Method for regulating and controlling factory-like indoor natural spawning of parent fishes of red plectropomus latifolius

Abstract

The invention discloses a method for regulating and controlling factory-like indoor natural oviposition of parent fishes of red pink bass, and relates to the technical field of breeding of red pink bass. The method comprises the steps of parent fish selection, parent fish seaborne net cage cultivation and indoor reproduction regulation and natural oviposition. According to indoor reproduction regulation and control of natural oviposition, conditions including water temperature, illumination period and nutrient enrichment for parent fish cultivation are regulated and controlled in a land-based factory-like indoor running water cement pond, parent fish gonad development and synchronous maturation are regulated and controlled, natural oviposition is achieved, and batches of high-quality fertilized eggs are obtained; according to the method, the parent fish can naturally lay eggs in the indoor breeding pond at the water temperature of 26-27 DEG C within the regulation period of one week, the egg laying period can reach 121 days, the fertilization rate reaches 95% or above, and the hatching rate reaches 85% or above. According to the method, factory-like indoor natural spawning of the pink pink bass is broken through for the first time, and batch breeding and breeding development of pink pink bass seedlings can be effectively promoted.

Description

Technical Field

[0001] This invention relates to the field of red snapper breeding technology, specifically to a method for regulating the natural spawning of red snapper broodstock in a factory setting. Background Technology

[0002] The red-spined sea bass (Cephalopholis sonnerati), also known as the grouper, is a species belonging to the order Perciformes, suborder Percoidei, family Serranidae, and genus Cephalophoros. It is prized for its vibrant red coloration, rich nutritional value, and delicate, sweet flesh rich in collagen, making it highly valued for both its edible and ornamental qualities. Wild red-spined sea bass are mainly distributed in the tropical and subtropical waters of the Pacific Ocean, feeding on small fish and crustaceans. Due to its scarcity in the wild and its role as a key species in coral reef ecosystems, maintaining the balance of the food chain in coral reef areas, it has extremely high conservation value. In 2018, it was assessed as "Near Threatened (NT)" on the IUCN Red List, meaning that the red-spined sea bass faces a high risk of extinction in the wild.

[0003] The red-spined perch, a prized aquaculture fish in my country, is highly sought after by consumers and enjoys a broad market demand. However, the wild population of red-spined perch has declined significantly due to overfishing and habitat destruction, and my country has yet to achieve a breakthrough in the technology for large-scale natural spawning in indoor cement ponds for red-spined perch. In the past few years, the breeding of red-spined perch has primarily relied on artificial spawning induction to obtain fertilized eggs. For example, Chinese invention patent CN 110100769 B authorizes an artificial breeding method for red-spined perch, but this method involves pond cultivation and hormone-induced artificial spawning. Chinese invention patent CN 118441072 A discloses a method for identifying the kinship of red-spined perch broodstock and a fully indoor breeding method, which uses marine cage cultivation and hormone-induced artificial spawning to obtain fertilized eggs, but neither method demonstrates large-scale spawning. Furthermore, the success rate of broodstock cultivation in open ponds and marine cages is greatly constrained by natural environmental factors such as water temperature, waves, and diseases. Furthermore, the asynchronous maturation and spawning times of male and female broodstock of the red-spotted bass, resulting in low spawning volumes, are problems in the artificial breeding of red-spotted bass broodstock. The use of hormone injection to induce spawning is a non-natural spawning method, which is difficult to operate, causes significant harm to the broodstock, and results in severe losses, potentially leading to poor gamete quality (over-mature eggs, low fertilization rate) and the inability to obtain large quantities of fertilized eggs in a long-term manner. Currently, there are no reports on indoor, factory-scale, large-scale natural spawning breeding methods for red-spotted bass. Therefore, breakthroughs in indoor natural spawning breeding technology for red-spotted bass, achieving factory-scale, long-cycle spawning, and reducing damage to broodstock and operational difficulties are of significant practical importance for promoting large-scale indoor artificial breeding of red-spotted bass. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a method for regulating the natural spawning of red sea bass broodstock in an indoor factory setting. Through a combination of land-sea relay cultivation and artificial reproductive regulation, the gonads of the broodstock mature synchronously and spawn naturally in an indoor cultivation pond, thereby obtaining high-quality fertilized eggs for mass natural spawning and providing a sufficient supply of high-quality fertilized eggs for the large-scale production of red sea bass fry.

