Artificial regulation and control method for annual natural oviposition of parent eleutheronema tetradactylum

Abstract

The invention discloses an artificial regulation and control method for all-year-round natural spawning of parent eleutheronema tetradactylum, and relates to the technical field of aquatic product breeding, and the method comprises the following steps: (1) performing batch spawning management on the parent eleutheronema tetradactylum; (2) composite environment regulation and control; (3) performing staged nutrient enrichment; (4) postpartum recovery of the parent fish; and (5) synergistically regulating and controlling the water quality by probiotics. The sexual gland development of the eleutheronema tetradactylum parent fish is regulated and controlled by adopting a composite management method of environment, biology, nutrition, parent fish management and the like, the seasonal limitation that the breeding period of the eleutheronema tetradactylum is short is broken through, natural oviposition all year round is achieved, the oviposition amount, the fertilization rate and the hatching rate of the parent fish and the survival rate of the postpartum parent fish are increased, and the survival rate of the postpartum parent fish is increased. The industrial problem of low overwintering survival rate of eleutheronema tetradactylum is also synchronously solved. Compared with the prior art, the whole-year egg laying amount of the eleutheronema tetradactylum parent fish is increased by 82%, the fertilization rate and the hatching rate are increased by 30%, and the survival rate of the postpartum parent fish is increased by 15%.

Description

Technical Field

[0001] The invention belongs to the technical field of aquatic breeding, and particularly relates to an artificial control method for the natural spawning of four-fingered threadfin broodstock throughout the year. Background Art

[0002] The four-fingered threadfin scorpion is a medium-sized warm-water fish of the family Cyprinidae, order Mugilius, and is widely distributed in the northern Indian Ocean and the western Pacific Ocean. The four-fingered threadfin scorpion has a relatively short spawning period in natural sea areas, which is only from late March to early May, and is about 50 days from start to finish. In order to solve the problem of the short spawning period of the four-fingered threadfin scorpion, scientists have been conducting scientific research to find better artificial control methods to extend its spawning cycle and promote the large-scale development of the industry. For example, the Chinese patent with publication number CN113812356A discloses a full-season breeding method for four-fingered threadfin scorpion broodstock, which enables the breeding season to last from mid-March to mid-November; the method includes selectively constructing a reproductive group from the breeding group, breeding broodstock in the breeding pond, feeding the broodstock with threadfin scorpion-specific feed, overwintering, pre-natal breeding, and spawning. Summary of the Invention

[0003] The invention aims to provide an artificial control method for the natural spawning of four-fingered threadfin broodstock throughout the year, thereby breaking through the seasonal restriction of four-fingered threadfin broodstock reproduction and realizing natural spawning throughout the year.

[0004] To achieve the above objectives, the present invention adopts the following technical solutions.

[0005] A method for artificially regulating the natural spawning of four-fingered threadfin broodstock throughout the year comprises the following steps:

[0006] (1) Batch spawning management of broodstock:

[0007] The mature broodstock population is divided into two groups, A and B, and stocked in different broodstock ponds for cultivation, with alternating induced spawning and spawning:

[0008] Group A: Induction and spawning time: June to August and December to February.

[0009] Group B: induced spawning and spawning time: March to May and September to November;

[0010] Among them, hot water pipes were laid at the bottom of the broodstock pond of Group A to heat the pond water in winter;

[0011] (2) Complex environmental regulation during the spawning period:

[0012] Water flow stimulation: 48 hours before spawning, start a 4-inch submersible pump to pump the reserved aquaculture seawater into the broodstock pond, creating a water flow impact on the broodstock in the pond at a speed of 2.4m / s. When the fish are observed to be chasing each other to spawn, stop flushing.

