Chinese knot fish egg washing liquid, Chinese knot fish breeding method and application of Chinese knot fish egg washing liquid and Chinese knot fish breeding method

Abstract

The invention relates to a Chinese knot fish egg washing liquid, a Chinese knot fish breeding method and application thereof, and belongs to the technical field of aquaculture. According to the present invention, water is adopted as a solvent, and the water comprises 8-10 g / L of sodium chloride, 0.1-0.5 g / L of calcium chloride, 0.1-0.4 g / L of potassium chloride, and 10-15 g / L of glucose. By means of the breeding method, the fertilization rate, the hatching rate and the fry survival rate of the Chinese knot fish artificial breeding are greatly increased, the problems that in the Chinese knot fish artificial breeding process, female fish spawning is difficult, and the fertilization rate is low are solved, and large-scale production of the Chinese knot fish is achieved; the method is of great significance to species protection, field population resource recovery, breeding popularization and resource utilization of the Chinese knot fishes.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and in particular to a Chinese knot fish egg washing liquid and a Chinese knot fish breeding method and applications thereof. Background Art

[0002] The Chinese knot fish (Torsinensis), belonging to the Cypriniformes order, Cyprinidae family, Barbinae subfamily, and genus Tor, is commonly known as the red-winged or red-gilled fish. It is found in the main stream and tributaries of the middle and lower Lancang River and is endemic to the Lancang River system. Large in size, with delicious meat and vibrant colors, the Chinese knot fish possesses both nutritional and ornamental value, as well as high economic value. Due to long-term, intense fishing pressure, coupled with the dense human population along the middle and lower Lancang River, invasive alien fish, and interference from human activities such as overfishing, hydropower development, environmental pollution, shipping, and dredging and quarrying, the wild population of the Chinese knot fish has shown a significant decline, and it is now listed as a Near Threatened Species (NT). Therefore, artificial breeding and aquaculture are urgently needed to meet market demand.

[0003] At present, although breakthroughs have been made in the artificial breeding technology of Chinese knot fish, for example, patent CN104957054A discloses an artificial breeding method for Chinese knot fish, patent CN113331091A discloses an artificial breeding method for Chinese knot fish, patent CN115250970A discloses an artificial breeding method and system for Chinese knot fish, and patent CN114617086A discloses an artificial proliferation method for Chinese knot fish, but the above breeding methods all have the problems of low induced spawning rate of female broodstock, unsmooth ovulation, and a large amount of mucus during the ovulation process, which hinders the sperm from entering the egg, resulting in an extremely low fertilization rate (the lowest fertilization rate is only 2%). These problems cannot meet the current market demand and are far from achieving large-scale production. Summary of the Invention

[0004] The purpose of the present invention is to provide a Chinese knot fish egg washing liquid and a Chinese knot fish breeding method and application thereof, so as to solve the problems of difficulty in spawning of female Chinese knot fish, low fertilization rate, hatching rate and seedling survival rate in the prior art.

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

[0006] The invention provides a Chinese knot fish egg washing liquid. The Chinese knot fish egg washing liquid uses water as a solvent and comprises components with the following concentrations: 8-10 g / L of sodium chloride, 0.1-0.5 g / L of calcium chloride, 0.1-0.4 g / L of potassium chloride, and 10-15 g / L of glucose.

[0007] The invention also provides application of the Chinese knot fish egg washing liquid in artificial breeding of Chinese knot fish.

[0008] The present invention also provides a method for breeding Chinese knot fish, comprising the following steps:

[0009] (1) releasing river snails into a Chinese knot fish breeding pond for 30 to 60 days to obtain Chinese knot fish broodstock;

[0010] (2) Select male Chinese knot fish broodstock with milky white semen flowing out when the abdomen is gently pressed as mature male broodstock, select female Chinese knot fish broodstock with soft abdomen and red and swollen genital pore as mature female broodstock, and the remaining Chinese knot fish broodstock as reserve broodstock;

[0011] (3) Inject the mature female broodstock with a luteinizing hormone-releasing hormone analogue LHRH-A2 5 μg / kg. 15 to 22 hours after the injection, inject the mature female broodstock with a luteinizing hormone-releasing hormone analogue LHRH-A2 10 μg / kg + dioxigenin 10 mg / kg + human chorionic gonadotropin HCG 200 IU / kg. At the same time, inject the mature male broodstock with a luteinizing hormone-releasing hormone analogue LHRH-A2 5 μg / kg + dioxigenin 5 mg / kg + human chorionic gonadotropin HCG 100 IU / kg.