[0005] The technical solution of this invention is as follows: A method for regulating the natural spawning of red snapper broodstock in an industrialized facility includes broodstock selection, marine cage culture of broodstock, and indoor reproductive regulation of natural spawning, specifically comprising the following steps: S1 Parent Fish Selection: Select parent fish with normal body color, no injuries on the body surface, and active and healthy behavior; S2 Broodstock Cage Culture: Broodstock are cultured using a combination of marine cage culture and land-based industrialized indoor water culture. When the natural seawater temperature is above 25℃, the broodstock are transferred to marine cage culture; when the natural seawater temperature is above 31℃, the broodstock are transferred to land-based industrialized aquaculture workshops for indoor culture.

[0006] S3 Indoor Reproduction Regulation Natural Spawning: By regulating the water temperature, light cycle, and nutrient fortifier composition of broodstock in factory-style indoor culture, the gonads of broodstock are regulated to mature and spawn naturally indoors in a relatively short period of time. S31 Water Temperature Control: The initial water temperature of the broodstock rearing pond is set at 23-24℃. After the broodstock are transferred to the indoor rearing pond, the temperature is gradually increased from 23-24℃ to 26-27℃ over one week at a rate of 0.5℃ / day. At this temperature, they begin to spawn. The temperature is maintained at this level for 4 months, and then the temperature is decreased to 23-24℃ at a rate of 0.5℃ / week. Spawning ends at this point.

[0007] S32 Light Cycle Control: The workshop interior adopts a canopy design that allows light to pass through, providing a natural light source with a maximum light intensity of 2000 Lx.

[0008] S33 Nutritionally Fortified Feed Composition: Throughout the indoor rearing process, the broodstock are fed with fresh mackerel, sand goby, squid, and nutritional fortifiers to promote the development of the gonads and gametes to the optimal state in a short period of time, improve gamete quality, and continuously obtain a large number of high-quality fertilized eggs. Preferably, in step S1, the selected parent fish should be at least 2 years old, with a total length of 30cm-40cm and a weight of 1-1.5kg.

[0009] Preferably, in step S2, during offshore cage culture, the dissolved oxygen is ≥6 mg / L, the salinity is 32-33, and the broodstock culture density is 4-5 kg / m³. 3 .

[0010] Preferably, in step S3, the natural spawning regulation method in land-based factory indoor culture is controlled from aspects such as culture facilities, sex ratio, culture density, feed feeding, and culture conditions; wherein, the culture facilities adopt indoor flowing water cement culture ponds set up in the land-based factory aquaculture workshop, the sex ratio is (2-3):1 for female fish and the culture density is 6-8 kg / m³; the culture conditions are flowing water culture, water exchange rate of 5 m³ / h, daily water exchange rate of 300%, dissolved oxygen ≥6 mg / L, pH=8-8.2, salinity 28-30, and regular pond cleaning and bottom brushing; Preferably, in step S2, during the marine cage culture stage, the feed includes 75-80 wt.% of fresh triggerfish, 15-20 wt.% of squid, 5 wt.% of oyster meat, and a nutritional fortifier accounting for 5 wt.‰ of the total weight of the fresh triggerfish and squid. The feeding amount is maintained at 3-4% of the fish's body weight, and the fish are fed once every two days.

[0011] Preferably, in the land-based factory-style indoor flowing water culture method in step S2 and in step S33, the feed includes 40 wt.% of fresh mackerel, 45 wt.% of sand goby, 15 wt.% of squid, and a nutrient fortifier accounting for 5 wt.‰ of the total mass of fresh mackerel, sand goby, and squid. The feeding amount is 3-4% of the body weight of the parent fish, and feeding is done once every two days until spawning ends.

[0012] Preferably, the nutritional fortifiers include 30-40 wt.% lecithin, 30-40 wt.% astaxanthin, and 20-40 wt.% complex vitamins. ， Multivitamins include vitamin A, vitamin C, and vitamin E. Compared with the prior art, the present invention has the following advantages: 1. The present invention discloses a method for regulating the natural spawning of red snapper broodstock in an industrialized indoor environment. High-quality broodstock are selected to construct multiple breeding parent populations. Through land-sea relay breeding of broodstock, the development and accumulation of broodstock within a suitable temperature range are ensured, allowing the broodstock to grow and develop under conditions closer to nature. The high quality of broodstock breeding provides a strong prerequisite for reproductive regulation of spawning.

