-family large yellow croaker fries, and belongs to the technical field of aquaculture. The method comprises the following steps: capturing wild fry of the halitium larimichthys crocea, transporting the wild fry to a culture pond for temporary culture, and then sequentially carrying out live bait domestication, chilled bait domestication, soft pellet feed domestication and artificial matched pellet feed domestication culture. According to the method, live baits loved by the wild sal-family pseudosciaena crocea are fed and are gradually transited to special artificial compound feed, so that the feeding habit and digestive system of the wild sal-family pseudosciaena crocea are gradually adapted, the wild sal-family pseudosciaena crocea can be successfully converted to eat the artificial compound feed after being domesticated for 20 days, the survival rate reaches 63% or above, and the phenomenon of batch death does not occur during domestication. According to the method, the survival rate of the fries domesticated from the wild sal-family large yellow croaker fries into the fries under the artificial breeding condition is effectively increased, and a guarantee is provided for building an artificial breeding basic parent fish group.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and in particular relates to a method for domesticating wild Naozhou large yellow croaker fry. Background Art

[0002] According to the population ecology, my country's yellow croaker is generally divided into three groups, namely the Fujian-Yuedong yellow croaker represented by Ningde, Fujian, the Daiqu yellow croaker in Zhoushan, Zhejiang, and the Naozhou yellow croaker mainly in the coastal waters of Naozhou, Guangdong. Among them, the yellow croakers of the Fujian-Yuedong and Daiqu populations have been developed and studied, and have formed industrial scales in Fujian, Zhejiang and other places, while the Naozhou yellow croaker has not yet been developed and utilized. The Naozhou yellow croaker has a unique advantage in adapting to the high sea conditions of deep-sea aquaculture. This feature makes it a more advantageous variety in the development of deep-sea aquaculture in Guangdong. After large-scale aquaculture, it will effectively solve the industrial development bottleneck of the poor high temperature resistance of the Fujian-Yuedong yellow croaker and the Zhejiang Daiqu yellow croaker, which cannot be fully aquacultured in the South China Sea. It is expected to become an important development variety for deep-sea aquaculture in the South China Sea in the future.

[0003] Due to the destruction of spawning grounds and overfishing, the germplasm resources of wild Naozhou large yellow croaker have shown obvious signs of decline. Maintaining a sufficient number of high-quality Naozhou large yellow croaker parents after artificial domestication has become one of the key technical bottlenecks restricting the large-scale artificial breeding and aquaculture promotion of Naozhou large yellow croaker. Since wild Naozhou large yellow croakers live in the middle and lower layers of the near sea, the stress during the capture process is relatively large, and the survival time under artificial breeding conditions is relatively short, making it difficult to build a basic broodstock population for artificial breeding. There are two main technical methods to solve the problem of artificial breeding of Naozhou large yellow croaker: one is to capture wild parents, obtain high-quality fertilized eggs through a series of operations such as temporary breeding, injection of oxytocin, and artificial insemination, and then hatch to obtain fry and fry, and then cultivate them into parents for breeding. The other method is to capture wild Naozhou large yellow croaker seedlings, make them adapt to the aquaculture environment through artificial domestication methods, and then cultivate them into parents for breeding. However, since wild Naozhou croakers are highly responsive to stress and are sensitive to environmental stimuli such as sound and light, if captured wild fry are not domesticated, they will often die in large numbers in a short period of time. Therefore, providing a method for domesticating wild Naozhou croaker fry has positive significance for the development of the artificial breeding industry of Naozhou croakers. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a method for domesticating wild Naozhou large yellow croaker fry, so as to improve the survival rate of wild Naozhou large yellow croaker fry domesticated into fry under artificial breeding conditions, and provide a guarantee for solving the problem of constructing a basic broodstock population for artificial breeding.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A method for domesticating wild Naozhou large yellow croaker seedlings comprises the following steps: capturing wild Naozhou large yellow croaker seedlings, transporting them to a breeding pond for temporary breeding, and then sequentially carrying out live bait domestication, chilled bait domestication, soft granular feed domestication and artificial compound granular feed domestication and breeding, wherein the proportion of domestication materials in the previous stage is gradually reduced in each domestication stage until the seedlings are adapted; the chilled bait domestication comprises feeding chilled fish meat, wherein the chilled fish meat is mackerel, blue round trevally or squid.

[0007] Preferably, the live bait domestication is feeding live dicynogloeospora, and the daily feeding amount of the live dicynogloeospora is 10-20% of the body weight of wild seedlings.