[0012] (4) 16 to 18 hours after the injection, the eggs are washed with Chinese knot fish egg washing solution to obtain ova, and the ova are mixed with semen to obtain a sperm-egg mixture;

[0013] (5) Mixing and stirring the sperm-egg mixture with water to obtain fertilized eggs, and incubating the fertilized eggs for 74 to 82 hours to obtain fry.

[0014] Preferably, the amount of the snails added in step (1) is 2% to 3% of the total weight of the Chinese knot fish per time;

[0015] The number of times of administration is 1 to 2 times / d;

[0016] The breeding density of the Chinese knot fish broodstock is 100 to 120 per pond.

[0017] Preferably, the weight of the mature male broodstock in step (2) is >1.5 kg / tail;

[0018] The body weight of the mature female broodstock is >2 kg / tail.

[0019] Preferably, the cleaning temperature in step (4) is 22-24°C;

[0020] The volume ratio of the egg and semen mixture is 10 to 15:1.

[0021] Preferably, the volume ratio of the sperm-egg mixture to water in step (5) is 1:2-3;

[0022] The stirring time is 2 to 3 minutes.

[0023] Preferably, the hatching density in step (5) is 0.8 to 10,000 grains / m 2 The incubation temperature is 22-24℃.

[0024] The invention also provides application of the breeding method in artificial breeding of Chinese knot fish.

[0025] The present invention has the following technical effects and advantages:

[0026] The Chinese knot fish egg washing liquid and the method for cleaning eggs and removing mucus before artificial insemination of the present invention can significantly increase the fertilization rate of Chinese knot fish artificial reproduction to more than 90%, solving the long-standing problem of low fertilization rate of Chinese knot fish artificial reproduction.

[0027] The breeding method of the present invention uses LHRH-A2, DOM, and HCG to induce spawning of Chinese knot fish, which has a good and stable spawning effect, greatly improves the hatching rate and seedling survival rate of Chinese knot fish, and solves the problem of low spawning rate of Chinese knot fish;

[0028] The breeding method of the present invention solves the problems of difficulty in spawning and low fertilization rate of female fish in the current artificial breeding process of Chinese knot fish, realizes the large-scale production of Chinese knot fish, and is of great significance to the species protection, wild population resource recovery, breeding promotion and resource utilization of Chinese knot fish. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of the breeding method of the present invention;

[0030] Figure 2 It is the model individual of Chinese knot fish;

[0031] Figure 3 It is the reproductive pore of mature male broodstock;

[0032] Figure 4 It is the reproductive pore of mature female broodstock;

[0033] Figure 5 For adopting the Chinese knot fish egg washing liquid of embodiment 1 to clean ovum;

[0034] Figure 6 These are the fertilized eggs of Chinese knot fish;

[0035] Figure 7 These are newly hatched fry of Chinese knot fish;

[0036] Figure 8 It is a juvenile Chinese knot fish;

[0037] Figure 9 It is a group of juvenile Chinese knot fish. DETAILED DESCRIPTION

[0038] The invention provides a Chinese knot fish egg washing liquid. The Chinese knot fish egg washing liquid uses water as a solvent and comprises components in the following concentrations: 8-10 g / L of sodium chloride, preferably 9.04 g / L; 0.1-0.5 g / L of calcium chloride, preferably 0.26 g / L; 0.1-0.4 g / L of potassium chloride, preferably 0.24 g / L; and 10-15 g / L of glucose, preferably 12 g / L.

[0039] The invention also provides application of the Chinese knot fish egg washing liquid in artificial breeding of Chinese knot fish.

