Net cage ecological breeding method for red nine-plectropomus latifolius

Abstract

The invention discloses an ecological cage culture method for red nine-pink bass, which comprises the following steps: selecting a proper sea area as a cage culture sea area, performing feed feeding and screening treatment according to the growth condition in the culture process, and performing disinfection, inspection and the like. Compared with an industrial breeding method, the method has the advantages that the facility cost and the operation cost are reduced, the breeding environment conforms to the growth rule of the red nine-pink bass, growth of the red nine-pink bass is promoted, and large-scale breeding is facilitated. Ocean space is fully utilized, land resources are saved, and the ecological pressure is small. The method has the advantages of low cost, convenience in operation, simplicity in operation, easiness in large-scale culture and eco-friendliness, can be popularized and applied in a large scale, and promotes the rapid growth of the red nine-plectropomus latifolius industry.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology, and more specifically to a method for ecological cage culture of red snapper. Background Technology

[0002] The red-spined sea bass (Cephalopholis sonnerati), commonly known as the red grouper, is a prized saltwater fish belonging to the grouper family. It has a bright red body and delicate, sweet flesh. It is mainly distributed in the coral reef areas of the tropical Indo-Pacific region, inhabiting depths of up to 120 meters. Due to its reliance on fishing and limited wild production, its market price is as high as 350-600 yuan per kilogram, and the price of its roe can even reach 120,000 yuan per kilogram, long considered a "luxury item" in the high-end seafood market. In recent years, with consumption upgrades and increased market demand, the artificial breeding and large-scale farming of the red-spined sea bass has become a research hotspot in the aquaculture field.

[0003] Factory farming allows for precise control of the aquaculture environment, significantly reducing the impact of natural disasters, harsh weather, and pests on the farming process, thus greatly improving the stability of the operation. However, with in-depth research and the gradual expansion of the farming scale, a series of problems have gradually emerged in the factory farming of red snapper. From a water quality perspective, red snapper have demanding requirements for their growth environment and are extremely sensitive to changes in parameters such as water temperature, salinity, and dissolved oxygen. The suitable water temperature for their growth is typically 22-28℃, salinity needs to be maintained at 28-35‰, and dissolved oxygen content must not be lower than 5mg / L. Fluctuations in water quality can exacerbate stress responses in the fish, reduce immunity, and consequently affect their growth and health. To maintain stable water quality, frequent water changes and professional water purification equipment are required during the farming process, which not only consumes a large amount of water resources but also increases farming costs and management difficulty. Regarding feed, red snapper are carnivorous fish with a relatively unique digestive system, requiring a high degree of precision in the nutritional composition of their feed. Currently, the research and development of high-quality artificial compound feed suitable for red snapper is still incomplete. The nutritional components of some feeds cannot fully meet their growth needs, resulting in slow growth rate and extended breeding cycle of red snapper, which further restricts the improvement of breeding efficiency.

[0004] To date, red snapper have only been farmed in factory-style facilities. While factory farming allows for precise control of the farming environment, it comes with high construction and operating costs. In contrast, offshore cage farming offers advantages such as low cost and ample space, making full use of marine resources. However, no research has been reported on the farming of red snapper in offshore cages. Developing offshore cage farming of red snapper is of significant practical importance for overcoming existing limitations and promoting large-scale, low-cost farming of this species. Summary of the Invention

[0005] In view of this, the present invention provides a method for ecological aquaculture of red snapper in net cages, which shortens the aquaculture cycle, increases aquaculture yield and product yield, reduces aquaculture costs, saves resources, and effectively solves the problems of poor aquaculture effect and low aquaculture success rate in the process of factory farming.

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

[0007] A method for ecological cage culture of red snapper includes the following steps:

[0008] Step 1: Sea Area Selection

[0009] Select sea areas with clear, unpolluted water, abundant plankton and fish and shrimp as food sources, and minimal impact from tides and waves as cage aquaculture areas.