[0008] Preferably, the daily feeding amount of the chilled bait is 4-5% of the body weight of the wild seedlings.

[0009] Preferably, the soft pellet feed domestication includes feeding soft pellet feed, wherein the soft pellet feed is composed of chilled fish meat added with eel powder compound feed in the chilled bait domestication stage, and the daily feeding amount of the soft pellet feed is 8-10% of the body weight of wild seedlings.

[0010] Preferably, the artificial compound granular feed domestication includes feeding artificial compound granular feed, which is composed of large yellow croaker compound feed, electrolytic multivitamins and live bacteria probiotics, and the daily feeding amount of the artificial compound granular feed is 8-10% of the body weight of wild seedlings.

[0011] Preferably, the acclimation culture conditions are: water temperature 23-25°C, pH 8.2-8.4, dissolved oxygen 5.5-6.5 mg / L, ammonia nitrogen 0.01-0.05 mg / L, and light 1000-2000 lux.

[0012] Preferably, the wild seedlings are wild large yellow croaker of the Naozhou ethnic group with a mass of 50-100g.

[0013] Preferably, during the transportation of the wild seedlings to the breeding pond, the water temperature is 22-24°C and the dissolved oxygen is ≥5.0 mg / L.

[0014] Preferably, esterified vitamin C is added to the culture pond, and the amount of esterified vitamin C added is 4-6 mg / m 3 Water body.

[0015] Preferably, during the domestication of the chilled bait, the soft pellet feed and the artificially compound pellet feed, after feeding the domestication material of each domestication stage, the residual material is sucked out and the water is changed.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The invention provides a method for domesticating wild Naozhou large yellow croaker seedlings, wherein appropriate bait is selected according to the natural feeding habits of the Naozhou large yellow croaker, and the feeding habits and digestive system of the wild Naozhou large yellow croaker are gradually adapted by feeding the live bait that the wild Naozhou large yellow croaker likes to eat, and the artificial compound feed can be successfully converted after 20 days of domestication, and the survival rate reaches more than 63%, and no mass death occurs during the domestication period. The invention effectively improves the survival rate of wild Naozhou large yellow croaker seedlings domesticated into seedlings under artificial breeding conditions, and provides a guarantee for solving the problem of building a basic parent fish population for artificial breeding. DETAILED DESCRIPTION

[0018] The invention provides a method for domesticating wild Naozhou large yellow croaker fry, comprising the following steps: capturing the wild Naozhou large yellow croaker fry, transporting them to an indoor breeding pond for temporary breeding, and then sequentially carrying out live bait domestication, ice fresh bait domestication, soft granular feed domestication and artificial compound granular feed domestication breeding.

[0019] The invention selects appropriate bait according to the natural feeding habits of the Naozhou large yellow croaker, gradually transitions to special artificial compound feed by feeding the wild Naozhou large yellow croaker with live bait that the fish likes to eat, so that the feeding habits and digestive system of the wild Naozhou large yellow croaker gradually adapt, and effectively improves the survival rate of the wild Naozhou large yellow croaker seedlings domesticated into seedlings under artificial breeding conditions.

[0020] The present invention sets a trap net on the migration route of Naozhou croaker in the sea area near Naozhou Island, Zhanjiang, Guangdong. The net is composed of a net wall, a net body and a net bag, with a total length of 140 meters, a total width of 140 meters, a total height of 5 meters, a net wall mesh of 5 centimeters, and a net body mesh of 10 centimeters. The purpose of capturing seedlings is achieved by setting an interception on the migration route of Naozhou croaker. The present invention allows the Naozhou croaker to be trapped in the net and then captured by interception, which can effectively improve the survival rate of capture and the survival rate of domestication. The seedlings described in the present invention are fry of 50-100g of wild Naozhou croaker. The present invention selects fry of this specification for capture, which is easy to domesticate and has a high survival rate.

[0021] The present invention places the captured wild seedlings into a live water tank and transports them back to the harbor, and then transports them to an indoor breeding pond. In the present invention, the wild seedlings are transported to the indoor breeding pond using a special live fish transport vehicle. During the transportation process, the water temperature is 22-24° C. and the dissolved oxygen is above 5 mg / L. The present invention uses pure oxygen to oxygenate the transport water body, and uses ice bars to control the temperature in the carriage, which can ensure the survival rate of the wild seedlings, so that the survival rate of the wild seedlings can reach 75%.