[0040] The present invention also provides a method for breeding Chinese knot fish, comprising the following steps:

[0041] (1) Intensive cultivation: adding river snails to the Chinese knot fish breeding pond for 30 to 60 days, preferably 50 days; changing the water every 2 to 4 days, preferably every 3 days, to obtain Chinese knot fish broodstock;

[0042] (2) Broodstock selection: select male Chinese knot broodstock with milky white semen flowing out when the abdomen is gently pressed as mature male broodstock, select female Chinese knot broodstock with soft abdomen and red and swollen genital pore as mature female broodstock, and the remaining Chinese knot broodstock as reserve broodstock;

[0043] (3) Artificial induction of spawning: Inject LHRH-A2 5 μg / kg into mature female broodstock. 15 to 22 hours, preferably 18 hours after the injection, inject LHRH-A2 10 μg / kg + DOM 10 mg / kg + HCG 200 IU / kg into mature female broodstock. Simultaneously, inject LHRH-A2 5 μg / kg + DOM 5 mg / kg + HCG 100 IU / kg into mature male broodstock.

[0044] (4) Artificial insemination: 16 to 18 hours after injection, preferably 18 hours later, the eggs are washed with Chinese knot fish egg washing solution to obtain ova, and the ova are mixed with semen to obtain a sperm-egg mixture;

[0045] (5) Fertilized egg hatching: The sperm-egg mixture and water are mixed and stirred to obtain fertilized eggs, which are then hatched for 74 to 82 hours, preferably 80 hours, to obtain fry.

[0046] In the present invention, daily cultivation is also included before the intensive cultivation described in step (1), and the daily cultivation includes the following steps: feeding bait into the Chinese knot fish breeding pond 1 to 2 times a day, preferably once; changing the water once every 2 to 4 days, preferably once every 3 days;

[0047] The amount of the bait added is 2% to 3% of the total weight of the Chinese knot fish per time, preferably 3% of the total weight of the Chinese knot fish per time;

[0048] The bait is preferably Tongwei No. 1056 expanded feed, purchased from Kunming Tongwei Feed Co., Ltd.

[0049] In the present invention, the amount of the snails added in step (1) is 2% to 3% of the total weight of the Chinese knot fish per time, preferably 3% of the total weight of the Chinese knot fish per time;

[0050] The frequency of administration is 1 to 2 times / day, preferably 1 time / day;

[0051] The breeding density of the Chinese knot fish broodstock is 100 to 120 per pond, preferably 110 per pond.

[0052] In the present invention, the weight of the mature male broodstock in step (2) is >1.5 kg / tail;

[0053] The body weight of the mature female broodstock is >2 kg / tail.

[0054] In the present invention, the cleaning temperature in step (4) is 22-24° C., preferably 24° C.; the number of cleanings is 3-5 times, preferably 5 times;

[0055] The volume ratio of the egg and semen mixture is 10-15:1, preferably 10:1.

[0056] In the present invention, the volume ratio of the sperm-egg mixture and water in step (5) is 1:2-3, preferably 1:3;

[0057] The stirring time is 2 to 3 minutes, preferably 3 minutes.

[0058] In the present invention, the hatching density in step (5) is 0.8 to 10,000 grains / m 2 , preferably 10,000 particles / m 2 ; The incubation temperature is 22-24°C, preferably 24°C; the incubation water exchange frequency is 10-12 times / d, preferably 10 times / d.

[0059] In the present invention, after the fertilized eggs are hatched in step (5), larvae culture is further included, and the larvae culture includes the following steps: no feeding is performed within 0 to 6 days after the larvae rupture, and dead eggs and dead larvae are removed every day; on the 7th day, the larvae are transferred to a culture tank, and over-fed with Shengso S1 microcapsule material every 4 hours from the 7th to the 15th day; over-fed with Shengso S3 microcapsule material every 12 hours from the 16th to the 31st day; and the larvae are cultured for 31 days to obtain juveniles;

[0060] The fry culture density is 2000 to 3000 per culture tank, preferably 2500 per culture tank;

[0061] The water exchange frequency for the fry culture is 2 to 3 times / day, preferably 3 times / day.

[0062] In the present invention, the Shengsuo S1 microcapsule material and the Shengsuo S3 microcapsule material were purchased from Shandong Shengsuo Feed Technology Co., Ltd.

[0063] The invention also provides application of the breeding method in artificial breeding of Chinese knot fish.

[0064] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0065] In the present invention, river snails were purchased from Pu'er City, Yunnan Province, Tongwei No. 1056 expanded material was purchased from Kunming Tongwei Feed Co., Ltd., and Shengsuo S1 microcapsule material and Shengsuo S3 microcapsule material were purchased from Shandong Shengsuo Feed Technology Co., Ltd.

