A method for artificial propagation of panchax pelliculatus

Abstract

The application discloses an artificial breeding method of Pseudobagrus euprystos, which comprises the following steps: temporarily raising strictly captured parent fish to make the maturity of female and male gonads basically consistent; controlling the number and type of injection of the parturifacient medicine to improve the parturifacient rate and make the parent fish population relatively concentrated in spawning; and laying non-toxic soft cloth on the bottom and around the spawning pool as fish nest. The non-toxic soft cloth material is easy to obtain and can be reused, which not only makes it easy to concentrate the eggs of Pseudobagrus euprystos in batches, improves the fertilization rate of the eggs, but also makes the fertilized eggs attached to the fish nest easy to peel off and not accumulated after peeling off, so that the operation is convenient and efficient, and the hatching rate and the emergence rate of the fertilized eggs are improved. The experimental results show that the parturifacient rate of the artificial breeding Pseudobagrus euprystos is more than 80%, the fertilization rate is more than 70%, the hatching rate is more than 80%, and the emergence rate is more than 70%, so that the problem of large-scale production of Pseudobagrus euprystos fry is solved.

Description

Technical Field

[0001] This invention belongs to the field of fish farming technology, and in particular relates to an artificial breeding method for topmouth gudgeon. Background Technology

[0002] Topmouth gudgeon ( Pseudorasbora parva The minnow (Gnaphalium affine), also known as the grass carp or flowerhorn fish, belongs to the Cyprinidae family, Gnaphalinae subfamily, and Gnaphalium genus. It is a small fish widely distributed in various freshwater bodies, primarily inhabiting the middle and lower layers of water, often feeding in shallow areas with fertile bottoms and abundant aquatic plants. Minnows are popular with consumers not only for their tender and delicious flesh but also for their ornamental value and as research models. However, due to asynchronous development of parent fish, scattered spawning, and the fact that mature females can spawn even in the absence of males, the fertilization rate is low, making large-scale artificial breeding difficult. Therefore, the current market supply of minnows is mainly based on wild-caught resources, which cannot meet market demand. Summary of the Invention

[0003] The present invention aims to solve the above-mentioned technical problems existing in the prior art and provides a method for artificial breeding of topmouth gudgeon.

[0004] The technical solution of this invention is: a method for artificially breeding topmouth gudgeon, which is carried out in the following steps:

[0005] Step 1. Collection of parent fish

[0006] Parent fish of minnows were collected from natural waters, with a male-to-female ratio of 1:2-3. The males were at least 7cm long, weighed at least 10g, were over one winter old, and had obvious tubercles on their snout and lower jaw. The females were 4-8cm long, weighed at least 4g, and had a full and soft abdomen.

[0007] Step 2. Temporary holding of parent fish

[0008] The captured topmouth gudgeon parent fish were placed in a temporary holding tank at a density of 100-150 fish / m². 3 The temporary holding pond has a water depth of 40-60cm and a water temperature of 11-15℃. After the parent fish are introduced into the pond, they are allowed to recover for 1-2 days before being fed. The amount of feed is 3-5% of the parent fish's body weight. During the temporary holding period, the water is changed every 3 days.

[0009] Step 3. Inducing spawning in parent fish

[0010] The fish is injected with a labor-inducing drug at the base of the dorsal fin muscle, the female fish is injected twice, the first injection is luteinizing hormone-releasing hormone No. 2, the injection amount is 2 ug / kg, the second injection is luteinizing hormone-releasing hormone No. 2 and chorionic gonadotropin, the injection amounts are 6 ug / kg and 2000 IU / kg respectively, and the interval between the two injections is 12 hours; the male fish is injected with luteinizing hormone-releasing hormone No. 2 at the same time as the second injection of the female fish, and the injection amount is 10 ug / kg; the injection is not for the purpose of diagnosis and treatment of diseases;