[0010] Step 2: Deploying the net cages

[0011] Step Two: Construction and Deployment of Fish Cages

[0012] The net cage adopts a floating frame, with a ring-shaped main frame composed of floating tubes and a radial support tube to reinforce the structure. The net cage is lined with netting. The size of the netting is calculated according to the circumference and depth of the net cage. After laser cutting, it is sewn into a cylindrical shape. The frame is assembled on land and then transported to the sea for fixing. The net cage is fixed, with a water depth of 9-10m and a height of 40-50cm above the water. The net cage does not contact the bottom of the water. It is placed in the water 10-15 days before the fish fry are released and disinfected.

[0013] Step 3: Seedling Selection

[0014] Juvenile red snapper with a body length of 2-3cm were selected for standardized cultivation in indoor cement ponds. After cultivation, juvenile red snapper with a size of 8-12cm, a weight of 30-40g, robust physique, healthy body surface without injury, deformity, or pathogens were selected for cage culture.

[0015] Step 4: Daily Feeding

[0016] The water temperature in the breeding area is maintained at 23-30℃. Artificial compound feed is provided during the breeding period, once a day, from 1:00 pm to 4:00 pm. Feeding is stopped for one day every 5 days.

[0017] Step 5: Regular screening

[0018] Regularly screen and separate fish according to individual differences, using the total body length as the screening indicator, and divide them into sizes in 2cm increments, and concentrate the breeding of red nine-spined perch of the same size.

[0019] Step Six: Insect Control and Disinfection

[0020] During the breeding process, in order to avoid parasites from damaging the red snapper, it is necessary to regularly and randomly sample the fish to check for parasites, and disinfect them by immersion in hydrogen peroxide with a final volume concentration of 5% every 8-10 days.

[0021] Step 7: Cage Management

[0022] During the aquaculture process, check the sturdiness of the net cages daily and promptly remove any algae attached to them.

[0023] Preferably, the sea area selected in step one has a water depth of 15-20m, a low tide depth of more than 10m, and a sea current velocity of 0.3-0.5m / s.

[0024] Preferably, the net cage is made of high-density polyethylene, and the netting is made of polyethylene mesh. The netting is replaced every 20 days. As the red snapper grows, the mesh size of the netting is changed from 1 inch to 1.8 inches.

[0025] Preferably, in step two, disinfection is carried out by soaking in 1g / L potassium permanganate solution.

[0026] Preferably, in step three, before placing the juvenile fish into the net cage, random samples are taken for microscopic examination to confirm that there are no parasites attached to the fish, and the fish are then disinfected by immersion in hydrogen peroxide with a final volume concentration of 5%.

[0027] Preferably, the net cage is a circular net cage with a circumference of 60m and a depth of 10m, and each net cage is stocked with 20,000 juvenile red snapper.

[0028] Preferably, in step four, the artificial compound feed has a crude protein content of 48% and a crude fat content of 8% by weight, and the feeding amount is 1.5%-2% of the fish's body weight.

[0029] Before feeding, add electrolytes and multivitamins and mix well. The amount added should be 1-1.5g / kg based on the fish's body weight to improve the red snapper's stress resistance and immunity. When red snapper are first stocked, they are small in size and do not eat much. The feeding amount should be adjusted appropriately according to 1.5%-2% of the fish's body weight. When the fry grow to more than 20cm in total length, gradually increase the amount to 3%-5% of the fish's body weight and adjust the feeding amount according to the feeding intensity.

[0030] Preferably, in step five, the dosage is 3-5 g / m 3 Add aquatic vitamin C to the water at a concentration of 1%, and disinfect all screening tools by soaking them in a 1% povidone-iodine solution beforehand to reduce the risk of pathogen infection. Handle the fish carefully during the screening process to avoid scratching them.

[0031] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method for ecological aquaculture of red snapper in net cages, which has the following beneficial effects:

[0032] Compared to factory farming methods, this invention reduces facility and operating costs, and the farming environment conforms to the growth patterns of the red snapper, promoting its growth and facilitating large-scale farming. This invention makes full use of marine space, conserves land resources, and exerts less ecological pressure. With its advantages of low cost, convenient operation, simple management, ease of large-scale farming, and eco-friendliness, this invention can be widely promoted and applied, driving the rapid growth of the red snapper industry.