[0066] Example 1: Preparation of Chinese knot fish egg washing solution

[0067] Take 9.04 g of sodium chloride, 0.26 g of calcium chloride, 0.24 g of potassium chloride, and 12 g of glucose and make up the volume in 1 L of water to obtain Chinese knot fish egg washing liquid.

[0068] Example 2: Cultivation of Chinese knot fish broodstock

[0069] (1) Daily cultivation: Chinese knot fish were cultured in a cement pond of 25 m × 10 m × 1.8 m, with a stocking density of 110 fish / pond; Tongwei No. 1056 expanded feed was added to the pond once at 18:00 every day, with each addition amount being 3% of the total Chinese knot fish weight; the water was changed once every 3 days, with a single water change volume of 1 / 3, to maintain good water quality, and to monitor relevant indicators such as water temperature, dissolved oxygen, pH, ammonia nitrogen, and nitrite;

[0070] (2) Intensive cultivation: Starting from September, snails were added to the breeding pond once at 8:00 and 18:00 every day, with the amount added each time being 3% of the total weight of the Chinese knot fish. The water was flushed once at 14:00 every day and the water was changed once every 3 days, with a single water change volume of 1 / 3. The water quality was maintained in good condition, and relevant indicators such as water temperature, dissolved oxygen, pH, ammonia nitrogen, and nitrite were monitored. The intensified cultivation was carried out for a total of 50 days to obtain Chinese knot fish broodstock.

[0071] Example 3: Breeding of Chinese knot fish

[0072] On October 21, 2023, the water temperature was 24° C. From the Chinese knot fish broodstock obtained in Example 2, two male Chinese knot fish broodstock with healthy bodies and milky white semen flowing out of their abdomens when lightly pressed were selected as mature male broodstock, with an average weight of 1.7 kg. Two female Chinese knot fish broodstock with soft abdomens and swollen genital pores were selected as mature female broodstock, with an average weight of 2.4 kg.

[0073] At 23:00 on the 21st, mature female broodstock were injected with LHRH-A2 5μg / kg, while mature male broodstock were not injected. 18 hours after the injection, mature female broodstock were injected with LHRH-A2 10μg / kg + DOM 10mg / kg + HCG 200IU / kg, while mature male broodstock were injected with LHRH-A2 5μg / kg + DOM 5mg / kg + HCG 100IU / kg.

[0074] Artificial insemination was performed at 9:00 a.m. on the 23rd. The mature female broodstock was wiped dry with a dry towel. After removing the eggs, the eggs were washed five times with the Chinese knot fish egg washing solution prepared in Example 1 until the eggs were separated from the mucus. 1 mL of semen was squeezed onto 15 mL of eggs and stirred evenly to obtain a sperm-egg mixture. Three times the volume of clean water of the sperm-egg mixture was then added to activate the sperm. After continuous stirring for 3 minutes, the mixture was washed five times with 24°C clean water to obtain fertilized eggs. A total of 12,000 eggs were laid, with a 100% induction rate. 10,800 fertilized eggs were obtained, with a fertilization rate of 90%. The broodstock after artificial insemination were cultured daily, and the postpartum mortality rate of the broodstock was 0%.

[0075] The fertilized eggs are evenly spread in a rectangular cement hatching tank of 6m×1m×0.6m. The tank is covered with white tiles. The inlet and outlet are located on both sides of the long side. The water depth in the hatching tank is controlled by an overflow pipe to 40cm. The laying density of the fertilized eggs is 10,000 eggs / m 2 The water was exchanged 12 times a day at a temperature of 24°C. After 76 hours, the fertilized eggs hatched and 10,000 fry were obtained, with a hatching rate of 92.59%.

[0076] The fry were not fed within 0 to 6 days after their membranes ruptured, and dead eggs and dead fry were sucked out with a plastic straw every morning and evening. On the 7th day, the fry were transferred to a circular glass culture tank with a diameter of 1 m and a height of 80 cm. The culture density was 2,000 fry per tank, and the tank was watered from the side and drained from the bottom. The tank bottom was tilted toward the drain outlet, and the water depth was controlled at 50 cm. From the 7th to 15th day, the fry were overfed with Shengsuo S1 microcapsule feed every 4 hours. From the 16th to 31st day, the fry were overfed with Shengsuo S3 microcapsule feed every 12 hours. After each feeding, residual bait and feces were sucked out 30 minutes later. The water was exchanged three times every day. After 31 days of cultivation, 9,000 fry were obtained with a survival rate of 90%. From the 32nd day onwards, the fry were cultivated using the daily cultivation method described in Example 2.