[0011] Step 4. Spawning of brood fish

[0012] The brood fish after injection is placed in a spawning pool, the fish density is 50-100 tails / m 2 , the number of male and female is 1:2-3, the initial water temperature of the spawning pool is 11-15℃, the water temperature in the spawning pool is increased to 22℃ at a rate of 1℃ per hour after the brood fish is placed, the bottom and surrounding of the spawning pool are paved with non-toxic soft cloth as fish nest, and the fish nest is replaced when the spawning density on the fish nest reaches 1000 particles / m 2 , until the brood fish no longer spawns;

[0013] Step 5. Collecting fertilized eggs and hatching

[0014] The fish nest with fertilized eggs is taken, the fertilized eggs on the fish nest are peeled off with a scraper and placed in a hatching device for hatching, the hatching water temperature is 18-23℃, and the dissolved oxygen in the water is maintained at least 5 mg / L, after the fry body gradually darkens and swims horizontally, it is placed in a cement pool for further hatching, the accumulated temperature during the whole hatching period is 150-170 degrees·day, and the orfella fry is obtained.

[0015] The preferred technical solution is that the non-toxic soft cloth is nylon cloth, polyester cloth or screen silk cloth.

[0016] The preferred technical solution is that the hatching device is a screen silk hatching basket composed of a cylinder and a cone, the cylinder is on the top and the cone is on the bottom, and the top point of the cone is downward.

[0017] The application strictly collects parent fish and makes the female and male fish gonad maturity basically consistent through temporary cultivation; the number of times and types of injection of the production accelerating drug are controlled, the production accelerating rate is improved, and the parent fish population is relatively concentrated in egg laying; the non-toxic soft cloth is laid on the bottom and around the egg laying pool as a fish nest, the non-toxic soft cloth material is easy to obtain and can be reused, which not only makes it easy to concentrate the eggs of the Pseudorasbora parva and lay eggs in batches, so that the fertilization rate of the eggs is improved, but also the fertilized eggs attached to the fish nest are easy to peel off and do not accumulate after peeling off, which is convenient and efficient, and improves the hatching rate and the emergence rate of the fertilized eggs. The experimental results show that the artificial propagation of the Pseudorasbora parva has a production accelerating rate of more than 80%, a fertilization rate of more than 70%, a hatching rate of more than 80%, and an emergence rate of more than 70%, which better solves the problem of large-scale production of Pseudorasbora parva fry. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the picture of the fish nest attached with fertilized eggs in Example 2 of the application.

[0019] Figure 2 is the picture of the egg receiving effect of the PVC pipe as the fish nest in Comparative Example 1.

[0020] Figure 3 is the picture of the egg receiving effect of the mussel shell as the fish nest in Comparative Example 1. DETAILED DESCRIPTION Example 1

[0021] The artificial propagation method of the Pseudorasbora parva of the application is performed in the following order:

[0022] Step 1. Parent fish collection

[0023] The parent fish of the Pseudorasbora parva is collected from natural water areas (such as ponds, reservoirs, rivers, etc.) in spring from March to April, the number ratio of the female fish to the male fish is 1:2-3, the male fish has a body length of at least 7 cm, a body weight of at least 10 g, is more than 1 winter age, and has obvious star chasing at the snout and the lower jaw under the eye; the female fish has a body length of 4-8 cm, a body weight of at least 4 g, a full and soft abdomen;

[0024] Step 2. Parent fish temporary cultivation

[0025] The collected parent fish of the Pseudorasbora parva is put into a temporary cultivation pool, the temporary cultivation density is 100-150 tails / m 3 , the temporary cultivation pool is a rectangular cement pool with an area of 8-10 m 2 , a water depth of 40-60 cm, and a water temperature of 11-15 ℃; after the parent fish is put into the pool, the fish is slowly put into the pool for 1-2 days, and then the bait is fed, the bait is 1.0 mm carp granular feed (the carp granular feed is the most widely used commercial fish granular feed for freshwater fish breeding), the feeding amount is 3-5% of the body weight of the parent fish, and the water is changed every 3 days during the temporary cultivation period;