[0013] 2. The present invention provides a method for regulating the natural spawning of red snapper broodstock in an industrialized indoor environment. By controlling water temperature and simulating natural spawning conditions with natural light, coupled with continuous flowing water cultivation and nutritional enhancement measures, the broodstock can experience natural environmental conditions to the maximum extent in the industrialized aquaculture workshop. This promotes the development of the gonads and gametes of the broodstock to the optimal state in a short period of time, achieving synchronous maturation of the gonads of male and female broodstock in a shorter time and realizing long-term natural spawning. This method achieves precise control of reproductive regulation and spawning of red snapper broodstock, and obtains high-quality fertilized eggs in batches.

[0014] 3. This invention provides a method for regulating the natural spawning of red snapper broodstock in an industrialized environment. Through the control of feed dosage and nutritional fortification, during the marine cage culture period, the broodstock are fed triggerfish, squid, oyster meat, and a 5‰ broodstock fortifier at a dosage of 3-4% of their body weight to promote growth and development. During the indoor reproductive regulation period, the feed is adjusted to mackerel, sand goby, squid, and a 5‰ broodstock fortifier, with the feed dosage maintained at 3-4% of body weight. Care is taken to control the broodstock's fat intake and reduce visceral fat accumulation, thereby effectively promoting the full development and maturation of the gonads and obtaining high-quality fertilized eggs. Attached Figure Description

[0015] Figure 1 This invention describes the water temperature change trend during the marine cage culture of red snapper broodstock in 2024.

[0016] Figure 2 This invention describes the trend of water temperature changes during indoor cultivation of red snapper broodstock in a factory-scale aquaculture workshop in 2024.

[0017] Figure 3 This invention describes the trend of spawning volume of red snapper broodstock in 2024. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0019] Example 1 This embodiment uses the factory-style indoor breeding of red snapper broodstock from Laizhou Mingbo Aquatic Products Co., Ltd. as an example for illustration.

[0020] In 2025, research on indoor culture and reproductive regulation of red snapper broodstock and natural spawning technology was carried out at Laizhou Mingbo Aquatic Products Company, successfully obtaining a large batch of high-quality fertilized eggs. The specific implementation process is as follows: S1 Parent Fish Selection Based on the criteria of being free from injury and ulceration, having normal body color, and being lively and healthy, broodstock with normal body color and lively and healthy were selected from wild leopard gill sea bass caught in the South China Sea. 1129 two-year-old broodstock with a total length of 30cm-40cm and a weight of 1-1.5kg were selected to form a total of 6 breeding groups.

[0021] S2 Broodstock Breeding The broodstock are cultivated using two methods: offshore net cages and land-based industrialized indoor flowing water systems. like Figure 1 As shown, on December 12, 2024, when the natural seawater temperature reached 25℃, the parent fish were transferred to deep-sea, wave-resistant net cages for summer rearing. The net cages were square wooden structures, measuring 4.5m × 4.5m × 3m, with a rearing density of 4-5 kg / m³. 3 .

[0022] During the marine cage culture period, the broodstock feed consisted of 75-80 wt.% fresh triggerfish, 15-20 wt.% squid, 5 wt.% oyster meat, and a nutrient fortifier comprising 5 wt.‰ of the total weight of the fresh triggerfish, squid, and oyster meat. The feeding amount was 3-4% of the fish's body weight, fed every two days at 12 noon. Culture conditions: dissolved oxygen ≥6 mg / L, salinity 32-33, and good broodstock development.

[0023] On May 13, 2025, when the natural seawater temperature exceeded 31℃, the broodstock were transferred to a land-based intensive aquaculture facility for indoor rearing. The broodstock were housed in 6.85m × 6.85m × 1m cement rearing tanks (effective volume approximately 40m³) within the land-based intensive aquaculture facility. 3 Indoor rearing: 1129 parent fish were placed in 6 rearing ponds according to the male-to-female ratio, with a rearing density of 6-8 kg / m³. 3 The sex ratio was (2-3):1 for females to males. Broodstock were transferred using a recirculating aquaculture system (RAS) live fish transport vehicle, with the water temperature controlled at 22-23℃, DO ≥ 6 mg / L, and broodstock density at 100-125 kg / m³.