[0077] Example 4: Breeding of Chinese knot fish

[0078] On October 25, 2023, the water temperature was 24° C. From the Chinese knot fish broodstock obtained in Example 2, healthy male Chinese knot fish broodstock with milky white semen flowing out when the abdomen was lightly pressed were selected as mature male broodstock, a total of 5 with an average weight of 1.8 kg, and female Chinese knot fish broodstock with soft abdomen and red and swollen genital pores were selected as mature female broodstock, a total of 7 with an average weight of 2.3 kg;

[0079] At 23:00 on the 25th, mature female broodstock were injected with LHRH-A2 5μg / kg, while mature male broodstock were not injected. 18 hours after the injection, mature female broodstock were injected with LHRH-A2 10μg / kg + DOM 10mg / kg + HCG 200IU / kg, while mature male broodstock were injected with LHRH-A2 5μg / kg + DOM 5mg / kg + HCG 100IU / kg.

[0080] Artificial insemination was performed at 9:00 a.m. on the 27th. The mature female broodstock was wiped dry with a dry towel. After removing the eggs, the eggs were washed four times with the Chinese knot fish egg washing solution prepared in Example 1 until the eggs were separated from the mucus. 1 mL of semen was squeezed onto 10 mL of eggs and stirred evenly to obtain a sperm-egg mixture. Three times the volume of clean water of the sperm-egg mixture was then added to activate the sperm. After continuous stirring for 2 minutes, the mixture was washed four times with 24°C clean water to obtain fertilized eggs. A total of 40,000 eggs were laid, with a 100% induction rate. 38,000 fertilized eggs were obtained, with a fertilization rate of 95%. The broodstock after artificial insemination were cultured daily, and the postpartum mortality rate of the broodstock was 0%.

[0081] The fertilized eggs are evenly spread in a rectangular cement hatching tank of 6m×1m×0.6m. The tank is covered with white tiles. The inlet and outlet are located on both sides of the long side. The water depth of the hatching tank is controlled by an overflow pipe to be 30cm. The laying density of the fertilized eggs is 10,000 eggs / m 2 The water was exchanged 10 times a day at a temperature of 24°C. After 75 hours, the fertilized eggs hatched and 36,000 fry were obtained, with a hatching rate of 94.74%.

[0082] The fry were not fed for 0 to 6 days after their membranes ruptured, and dead eggs and fry were sucked out with a plastic straw every morning and evening. On the 7th day, the fry were transferred to a circular glass culture tank with a diameter of 1 m and a height of 80 cm. The culture density was 3,000 fry per tank, and the tank was watered from the sides and drained from the bottom. The tank bottom was tilted toward the drain outlet, and the water depth was controlled at 60 cm. From the 7th to 15th day, the fry were overfed with Shengsuo S1 microcapsule feed every 4 hours. From the 16th to 31st day, the fry were overfed with Shengsuo S3 microcapsule feed every 12 hours. After each feeding, residual bait and feces were sucked out 30 minutes later. The water was exchanged twice a day. After 31 days of cultivation, 33,000 fry were obtained with a survival rate of 91.67%. From the 32nd day onwards, the fry were cultivated using the daily cultivation method described in Example 2.

[0083] Example 5: Breeding of Chinese knot fish

[0084] On October 2, 2024, the water temperature was 23° C. From the Chinese knot fish broodstock obtained in Example 2, healthy male Chinese knot fish broodstock with milky white semen flowing out when the abdomen was lightly pressed were selected as mature male broodstock, a total of 3, with an average weight of 1.9 kg, and female Chinese knot fish broodstock with soft abdomens and red and swollen genital pores were selected as mature female broodstock, a total of 5, with an average weight of 2.5 kg;

[0085] At 23:00 on the 2nd day, mature female broodstock were injected with LHRH-A2 5μg / kg, while mature male broodstock were not injected. 18 hours after the injection, mature female broodstock were injected with LHRH-A2 10μg / kg + DOM 10mg / kg + HCG 200IU / kg, while mature male broodstock were injected with LHRH-A2 5μg / kg + DOM 5mg / kg + HCG 100IU / kg.