[0022] After the wild seedlings in the present invention arrive at the breeding farm, it is preferred to apply erythromycin ointment to the damaged parts of the fish body to kill pathogens, promote wound healing, and avoid the death of parent fish. As an practicable method, after the wild seedlings arrive at the breeding farm, the fish are slowly picked up with a hand net and put into a plastic bucket filled with half a bucket of water, and then the fish eyes are wrapped with a wet towel, and the damaged parts of the fish body are applied with erythromycin ointment, and then slowly transferred to an indoor breeding pond. As an practicable method, the indoor breeding pond has a specification of 5m long × 4m wide × 1.5m high.

[0023] In the present invention, esterified vitamin C is added to the water in the indoor culture pond, and the amount of esterified vitamin C added is 4-6 mg / m 3 Water. The present invention can alleviate environmental stress by adding esterified vitamin C to the water, avoid the short survival time of wild seedlings due to greater stress, and improve the survival rate of wild seedlings. In the specific embodiment of the present invention, the esterified vitamin C is purchased from Guangzhou Zhengge Agriculture and Animal Husbandry Service Co., Ltd.

[0024] In the present invention, the wild seedlings are temporarily raised in an indoor breeding pond for 2-4 days, preferably for 3 days; after the temporary raising, the feed is acclimated. The wild seedlings in the present invention are temporarily raised in oxygenated flowing water, and no feeding is given during the temporary raising stage. The stocking density of the wild seedlings during the temporary raising stage is 2-3 tails / m 3 The present invention can reduce the stress of wild seedlings and improve their survival rate by temporarily raising wild seedlings.

[0025] In the present invention, the conditions for temporary rearing and domestication of wild seedlings are: water temperature 23-25°C, salinity 28-30, pH 8.2-8.4, dissolved oxygen 5.5-6.5 mg / L, ammonia nitrogen 0.01-0.05 mg / L, illumination 1000-2000 lux, and flow rate 0.3-0.5 m / s. As an implementable method, the present invention uses a sunshade net on the surface of the culture pond to adjust the light intensity. The large yellow croaker of the Naozhou tribe of the present invention is a fish of the middle and lower layers. By controlling the light intensity through shading, the stress of the environment can be alleviated and the survival rate of domestication can be improved.

[0026] After the temporary rearing, the present invention conducts live bait acclimation, feeds live double-toothed perineri twice a day at regular intervals, and preferably feeds at 8:00 and 14:00 according to the feeding habits of the Naozhou large yellow croaker; the live double-toothed perineri is 5.0-8.0 cm long, and the daily feeding amount of the lugworm is 10%-20% of the body weight of the wild seedlings, and the feeding situation of the seedlings is observed. As an practicable method, the present invention removes the remaining lugworms in the pond at 18:00 every day.

[0027] The live bait of the present invention is acclimated for 4-6 days, preferably for 5 days, and it is found that the wild Naozhou large yellow croaker fry actively chases and feeds on the live double-toothed perineri and has a food-grabbing phenomenon. At this time, the acclimation of the chilled bait can be started.

[0028] The present invention performs chilled bait domestication. According to the feeding characteristics of the large yellow croaker of the Naozhou tribe, the chilled fish meat is fed at fixed time and fixed point three times a day. The daily feeding amount of the chilled fish meat is 4-5% of the body weight of wild seedlings. The present invention preferably feeds at 8:00, 12:00 and 16:00. The present invention facilitates feeding by cutting the fish meat into blocks, and is not easy to pollute water quality. The chilled fish meat of the present invention is fresh seawater fish purchased from the market, and the chilled fish meat is preferably mackerel, blue round scad or squid. As an practicable method, the present invention washes the fish meat, shaves the back muscles, disinfects with iodine preparations, cuts into blocks and then feeds.

[0029] The present invention feeds chilled fish meat for 1 hour each time, and then feeds live dicynogloeospora after the end, and the feeding amount of the live dicynogloeospora is reduced day by day. In the present invention, on the 1st to 2nd day of chilled bait acclimation, the feeding amount of the live dicynogloeospora is reduced by 25-35% compared with the live bait acclimation stage, on the 3rd day, the feeding amount of the live dicynogloeospora is reduced by 45-55% compared with the live bait acclimation stage, on the 4th day, the feeding amount of the live dicynogloeospora is reduced by 75-85% compared with the live bait acclimation stage, and on the 5th day, it is observed that the wild Naozhou large yellow croaker seedlings can normally eat chilled fish meat, and the acclimation of soft granular feed begins at this time.

