Artificial propagation method for culter oxyculter

Abstract

The invention discloses an artificial propagation method for culter oxyculter. In the breeding peak period of each year, namely from late May to mid-late June, parent fishes with good sexual maturity are selected from artificially domesticated culter oxyculta for artificial breeding, and the female-male ratio is 1: 2. Injecting artificial spawning induction medicine into the parent fish, and after effect time is reached, respectively taking seminal fluid and ova of the male fish and the female fish for artificial insemination. Fertilized eggs are incubated in the incubation pond for about 5 days and then transferred into the pond for cultivation after swimming flatly, and rotifers cultivated in the pond are mainly used as initial feed. And starting to gradually feed compound feed for domestication when the rotifers grow to about 3cm after being fed for one month. The artificial propagation method disclosed by the invention has the characteristics of high induced spawning rate, high fertilization rate, high hatching rate, high survival rate and the like, and also has the characteristic of low parent death rate. The method is suitable for large-scale culter oxyculter fry breeding as required, and has the advantages of high efficiency, simplicity, convenience and facilitation of popularization. The method provided by the invention provides solid theoretical and technical support for resource protection and aquaculture variety cultivation of culter oxyculter.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and in particular relates to an artificial propagation method of Pseudoacanthus bream. Technical Background

[0002] Culteroxycephaloides belongs to the Cypriniformes, Cyprinidae, Cultrinae, Culter. Also known as Culteroxycephaloides, Duck-billed Redtail, Pointed Redtail (Sichuan), Duck-billed, Duck-billed Fish (Shaanxi). Culteroxycephaloides is distributed in the Yangtze River section from Yibin, Sichuan to Nanjing, Jiangsu. It is endemic to the Yangtze River and is more common in the middle and upper reaches. It also enters the middle and lower reaches of tributaries such as the Minjiang River (Qingyi River), Tuojiang River, Wujiang River, Jialing River (Qujiang River, Fujiang River), and Hanjiang River, as well as large lakes connected to the river such as Dongting Lake and Poyang Lake. Culteroxycephaloides mostly lives in the middle and upper layers of flowing water or deeper still water bodies. It mainly feeds on small fish and shrimp. Its meat is delicate and has high nutritional value. Due to the large-scale fishing in recent years and the changes in its natural water environment, the natural population of Pseudo-sharphead bream has decreased significantly, and the market is in a state of supply exceeding demand. Therefore, it is of great significance to develop the breeding industry of Pseudo-sharphead bream. At present, the most important factor restricting the large-scale breeding of Pseudo-sharphead bream, in addition to breeding technology, feed and diseases, is the lack of breakthroughs in artificial breeding technology of Pseudo-sharphead bream. At present, there is a lack of systematic research on the artificial breeding of Pseudo-sharphead bream seedlings, resulting in very low artificial breeding rates, fertilization rates and hatching rates of Pseudo-sharphead bream seedlings. Summary of the invention

[0003] The purpose of the present invention is to provide an artificial propagation method of Pseudo-apex carp, solve the difficult problems of artificial propagation of Pseudo-apex carp, and improve the induced fertilization rate, fertilization rate and hatching rate of artificial propagation of Pseudo-apex carp.

[0004] In order to achieve the above-mentioned invention object, the present invention adopts the following technical solutions:

[0005] An artificial propagation method of Pseudocephalus bream comprises the following steps:

[0006] (1) During the peak breeding period of each year, i.e., from late May to mid-late June, sexually mature broodstock are selected from artificially domesticated Pseudoacanthus sphenodon. Female Pseudoacanthus sphenodon should weigh more than 2 kg, have a clear ovary outline, a swollen, soft and elastic abdomen, loosely arranged scales on the sides of the body, and the ovaries should feel loose and swaying when the abdominal wall is patted. The genital opening should be round and red. Male Pseudoacanthus sphenodon should have milky white and viscous semen flowing out when the genital opening is lightly pressed.

[0007] (2) Injection of artificial induced labor drugs into the broodstock at the base of the pectoral fin. The injected drugs consist of human chorionic gonadotropin (HCG), luteinizing hormone analog (LRH-A2) and dioic acid (DOM). The first injection is only given to female fish. The induced labor drug is LRH-A2 12ug / kg. ， After an interval of 10 hours, the second injection was given. The second injection drug was a mixture of HCG 1200IU / kg, LRH-A28ug / kg, and DOM 16mg / kg, and the male fish had 6ug / kg.