[0086] Artificial insemination was performed at 9:00 a.m. on the 4th. The mature female broodstock was wiped dry with a dry towel. After removing the eggs, the eggs were washed four times with the Chinese knot fish egg washing solution prepared in Example 1 until the eggs were separated from the mucus. 1 mL of semen was squeezed onto 12 mL of eggs and stirred evenly to obtain a sperm-egg mixture. Then, 2 times the volume of clean water of the sperm-egg mixture was added to activate the sperm. After continuous stirring for 2 minutes, the mixture was washed four times with 23°C clean water to obtain fertilized eggs. A total of 30,000 eggs were laid, with a 100% induction rate. 28,000 fertilized eggs were obtained, with a fertilization rate of 93.33%. The broodstock after artificial insemination were cultured daily, and the postpartum mortality rate of the broodstock was 0%.

[0087] The fertilized eggs were evenly spread in a rectangular cement hatching tank of 6m×1m×0.6m. The tank was covered with white tiles. The inlet and outlet were located on both sides of the long side. The water depth in the hatching tank was controlled by an overflow pipe to 40cm. The laying density of the fertilized eggs was 8,000 eggs / m 2 The water was exchanged 12 times a day at a water temperature of 23°C. After 80 hours, the fertilized eggs hatched and 27,000 fry were obtained, with a hatching rate of 96.43%.

[0088] The fry were not fed within 0 to 6 days after their membranes ruptured, and dead eggs and fry were sucked out with a plastic straw every morning and evening. On the 7th day, the fry were transferred to a circular glass culture tank with a diameter of 1 m and a height of 80 cm. The culture density was 2,000 fry per tank, and the tank was watered from the sides and drained from the bottom. The tank bottom was tilted toward the drain outlet, and the water depth was controlled at 50 cm. From the 7th to 15th day, the fry were overfed with Shengsuo S1 microcapsule feed every 4 hours. From the 16th to 31st day, the fry were overfed with Shengsuo S3 microcapsule feed every 12 hours. After each feeding, residual bait and feces were sucked out 30 minutes later. The water was exchanged three times every day. After 31 days of cultivation, 25,000 fry were obtained with a survival rate of 92.59%. From the 32nd day onwards, the fry were cultivated using the daily cultivation method described in Example 2.

[0089] Example 6: Breeding of Chinese knot fish

[0090] On October 8, 2024, the water temperature was 23° C. From the Chinese knot fish broodstock obtained in Example 2, healthy male Chinese knot fish broodstock with milky white semen flowing out when the abdomen was lightly pressed were selected as mature male broodstock, a total of 5 with an average weight of 1.6 kg, and female Chinese knot fish broodstock with soft abdomens and red and swollen genital pores were selected as mature female broodstock, a total of 8 with an average weight of 2.6 kg;

[0091] At 24:00 on the 8th, mature female broodstock were injected with LHRH-A2 5μg / kg, while mature male broodstock were not injected. 18 hours after the injection, mature female broodstock were injected with LHRH-A2 10μg / kg + DOM 10mg / kg + HCG 200IU / kg, while mature male broodstock were injected with LHRH-A2 5μg / kg + DOM 5mg / kg + HCG 100IU / kg.

[0092] Artificial insemination was performed at 11:00 on the 10th. The mature female broodstock was wiped dry with a dry towel. After removing the eggs, they were washed five times with the Chinese knot fish egg washing solution prepared in Example 1 until the eggs were separated from the mucus. 1 mL of semen was squeezed onto 15 mL of eggs and stirred evenly to obtain a sperm-egg mixture. Then, 2 times the volume of clean water of the sperm-egg mixture was added to activate the sperm. After continuous stirring for 2 minutes, the mixture was washed three times with 23°C clean water to obtain fertilized eggs. A total of 40,000 eggs were laid, with an induction rate of 87.5%. 36,000 fertilized eggs were obtained, with a fertilization rate of 90%. The broodstock after artificial insemination were cultured daily, and the postpartum mortality rate of the broodstock was 0%.