[0030] In the chilled bait acclimation stage of the present invention, the amount of water change is increased, and 30 minutes after each feeding of chilled fish meat, the residual bait is sucked and the water is changed, and the amount of water change is 100%. As an implementable method, the present invention adopts a siphon method to suck the residual bait. The present invention ensures that the water quality meets the growth requirements of the wild seedlings of the Naozhou tribe large yellow croaker by timely removing the residual bait and performing a large amount of water change.

[0031] The present invention performs soft pellet feed domestication, feeds the soft pellet feed at regular times and fixed points three times a day, and the daily feeding amount of the soft pellet feed is 8-10% of the body weight of wild seedlings; the present invention preferably feeds at 8:00, 12:00 and 16:00. The soft pellet feed is composed of chilled fish meat in the chilled bait domestication stage, and eel powdered compound feed is added. The added mass of the chilled fish meat is 75-85% of the mass of the soft pellet feed. As an implementable method, the chilled fish meat is minced and then added with eel powdered compound feed, and then water is added and stirred evenly, and then fed after being kneaded into 1-2 cm strips. In the specific embodiment of the present invention, the eel powdered compound feed is purchased from Fujian Tianma Feed Co., Ltd.

[0032] The present invention feeds soft pellet feed for 30 minutes each time, and then feeds chilled fish meat after the feeding, and the feeding amount of the chilled fish meat decreases day by day. In the present invention, on the first day of soft pellet feed acclimation, the feeding amount of the chilled fish meat is reduced by 45-55% compared with the chilled bait acclimation stage, on the second day, the feeding amount of the chilled fish meat is reduced by 75-85% compared with the chilled bait acclimation stage, and on the third day, it is observed that the wild Naozhou large yellow croaker seedlings can normally eat the soft pellet feed, and the acclimation of the artificial compound pellet feed begins at this time.

[0033] In the soft pellet feed domestication stage of the present invention, after each feeding of the soft pellet feed, the sewage is sucked out and the water is changed, and the amount of water changed is 80-100%; as an practicable method, the present invention adopts a siphon method to absorb the residual bait. The present invention ensures that the water quality meets the growth requirements of the wild seedlings of the Naozhou tribe large yellow croaker by timely removing the residual bait and changing a large amount of water. As an practicable method, the present invention adds EM bacteria to regulate the water quality according to the water quality conditions. The EM bacteria are purchased from Hubei Fengtian Biotechnology Co., Ltd., and the method of use refers to the method recommended by the manufacturer.

[0034] The present invention performs artificial compound granular feed domestication, feeds the artificial compound granular feed at a fixed time and place three times a day, and the daily feeding amount of the artificial compound granular feed is 8-10% of the body weight of wild seedlings; the present invention preferably feeds at 8:00, 12:00 and 16:00. The artificial compound granular feed is composed of large yellow croaker compound feed, electrolytic multivitamin and live bacteria probiotics, and the mass ratio of the large yellow croaker compound feed, electrolytic multivitamin and live bacteria probiotics is 1000:0.8-1.2:2.8-3.2. As an implementable method, the electrolytic multivitamin and live bacteria probiotics are dissolved in water, and then adsorbed with large yellow croaker compound feed, and the material-liquid ratio of the large yellow croaker compound feed to the aqueous solution is 50-100g:1mL, preferably 60-80g:1mL, and more preferably 70g:1mL. In the specific embodiment of the present invention, the electrolytic multivitamin was purchased from Zhejiang Shengda Biotechnology Co., Ltd., the live bacteria probiotic was purchased from Cangzhou Yihong Biotechnology Co., Ltd., and the large yellow croaker compound feed was purchased from Fujian Tianma Technology Group Co., Ltd.

[0035] The present invention feeds artificial compound granular feed for 30 minutes each time, and then feeds soft granular feed after the feeding, and the feeding amount of the soft granular feed is reduced day by day. In the present invention, on the first day of artificial compound granular feed acclimation, the feeding amount of the soft granular feed is reduced by 25-35% compared with the soft granular feed acclimation stage, on the second day, the feeding amount of the soft granular feed is reduced by 45-55% compared with the soft granular feed acclimation stage, on the third day, the feeding amount of the soft granular feed is reduced by 75-85% compared with the soft granular feed acclimation stage, and on the fourth day, it is observed that the wild Naozhou large yellow croaker seedlings can normally eat the artificial compound granular feed, and at this time, the wild Naozhou large yellow croaker seedlings are successfully acclimated.