[0008] (3) After the injection of artificial oxytocin, the broodstock were placed in a temporary holding pond to block light and stimulate running water, and the water temperature was maintained at 23°C and the dissolved oxygen was above 8 mg / L;

[0009] (4) During artificial insemination, the mature eggs of the female fish are squeezed into a dry bowl, and the semen of the male fish is squeezed into a bowl containing sperm preservation solution for dilution. The diluted semen is poured into the eggs and stirred for 3-5 minutes to fertilize them. After fertilization, the eggs are debonded with yellow mud water or talcum powder for 3 minutes;

[0010] (5) Place the debonded fertilized eggs in a dark incubation pool. The length and width of the incubation pool are 4 to 5 meters, and the depth is 1 meter. Disinfect the pool before use, maintain the water temperature at 23°C, the dissolved oxygen is above 8 mg / L, and the water is micro-flowed. Change one-fifth of the water in the incubation pool every day.

[0011] (6) After the fertilized eggs are hatched in the hatching pond for 5 to 6 days and can swim horizontally, they are transferred to the pond for cultivation. The rotifers cultivated in the pond are used for the larvae to open their mouths. After that, the rotifers cultivated in the pond are fed for a full month. When they grow to 3 cm to 4 cm, they are domesticated with compound feed.

[0012] As a preferred technical solution of the present invention, the formula of the sperm preservation solution is: 7.5g sodium chloride, 0.3g potassium chloride, 0.3g calcium chloride, 0.3g magnesium sulfate heptahydrate, 3.0g glucose, and double distilled water to make up to 1000ml.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention is the first to systematically study the artificial propagation of Pseudoacanthus sphenodon, and the artificial propagation method provided has the characteristics of high induced fertilization rate, high fertilization rate, high hatching rate, high survival rate, etc., and also has the characteristics of low parent mortality rate. It is suitable for large-scale Pseudoacanthus sphenodon seed propagation according to demand, and has the advantages of high efficiency, simplicity and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is the monthly variation curve of gonad development status of male and female Pseudo-apex carp. In the figure: a is the percentage of female individuals whose gonads are in stage IV or V in the total number of individuals; b is the percentage of male individuals whose gonads are in stage IV or V in the total number of individuals. DETAILED DESCRIPTION

[0016] In the artificial breeding practice of Pseudo-apex bream, the sex discrimination of the parents is the premise of large-scale production. The method of distinguishing sex is as follows: first, when the water temperature reaches about 26 degrees at the end of May and the beginning of June each year, the belly of the female fish becomes larger, and the male fish becomes slender; second, before breeding, the back scales of the male fish feel rough, and the back scales of the female fish are smooth. This is used as the basis for distinguishing the sex of the fish, and combined with whether the male fish can squeeze out semen, as the method of distinguishing the sex of Pseudo-apex bream in the present invention.

[0017] Obtaining well-developed Pseudo-sharpenio carp parents is also one of the difficulties in artificial breeding of Pseudo-sharpenio carp. After continuous gonadal anatomical observations for several months, it was found that the testes of male Pseudo-sharpenio carp were only thin lines or cylindrical (pink), and did not show the milky white color of the IV or V testes of most other freshwater fish. In addition, a large amount of semen flowed out when lightly pressed. Therefore, the month to select male Pseudo-sharpenio carp as breeding parents is a difficult problem. The inventor summarized the gonadal development status of male and female Pseudo-sharpenio carp in several months through gonadal anatomical observations (see Figure 1 ). Based on the above results, the inventors selected the time period from late May to mid-to-late June each year when the gonads of both male and female Pseudo-sharphead bream were well developed as the time for selecting Pseudo-sharphead bream parents. The inventors successfully bred Pseudo-sharphead bream many times by artificially inducing spawning, fertilizing, and hatching the parents. Three specific examples are given below:

[0018] Example 1

[0019] 1. Parent selection

[0020] 98 sexually mature broodstock were selected from the domesticated Pseudoacanthus sphenodon. Female fish weighed more than 1500g, with a swollen and soft abdomen and a round and red genital opening. Male fish weighed more than 1000g, were strong and flexible, and most of them could squeeze out semen. The male-female ratio was 1:1.

[0021] 2. Methods of inducing labor

[0022] Artificial induction drugs include HCG, LRH-A2 and DOM. The dosage of induction drugs is shown in Table 1. The method of induction is injection at the base of the pelvic fin. The first injection is only LRH-A2, and the interval between the injection and the second injection is 10 hours. The second injection is a mixture of HCG, LRH-A2 and DOM. The dosage of male fish is halved.

