Industrialized cultivation method for cephalopholis sonnerati fry

Abstract

The present invention relates to the technical field of aquaculture and breeding of seawater fishes, in particular to an industrialized cultivation method for cephalopholis sonnerati fry, comprising the steps of successively subjecting parent fishes of cephalopholis sonnerati to feed domestication and nutrient enrichment at a water temperature of 25-29°C and under a flowing water condition, so as to obtain parent fishes with fully developed gonads, etc. The present invention takes strict measures for fry quality control and infectious disease prevention and control during industrialized workshop cultivation, so as to effectively optimize the growth conditions of fry, thus increasing the growth rate and improves the health conditions and adaptability of fry while reducing the risk of diseases. By means of standardized breeding management and technical means, the growth environment and feeding management of fry can be controlled, thus effectively improving production efficiency. The cultivated cephalopholis sonnerati has the advantages of fast growth rate, high disease resistance, strong vigor, tender and delicious flesh and good market prospects.

Description

A method for industrialized cultivation of red spiny perch seedlings Technical Field

[0001] This invention relates to the field of marine fish aquaculture and breeding technology, and in particular to a method for the industrialized cultivation of red snapper fry. Background Technology

[0002] The red-spined sea bass (Cephalopholis sonnerati), also known as the Song's nine-spined sushi, reticulated sea bass, or red shad, belongs to the genus Cephalophorus in the family Serranidae of the order Perciformes. It is distributed in the tropical and subtropical waters of the Indo-Pacific, including the waters of East Africa, southern Japan, Australia, and Taiwan. In China, it is found in the waters of the South China Sea islands and Hainan Island. The fish is bright red, with numerous dark red round spots on the upper half of its sides and head. Juveniles have scattered black spots on their sides. The red-spined sea bass is a tropical coastal coral reef fish, inhabiting rocky areas and outer reef slopes at depths of 10–100 meters. Juveniles swim among sponges or coral reef heads, feeding on small fish, shrimp, crabs, and arthropods.

[0003] Red-spined perch, a prized aquaculture fish in my country, is highly sought after by consumers. Currently, the wild population of red-spined perch has declined significantly due to overfishing, and my country has yet to achieve a breakthrough in artificial breeding technology. There are currently no reports of successful factory-scale breeding of red-spined perch fry, nor any reports of artificially bred fry. Factory-scale breeding offers advantages such as stable water quality, high fry yield per unit area of ​​water, and low incidence of aquaculture diseases. During the breeding period, the growth and health of the fry can be effectively controlled, enabling large-scale, high-efficiency fry production and providing a stable supply, which is crucial for promoting the development of aquaculture and improving its profitability. Therefore, breaking through the artificial breeding technology of red-spined perch fry, establishing factory-scale fry cultivation methods, and realizing large-scale aquaculture of artificially bred fry have become major challenges urgently needing to be addressed in the grouper aquaculture industry.

[0004] Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method for the industrialized cultivation of red nine-spined perch seedlings. This method features stable seedling cultivation technology and a simple seedling cultivation process, enabling the mass cultivation of red nine-spined perch and realizing the industrialized breeding and aquaculture of red nine-spined perch seedlings.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for the industrialized cultivation of red snapper fry, comprising the following steps:

[0008] 1) Red snapper broodstock were subjected to feeding acclimatization and nutritional fortification in water at a temperature of 25-29℃ and under flowing water conditions to obtain broodstock with mature gonads.

[0009] The feed acclimatization includes: feeding the red snapper broodstock with live fish for 5 days after they are introduced into the pond, and then replacing the live fish with fresh bonito slices after they have stabilized.

[0010] The nutritional fortification includes: selecting parent fish weighing 2-5 jin (1.5-2 catties) and feeding them high-protein fresh feed twice a day;

[0011] 2) Naturally spawn and fertilize the mature broodstock from step 1) to obtain fertilized eggs;

[0012] 3) After the fertilized eggs obtained in step 2) are incubated to the myosarcophagus stage, they are then incubated in an incubation bag to obtain larvae;

[0013] The conditions for hatching the fertilized eggs to the myosarcogenetic stage include: a fertilized egg density of 2 million eggs / m³. 3 The water temperature is 26–28℃, the salinity is 32‰, and the pH value is 7.6–8.0.

[0014] 4) Feed the fry obtained in step 3) with live feed, and obtain fry 20 days after laying eggs;

[0015] When the fry are 3 to 7 days old, feed them daily with SS-type rotifers or copepod nauplii at a density of 3 to 5 nauplii / mL.

[0016] When the fry are 8-12 days old, feed them L-type rotifers at a density of 2-3 rotifers / mL.

[0017] When the fry are 13 to 18 days old, feed them Artemia nauplii at a density of 1 to 2 nauplii / mL.

[0018] When the larvae are 18 to 24 days old, feed them copepod nauplii at a density of 1 to 2 nauplii / mL.

[0019] When the larvae are 25-34 days old, feed them Artemia and copepod nauplii at a density of 1-2 nauplii / mL.

[0020] When the fry reach 35 days of age, feed them Artemia and copepod nauplius at a density of 1-2 per mL.