[0013] Salinity control: The salinity of the broodstock pond water is controlled within the range of 26-30‰ throughout the year;

[0014] Precise temperature control: During the spawning period, the water temperature of the broodstock pond is controlled at 26-31°C to ensure the spawning temperature. During the low temperature period, the following measures are taken to maintain the appropriate spawning temperature:

[0015] In winter, the A group broodstock pond uses a double-layer inflatable membrane to build an insulation shed, which is completed from October to early November to improve thermal insulation performance and save energy, providing sufficient temperature for the A group broodstock to spawn in winter;

[0016] b. When the water temperature in the parent fish pond of Group A is lower than 26°C during the spawning period, hot water will be supplied to the bottom hot water pipe to raise the water temperature to above 26°C;

[0017] (3) Phased nutritional enhancement during the spawning period:

[0018] From 30 days before spawning to the beginning of the spawning period, feeding high-protein pelleted feed supplemented with fish oil, egg yolk protein, shrimp, oysters, squid, etc. as nutritional enhancers, and increasing the feeding of vitamin E and vitamin C, wherein the feeding amount of fish oil, egg yolk protein, vitamin E, and vitamin C is 2-3% of the weight of the high-protein pelleted feed, and the feeding amount of shrimp, oysters, and squid is 0.3% of the weight of the broodstock, to promote the development of oocytes and yolk production in the gonads of the broodstock; the crude protein content of the high-protein pelleted feed is ≥45%;

[0019] For Group A broodstock that spawn in winter, normal feeding is performed during the overwintering period, and Antarctic krill meal and Schizochytrium algae meal are also fed 30 days before spawning to enhance nutrition, improve immunity, and promote digestion of the spawning broodstock. The feeding amounts of Antarctic krill meal and Schizochytrium algae meal are 3% and 1.2% of the mass of the high-protein pellet feed, respectively. During the winter spawning period, Group A broodstock are fed a vitamin complex in addition to the high-protein pellet feed. The vitamin complex is fed at a feeding amount of 2% of the mass of the high-protein pellet feed, and the vitamin complex contains 800 IU / kg of vitamin E and 5‰ of vitamin C.

[0020] (4) Postpartum recovery of broodstock:

[0021] During the period of alternating spawning of parent fish in groups A and B, the parent fish that have completed induced spawning and spawning enter a postpartum recovery stage with a recovery period of 1 month. During the postpartum recovery stage, multivitamins are fed in combination with high-protein pellet feed to accumulate nutrition and energy for the next stage of spawning and to promote good gonadal development, thereby preparing for the production of high-quality male and female gametes. The feeding amount of the multivitamin is 2% of the mass of the high-protein pellet feed, which includes 800 IU / kg of vitamin E and 5‰ of vitamin C.

[0022] The present invention uses a composite management method including environmental, biological, nutritional, and broodstock management to regulate the gonadal development of four-fingered threadfin broodstock to achieve the purpose of natural spawning throughout the year, while also overcoming the deficiency of the broodstock from mid-November to mid-March in the patent with publication number CN113812356A. The present invention adopts a batch spawning management method to fully restore the broodstock's physical condition after giving birth, providing ample time for supplementing nutrients for their gonadal development, and can continuously produce more orderly and better-quality gametes, so that the present invention has a higher broodstock egg production, better fertilization rate, hatchability, and higher postpartum broodstock survival rate. In addition, unlike the CN113812356A patent, which uses a water flow with a flow rate of 0.4 to 0.6 m / s to promote progressive gonadal development during prenatal cultivation, the present invention uses a water flow with a larger flow rate of 2.4 m / s to stimulate and initiate spawning, and once the spawning cycle begins, the water flow impact is stopped, which is conducive to concentrated spawning of broodstock, resulting in a large and orderly egg production and improved spawning effect.

[0023] Preferably, each broodstock pond of 2 to 3 mu is stocked with 300 to 400 broodstock, and the ratio of male to female broodstock in the broodstock pond is 1:1 to 1:2.

[0024] Preferably, the broodstock of group B are in the postpartum recovery stage during the winter, that is, they are fed with the above-mentioned recovery period compound vitamins combined with high-protein granular feed, and an ordinary wintering shed is built for the broodstock pond of group B for wintering.