[0023] 3. Artificial insemination method

[0024] 10 hours after the second injection, check the broodstock every two hours to see if they have laid eggs. Artificial insemination can only be performed if eggs flow out of the female fish's abdomen when gently squeezed. Dissect the male fish to remove the testis, place it on an 80-mesh gauze, grind it with a mortar, and then add a small amount of sperm preservation solution to dilute it. The filtrate is collected as semen. Sperm preservation solution formula: 7.5g sodium chloride, 0.3g potassium chloride, 0.3g calcium chloride, 0.3g magnesium sulfate heptahydrate, 3.0g glucose, and double distilled water to 1000ml. Squeeze the mature eggs into a dry ceramic bowl, add semen and mix well for fertilization for 3 minutes.

[0025] 4. Fertilized egg hatching method

[0026] After the sperm and eggs are mixed, use yellow mud water or talcum powder to detackify for 3 minutes. Place in a hatching pool away from light for incubation. The hatching pool area should not be too large, generally 4m x 4m (length x width) or 5m x 5m (length x width). The depth of the hatching pool is preferably 1m. The density of fish eggs is 3000 grains / m 2 Keep the water temperature at 23°C, dissolved oxygen above 8 mg / L, micro-flow water, and change one-fifth of the water every day.

[0027] The hatching pond is used as a nursery pond. The physical condition of the Pseudoacanthus sphenodon is weak in the bloom stage. Using the hatching pond as a nursery pond can reduce the damage during the transfer process and improve the survival rate.

[0028] Example 2

[0029] 1. Parent selection

[0030] 112 sexually mature broodstock were selected from artificially domesticated Pseudoacanthus sphenodon. Female fish weighed more than 1500g, with a swollen and soft abdomen and a round and red genital opening. Male fish weighed more than 1000g, were strong and flexible, and most of them could squeeze out semen. The male-female ratio was 1:2.

[0031] 2. Methods of inducing labor

[0032] Artificial induction drugs include HCG, LRH-A2 and DOM. The dosage of induction drugs is shown in Table 1. The method of induction is injection at the base of the pelvic fin. The first injection is only LRH-A2, and the interval between the injection and the second injection is 10 hours. The second injection is a mixture of HCG, LRH-A2 and DOM. The dosage of male fish is halved.

[0033] 3. Artificial insemination method

[0034] 10 hours after the second injection, check the broodstock every two hours to see if they have laid eggs. Artificial insemination can only be performed if eggs flow out of the female fish's abdomen when gently squeezed. Dissect the male fish to remove the testis, place it on an 80-mesh gauze, grind it with a mortar, and then add a small amount of sperm preservation solution to dilute it. The filtrate is collected as semen. Sperm preservation solution formula: 7.5g sodium chloride, 0.3g potassium chloride, 0.3g calcium chloride, 0.3g magnesium sulfate heptahydrate, 3.0g glucose, and double distilled water to 1000ml. Squeeze the mature eggs into a dry ceramic bowl, add semen and mix well for fertilization for 3 minutes.

[0035] 4. Fertilized egg hatching method

[0036] After the sperm and eggs are mixed, use yellow mud water or talcum powder to detackify for 3 minutes. Place in a hatching pool away from light for incubation. The hatching pool area should not be too large, generally 4m x 4m (length x width) or 5m x 5m (length x width). The depth of the hatching pool is preferably 1m. The density of fish eggs is 3000 grains / m 2 Keep the water temperature at 23°C, dissolved oxygen above 8 mg / L, micro-flow water, and change one-fifth of the water every day.

[0037] The hatching pond is used as a nursery pond. The physical condition of the Pseudoacanthus sphenodon is weak in the bloom stage. Using the hatching pond as a nursery pond can reduce the damage during the transfer process and improve the survival rate.

[0038] Example 3

[0039] 1. Parent selection

[0040] 70 sexually mature broodstock were selected from the domesticated Pseudoacanthus sphenodon. Female fish weighed more than 1500g, with a swollen and soft abdomen and a round and red genital opening. Male fish weighed more than 1000g, were strong and flexible, and most of them could squeeze out semen. The male-female ratio was 1:1.1.

[0041] 2. Methods of inducing labor

[0042] Artificial induction drugs include HCG, LRH-A2 and DOM. The dosage of induction drugs is shown in Table 1. The method of induction is injection at the base of the pelvic fin. The first injection is only LRH-A2, and the interval between the injection and the second injection is 10 hours. The second injection is a mixture of HCG, LRH-A2 and DOM. The dosage of male fish is halved.