[0021] 5) After temporarily raising the fish fry obtained in step 4) for 1 day, they are then artificially cultured in an indoor workshop, including:

[0022] Aquaculture conditions in Workshop A:

[0023] The aquaculture water is fresh seawater that has been settled, filtered, and disinfected. The aquaculture water is regularly tested for pathogens and water quality to prevent the aquaculture water carrying pathogens or substandard water quality from affecting the fish fry. The water quality indicators are controlled as follows: pH 7.5-7.9, dissolved oxygen ≥5mg / L, ammonia nitrogen ≤0.5mg / L, and nitrite ≤0.05mg / L.

[0024] The seedling pond is a square cement pond with rounded corners measuring 4×4×1.2m, with a water depth of not less than 1m. It adopts central aeration and flowing water culture, and the daily water exchange volume is not less than 200% of the total water volume.

[0025] During the seedling stage, the breeding workshop, fish fry, seedling equipment, and seedling workers must be strictly disinfected to prevent the occurrence of diseases.

[0026] Methods for selecting B-type fish fry

[0027] After the red snapper fry cultivated in the outdoor pond were transferred to the indoor workshop, they were temporarily held in net cages in cement ponds and withheld from feeding for one day. Electrolytes and multivitamins were added to the water to alleviate the stress of the fry during transportation. During the temporary holding period, the vitality and swimming behavior of the fry were observed, and individuals with obvious injuries, deformities, or poor condition were promptly removed. Fry were sampled from each pond for testing, and nerve necrosis virus was detected using PCR. Healthy, disease-free red snapper fry with normal coloration and free swimming were selected for further cultivation.

[0028] C fish fry screening and pond separation methods

[0029] After the fry reach 45 days of age and are 3-5 cm in length, they should be screened every 7 days, with the interval between screenings gradually increasing in the later stages. Screening and separating the fry into different ponds will adjust the stocking density and improve the living environment of the fry. Before and after separating the fry into different ponds, stress prevention and disinfection should be carried out to reduce the mortality of fry due to stress or infection by pathogens caused by scratches on the fish body. After screening, the fry should be transferred to different ponds according to their size for intermediate rearing.

[0030] D Fish Fry Standardized Cultivation Method

[0031] Cultivation environment: During the fry cultivation period, natural light rhythm is adopted, water temperature is maintained at 26-29℃, and continuous flowing water is used for rearing;

[0032] Feeding: Before the fry reach 2cm in length, feed them adult copepods and adult brine shrimp. After the fry gather in the pond, feed them in the densely populated areas. Follow the principle of feeding small amounts frequently to avoid affecting water quality. When the fry are 2-3cm in length, feed them a mixture of formulated feed, copepods, and adult brine shrimp. Feed them a small amount of formulated feed first, then add brine shrimp. After the fry reach 3cm in length, feed them only formulated feed, with a daily feeding amount of 8%-10% of their body weight.

[0033] Daily management: During the fry rearing period, pay attention to the stimulation of the external environment on the fry and avoid noise and light affecting the fry's feeding; clean and change the water in the fry rearing pond twice a day, and remove uneaten feed and excrement from the bottom of the pond to avoid water quality deterioration, which would affect the survival and development of the fry.

[0034] Disease prevention and control: Seedling tools are strictly disinfected daily, used by designated personnel, and placed in fixed locations; common pathogens in fish and aquaculture water are checked regularly to ensure early prevention and control; diseased fish with obvious symptoms are promptly removed and culled from the seedling pond, and the entire pond is regularly sprayed with electrolyte multivitamins and Bacillus subtilis to increase the fish's immunity; culled and dead fish fry are disposed of in a harmless manner to avoid infecting healthy fish fry.

[0035] Preferably, in step 1), the red snapper broodstock are fed and fortified with nutrients in a land-based cement pond with dimensions of 8m×8m×1.5m and a water depth of 1.2m.

[0036] The stocking density of the red snapper broodstock was 1–3 fish / m³. 3 .

[0037] Preferably, in step 1), after the red snapper broodstock are introduced into the pond, they are withheld from feeding for 2-3 days, during which time the entire pond is electrolyzed with multivitamins, and the dosage of the electrolyzed multivitamins is 0.2 g / m³. 3 ;

[0038] The live fish is 10cm in length;

[0039] The amount of live fish and fresh bonito slices fed was 3 to 5% of the body weight of the red snapper broodstock.

[0040] Preferably, in step 1), nutrient fortification is performed when the water temperature is 26°C.

[0041] The high-protein fresh feed includes one or more of squid, skipjack tuna, and shelled oysters, and the amount of the high-protein fresh feed is 3 to 4% of the body weight of the red snapper broodstock.

[0042] Preferably, the conditions for incubating the fertilized eggs to the myosarthogenesis stage in step 3) further include: during the incubation process, the air is stopped and the eggs are left to stand still every 2 hours to remove dead eggs and debris that have sunk to the bottom, and fresh water is added to the original water level.

[0043] Preferably, in step 4), the fry are fed with live feed in the fry rearing pond, which is first disinfected and fertilized.

[0044] The disinfection process includes: removing the attached substances from the pond walls, pond bottom and aerator, and then exposing them to the sun for 5 to 7 days;

[0045] After cleaning and removing the black organic matter and moss particles from the sand layer at the bottom of the pond, prepare a bleaching powder solution at a rate of 30 kg / mu, and evenly sprinkle it on the pond walls and bottom. Then drain the bleaching powder solution and add seawater.