[0033] This invention only requires setting up simple facilities such as cage frames and netting in suitable sea areas. Compared with factory farming, which requires building enclosed workshops and equipping various water treatment systems and aquaculture equipment, the initial construction cost is significantly lower. Moreover, it utilizes the natural seawater environment and does not require consuming large amounts of energy for water circulation and temperature control like factory farming, resulting in lower energy consumption costs. Furthermore, the daily management of cage farming is relatively simple, and the labor costs are relatively low.

[0034] The seawater cages used in this invention are directly set up in natural sea areas, where the environment is closer to the natural habitat of the red-spined perch. They possess natural water flow, temperature, and salinity conditions, which helps the red-spined perch maintain its natural growth state and behavioral habits, better aligning with its growth patterns. In this natural seawater environment, the red-spined perch can feed on natural plankton and other food sources, and has relatively more space to move around, resulting in more delicious and flavorful meat. This product quality is often more favored by consumers and may give it greater price competitiveness in the market.

[0035] The marine cage aquaculture method used in this invention can utilize vast marine space resources without occupying land resources. For areas with scarce land resources, it is an excellent marine aquaculture method that can effectively expand aquaculture space. Furthermore, a rationally laid-out marine cage aquaculture has a relatively small impact on the marine ecological environment. The excrement of red snapper in the cages can be naturally decomposed and purified by the marine environment to a certain extent, unlike factory aquaculture which produces a large amount of aquaculture wastewater that requires centralized treatment, thus placing relatively less pressure on the surrounding ecological environment. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] The specific implementation method of the net cage ecological aquaculture method for red nine-spined perch is as follows:

[0038] Step 1: Sea Area Selection

[0039] The sea area where the cages are located has clear water with a dissolved oxygen content of 5g / L, a pH value between 7.8 and 8.2, a salinity of around 29‰, and a seawater temperature between 23 and 30℃. There are no industrial wastewater or domestic sewage discharge outlets near the sea area. The seawater is rich in plankton and biological food such as fish and shrimp. The sea area is located on the leeward side of the shore and is less affected by tides and waves. The water depth is 15-20m, and the water depth is more than 10m at low tide. The sea current speed is 0.3-0.5m / s.

[0040] Step Two: Fabrication and Installation of Fish Cages

[0041] The structural design is based on the water depth, wave height, and aquaculture requirements of the target sea area, determining the cage diameter, depth, and anchoring scheme. HDPE floating pipes are hot-melt welded into a ring-shaped main frame, complemented by radial support pipes to enhance stability. The cage is made of high-density polyethylene, and the netting is made of UV-resistant knotless polyethylene netting, cut into cylindrical shapes and reinforced with edge binding. During onshore assembly, the top of the netting is secured to the frame with ropes, and a counterweight chain is suspended at the bottom to ensure vertical deployment. After assembly, the cage is transported to the target sea area, where it is connected and secured to the anchor chains.

[0042] The net cage is a circular net cage with a diameter of 20m and a height of 10m. It is lined with a layer of netting with a specification of 1-1.8 inches. The net cage is fixed and is submerged in water at a depth of about 9m, with a height of 40-50cm above the water. The net cage does not contact the bottom of the water. The net cage is put into the water 10-15 days before the fish fry are stocked. Before being put into the water, it is disinfected by soaking in potassium permanganate with a concentration of 1g / L and the impurities attached to the net cage are cleaned with a high-pressure water gun.

[0043] Step 3: Seedling Selection

[0044] Juvenile red snapper with a body length of 2-3cm were selected and cultured in indoor cement ponds in a standardized manner. After the culture was completed, juvenile red snapper with a body length of 8-12cm, a weight of 30-40g, a symmetrical and plump body shape, no deformities, smooth body surface, no damage, ulcers, and no pathogens were selected for net cage culture. Before the juvenile fish were put into the net cage, random samples were taken for microscopic examination to confirm that there were no parasites attached to the fish body, and the fish were disinfected by immersion in hydrogen peroxide with a final volume concentration of 5%.