[0036] In the artificial compound pellet feed domestication stage of the present invention, after each feeding of the artificial compound pellet feed, the sewage is sucked out and the water is changed, and the amount of water changed is 80-100%; as an implementable method, the present invention adopts a siphon method to absorb the residual bait. The present invention ensures that the water quality meets the growth requirements of the wild seedlings of the Naozhou tribe large yellow croaker by timely removing the residual bait and changing a large amount of water. As an implementable method, the present invention adds EM bacteria to regulate the water quality according to the water quality conditions. The EM bacteria are purchased from Hubei Fengtian Biotechnology Co., Ltd., and the method of use refers to the method recommended by the manufacturer.

[0037] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example 1

[0039] Capturing wild seedlings: Set up trap nets on the migration route of Naozhou croaker in the waters near Naozhou Island, Zhanjiang, Guangdong. The net consists of a net wall, a net body and a net bag, with a total length of 140 meters, a total width of 140 meters, a total height of 5 meters, a net wall mesh of 5 cm, and a net body mesh of 10 cm. Set up interception on the migration route of Naozhou croaker to capture seedlings. Select 50-100g of wild Naozhou croaker seedlings, slowly put the seedlings into the live water tank with a hand net, and oxygenate the live water tank to more than 5mg / L.

[0040] Transport to the breeding pond: After the fishing boat returns to the harbor, use plastic buckets to slowly transfer the wild seedlings with water to a special live fish transport vehicle. The live fish transport vehicle uses pure oxygen to increase the oxygen concentration to more than 5mg / L, and uses ice bars to cool the compartment to control the water temperature at 23℃. After arriving at the breeding farm, use a hand net to slowly scoop up the fish and put it into a plastic bucket filled with half a bucket of water, then wrap the fish eyes with a wet towel, apply erythromycin ointment to the damaged parts of the fish body, and then slowly transfer it to an indoor breeding pond (5m long × 4m wide × 1.5m high).

[0041] Temporary domestication: Sprinkle esterified vitamin C in the water in advance, with a dosage of 5 mg per cubic meter of water, to alleviate the stress response caused by environmental changes. Water quality conditions are: water temperature 25℃, salinity 28, pH8.3, dissolved oxygen 6.0 mg / L, ammonia nitrogen 0.02 mg / L, water flow rate 0.5 m / s, temporary domestication for 2 days, no feeding during the temporary domestication period, and use a sunshade net to adjust the light intensity on the pool surface to control it at 1500 lux.

[0042] Live feed acclimation: After the temporary rearing, live double-toothed peri-negworms are regularly released at 8:00 and 14:00 every day. The body length is 5.0-8.0cm, and the stocking density is 3-5 per square meter. The daily feeding amount of negworms is 15% of the body weight of wild seedlings. Observe the feeding situation of the seedlings. The remaining negworms in the pond are scooped out with a scoop net at 18:00 every day. The water quality control is the same as that in the temporary rearing stage. After 6 days of live feed acclimation, the wild Naozhou tribe yellow croaker seedlings actively chase the negworms and have a phenomenon of snatching food. At this time, the acclimation of ice fresh bait can be started.

[0043] Frozen bait acclimation: From the first day of acclimation, the daily feeding amount of frozen fish meat is 4% of the body weight of wild fry fish. Frozen fish meat is fed at a fixed point beside the pond at 8:00, 12:00 and 16:00 every day. The fish meat is fresh mackerel purchased from the market that day, which is washed, the back muscles are shaved, iodine-sterilized, and cut into 1-2cm 3 Feed in blocks. Each feeding lasts for 1 hour, and then feed live dicynogloeiformes. The amount of live dicynogloeiformes fed decreases day by day. On the 1st and 2nd days of acclimation with chilled bait, the amount of live dicynogloeiformes fed is reduced by 30% compared with the live bait acclimation stage. On the 3rd day, the amount of live dicynogloeiformes fed is reduced by 50% compared with the live bait acclimation stage. On the 4th day, the amount of live dicynogloeiformes fed is reduced by 80% compared with the live bait acclimation stage. From the 5th day, it was observed that wild Naozhou large yellow croaker fry were able to eat chilled fish meat normally, and at this time, acclimation with soft granular feed began.

[0044] During the acclimation period of chilled bait, the water quality conditions should be controlled in the same way as in the temporary breeding stage. In addition, the amount of water change should be increased. Half an hour after each feeding of chilled fish, the remaining bait should be sucked out by siphoning and the water should be changed. The water change amount should be 100%.