[0024] During indoor rearing, the broodstock feed consisted of 40 wt.% fresh mackerel, 45 wt.% sand eel, and 15 wt.% squid, along with a nutrient fortifier comprising 5 wt.‰ of the total weight of the fresh mackerel, sand eel, and squid. The feeding amount was 3-4% of the broodstock's body weight, given every two days at noon. Other rearing conditions included: flow-through rearing with a water exchange rate of 5 m³ / h, a daily water exchange rate of 300%, dissolved oxygen ≥ 6 mg / L, pH = 8-8.2, salinity 28-30, and regular pond cleaning and bottom scrubbing; the water temperature was increased from the initial 23-24℃ to 26-27℃ at a rate of 0.5℃ / day.

[0025] S3 Reproductive Regulation Natural Ovulation After being transferred to the flow-through culture tank of a land-based factory aquaculture workshop on May 13, 2025, the broodstock were regulated to achieve gonadal maturation and natural spawning through artificial temperature control, natural light, and nutrient enhancement. S31 Water Temperature Control Starting on May 13, 2025, high-temperature steam was supplied to the workshop pipelines via the boiler of the thermal power plant. Combined with the workshop heat exchanger, the waste heat from the workshop's exhaust water was used to regulate the water temperature for broodstock rearing, which is water-saving, energy-saving, and environmentally friendly. The temperature was increased from 23-24℃ on May 13 at a rate of 0.5℃ / day over one week to 26-27℃ on May 19 to induce spawning. After maintaining this temperature for 4 months, the temperature was gradually reduced at a rate of 0.5℃ / day until spawning ended.

[0026] S32 Irradiance Regulation The workshop interior features a canopy design that allows natural light to pass through, with a maximum light intensity of 2000 Lx.

[0027] S33 Nutritional Fortification After transferring the broodstock to a factory-style indoor flowing-water rearing tank, and synchronizing with temperature and light control, the broodstock's diet was adjusted to a mixture of 40 wt.% fresh mackerel, 45 wt.% small yellow croaker, and 15 wt.% squid, fed at a rate of 3-4% of their body weight every two days. Simultaneously, a nutritional fortifier consisting of 40 wt.% lecithin, 40 wt.% astaxanthin, and 20 wt.% complex vitamins was added to the mixed diet at a rate of 5 wt.‰ of the mixed diet, mixed and stirred onto the surface of the fresh fish to enhance the broodstock's nutrition and improve gamete quality.

[0028] Through the above reproductive regulation measures, the gonads of the broodstock developed well and reached synchronous maturity. The broodstock spawned naturally in the indoor rearing pond, yielding 39.985 kg of high-quality, floating fertilized eggs. The spawning period lasted 121 days (e.g., Figure 3 As shown in the figure, the average fertilization rate is over 95% and the hatching rate is over 85%, providing a sufficient supply of high-quality fertilized eggs for large-scale seedling cultivation.

[0029] Comparative Example 1 Another batch of broodstock of the same number as in Example 1 was cultured indoors in a land-based industrialized workshop under the same conditions and timeframes for reproductive regulation. The difference from Example 1 was that in steps S2 and S3, the broodstock were placed in a recirculating aquaculture tank, and the culture conditions were recirculating aquaculture. The results showed that the culture method in Comparative Example 1 did not yield fertilized eggs during 2024.