[0046] The fertilization process includes: adding fresh Chlorella to the pond to maintain water transparency at 35-40cm; regularly adding bio-organic fertilizer and EM bacteria; and controlling water quality indicators as follows: water temperature 25-29℃, seawater specific gravity 1.022-1.024, pH 7.5-7.8, dissolved oxygen ≥5mg / L, ammonia nitrogen ≤0.5mg / L, and nitrite ≤0.05mg / L.

[0047] Preferably, 12 hours before the fry enter the fry rearing pond, the entire pond is sprayed with an electrolytic multivitamin or vitamin C at a final concentration of 0.8 to 1 ppm.

[0048] Preferably, in step 5), during the temporary rearing of fish fry, electrolytic multivitamins are added to the water at a concentration of 0.2 g / m³. 3 .

[0049] The red spiny perch broodstock mentioned are wild red spiny perch aged 2-5 years introduced from the Nansha Islands.

[0050] In this invention, the egg placement time is 14-16 hours after fertilization, which corresponds to the myosarthogenesis stage under a microscope. The proportion of fertilized eggs floating to the surface is 80-85%. The method for removing dead eggs and debris in this invention is as follows: The oxygen supply to the incubation tank is stopped. Normally developing fertilized eggs will float to the surface, while unfertilized eggs, dead eggs, and debris will sink to the bottom of the incubation tank. The drain valve at the bottom of the incubation tank is opened to remove the unfertilized eggs, dead eggs, and debris. Then, fresh water is added to the original water level, and aeration is restored.

[0051] The beneficial effects of this invention are:

[0052] 1. The method of this invention ensures excellent genetic quality by strictly selecting parent fish; regularly checking the hatching status of fertilized eggs and the development of fry; optimizing the hatching environment; controlling water quality conditions; reducing stress mortality in fry; and effectively improving the survival rate of red snapper fry.

[0053] 2. The method of the present invention effectively reduces the problems of enteritis caused by excessive intake of feed or cannibalism caused by insufficient intake of feed at different stages of the red snapper larvae and juveniles by feeding them different types and densities of feed.

[0054] 3. The method of this invention effectively optimizes the growth conditions of fish fry by implementing strict quality control and disease prevention measures during the factory-scale cultivation process, thereby improving the growth rate, health status, and adaptability of the fry and reducing the risk of disease. Through standardized aquaculture management and technical means, the growth environment and feeding management of the fish fry can be controlled, effectively improving production efficiency.

[0055] 4. The red spiny perch cultivated by the method of this invention has the advantages of fast growth rate, strong disease resistance, strong vitality, delicious meat, and good market prospects. Attached Figure Description

[0056] Figure 1 shows the parent fish of the red snapper;

[0057] Figure 2 shows 30-day-old red snapper fry;

[0058] Figure 3 shows 6-month-old red snapper fry. Detailed Implementation

[0059] This invention provides a method for the industrialized cultivation of red snapper fry, comprising the following steps:

[0060] 1. Establishment of breeding methods for red snapper broodstock

[0061] Red-spined perch broodstock are raised in land-based cement ponds, each measuring 8m × 8m × 1.5m with a water depth of 1.2m. The stocking density is 1-3 fish / m². 3 Water temperature 25-29℃. Natural light rhythm, aerated and air-flow culture. Before introducing broodstock, screen them, removing those with skin damage, parasites, or other abnormalities for separate feeding or culling. Gradually replace their feed with live small fish (around 10cm) and fresh skipjack tuna slices. Control the feeding amount, ideally 3%-5% of the broodstock's body weight. Select healthy, disease-free, and vigorous wild red snapper weighing 2.5-5 catties ​​as broodstock, and transfer them to a fish farm in Lingshui, Hainan in March 2023, where the water temperature is stabilized at 26-28℃. Feed them twice daily with fresh squid, skipjack tuna, and shelled oysters for nutritional enhancement to promote further gonadal development and maturation.

[0062] 2. Establishment of Artificial Propagation Methods for Red-spined Bass Juveniles

[0063] Mature red snapper broodstock were placed in net cages to allow for natural spawning and fertilization. The fertilized eggs floating in the cages were then collected using an egg-collecting net. The collected fertilized eggs were placed in incubation tanks with drain valves at the bottom. Incubation conditions were maintained at a water temperature of 26-28℃, a salinity of 32‰, and a pH of 7.6-8.0. During incubation, aeration was stopped every 2 hours to allow the tanks to settle, removing dead eggs and debris from the bottom, and replenishing the water to the original level. Once the fertilized embryos reached the myosarthogenesis stage, the floating fertilized eggs were collected, packed into bags, and prepared for transport.

[0064] 3. Establishment of artificial breeding methods for red spiny perch fry

[0065] (1) Pond clearing and fertilization of fry rearing ponds

[0066] After cleaning the pond walls, bottom, and aerator with a high-pressure water gun to remove attached organisms, expose the pond to direct sunlight for 5-7 days. Prepare a bleaching powder solution at a dosage of 30 kg / mu and evenly sprinkle it on the pond walls and bottom to kill harmful organisms. After 24 hours, drain the bleaching powder solution and add seawater. Cultivate basic biological feed 1-3 days before hatching. Add fresh Chlorella to the pond to maintain water transparency at 35-40 cm. Regularly add biological organic fertilizer and photosynthetic bacteria to the pond water to increase its nutrient content.