[0025] Furthermore, the present invention also includes the use of probiotics to synergistically regulate water quality; specifically, every 10 days, one of the following methods is used alternately to regulate water quality in the broodstock pond, degrade and transform metabolites, and prevent the growth and collapse of cyanobacteria: a. Use a 3:1 mass ratio of Bacillus and Lactobacillus plantarum to spray the entire pond; b. Use Clostridium butyricum combined with beneficial bacteria such as Bacillus, lactic acid bacteria, and yeast to spray the water surface once a day for three consecutive days; c. Use 100-250g per mu of cyanobacteria algae-lysing bacteria to spray the entire pond. By combining the above three methods at different times and spaces to regulate water quality, the present invention achieves a better synergistic regulation effect.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention breaks through the seasonal limitation of the short breeding period of the four-fingered threadfin prawn, realizes natural spawning throughout the year, and simultaneously solves industry problems such as low overwintering survival rate, thereby increasing the spawning volume, fertilization rate, hatching rate and post-natal survival rate of broodstock. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is described clearly and completely below using embodiments.

[0029] Example 1

[0030] Follow these steps to implement artificial control of natural spawning throughout the year:

[0031] 1. Preparation of broodstock ponds and management of broodstock batch spawning

[0032] Divide the mature broodstock group into two groups, A and B, and implement alternating induction of spawning and spawning:

[0033] Group A: Induction and spawning time: June to August, December to February,

[0034] Group B: induced spawning and spawning time: March to May, September to November;

[0035] The broodstock groups A and B were stocked in different broodstock ponds for breeding.

[0036] The broodstock pond covers an area of 2 to 3 mu, with a water depth of 1.5 to 1.8 meters. Each diagonal corner of the broodstock pond is equipped with a waterwheel-type aerator (2.0kW / unit) and an egg collection device to control the dissolved oxygen at 5.1 to 7.6 mg / L, and the dissolved oxygen rate in the pond is monitored by an environmental detection system. Each broodstock pond is equipped with an automatic feeding machine. Next to the broodstock pond is a water reservoir to store aquaculture seawater with the same salinity as the broodstock pond water.

[0037] Hot water pipes are laid at the bottom of the broodstock pond in Group A, and there is a land-based boiler room with a boiler heating device. The boiler and the hot water pipes form a closed-circulation water heating system, which can heat the water in the broodstock pond in winter; the broodstock pond in Group B does not have a boiler heating system.

[0038] Each broodstock pond is stocked with 300 to 400 broodstock, with male and female broodstock mixed in a ratio of 1:1 to 1:2.

[0039] Before the broodstock are put into the pond, the pond should be cleaned, exposed to the sun and dry-limeed 7 to 15 days in advance. Then, the transparency and salinity of the pond water should be adjusted and fertilized by adding fertilizers and compound microbial preparations.

[0040] Select mature four-fingered threadfin broodstock with plump bodies and slightly or obviously swollen abdomens observed with the naked eye, and carefully move them into the broodstock pond for cultivation.

[0041] 2. Complex environmental regulation during the spawning period

[0042] Water flow stimulation: 48 hours before spawning, use a 4-inch submersible pump to pump the reserved aquaculture seawater with the same salinity as the reservoir into the broodstock pond, forming a water flow impact on the broodstock in the pond with a water flow speed of 2.4m / s; when the fish are observed to have tail-chasing spawning behavior, stop flushing.

[0043] Salinity control: The salinity of the water in the brooding pond is controlled within the range of 26-30‰ throughout the year. The high-salinity seawater or fresh water used to adjust the salinity must be precipitated and filtered to ensure that the water is fresh, clean, pollution-free and free of pathogens.

[0044] Precise temperature control: During the spawning period, the water temperature of the broodstock pond is controlled at 26-31°C, and the following measures are taken to maintain the appropriate spawning temperature during the low-temperature spawning period:

[0045] a. In winter, the broodstock pond in Group A uses a double-layer inflatable membrane to build an insulation shed, which is completed from October to early November to improve thermal insulation performance and save energy, providing sufficient temperature for broodstock to spawn in winter.

[0046] b. When the water temperature is below 26°C, start the circulating water heating system to flow hot water into the hot water pipe at the bottom of the Group A broodstock pond to raise the pond water temperature to above 26°C.