[0093] The fertilized eggs are evenly spread in a rectangular cement hatching tank of 6m×1m×0.6m. The tank is covered with white tiles. The inlet and outlet are located on both sides of the long side. The water depth in the hatching tank is controlled by an overflow pipe to 40cm. The laying density of the fertilized eggs is 10,000 eggs / m 2The water was exchanged 10 times a day at a water temperature of 23°C. After 78 hours, the fertilized eggs hatched and 35,000 fry were obtained, with a hatching rate of 97.22%.

[0094] The fry were not fed within 0 to 6 days after their membranes ruptured, and dead eggs and fry were sucked out with a plastic straw every morning and evening. On the 7th day, the fry were transferred to a circular glass culture tank with a diameter of 1 m and a height of 80 cm. The culture density was 3,000 fry per tank, and the tank was watered from the side and drained from the bottom. The tank bottom was tilted toward the drain outlet, and the water depth was controlled at 60 cm. From the 7th to 15th day, the fry were overfed with Shengsuo S1 microcapsule feed every 4 hours. From the 16th to 31st day, the fry were overfed with Shengsuo S3 microcapsule feed every 12 hours. After each feeding, residual bait and feces were sucked out 30 minutes later. The water was exchanged three times every day. After 31 days of cultivation, 32,000 fry were obtained with a survival rate of 91.43%. From the 32nd day onwards, the fry were cultivated using the daily cultivation method described in Example 2.

[0095] Example 7: Breeding of Chinese knot fish

[0096] On October 20, 2024, the water temperature was 22° C. From the Chinese knot fish broodstock obtained in Example 2, healthy male Chinese knot fish broodstock with milky white semen flowing out when the abdomen was lightly pressed were selected as mature male broodstock, a total of 5 with an average weight of 1.8 kg, and female Chinese knot fish broodstock with soft abdomen and red and swollen genital pores were selected as mature female broodstock, a total of 8 with an average weight of 2.5 kg;

[0097] At 22:00 on the 20th, mature female broodstock were injected with LHRH-A2 5μg / kg, while mature male broodstock were not injected. 18 hours after the injection, mature female broodstock were injected with LHRH-A2 10μg / kg + DOM 10mg / kg + HCG 200IU / kg, while mature male broodstock were injected with LHRH-A2 5μg / kg + DOM 5mg / kg + HCG 100IU / kg.

[0098] Artificial insemination was performed at 8:30 a.m. on the 22nd. The mature female broodstock was wiped dry with a dry towel. After removing the eggs, they were washed four times with the Chinese knot fish egg washing solution prepared in Example 1 until the eggs were separated from the mucus. 1 mL of semen was squeezed onto 12 mL of eggs and stirred evenly to obtain a sperm-egg mixture. Then, 2 times the volume of clean water of the sperm-egg mixture was added to activate the sperm. After continuous stirring for 3 minutes, the mixture was washed four times with 22°C clean water to obtain fertilized eggs. A total of 45,000 eggs were laid, with a 100% induction rate. 42,000 fertilized eggs were obtained, with a fertilization rate of 93.33%. The broodstock after artificial insemination were cultured daily, and the postpartum mortality rate of the broodstock was 0%.

[0099] The fertilized eggs are evenly spread in a rectangular cement hatching tank of 6m×1m×0.6m. The tank is covered with white tiles. The inlet and outlet are located on both sides of the long side. The water depth in the hatching tank is controlled by an overflow pipe to 30cm. The laying density of the fertilized eggs is 10,000 eggs / m 2 The water was exchanged 12 times a day at a water temperature of 22°C. After 82 hours, the fertilized eggs hatched and 40,000 fry were obtained, with a hatching rate of 95.24%.

[0100] The fry were not fed within 0 to 6 days after their membranes ruptured, and dead eggs and dead fry were sucked out with a plastic straw every morning and evening. On the 7th day, the fry were transferred to a circular glass culture tank with a diameter of 1 m and a height of 80 cm. The culture density was 3,000 fry per tank, and the tank was watered from the sides and drained from the bottom. The tank bottom was tilted toward the drain outlet, and the water depth was controlled at 60 cm. From the 7th to 15th day, the fry were overfed with Shengsuo S1 microcapsule feed every 4 hours. From the 16th to 31st day, the fry were overfed with Shengsuo S3 microcapsule feed every 12 hours. After each feeding, residual bait and feces were sucked out 30 minutes later. The water was exchanged three times every day. After 31 days of cultivation, 36,000 fry were obtained with a survival rate of 90%. From the 32nd day onwards, the fry were cultivated using the daily cultivation method described in Example 2.