[0067] (2) Hatching of fertilized eggs

[0068] Fresh seawater filtered through a 150-mesh sieve is injected into the hatching bag. Air stones are placed 25cm below the water surface, one per square meter, to continuously oxygenate the water. After laying the eggs, the hatching progress is observed every 2-3 hours using a beaker. If fry appear, the aeration rate is reduced and maintained at a slight level. Three days after hatching, the fry will have developed eye spots, mouth clefts, and their yolk sacs will be depleted. At this point, the hatching bag is opened, allowing the fry to enter the pond. Before opening the bag, an electrolytic multivitamin is applied to the entire pond to alleviate stress on the fry.

[0069] (3) Fry and juvenile fish rearing and harvesting

[0070] After opening the bags, observe the amount of live food in the pond daily using a beaker. If the food is insufficient, introduce SS rotifers or copepod nauplii into the pond. Around 15 days after opening, the fry will metamorphose into juveniles, with enlarged mouths and increased food intake. At this time, feed them adult copepods fortified with a mixture of Chlorella, amino acids, and electrolytes. As the fry become more active, gradually increase the aeration rate to ensure stable dissolved oxygen levels in the pond. The juveniles are ready for harvest after approximately 30 days of rearing.

[0071] Stop feeding the fish fry one day before harvesting, and sprinkle vitamin C throughout the pond 12 hours before harvesting to avoid stress damage to the fry. Drain the water to a depth of 1 meter, and pull the net 2-3 times depending on the number of fry to collect and estimate the number of juveniles.

[0072] 4. Establishment of an indoor artificial rearing method for red-spined bass fry

[0073] (1) Farming conditions

[0074] The aquaculture water is fresh seawater that has undergone sedimentation, filtration, and disinfection. Regular pathogen and water quality testing is conducted to prevent the use of water carrying pathogens or with substandard water quality from affecting fish fry rearing. Water quality indicators are controlled as follows: pH 7.5-7.9, dissolved oxygen ≥5 mg / L, ammonia nitrogen ≤0.5 mg / L, and nitrite ≤0.05 mg / L.

[0075] The seedling rearing ponds are 4×4×1.2m square cement ponds with rounded corners, and a water depth of no less than 1m. They use central aeration and flow-through aquaculture. The daily water exchange rate is no less than 200% of the total water volume.

[0076] During the seedling stage, the breeding workshop, fish fry, seedling equipment, and seedling workers must all undergo strict disinfection to prevent the occurrence of diseases.

[0077] (2) Fish fry selection method

[0078] After transferring the red snapper fry raised in outdoor ponds to the indoor workshop, they were temporarily held in net cages within cement tanks and withheld from feeding for one day. Electrolytes and multivitamins were added to the water to alleviate the stress of the fry during transportation. During the temporary holding period, the vitality and swimming behavior of the fry were observed, and individuals with obvious injuries, deformities, or poor condition were promptly removed. Fry were sampled from each tank for testing, and neural necrosis virus (NNV) was detected using PCR. Healthy, disease-free red snapper fry with normal coloration and free swimming were selected for further cultivation.

[0079] (3) Fish fry screening and pond separation methods

[0080] After 45 days of age, the fry exhibit significant size differentiation due to differences in feeding ability and growth rate, leading to a "big fish eat small fish" phenomenon. When the mouths of larger fry are not large enough to swallow smaller ones, larger fry may choke and die, while smaller fry may be bitten to death. Therefore, different sizes of separating fry sieves should be used to separate the fry according to their body length. Fine and soft nylon mesh sieves should be selected. When the fry are 3-5cm in length, they should be separated every 7 days, gradually increasing the interval later. Separating the fry into different ponds allows for adjustment of stocking density and improves the fry's living environment. Before and after separation, stress-reduction and disinfection measures should be implemented to reduce mortality caused by stress or pathogen infection from scratches. After separation, the fry are transferred to separate ponds according to size for intermediate rearing.

[0081] (4) Standardized fish fry cultivation methods

[0082] Cultivation environment: During the fry cultivation period, natural light rhythm is adopted, water temperature is maintained at 26-29℃, and continuous flowing water is used for feeding.

[0083] Feeding: Before the fry reach 2cm in length, the main feed consists of adult copepods and adult arthropods. Once the fry have gathered in the pond, feed them in areas where they are densely packed. Feeding should be done in small amounts frequently to avoid affecting water quality. When the fry are 2-3cm long, the feed should consist of formulated feed mixed with adult copepods and arthropods. Feed a small amount of formulated feed first, followed by arthropods, etc. Once the fry reach 3cm in length, feed them entirely with formulated feed, at a daily rate of 8%-10% of their body weight. The feeding amount should be adjusted according to the size and density of the fry to ensure their feeding needs are met without affecting water quality. Uneaten feed should be removed promptly after feeding.

[0084] Daily Management: During the fry rearing period, pay attention to the stimulation of the external environment on the fry. Avoid factors such as noise and light that may affect the fry's feeding. Clean and change the water in the rearing pond twice a day, removing uneaten feed and excrement from the bottom of the pond to prevent water quality deterioration and affect the survival and development of the fry.