[0045] Soft pellet feed acclimation stage: From the first day of soft pellet feed acclimation, soft pellet feed is fed at a fixed point by the pool at 8:00, 12:00 and 16:00 every day. The soft pellet feed is mainly made of the chilled fish meat used in the previous stage, which is crushed as the feed base, accounting for 80%, and eel powdered compound feed is added, accounting for 20%. After adding an appropriate amount of water and stirring evenly, it is kneaded into 1-2cm strips for feeding. The daily feeding amount of soft pellet feed is 10% of the body weight of wild seedlings. Regular feeding lasts for 30 minutes every day, and then chilled fish meat is fed. On the first day of soft pellet feed acclimation, the amount of fish meat fed is reduced by 50%, and on the second day, the amount of fish meat fed is reduced by 80%. From the third day, it is observed that wild Naozhou large yellow croaker seedlings can normally eat soft pellet feed, and then the acclimation of artificial compound feed begins.

[0046] During the soft pellet feed acclimation period, the water quality conditions should be controlled in the same way as in the temporary breeding stage. In addition, the amount of water change should be increased. After each feeding of soft pellet feed, the sewage should be sucked out and the water should be changed in time. The water change amount should be 80-100%.

[0047] Artificial compound pellet feed acclimation stage: From the first day of artificial compound pellet feed acclimation, feed artificial compound pellet feed at a fixed point by the pool at 8:00, 12:00 and 16:00 every day. Purchase the large yellow croaker compound feed produced by Fujian Tianma Technology Group Co., Ltd., supplemented with electrolytic multivitamins and live bacteria probiotics, and the mass ratio of large yellow croaker compound feed, electrolytic multivitamins, and live bacteria probiotics is 1000:1:3. First dissolve the electrolytic multivitamins and live bacteria probiotics in water, and then fully adsorb them with large yellow croaker compound feed. The large yellow croaker compound feed and the liquid-to-liquid ratio of the aqueous solution is 70g:1mL. After adsorption, dry it for 10 minutes before feeding. The daily feeding amount of artificial compound pellet feed is 9% of the body mass of wild seedlings. Feed it regularly and continuously for 30 minutes every day, and then feed soft pellet feed. On the first day of artificial compound feed acclimation, the soft pellet feed was reduced by 30%, on the second day, the soft pellet feed was reduced by 50%, and on the third day, the soft pellet feed was reduced by 80%. From the fourth day onwards, the seedlings were able to eat the artificial compound feed normally, indicating that the wild Naozhou large yellow croaker seedlings were successfully acclimated.

[0048] During the acclimation period of artificial compound pellet feed, the water quality conditions should be controlled in the same way as in the temporary breeding stage. In addition, the amount of water change should be increased. After each feeding of artificial compound pellet feed, the sewage should be sucked out and the water should be changed in time. The water change amount should be 80-100%.

[0049] In this embodiment, 150 wild large yellow croaker fry were captured for domestication. After 20 days of domestication, 95 fry were successfully converted to eat artificial compound feed, with a survival rate of about 63.3%. No mass death occurred during the domestication period.

[0050] Example 2

[0051] Capturing wild seedlings: In the waters near Naozhou Island, Zhanjiang, Guangdong, a trap net is set up on the migration route of Naozhou croaker. The net consists of a net wall, a net body and a net bag, with a total length of 140 meters, a total width of 140 meters, a total height of 5 meters, a net wall mesh of 5 cm, and a net body mesh of 10 cm. Set up interception on the migration route of Naozhou croaker to capture seedlings. Select 50-100g of wild Naozhou croaker seedlings, slowly put the seedlings into the live water tank with a hand net, and oxygenate the live water tank to more than 5mg / L.

[0052] Transport to the breeding pond: After the fishing boat returns to the harbor, the wild seedlings are slowly transferred to the special live fish transport vehicle with water in a plastic bucket. The live fish transport vehicle uses pure oxygen to increase the oxygen concentration to 6mg / L, and the compartment is cooled with ice bars to control the water temperature at 22℃. After arriving at the breeding farm, the fish are slowly picked up with a hand net and put into a plastic bucket filled with half a bucket of water, and then the fish eyes are wrapped with a wet towel. After applying erythromycin ointment to the damaged part of the fish body, it is slowly transferred to the indoor breeding pond (5m long × 4m wide × 1.5m high).