[0047] 3. Use probiotics to coordinate water quality control

[0048] a. Use Bacillus and Lactobacillus plantarum, mix them in a mass ratio of 3:1, and spray them throughout the pond; b. Spray 50 grams of Butyric Acid Enterol and 0.5 kilograms of active enzymes produced by Guangzhou Xinhailisheng Biotechnology Co., Ltd. on each acre of pond water surface (the above two products contain beneficial bacteria such as Clostridium butyricum, Bacillus, lactic acid bacteria and yeast) once a day. Stop after 3 consecutive days and switch to method a or c; c. Use 100-250 grams of cyanobacteria algae-lysing bacteria per acre and spray it throughout the pond. During the entire broodstock breeding process, the above three methods are used once a month, and one method is used alternately every 10 days to synergistically regulate water quality, degrade and transform metabolites, and prevent the reproduction of cyanobacteria and algae collapse.

[0049] 4. Phased nutrition enhancement during the spawning period

[0050] In daily management, use complete artificial floating pellet feed produced by regular feed manufacturers (hereinafter referred to as high-protein pellet feed), with a crude protein content of more than 45%. Feed once in the morning and afternoon, and the daily feeding amount is 3-5% of the fish body weight.

[0051] From 30 days before spawning until the start of the spawning period, supplement the high-protein pelleted feed with fish oil, egg yolk protein, shrimp, oysters, squid, etc. as nutritional supplements. Also, appropriately increase the amount of vitamin E and vitamin C. Fish oil, egg yolk protein, vitamin E, and vitamin C should constitute 2-3% of the weight of the high-protein pelleted feed, and shrimp, oysters, and squid should be 0.3% of the broodstock's body weight to promote oocyte development and yolk production in the broodstock's gonads. High-protein pelleted feed should be used during the spawning period.

[0052] For Group A broodstock planned to spawn in winter, normal feeding was performed during the wintering period. 30 days prior to spawning, in addition to the aforementioned nutritional fortification methods, they were also fed Antarctic krill meal and Schizochytrium algae meal to enhance nutrition, improve immunity, and promote digestion. The feeding amounts of Antarctic krill meal and Schizochytrium algae meal were 3% and 1.2% of the mass of the high-protein pellet feed, respectively (see Table 1).

[0053] During the winter spawning period, the broodstock of Group A were fed a multivitamin supplemented with a high-protein pellet feed. The multivitamin was fed at a rate of 2% of the mass of the high-protein pellet feed, and the multivitamin contained 800 IU / kg of vitamin E and 5‰ of vitamin C (see Table 1).

[0054] Table 1

[0055]

[0056] 5. Postpartum recovery of broodstock

[0057] During the period of alternating spawning of broodstock in groups A and B, the broodstock that have completed induced spawning and spawning enter the postpartum recovery stage, and the recovery period is 1 month.

[0058] During the postpartum recovery phase, good water quality conditions should be maintained, and good nutrition should be maintained to promote the recovery of the health of the postpartum broodstock. High-protein pellet feed + 2% multivitamins (including VE 800IU / kg, VC 5‰) should be used for feeding to accumulate nutrients and energy for the next stage of spawning and to promote good gonad development, in preparation for the production of high-quality male and female gametes.

[0059] For the overwintering period of Group B broodstock, which is the postpartum recovery stage, the above-mentioned recovery period compound vitamins are used in combination with high-protein granular feed for feeding. After the recovery period, they are fed according to the conventional overwintering management until the next nutritional fortification begins, and an ordinary overwintering shed is built for the Group B broodstock pond for overwintering.

[0060] According to the method for artificially controlling year-round spawning of four-fingered threadfin broodstock of the present embodiment, approximately 2,000 broodstock are spawned, and the annual spawning amount of the broodstock is approximately 330 million eggs, which is approximately 28% higher than the all-season spawning amount of Chinese patent CN113812356A and 82% higher than the existing general technology; the average fertilization rate of the present embodiment is approximately 90%, and the average hatching rate is approximately 85%, both of which are approximately 10% higher than those of Chinese patent CN113812356A and 30% higher than those of the existing general technology; the post-natal broodstock survival rate of the present embodiment is approximately 98%, which is approximately 5% higher than that of Chinese patent CN113812356A and 15% higher than those of the existing general technology.