[0085] Disease prevention and control: Nursery tools must be strictly disinfected daily, used by designated personnel, and placed in fixed locations. Regularly check for common pathogens on the fish and in the aquaculture water to ensure early prevention and control. Promptly remove and cull diseased fish showing obvious symptoms from the nursery pond, and regularly apply electrolyte multivitamins and Bacillus subtilis to the entire pond to enhance the fish's immunity. Culled and dead fry must be disposed of harmlessly to prevent the spread of disease to healthy fry.

[0086] (5) Growth performance test of red snapper seedlings

[0087] The weight and total length of red sea bass fry in the factory farming workshop were measured regularly, and the number of surviving red sea bass fry was counted to evaluate the growth performance of the red sea bass fry.

[0088] To further explain, the method for removing dead eggs and debris is as follows: Stop the oxygen supply to the incubation tank. Normally developing fertilized eggs will float to the surface, while unfertilized eggs, dead eggs, and debris will sink to the bottom of the incubation tank. Open the drain valve at the bottom of the incubation tank to remove the unfertilized eggs, dead eggs, and debris. Then, add fresh water to the original level and resume aeration.

[0089] To further illustrate the present invention, the following detailed description is provided in conjunction with embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0090] Example 1

[0091] Red spiny perch broodstock breeding methods

[0092] The success of breeding red snapper broodstock directly affects the development of fertilized eggs and the survival and growth of fry. Therefore, strengthening the breeding of broodstock can effectively improve the success rate of artificial fry rearing. The main steps include: improving aquaculture conditions, acclimatizing to feed, and nutritional fortification. Specific methods are as follows:

[0093] (1) Improved breeding conditions

[0094] Red-spined perch broodstock are raised in land-based cement ponds, each measuring 8m × 8m × 1.5m with a water depth of 1.2m. The stocking density is 2 fish / m². 3 Water temperature 25-29℃. Natural light rhythm, aeration with airflow and water supply.

[0095] (2) Food domestication

[0096] Before introducing the parent fish into the pond, screen them and remove any individuals with abnormal conditions such as body surface damage or parasites, either feeding them separately or culling them. After introduction, withhold food for 3 days, during which time apply electrolyte multivitamins to the entire pond at a dosage of 0.2g / m³. 3 To reduce stress on the parent fish, feed them mainly live small fish around 10cm in size for the first 5 days after introduction. Once the parent fish are stable, gradually replace the feed with sliced ​​fresh skipjack tuna. Control the amount of feed given, ideally 3%-5% of the parent fish's body weight. Promptly remove any uneaten food.

[0097] (3) Nutritional fortification

[0098] Select red snapper weighing 2-5 catties, with intact body shape, free from disease, injury, deformities, and high vitality as broodstock. When the water temperature reaches 26℃, fortify their nutrition. Feed them twice daily with high-protein fresh feed such as squid, skipjack tuna, and shelled oysters to promote gonadal development and maturation. The daily feed amount is 3%-4% of the broodstock's body weight.

[0099] Example 2

[0100] Artificial propagation methods for red snapper juveniles

[0101] (1) Egg laying and fertilization

[0102] After intensive rearing of the broodstock, the gonadal development of the broodstock was observed daily. Mature female red snapper exhibited a swollen and soft abdomen with a clearly defined ovary that felt elastic to the touch. Mature males showed a small amount of milky-white semen when their abdomen was gently pressed. Mature red snapper broodstock were then placed in a net cage to allow for natural spawning and fertilization. The fertilized eggs floating in the cage were then collected using an egg-collecting net. The collected fertilized eggs were then placed in incubation tanks.

[0103] (2) Hatching of fertilized eggs

[0104] The incubation chamber has a volume of 200L and a drain valve at the bottom. Fertilized eggs are placed in the incubation chamber for incubation at a density of 2 million eggs / m². 3The incubation conditions are a water temperature of 26-28℃, a salinity of 32‰, and a pH of 7.6-8.0. During incubation, aeration should be stopped every 2 hours to allow the eggs and debris to settle at the bottom, and fresh water should be added to restore the original water level. Once the fertilized embryos have developed to the myosarthogenesis stage, they can be packaged and transported to a pond for further incubation.

[0105] Example 3

[0106] Artificial cultivation methods for red spiny perch fry

[0107] The artificial breeding method for red snapper fry includes the following steps: disinfection and fertilization of the rearing pond, hatching of fertilized eggs, feeding with live feed, and release of fry into the pond. The specific operations for the above steps are as follows:

[0108] (1) Disinfection and fertilization of fry rearing ponds

[0109] After using a high-pressure water gun to wash away any attached materials from the pond walls, bottom, and aerator, expose the pond to direct sunlight for 7 days. Clean out the black organic matter and algae particles from the sand layer at the bottom of the pond. Prepare a bleaching powder solution at a rate of 30 kg / mu and evenly sprinkle it on the pond walls and bottom to kill harmful organisms. Drain the bleaching powder solution and add seawater. Cultivate basic biological feed for 3 days before hatching. Add fresh Chlorella vulgaris to the pond to maintain water transparency at 35-40 cm. Regularly add 1 g / m³ of algae to the pond water. 3 Adding EM bacteria increases water nutrition and cultivates plankton. During the aquaculture period, water quality is monitored regularly, with the following parameters controlled: water temperature 25-29℃, seawater specific gravity 1.022-1.024 (salinity 29-32), pH 7.5-7.8, dissolved oxygen ≥5mg / L, ammonia nitrogen ≤0.5mg / L, and nitrite ≤0.05mg / L.