[0026] Step 3. Parent fish production acceleration

[0027] The fish are injected with the oviposition drug at the base of the dorsal fin muscle, the female fish are injected twice, the first injection is 2ug / kg of luteinizing hormone releasing hormone No.2, the second injection is 6ug / kg of luteinizing hormone releasing hormone No.2 and 2000IU / kg of chorionic gonadotropin, the interval between the two injections is 12 hours; the male fish are injected with 10ug / kg of luteinizing hormone releasing hormone No.2 at the same time as the second injection of the female fish; the injection is not for diagnosis or treatment of diseases;

[0028] Step 4. Spawning of the brood fish

[0029] The brood fish after injection of the oviposition drug are placed in the spawning pool, the fish density is 50-100 tails / m 2 , the number of male and female fish is 1:2-3, the initial water temperature of the spawning pool is 11-15℃, after the brood fish are placed in the spawning pool, the water temperature of the spawning pool is increased to 22℃ at a rate of 1℃ per hour, and the brood fish are naturally spawned and fertilized; the bottom and surrounding of the spawning pool are paved with non-toxic soft cloth as fish nest, the non-toxic soft cloth can be nylon cloth and polyester cloth, when the spawning density on the fish nest reaches 1000 eggs / m 2 , the fish nest is replaced, until the brood fish no longer spawn;

[0030] Step 5. Collection of fertilized eggs and hatching

[0031] The fish nest with fertilized eggs is taken, including the fish nest with spawning density of 1000 eggs / m 2 and the fish nest paved when the brood fish no longer spawn, the fertilized eggs attached to the fish nest are peeled off with a scraper and placed in a hatching tank for hatching, the hatching water temperature is 18-23℃, a sunshade net is placed above the hatching tank for shading treatment, the dissolved oxygen in the water is maintained at 7mg / L, during the hatching process, dead eggs are removed every day and the water quality is kept clean, after the fry's body gradually darkens and swims horizontally, it is placed in a cement pool for further hatching, the whole hatching period is 150-170 degrees·day, i.e. 8 days of hatching, and the Procambarus clarkii fry is obtained. Example 2

[0032] The breeding steps are basically the same as those of Example 1, and the difference from Example 1 is that the non-toxic soft cloth is 80-mesh silk cloth, and the hatching device is a silk hatching basket composed of a cylinder and a cone, the cylinder is on the top and the cone is on the bottom, and the top point of the cone is downward, the diameter of the cylinder is 52cm, the height is 45cm, the height of the cone is 70cm, and the diameter of the joint between the cylinder and the cone is also 45cm, and the mesh size of the silk cloth used in the hatching basket is 60 mesh. The picture of the fish nest with fertilized eggs in this example 2 is shown in Figure 1 .

[0033] Comparative Experiment 1:

[0034] The propagation steps of Comparative Example 1 and Example 1 are basically the same, and the difference between Example 1 and Comparative Example 1 is that the fish nest is a PVC pipe or a mussel shell.

[0035] The propagation results of Pseudobagrus fulvidraco in Example 1, Example 2 and Comparative Example 1 of the present application are shown in Table 1.

[0036] Table 1

[0037]

[0038] Note: The same column marked with different lowercase letters indicates that the difference between groups is significant P <0.05).

[0039] The experimental results show that the non-toxic soft cloth (nylon cloth, polyester cloth or silk gauze cloth) fish nest can collect the eggs produced by Pseudobagrus fulvidraco in batches, and the egg receiving effect is good; the egg receiving effect of the PVC pipe fish nest is better than that of the mussel shell fish nest because Pseudobagrus fulvidraco will produce part of the eggs on the pool wall due to the small egg receiving area of the PVC pipe and the mussel shell; during the incubation process, the fertilized eggs on the non-toxic soft cloth fish nest are easy to peel off and do not accumulate after peeling off, and in particular, the fertilized eggs on the silk gauze cloth fish nest are easy to peel off and the incubation management is simple and the incubation rate is high after using the incubation basket.