Claims

1. A method for artificially controlling the natural spawning of four-fingered threadfin broodstock throughout the year, characterized in that: The following steps are involved: (1) Batch spawning management of broodstock: The mature broodstock population is divided into two groups, A and B, and stocked in different broodstock ponds for cultivation, with alternating induced spawning and spawning: Group A: Induction and spawning time: June to August and December to February. Group B: induced spawning and spawning time: March to May and September to November; Among them, hot water pipes were laid at the bottom of the broodstock pond of Group A to heat the pond water in winter; (2) Complex environmental regulation during the spawning period: Water flow stimulation: 48 hours before spawning, start a 4-inch submersible pump to pump the reserved aquaculture seawater into the broodstock pond, creating a water flow impact on the broodstock in the pond at a speed of 2.4m / s. When the fish are observed to be chasing each other to spawn, stop flushing. Salinity control: The salinity of the broodstock pond water is controlled within the range of 26-30‰ throughout the year; Precise temperature control: During the spawning period, the water temperature of the broodstock pond is controlled at 26-31°C to ensure the spawning temperature. During the low temperature period, the following measures are taken to maintain the appropriate spawning temperature: In winter, the A group broodstock pond uses a double-layer inflatable membrane to build an insulation shed, which is completed from October to early November to improve thermal insulation performance and save energy, providing sufficient temperature for the A group broodstock to spawn in winter; b. When the water temperature in the parent fish pond of Group A is lower than 26°C during the spawning period, hot water will be supplied to the bottom hot water pipe to raise the water temperature to above 26°C; (3) Phased nutritional enhancement during the spawning period: From 30 days before spawning to the beginning of the spawning period, feed high-protein pellet feed supplemented with fish oil, egg yolk protein, shrimp, oysters, squid, etc. as nutritional enhancers, and increase the feeding of vitamin E and vitamin C; For Group A broodstock that spawn in winter, they were fed a normal diet during the winter, and supplemented with Antarctic krill meal and Schizochytrium meal 30 days before spawning. During the winter spawning period, Group A broodstock were fed a high-protein pelleted diet supplemented with multivitamins. (4) Postpartum recovery of broodstock: During the period of alternating spawning of parent fish in groups A and B, the parent fish that have completed induced spawning and spawning enter the postpartum recovery stage, which lasts for 1 month. During the postpartum recovery stage, they are fed with a combination of multivitamins and high-protein granular feed.

2. The artificial control method for natural spawning of four-fingered threadfin broodstock throughout the year according to claim 1, wherein: It also includes the use of probiotics to coordinately regulate water quality; specifically: use one of the following methods alternately once every 10 days to regulate the water quality in the broodstock pond: a. Use a compound of Bacillus and Lactobacillus plantarum to spray the entire pond; b. Use Clostridium butyricum combined with Bacillus, lactic acid bacteria and yeast to spray the water surface, once a day for 3 consecutive days; c. Use cyanobacteria algae-lysing bacteria to spray the entire pond.

3. The artificial control method for natural spawning of four-fingered threadfin broodstock throughout the year according to claim 2, wherein: Each broodstock pond of 2 to 3 mu is stocked with 300 to 400 broodstock, and the ratio of male to female broodstock in the broodstock pond is 1:1 to 1:

2.

4. The artificial control method for natural spawning of four-fingered threadfin broodstock throughout the year according to claim 3, wherein: The broodstock of Group B were in the postpartum recovery stage during the winter, that is, they were fed with the above-mentioned recovery period compound vitamins combined with high-protein granular feed, and an ordinary wintering shed was built for the broodstock pond of Group B for wintering.

5. The artificial control method for natural spawning of four-fingered threadfin broodstock throughout the year according to claim 4, characterized in that: In step (3), the feeding amount of fish oil, egg yolk protein, vitamin E and vitamin C is 2-3% of the mass of the high-protein pellet feed, and the feeding amount of shrimp, oyster and squid is 0.3% of the body weight of the broodstock.

6. The method for artificially controlling the natural spawning of four-fingered threadfin broodstock throughout the year according to claim 5, wherein: In step (3), the feeding amounts of the Antarctic krill meal and Schizochytrium algae meal are 3% and 1.2% of the mass of the high-protein pellet feed, respectively.

7. The method for artificially controlling the natural spawning of four-fingered threadfin broodstock throughout the year according to claim 6, wherein: In steps (3) and (4), the feeding amount of the multivitamin is 2% of the mass of the high-protein pellet feed, and the multivitamin contains 800 IU / kg vitamin E and 5‰ vitamin C.

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