[0110] (2) Hatching of fertilized eggs

[0111] Fertilized egg hatching: Fresh seawater filtered through a 150-mesh sieve is injected into the hatching bag. Air stones are placed 25cm below the water surface, with one air stone per square meter for continuous oxygenation. When laying the eggs, the bag containing the fertilized eggs is first immersed in the hatching bag for 15 minutes to balance the temperature difference. Then, 1 / 3 of the bag is filled with fresh water before the fertilized eggs are poured out. After laying the eggs, the hatching progress is observed every 2 hours using a beaker. During the hatching period, the aeration rate is increased. If fry appear, the aeration rate is reduced and maintained at a slight aeration. Three days after laying the eggs, the fry have developed eye spots, their mouths are about to form, and their yolk sacs are almost depleted. At this time, the hatching bag is opened, and the fry are released into the pond. 12 hours before opening the bag, the entire pond is sprayed with 1ppm of electrolyte multivitamins or vitamin C to alleviate stress and maintain nutritional balance in the fry.

[0112] (3) Feeding with live bait

[0113] After opening the bag, use a beaker to take water from the pond daily to observe the amount of biological feed in the pond, and control the amount of plankton by controlling the amount of Chlorella and fertilizer paste used.

[0114] When the fry are 3-7 days old, feed them daily with SS-type rotifers or copepod nauplii with a size ≤100μm, and maintain the feed density in the pond at 3-5 fry / mL.

[0115] When the fry are 8-12 days old, feed them nutritionally fortified L-type rotifers at a density of 2-3 rotifers / mL.

[0116] When the fry are 12-18 days old, their diet gradually changes from L-type rotifers to Artemia nauplii, with a density of 1-2 nauplii / mL.

[0117] After the fry reach 18 days of age, start feeding them 1-2 copepod nauplii per mL.

[0118] Feed 25-day-old fry with 1-2 Artemia worms and small copepods per mL. Feed 35-day-old fry with 1-2 Artemia worms and adult copepods per mL.

[0119] (4) Fish fry are released from the pond

[0120] Approximately 20 days after egg laying, observe the feeding and swimming behavior of the fry to determine if they are ready for harvest. Stop feeding the fry one day before harvesting, and apply a final concentration of 0.2 g / m³ to the entire pond 12 hours before harvesting. 3 Electrolysis with multidimensional agents helps prevent stress damage to fish fry; drain water to a depth of 1 meter, and pull the net 2-3 times depending on the number of fish fry to collect and estimate the number of juveniles.

[0121] Example 4

[0122] Indoor artificial rearing method for red snapper fry

[0123] The red snapper fry collected from the outdoor pond will be transferred to an indoor workshop for standardized breeding. The specific steps are as follows:

[0124] (1) Farming conditions

[0125] The aquaculture water is fresh seawater that has undergone sedimentation, filtration, and disinfection. Regular pathogen and water quality testing is conducted to prevent the use of water carrying pathogens or with substandard water quality from affecting fish fry rearing. Water quality indicators are controlled as follows: pH 7.5-7.9, dissolved oxygen ≥5 mg / L, ammonia nitrogen ≤0.5 mg / L, and nitrite ≤0.05 mg / L.

[0126] The seedling rearing ponds are 4×4×1.2m square cement ponds with rounded corners, 1m deep, and use central aeration and flowing water culture. The daily water exchange rate is 200% of the total water volume.

[0127] During the seedling stage, the breeding workshop, fish fry, seedling equipment, and seedling workers must all undergo strict disinfection to prevent the occurrence of diseases.

[0128] (2) Fish fry selection method

[0129] After transferring the red snapper fry raised in outdoor ponds to the indoor workshop, they were temporarily held in net cages within cement tanks and withheld from feeding for one day. Electrolytes and multivitamins were added to the water to alleviate the stress of the fry during transportation. During the temporary holding period, the vitality and swimming behavior of the fry were observed, and individuals with obvious injuries, deformities, or poor condition were promptly removed. Fry were sampled from each tank for testing, and neural necrosis virus (NNV) was detected using PCR. Healthy, disease-free red snapper fry with normal coloration and free swimming were selected for further cultivation.

[0130] (3) Fish fry screening and pond separation methods

[0131] After 45 days of age, the fry exhibit significant size differentiation due to differences in feeding ability and growth rate, leading to a "big fish eat small fish" phenomenon. When the mouths of larger fry are not large enough to swallow smaller ones, larger fry may choke and die, while smaller fry may be bitten to death. Therefore, different sizes of separating fry sieves should be used to separate the fry according to their body length. Fine and soft nylon mesh sieves should be selected. When the fry are 3-5cm in length, they should be separated every 7 days, gradually increasing the interval later. Separating the fry into different ponds allows for adjustment of stocking density and improves the fry's living environment. Before and after separation, stress-reduction and disinfection measures should be implemented to reduce mortality caused by stress or pathogen infection from scratches. After separation, the fry are transferred to separate ponds according to size for intermediate rearing.

[0132] (4) Standardized fish fry cultivation methods

[0133] Cultivation environment: During the fry cultivation period, natural light rhythm is adopted, water temperature is maintained at 26-29℃, and continuous flowing water is used for feeding. The cultivation density depends on the size of the fry.