[0040] The egg receiving effects of the PVC pipe and the mussel shell as the fish nest in Comparative Example 1 are shown in Table 2 and Table 3, respectively. Figure 2 Figure 3 It can be clearly seen that the egg receiving effect of the silk gauze cloth as the fish nest in Example 2 is better than that of the PVC pipe and the mussel shell. Figure 1

[0041] Comparative Experiment 2:

[0042] According to the method of Example 2, artificial propagation of Pseudobagrus fulvidraco is carried out, and Comparative Example 2 is a plurality of experimental groups using different injection times, drug types and doses of injection for inducing spawning than Example 2, the effect time, the spawning rate and the fertilization rate of each experimental group are counted, and the details are shown in Table 2.

[0043]

[0044] Note: The same column marked with different lowercase letters indicates that the difference between groups is significant P <0.05.

[0045] Batch 1-2 and 4 in Table 2 are Comparative Example 2, and batch 3 is Example 2 of the present application. The experimental results show that the spawning effect of Example 2 of the present application is the best, and the spawning rate reaches 80%, and the fertilization rate is 77%.​​

Claims

1. A method for the artificial breeding of topmouth gudgeon, characterized in that... Follow these steps in sequence: Step 1. Collection of parent fish In spring, from March to April, adult minnows are collected from natural waters with a male-to-female ratio of 1:2-3. The males are at least 7cm long, weigh at least 10g, are over one year old, and have obvious tubercles on their snout and lower jaw. The females are 4-8cm long, weigh at least 4g, and have a full and soft abdomen. Step 2. Temporary holding of parent fish The captured topmouth gudgeon parent fish were placed in a temporary holding tank at a density of 100-150 fish / m². 3 The temporary holding tank has an area of ​​8-10m². 2 The rectangular cement pond has a water depth of 40-60cm and a water temperature of 11-15℃. After the parent fish are introduced into the pond, they should be allowed to recover for 1-2 days before being fed. The amount of feed should be 3-5% of the parent fish's body weight. During the temporary holding period, the water should be changed every 3 days. Step 3. Inducing spawning in parent fish The spawning-inducing drugs were injected into the dorsal fin base muscles of the parent fish. The female fish underwent two injections to induce spawning. The first injection was luteinizing hormone-releasing hormone (LH-2) at a dose of 2 μg / kg. The second injection was LH-2 and human chorionic gonadotropin (hCG) at doses of 6 μg / kg and 2000 IU / kg, respectively, with a 12-hour interval between the two injections. The male fish received LH-2 at the same time as the female's second injection, at a dose of 10 μg / kg. The injections were not for the purpose of diagnosing or treating any diseases. Step 4. Parent fish spawning After being injected with spawning-inducing agents, the parent fish are placed in the spawning pond at a stocking density of 50-100 fish / m². 2 The female-to-male ratio is 1:2-3. The initial water temperature of the spawning pond is 11-15℃. After the parent fish are introduced, the water temperature in the spawning pond is increased to 22℃ at a rate of 1℃ per hour. The bottom and surrounding area of ​​the spawning pond are covered with non-toxic soft cloth as fish nests. The spawning density on the fish nests reaches 1000 eggs / m². 2 Replace the fish nests promptly until the parent fish stop laying eggs. The non-toxic soft cloth is an 80-mesh silk cloth. Step 5. Collect the fertilized eggs and hatch them. Take the fish nests with fertilized eggs attached, use a scraper to peel off the fertilized eggs from the fish nests and put them into an incubation device for incubation. The incubation water temperature is 18-23℃, and the dissolved oxygen in the water is maintained at at least 5mg / L. After the fish fry gradually turn black and swim horizontally, they are placed in a cement pond for continued incubation. The accumulated temperature during the entire incubation period is 150-170 degrees per day to obtain minnow fry. The incubation device is a silk incubation basket composed of a cylinder and a cone, with the cylinder on top and the cone on the bottom, with the apex of the cone pointing downwards.

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