[0045] Step 4: Daily Feeding

[0046] The water temperature in the breeding area is maintained at 23-30℃. Each net cage is stocked with 20,000 juvenile red snapper. During the breeding period, a formulated feed with a crude protein content of 48% and a crude fat content of 8% is provided, fed once daily at a rate of 1.5%-2% of the fish's body weight. A fixed feeding time should be established to help the red snapper develop good feeding habits, improve feeding efficiency, and increase feed utilization. Feed is delivered slowly by hand, with close observation of feeding behavior. Before feeding, electrolytes and multivitamins should be added and mixed thoroughly at a rate of 1-1.5g / kg of fish body weight. When the red snapper are initially small and have low feeding rates, the feeding amount should be adjusted appropriately at 1.5%-2% of the fish's body weight. As the fry grow to over 20cm in total length, the feeding amount is gradually increased to 3%-5% of the fish's body weight, and the feeding amount is adjusted according to the feeding intensity. Feeding time is from 1:00 pm to 4:00 pm. After every 5 days of feeding, you need to stop feeding for 1 day to avoid the red sea bass eating too much and causing intestinal diseases.

[0047] Step 5: Regular screening

[0048] Because juvenile red snapper exhibit individual growth differences, competition for food among larger fish can lead to slow growth or even death in smaller fish. To improve survival rates, timely screening and separation are necessary during the rearing process. Regularly check the growth of the red snapper during rearing; if the size difference exceeds 20%, screening should be considered. Use total body length as the screening criterion, dividing the fish into size increments of 2cm. Group red snapper of the same size together for rearing. Screening should be carried out on sunny, windless days with suitable water temperatures. Screening is prone to stress and pathogen infection, causing production losses; therefore, a final concentration of 3-5g / m³ should be maintained before and after screening. 3 Add aquatic vitamin C to the water at a concentration of 1% to reduce fish stress. Disinfect all screening tools by soaking them in a 1% povidone-iodine solution beforehand. Avoid scratching the fish during the screening process. After screening, closely observe the activity, feeding, and health of the fry. Promptly identify and treat injured, sick, or severely stressed fry. If abnormal swimming or refusal to eat is observed, analyze the cause and take appropriate measures. The size of the fry after screening may vary. Adjust the feeding amount and frequency according to the feeding ability and nutritional needs of the fry of different sizes. For smaller fry, increase the number of feedings and reduce the amount of food given each time.

[0049] Step Six: Insect Control and Disinfection

[0050] During the breeding process, in order to avoid damage to the red snapper by parasites, it is necessary to regularly and randomly sample the fish to check for parasites. Every 8-10 days, the fish should be disinfected by immersion in hydrogen peroxide with a final concentration of 5%. After disinfection, the activity, feeding and breathing of the fish should be closely observed. If any abnormal reactions are found, such as swimming wildly, jumping or surfacing, measures should be taken in time. If dead fish appear after disinfection, they should be removed in time and disposed of in a harmless manner to prevent the dead fish from rotting and deteriorating, polluting the water and spreading pathogens.

[0051] Step 7: Cage Management

[0052] During the aquaculture process, the sturdiness of the net cages is checked daily, and algae attached to the net cages are removed in a timely manner to maintain the water exchange rate inside and outside the net cages. The netting is replaced every 20 days. As the red snapper grows in size, the netting size is changed from 1 inch to 1.8 inches.

[0053] Example 1

[0054] From July 2024 to February 2025, a red snapper farming experiment was conducted in the waters near Xidao Island, Sanya City, using the method described in this invention. Six high-density polyethylene net cages were selected, with a circumference of 60m and a depth of 9m. The netting used was polyethylene mesh.

[0055] Juvenile red snapper were raised in standardized indoor cement tanks, fed with live food such as brine shrimp and formulated feed containing 48% crude protein and 8% crude fat. Once the juveniles reached 8-12cm in length, they were transferred to marine cages at a stocking density of 10 fish / m². 3 .

[0056] During cage culture, feed the fish with a crude protein content of 48% and a crude fat content of 8% between 13:00 and 16:00. In the early stage of culture, the daily feed amount is 1.5%-2% of the fish's body weight. As the fish grow to more than 20cm, the daily feed amount increases to 3%-5% of the fish's body weight.

[0057] During the breeding period, the net cages should be inspected regularly, and any attached materials should be cleaned up in a timely manner. The netting should be replaced every 20 days. Temperature, dissolved oxygen, pH and other indicators should be tested daily. The body length and weight of the red snapper should be measured regularly to monitor its growth. The netting should be screened every 2 months.