[0134] Feeding: Before the fry reach 2cm in length, the main feed consists of adult copepods and adult arthropods. Once the fry have gathered in the pond, feed them in areas where they are densely packed. Feeding should be done in small amounts frequently to avoid affecting water quality. When the fry are 2-3cm long, the feed should consist of formulated feed mixed with adult copepods and arthropods. Feed a small amount of formulated feed first, followed by arthropods, etc. Once the fry reach 3cm in length, feed them entirely with formulated feed, at a daily rate of 8%-10% of their body weight. The feeding amount should be adjusted according to the size and density of the fry to ensure their feeding needs are met without affecting water quality. Uneaten feed should be removed promptly after feeding.

[0135] Daily Management: During the fry rearing period, pay attention to the stimulation of the external environment on the fry. Avoid factors such as noise and light that may affect the fry's feeding. Clean and change the water in the rearing pond twice a day, removing uneaten feed and excrement from the bottom of the pond to prevent water quality deterioration and affect the survival and development of the fry.

[0136] Disease prevention and control: Nursery tools must be strictly disinfected daily, used by designated personnel, and placed in fixed locations. Regularly check for common pathogens on the fish and in the aquaculture water to ensure early prevention and control. Promptly remove and cull diseased fish showing obvious symptoms from the nursery pond, and regularly apply electrolyte multivitamins and Bacillus subtilis to the entire pond to enhance the fish's immunity. Culled and dead fry must be disposed of harmlessly to prevent the spread of disease to healthy fry.

[0137] Example 5: Growth Performance Test of Red Nine-Spined Bass Fry

[0138] The weight and total length of red snapper fry in the factory-farmed aquaculture facility were measured to evaluate their growth performance. The current number of fry was also counted, and the survival rate was calculated. Thirty red snapper fry were randomly selected, and their weight and total length were measured using a 0.1g precision scale and a 0.1mm ruler. The results in the table below show that the average weight gain rate of the red snapper fry was 2.19g / day, and the average body length growth rate was 0.11cm / day. No large-scale disease outbreaks occurred during the farming process. In April 2023, 13,000 selected red snapper fry were collected and placed in the factory-farmed nursery for cultivation. In November 2023, the number of surviving red snapper fry was counted as 11,500, with a survival rate of 88.5%.

[0139] Table 1. Results of weight and total length of red snapper fry

[0140] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for the industrialized cultivation of red spiny perch fry, characterized in that, Includes the following steps: 1) Red snapper broodstock were subjected to feeding acclimatization and nutritional fortification in water at a temperature of 25-29℃ and under flowing water conditions to obtain broodstock with mature gonads. The feed acclimatization includes: feeding the red snapper broodstock with live fish for 5 days after they are introduced into the pond, and then replacing the live fish with fresh bonito slices after they have stabilized. The nutritional fortification includes: selecting parent fish weighing 2-5 jin (1.5-2 catties) and feeding them high-protein fresh feed twice a day; 2) Naturally spawn and fertilize the mature broodstock from step 1) to obtain fertilized eggs; 3) After the fertilized eggs obtained in step 2) are incubated to the myosarcophagus stage, they are then incubated in an incubation bag to obtain larvae; The conditions for hatching the fertilized eggs to the myosarcogenesis stage include: a density of 2 million fertilized eggs / m3, a water temperature of 26-28℃, a salinity of 32‰, and a pH of 7.6-8.