[0043] 3. Artificial insemination method

[0044] 10 hours after the second injection, check the broodstock every two hours to see if they have laid eggs. Artificial insemination can only be performed if eggs flow out of the female fish's abdomen when gently squeezed. Dissect the male fish to remove the testis, place it on an 80-mesh gauze, grind it with a mortar, and then add a small amount of sperm preservation solution to dilute it. The filtrate is collected as semen. Sperm preservation solution formula: 7.5g sodium chloride, 0.3g potassium chloride, 0.3g calcium chloride, 0.3g magnesium sulfate heptahydrate, 3.0g glucose, and double distilled water to 1000ml. Squeeze the mature eggs into a dry ceramic bowl, add semen and mix well for fertilization for 3 minutes.

[0045] 4. Fertilized egg hatching method

[0046] After the sperm and eggs are mixed, use yellow mud water or talcum powder to detackify for 3 minutes. Place in a hatching pool away from light for incubation. The hatching pool area should not be too large, generally 4m x 4m (length x width) or 5m x 5m (length x width). The depth of the hatching pool is preferably 1m. The density of fish eggs is 3000 grains / m 2 Keep the water temperature at 23°C, dissolved oxygen above 8 mg / L, micro-flow water, and change one-fifth of the water every day.

[0047] The hatching pond is used as a nursery pond. The physical condition of the Pseudoacanthus sphenodon is weak in the bloom stage. Using the hatching pond as a nursery pond can reduce the damage during the transfer process and improve the survival rate.

[0048] The effects of Examples 1 to 3 and the dosage of artificial labor-inducing drugs on the effect time, parent labor-inducing rate, fertilization rate, parent mortality rate, hatching rate and survival rate 7 days after hatching are shown in Table 1.

[0049] Table 1 Effects of oxytocin dosage on the reproductive effect of Pseudoacanthus sphenodon

[0050]

[0051] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for artificial propagation of Pseudoacanthus sphenodon, characterized in that: The steps include: (1) During the peak breeding season of each year, i.e. from late May to mid-late June, sexually mature broodstock are selected from artificially domesticated Pseudoacanthus sphenodon. Female Pseudoacanthus sphenodon should weigh more than 2 kg, have a clear ovary outline, a swollen, soft and elastic abdomen, loosely arranged scales on the sides of the body, and the ovaries should feel loose and swaying when the abdominal wall is patted. The genital opening should be round and red. Male Pseudoacanthus sphenodon should have milky white and sticky semen flowing out when the genital opening is lightly pressed. (2) Injection of artificial induced labor drugs into broodstock at the base of the pectoral fin. The injected drugs consist of human chorionic gonadotropin (HCG), luteinizing hormone analog (LRH-A2) and dioic acid (DOM). The first injection is only given to female fish. The induced labor drug is LRH-A2 12ug / kg. After an interval of 10 hours, the second injection is given. The second injection is a mixture of HCG 1200IU / kg, LRH-A2 8ug / kg, and DOM 16mg / kg. The male fish is given 6ug / kg. (3) Place the broodstock injected with artificial induced labor drugs in a temporary holding pond to block light and stimulate water flow, maintain the water temperature at 23°C, and maintain the dissolved oxygen level above 8 mg / L; During artificial insemination, squeeze the mature eggs of the female fish into a dry bowl, and squeeze the semen of the male fish into a bowl containing sperm preservation solution for dilution. Pour the diluted semen into the eggs and stir for 3-5 minutes to fertilize them. After fertilization, use yellow mud water or talcum powder to detackify for 3 minutes; (4) Place the debonded fertilized eggs in a hatching pool away from light for incubation. The length and width of the hatching pool are 4-5 meters, and the depth is 1 meter. Disinfect the pool before use, maintain the water temperature at 23°C, the dissolved oxygen is above 8 mg / L, and the water is micro-flowing. Change one-fifth of the water in the hatching pool every day. (5) After the fertilized eggs are hatched in the hatching pond for 5 to 6 days and can swim horizontally, they are transferred to the pond for cultivation. The rotifers cultivated in the pond are used for the larvae to open their mouths. After that, the rotifers cultivated in the pond are fed for a full month. When they grow to 3 cm to 4 cm, they are domesticated with compound feed.

2. The artificial propagation method of Pseudocephalus bream as claimed in claim 1, characterized in that: The formula of the sperm preservation solution is: 7.5 g sodium chloride, 0.3 g potassium chloride, 0.3 g calcium chloride, 0.3 g magnesium sulfate heptahydrate, 3.0 g glucose, and double distilled water to make up to 1000 ml.

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