[0053] Temporary domestication: Sprinkle esterified vitamin C in the water in advance, with a dosage of 6 mg per cubic meter of water, to alleviate the stress response caused by environmental changes. Water quality conditions are: water temperature 24℃, salinity 29, pH8.4, dissolved oxygen 5.5mg / L, ammonia nitrogen 0.03mg / L, water flow rate 0.4m / s, temporary domestication for 3 days, no feeding during the temporary domestication period, and use a sunshade net to adjust the light intensity on the pool surface to control it at 1200lux.

[0054] Live feed acclimation: After the temporary rearing, live double-toothed peri-negworms are regularly released at 8:00 and 14:00 every day. The body length is 5.0-8.0cm, and the stocking density is 3-5 per square meter. The daily feeding amount of negworms is 15% of the body weight of wild seedlings. The feeding situation of the seedlings is observed. The remaining negworms in the pond are scooped out with a scoop net at 18:00 every day. The water quality control is the same as that in the temporary rearing stage. After 5 days of live feed acclimation, the wild Naozhou tribe yellow croaker seedlings actively chase the negworms and have a phenomenon of snatching food. At this time, the acclimation of ice fresh bait can be started.

[0055] Frozen bait acclimation: From the first day of acclimation, the daily feeding amount of frozen fish meat is 4% of the body weight of wild fry fish. Frozen fish meat is fed at a fixed point beside the pond at 8:00, 12:00 and 16:00 every day. The fish meat is fresh blue round scad purchased from the market that day. It is washed, the back muscles are shaved, iodine-sterilized, and cut into 2cm 3 Feed in blocks. Each feeding lasts for 1 hour, and then feed live dicynogloeiformes. The amount of live dicynogloeiformes fed decreases day by day. On the 1st and 2nd days of acclimation with chilled bait, the amount of live dicynogloeiformes fed is reduced by 28% compared with the live bait acclimation stage. On the 3rd day, the amount of live dicynogloeiformes fed is reduced by 52% compared with the live bait acclimation stage. On the 4th day, the amount of live dicynogloeiformes fed is reduced by 76% compared with the live bait acclimation stage. From the 5th day, it was observed that wild Naozhou large yellow croaker fry were able to eat chilled fish meat normally, and the acclimation of soft granular feed began at this time.

[0056] During the acclimation period of chilled bait, the water quality conditions should be controlled in the same way as in the temporary breeding stage. In addition, the amount of water change should be increased. Half an hour after each feeding of chilled fish, the remaining bait should be sucked out by siphoning and the water should be changed. The water change amount should be 100%.

[0057] Soft pellet feed acclimation stage: From the first day of soft pellet feed acclimation, soft pellet feed is fed at a fixed point by the pool at 8:00, 12:00 and 16:00 every day. The soft pellet feed is mainly made of the chilled fish meat used in the previous stage as the feed basis, accounting for 76%, and eel powder compound feed is added, accounting for 24%. After adding an appropriate amount of water and stirring evenly, it is kneaded into 2cm strips for feeding. The daily feeding amount of soft pellet feed is 10% of the body weight of wild seedlings. Feeding is carried out regularly for 30 minutes every day, and then chilled fish meat is fed. On the first day of soft pellet feed acclimation, the feeding amount of chilled fish meat is reduced by 48% compared with the chilled bait acclimation stage. On the second day, the feeding amount of chilled fish meat is reduced by 82% compared with the chilled bait acclimation stage. From the third day, it is observed that wild Naozhou large yellow croaker seedlings can normally eat soft pellet feed, and then the acclimation of artificial compound feed begins.

[0058] During the soft pellet feed acclimation period, the water quality conditions should be controlled in the same way as in the temporary breeding stage. In addition, the amount of water change should be increased. After each feeding of soft pellet feed, the sewage should be sucked out and the water should be changed in time, and the water change amount should be 100%.