Claims

1. A method of regulating natural spawning of red grouper broodstock in a factory-like indoor environment, characterized by, The method comprises parent fish selection, parent fish offshore net cage cultivation and indoor reproductive regulation natural spawning, and specifically comprises the following steps. S1: parent fish selection: selecting parent fish with normal body color, no injury on body surface and active and healthy; S2: parent fish offshore net cage cultivation: parent fish are cultivated in offshore net cages and land-based factory indoor flow water cultivation mode, i.e., when the natural seawater temperature is higher than 25℃, the parent fish are transferred to offshore net cages for cultivation; when the natural seawater temperature is higher than 31℃, the parent fish are transferred to land-based factory cultivation workshops for indoor cultivation; S3: indoor reproductive regulation natural spawning: the water temperature, light cycle and nutrition enhancer proportion of parent fish factory indoor cultivation are regulated, so that the parent fish gonad development is regulated to maturity and natural spawning is realized in the indoor environment within 1 week; S31: water temperature regulation: the initial water temperature of the parent fish cultivation pool is set to 23-24℃, after the parent fish are transferred to the indoor cultivation pool, the water temperature is gradually increased at a rate of 0.5℃ / day from 23-24℃ to 26-27℃, and then the spawning starts, and after 4 months at this temperature, the water temperature is decreased at a rate of 0.5℃ / week to 23-24℃, and then the spawning ends; S32: light cycle regulation: the land-based factory cultivation workshop is designed with a roof that can transmit natural light, and the maximum light intensity is 2000Lx; S33: nutrition-enhanced bait composition: the indoor cultivation of parent fish uses bait of ice-fresh mackerel, sand eel, squid and nutrition enhancer to promote the gonad and gamete development of parent fish to the best state in a short time, improve the quality of gametes, and continuously obtain batches of high-quality fertilized eggs.

2. A method of regulating natural spawning of red grouper broodstock in a factory-like indoor environment according to claim 1, characterized in that, In step S1, the selected parent fish is 2 years old, 30-40 cm in length and 1-1.5 kg in weight.

3. A method of regulating natural spawning of red grouper broodstock in factory-like indoor conditions according to claim 1, characterized in that, In step S2, when the offshore net cage is cultivated, the dissolved oxygen is ≥ 6 mg / L, the salinity is 32-33, and the brood fish cultivation density is 4-5 kg / m 3 .

4. The method of regulating natural spawning of Plectropomus leopardus broodstock in factory-like indoor conditions according to claim 1, characterized in that, In step S2, the land-based factory indoor flow water cultivation mode is controlled from the aspects of cultivation facilities, gender matching, cultivation density, bait feeding and cultivation conditions; wherein the cultivation facilities are indoor flow water cement cultivation pools set in the land-based factory cultivation workshop, the gender matching is that the number ratio of female fish to male fish is (2-3):1, the cultivation density is 6-8 kg / m³, the cultivation conditions are flow water cultivation, the water exchange amount is 5 m³ / h, the daily water exchange rate is 300%, the dissolved oxygen is ≥6 mg / L, the pH is 8-8.2, the salinity is 28-30, and the pool is cleaned and the bottom is brushed regularly; and the water temperature is increased from the initial 23-24℃ to 26-27℃ at a rate of 0.5℃ / day.

5. The method of regulating natural spawning of Plectropomus leopardus broodstock in factory-like indoor conditions according to claim 1, characterized in that, In step S2, during the offshore net cage cultivation stage, the bait includes 75-80wt.% of ice-fresh cannonball fish, 15-20wt.% of squid, 5wt.% of oyster meat and 5wt.‰ of nutrition enhancer accounting for the total mass of ice-fresh cannonball fish and squid, and the feeding amount is kept at 3-4% of the fish weight, and the feeding is performed once every two days.

6. The method of regulating natural spawning of Plectropomus leopardus broodstock in factory-like indoor conditions according to claim 1, characterized in that, In the land-based factory indoor flow water cultivation mode of step S2 and step S3, the bait includes 40wt.% of ice-fresh mackerel, 45wt.% of sand eel, 15wt.% of squid and 5wt.‰ of nutrition enhancer accounting for the total mass of ice-fresh mackerel, sand eel and squid, and the feeding amount is 3-4% of the parent fish weight, and the feeding is performed once every two days until the spawning ends.

7. The method of regulating natural spawning of red grouper broodstock in factory- type indoor conditions according to claim 1, 5 or 6, characterized in that, The nutritional supplement includes lecithin 30-40 wt.%, astaxanthin 30-40 wt.% and complex vitamins 20-40 wt.%.

8. A method of regulating natural spawning of red grouper broodstock in factory-like indoor conditions according to claim 1, characterized in that, In step S2, the circulating water live fish transport vehicle is used when the brood fish is transferred, the water temperature of the circulating water live fish transport vehicle is controlled to be constant at 22-23℃, DO≥6 mg / L, and the density of the brood fish is 100-125 kg / m³.

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