0. 4) Feed the fry obtained in step 3) with live feed, and fry will be obtained 20 days after laying eggs; When the fry are 3 to 7 days old, feed them daily with SS-type rotifers or copepod nauplii at a density of 3 to 5 nauplii / mL. When the fry are 8-12 days old, feed them L-type rotifers at a density of 2-3 rotifers / mL. When the fry are 13 to 18 days old, feed them Artemia nauplii at a density of 1 to 2 nauplii / mL. When the larvae are 18 to 24 days old, feed them copepod nauplii at a density of 1 to 2 nauplii / mL. When the larvae are 25-34 days old, feed them Artemia and copepod nauplii at a density of 1-2 nauplii / mL. When the fry reach 35 days of age, feed them Artemia and copepod nauplius at a density of 1-2 per mL. 5) After temporarily raising the fish fry obtained in step 4) for 1 day, they are then artificially cultured in an indoor workshop, including: Aquaculture conditions in Workshop A: The aquaculture water is fresh seawater that has been settled, filtered, and disinfected. The aquaculture water is regularly tested for pathogens and water quality to prevent the aquaculture water carrying pathogens or substandard water quality from affecting the fish fry. The water quality indicators are controlled as follows: pH 7.5-7.9, dissolved oxygen ≥5mg / L, ammonia nitrogen ≤0.5mg / L, and nitrite ≤0.05mg / L. The seedling pond is a square cement pond with rounded corners measuring 4×4×1.2m, with a water depth of not less than 1m. It adopts central aeration and flowing water culture, and the daily water exchange volume is not less than 200% of the total water volume. During the seedling stage, the breeding workshop, fish fry, seedling equipment, and seedling workers must be strictly disinfected to prevent the occurrence of diseases. Methods for selecting B-type fish fry After transferring the red snapper fry cultivated in outdoor ponds to the indoor workshop, they were temporarily held in net cages in cement ponds and withheld from feeding for one day. Electrolytes and multivitamins were added to the water to alleviate the stress of the fry during transportation. During the temporary holding period, the vitality and swimming behavior of the fry were observed, and individuals with obvious injuries, deformities, or poor condition were promptly removed. Fry were sampled from each pond for testing, and nerve necrosis virus was detected using PCR. Healthy, disease-free red snapper fry with normal coloration and free swimming were selected for further cultivation. C fish fry screening and pond separation methods After the fry reach 45 days of age and are 3-5 cm in length, they should be screened every 7 days, with the interval between screenings gradually increasing in the later stages. Screening and separating the fry into different ponds will adjust the stocking density and improve the living environment of the fry. Before and after separating the fry into different ponds, stress prevention and disinfection should be carried out to reduce the mortality of fry due to stress or infection by pathogens caused by scratches on the fish body. After screening, the fry should be transferred to different ponds according to their size for intermediate rearing. D Fish Fry Standardized Cultivation Method Cultivation environment: During the fry cultivation period, natural light rhythm is adopted, water temperature is maintained at 26-29℃, and continuous flowing water is used for rearing; Feeding: Before the fry reach 2cm in length, feed them adult copepods and adult brine shrimp; after the fry gather in the pond, feed them in the densely populated areas; follow the principle of feeding small amounts frequently to avoid affecting water quality; when the fry are 2-3cm in length, feed them formulated feed. The feed is a combination of copepods and adult artichokes. When feeding, first feed a small amount of the formulated feed, then feed the artichokes, etc. Once the fish fry reach a length of 3cm, they should be fed entirely with formulated artificial feed, with a daily feeding amount of 8% to 10% of the fish's body weight. Daily management: During the fry rearing period, pay attention to the stimulation of the external environment on the fry and avoid noise and light affecting the fry's feeding; clean and change the water in the fry rearing pond twice a day, and remove uneaten feed and excrement from the bottom of the pond to avoid water quality deterioration, which would affect the survival and development of the fry. Disease prevention and control: Seedling tools are strictly disinfected daily, used by designated personnel, and placed in fixed locations; common pathogens in fish and aquaculture water are checked regularly to ensure early prevention and control; diseased fish with obvious symptoms are promptly removed and culled from the seedling pond, and the entire pond is regularly sprayed with electrolyte multivitamins and Bacillus subtilis to increase the fish's immunity; culled and dead fish fry are disposed of in a harmless manner to avoid infecting healthy fish fry.

2. The method for industrialized cultivation of red spiny perch seedlings according to claim 1, characterized in that, In step 1), the red snapper broodstock were fed and fortified with nutrients in a land-based cement pond with dimensions of 8m×8m×1.5m and a water depth of 1.2m. The stocking density of the red snapper broodstock was 1–3 fish / m³. 3 .

3. The method for industrialized cultivation of red snapper fry according to claim 1 or 2, characterized in that, In step 1), after the red snapper broodstock are introduced into the pond, they are withheld from feeding for 2-3 days. During this period, the entire pond is electrolyzed with multivitamins, and the dosage of the electrolyzed multivitamins is 0.2 g / m³. 3 ; The live fish is 10cm in length; The amount of live fish and fresh bonito slices fed was 3 to 5% of the body weight of the red snapper broodstock.

4. The method for industrialized cultivation of red spiny perch seedlings according to claim 1, characterized in that, In step 1), nutrient fortification is performed when the water temperature is 26°C. The high-protein fresh feed includes one or more of squid, skipjack tuna, and shelled oysters, and the amount of the high-protein fresh feed is 3 to 4% of the body weight of the red snapper broodstock.

5. The method for industrialized cultivation of red spiny perch seedlings according to claim 1, characterized in that, The conditions for incubating the fertilized eggs to the myosarthogenesis stage in step 3) also include: during the incubation process, the air is stopped and the eggs are left to stand still every 2 hours to remove the dead eggs and debris that have sunk to the bottom, and fresh water is added to the original water level.

6. The method for industrialized cultivation of red spiny perch fry according to claim 1, characterized in that, In step 4), the fry are fed with live feed in the fry rearing pond, which is first disinfected and fertilized. The disinfection process includes: removing the attached substances from the pond walls, pond bottom and aerator, and then exposing them to the sun for 5 to 7 days; After cleaning and removing the black organic matter and moss particles from the sand layer at the bottom of the pond, prepare a bleaching powder solution at a rate of 30 kg / mu, and evenly sprinkle it on the pond walls and bottom. Then drain the bleaching powder solution and add seawater. The fertilization process includes: adding fresh Chlorella to the pond to maintain water transparency at 35-40cm; regularly adding bio-organic fertilizer and EM bacteria; and controlling water quality indicators as follows: water temperature 25-29℃, seawater specific gravity 1.022-1.024, pH 7.5-7.8, dissolved oxygen ≥5mg / L, ammonia nitrogen ≤0.5mg / L, and nitrite ≤0.05mg / L.

7. The method for industrialized cultivation of red spiny perch fry according to claim 6, characterized in that, Twelve hours before the fry enter the rearing pond, the entire pond is sprayed with an electrolytic multivitamin or vitamin C at a final concentration of 0.8–1 ppm.

8. The method for industrialized cultivation of red spiny perch fry according to claim 1, characterized in that, In step 5), during the temporary rearing of fish fry, electrolytic multivitamins are added to the water at a concentration of 0.2 g / m³. 3 .

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