[0058] The growth of the red-spined perch was measured after 8 months of breeding. The average weight of the red-spined perch was 215g, and the average weight gain was 180g.

[0059] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for ecological cage aquaculture of red snapper, characterized in that, Includes the following steps: Step 1: Sea Area Selection Select sea areas with clear, unpolluted water, abundant plankton and fish and shrimp as food sources, and minimal impact from tides and waves as cage aquaculture areas. Step Two: Construction and Deployment of Fish Cages The net cage adopts a floating frame, with a ring-shaped main frame composed of floating tubes and a radial support tube to reinforce the structure. The net cage is lined with netting. The size of the netting is calculated according to the circumference and depth of the net cage. After laser cutting, it is sewn into a cylindrical shape. The frame is assembled on land and then transported to the sea for fixing. The net cage is fixed, with a water depth of 9-10m and a height of 40-50cm above the water. The net cage does not contact the bottom of the water. It is placed in the water 10-15 days before the fish fry are released and disinfected. Step 3: Seedling Selection Juvenile red snapper with a body length of 2-3cm were selected for standardized cultivation in indoor cement ponds. After cultivation, juvenile red snapper with a size of 8-12cm, a weight of 30-40g, robust physique, healthy body surface without injury, deformity, or pathogens were selected for cage culture. Step 4: Daily Feeding The water temperature in the breeding area is maintained at 23-30℃. Artificial compound feed is fed once a day during the breeding period, from 1:00 pm to 4:00 pm. Feeding is stopped for one day every 5 days. Step 5: Regular screening Regularly screen and separate fish according to individual differences, using the total body length as the screening index, and divide them into sizes in 2cm increments, and raise red nine-spined perch of the same size together. Step Six: Insect Control and Disinfection During the breeding process, fish are regularly sampled randomly to check for parasites, and disinfected by immersion in hydrogen peroxide with a final volume concentration of 5% every 8-10 days. Step 7: Cage Management During the aquaculture process, check the sturdiness of the net cages daily and promptly remove any algae attached to them.

2. The method for ecological cage aquaculture of red snapper according to claim 1, characterized in that, The selected sea area in step one has a water depth of 15-20m, a low tide depth of more than 10m, and a sea current speed of 0.3-0.5m / s.

3. The method for ecological aquaculture of red snapper in net cages according to claim 1, characterized in that, The net cage is made of high-density polyethylene, and the netting is made of polyethylene mesh. The netting is replaced every 20 days. As the red snapper grows, the mesh size of the netting is changed from 1 inch to 1.8 inches.

4. The method for ecological aquaculture of red snapper in net cages according to claim 1, characterized in that, In step two, disinfection is carried out by soaking in 1g / L potassium permanganate solution.

5. The method for ecological cage aquaculture of red snapper according to claim 1, characterized in that, In step three, before placing the juvenile fish into the net cage, random samples were taken for microscopic examination to confirm that there were no parasites attached to the fish. The fish were then disinfected by immersion in hydrogen peroxide with a final volume concentration of 5%.

6. The method for ecological cage aquaculture of red snapper according to claim 1, characterized in that, The net cages are circular with a circumference of 60 meters and a depth of 10 meters, and each net cage is stocked with 20,000 juvenile red snapper.

7. The method for ecological cage aquaculture of red snapper according to claim 1, characterized in that, In step four, the crude protein content of the artificial compound feed is 48% and the crude fat content is 8% by mass percentage. The feeding amount is 1.5%-2% of the fish's body weight; Before feeding, add electrolyte multivitamins and mix well. The amount added is 1-1.5g / kg based on the fish's weight. When the red sea bass is first stocked, the feeding amount is 1.5%-2% of the fish's weight. When the fry grow to more than 20cm in total length, gradually increase it to 3%-5% of the fish's weight.

8. The method for ecological cage aquaculture of red snapper according to claim 1, characterized in that, In step five, the dosage before and after sieving is 3-5 g / m³. 3 Add aquatic vitamin C to the water at a concentration of 1%, and disinfect all screening tools by soaking them in a 1% povidone-iodine solution beforehand, while avoiding scratching the fish during the screening process.