[0101] Experimental Example 1: Statistics of Chinese knot fish breeding results

[0102] Adopt the breeding method of Chinese knot fish described in embodiment 3~7 to breed Chinese knot fish, the breeding process is as follows Figures 1 to 9 The breeding results are shown in Table 1.

[0103] Table 1. Reproduction results of Chinese knot fish

[0104]

[0105] The results show that the breeding method of the present invention can increase the artificial breeding fertilization rate, hatching rate and seedling survival rate of Chinese knot fish to more than 90%.

[0106] As can be seen from the above examples, the present invention provides a Chinese knot fish egg washing liquid and a Chinese knot fish breeding method and application thereof. The breeding method of the present invention greatly improves the fertilization rate, hatching rate and seedling survival rate of Chinese knot fish artificial breeding.

[0107] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A Chinese knot fish egg washing liquid, characterized in that: The Chinese knot fish egg washing liquid uses water as a solvent and comprises components with the following concentrations: 8-10 g / L of sodium chloride, 0.1-0.5 g / L of calcium chloride, 0.1-0.4 g / L of potassium chloride, and 10-15 g / L of glucose.

2. Application of the Chinese knot fish egg washing liquid according to claim 1 in artificial breeding of Chinese knot fish.

3. A method for breeding Chinese knot fish, characterized in that: The steps include: (1) releasing river snails into a Chinese knot fish breeding pond for 30 to 60 days to obtain Chinese knot fish broodstock; (2) Select male Chinese knot fish broodstock with milky white semen flowing out when the abdomen is gently pressed as mature male broodstock, select female Chinese knot fish broodstock with soft abdomen and red and swollen genital pore as mature female broodstock, and the remaining Chinese knot fish broodstock as reserve broodstock; (3) Inject the mature female broodstock with a luteinizing hormone-releasing hormone analogue LHRH-A2 5 μg / kg. 15 to 22 hours after the injection, inject the mature female broodstock with a luteinizing hormone-releasing hormone analogue LHRH-A2 10 μg / kg + dioxigenin 10 mg / kg + human chorionic gonadotropin HCG 200 IU / kg. At the same time, inject the mature male broodstock with a luteinizing hormone-releasing hormone analogue LHRH-A2 5 μg / kg + dioxigenin 5 mg / kg + human chorionic gonadotropin HCG 100 IU / kg. (4) 16 to 18 hours after the injection, the eggs are washed with Chinese knot fish egg washing solution to obtain ova, and the ova are mixed with semen to obtain a sperm-egg mixture; (5) mixing and stirring the sperm-egg mixture with water to obtain fertilized eggs, and incubating the fertilized eggs for 74 to 82 hours to obtain fry; The Chinese knot fish egg washing liquid described in step (4) is the Chinese knot fish egg washing liquid described in claim 1.

4. The breeding method according to claim 3, characterized in that The amount of the snails added in step (1) is 2% to 3% of the total weight of the Chinese knot fish per time; The number of times of administration is 1 to 2 times / d; The breeding density of the Chinese knot fish broodstock is 100 to 120 per pond.

5. The breeding method according to claim 4, characterized in that The weight of the mature male broodstock in step (2) is greater than 1.5 kg per tail; The body weight of the mature female broodstock is >2 kg / tail.

6. The breeding method according to claim 5, characterized in that The cleaning temperature in step (4) is 22-24°C; The volume ratio of the egg and semen mixture is 10-15:

1.

7. The breeding method according to claim 6, characterized in that The volume ratio of the sperm-egg mixture to water in step (5) is 1:2-3; The stirring time is 2 to 3 minutes.

8. The breeding method according to claim 7, characterized in that The hatching density in step (5) is 0.8 to 10,000 grains / m 2 The incubation temperature is 22-24℃.

9. Use of the breeding method according to any one of claims 3 to 9 in artificial breeding of Chinese knot fish.

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