[0059] Artificial compound pellet feed acclimation stage: From the first day of artificial compound pellet feed acclimation, feed artificial compound pellet feed at a fixed point by the pool at 8:00, 12:00 and 16:00 every day. Purchase the large yellow croaker compound feed produced by Fujian Tianma Technology Group Co., Ltd., supplemented with electrolytic multivitamins and live bacteria probiotics, and the mass ratio of large yellow croaker compound feed, electrolytic multivitamins, and live bacteria probiotics is 1000:1.1:2.8. First dissolve the electrolytic multivitamins and live bacteria probiotics in water, and then fully adsorb them with large yellow croaker compound feed. The large yellow croaker compound feed and the liquid ratio of the aqueous solution are 80g:1mL. After adsorption, dry it for 15 minutes before feeding. The daily feeding amount of artificial compound pellet feed is 8% of the body mass of wild seedlings. Feed it regularly and continuously for 30 minutes every day, and then feed soft pellet feed. On the first day of artificial compound feed acclimation, the soft pellet feed was reduced by 32%, on the second day, the soft pellet feed was reduced by 48%, and on the third day, the soft pellet feed was reduced by 80%. From the fourth day onwards, the seedlings were able to eat the artificial compound feed normally, indicating that the wild Naozhou large yellow croaker seedlings were successfully acclimated.

[0060] During the acclimation period of artificial compound granular feed, the water quality conditions should be controlled in the same way as in the temporary breeding stage. In addition, the amount of water change should be increased. After each feeding of artificial compound granular feed, the sewage should be sucked out and the water should be changed in time, and the water change amount should be 100%.

[0061] In this embodiment, 210 wild large yellow croaker fry were captured for domestication. After 20 days of domestication, 140 fry were successfully converted to feed on artificial compound feed, with a survival rate of about 66.7%. No mass death occurred during the domestication period.

[0062] Example 3

[0063] The difference between this embodiment and embodiment 1 is that the conditions for temporary rearing and acclimatization of wild seedlings are: water temperature 25°C, salinity 30, pH 8.2, dissolved oxygen 6.5 mg / L, ammonia nitrogen 0.04 mg / L, light 2000 lux, and water flow rate 0.4 m / s.

[0064] In this embodiment, 180 wild large yellow croaker fry were captured for domestication. After 20 days of domestication, 130 fry were successfully converted to feed on artificial compound feed, with a survival rate of about 72.2%. No mass death occurred during the domestication period.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for domesticating wild Naozhou large yellow croaker fry, characterized in that: The method comprises the following steps: capturing wild Naozhou large yellow croaker seedlings, transporting them to a breeding pond for temporary breeding, and then sequentially carrying out live bait acclimatization, chilled bait acclimatization, soft granular feed acclimatization and artificial compound granular feed acclimatization breeding, and gradually reducing the proportion of acclimatization materials in the previous stage in each acclimatization stage until the seedlings are adapted; the chilled bait acclimatization comprises feeding chilled fish meat, and the chilled fish meat is mackerel, blue round trevally or squid.

2. The acclimation method according to claim 1, characterized in that: The live bait domestication is feeding live dicynogloeospora, and the daily feeding amount of the live dicynogloeospora is 10-20% of the body weight of wild seedlings.

3. The acclimation method according to claim 1, characterized in that: The daily feeding amount of the chilled bait is 4-5% of the body weight of the wild seedlings.

4. The acclimation method according to claim 1, characterized in that: The soft pellet feed domestication includes feeding the soft pellet feed, which is composed of the chilled fish meat in the chilled bait domestication stage and the eel powder compound feed, and the daily feeding amount of the soft pellet feed is 8-10% of the body weight of the wild seedlings.

5. The acclimation method according to claim 1, characterized in that: The artificial compound granular feed domestication includes feeding the artificial compound granular feed, which is composed of large yellow croaker compound feed, electrolytic multivitamins and live bacteria probiotics. The daily feeding amount of the artificial compound granular feed is 8-10% of the body weight of wild seedlings.

6. The acclimation method according to claim 1, characterized in that: The acclimation and culture conditions are: water temperature 23-25° C., pH 8.2-8.4, dissolved oxygen 5.5-6.5 mg / L, ammonia nitrogen 0.01-0.05 mg / L, and light 1000-2000 lux.

7. The acclimation method according to claim 1, characterized in that: The wild seedlings are wild large yellow croaker of the Naozhou tribe with a mass of 50-100g.

8. The acclimation method according to claim 1, characterized in that: During the transportation of the wild seedlings to the breeding pond, the water temperature is 22-24°C and the dissolved oxygen is ≥5.0 mg / L.

9. The acclimation method according to claim 1, characterized in that: Esterified vitamin C is added into the culture pond, and the amount of esterified vitamin C added is 4-6 mg / m 3 Water body.

10. The acclimation method according to claim 1, characterized in that: During the domestication process of the chilled bait, the soft pellet feed and the artificial compound pellet feed, after feeding the domestication material at each domestication stage, the residual material is sucked out and the water is changed.