Method for removing fish egg static water hatching water mould by low carbon and environmental protection

Abstract

The application discloses a low-carbon and environment-friendly method for removing saprolegnia during static water hatching of fish eggs, and relates to the technical field of aquaculture. The method comprises the following steps in sequence: object selection, domestication, starvation, artificial induced spawning and hatching, and removal of saprolegnia. The method can effectively remove saprolegnia eggs generated during static water hatching, and is safe, simple, green, low-carbon, environment-friendly, energy-saving and power-saving, and can effectively reduce greenhouse gas emissions. The method solves the problems of drug residues, high energy consumption and complexity in the control of saprolegnia disease during the static water hatching of fish eggs.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aquaculture technology, in particular to a low-carbon and environmentally-friendly method for removing Saprolegnia in static water incubation of fish eggs. BACKGROUND

[0002] Saprolegniasis is a fungal disease caused by Saprolegnia, and more than ten kinds of Saprolegnia have been found on the body surface and fish eggs of freshwater aquatic animals in China. Among them, the most common are Saprolegnia and Saprolegnia, and the optimum temperature for reproduction is 13-18℃. Saprolegnia has a wide range of temperature adaptation and no selectivity to aquatic animal species. Any organism that is injured and egg grains at low temperature can be infected and cause disease. The eggs infected with Saprolegnia have internal mycelium invading the egg membrane, and a large number of external mycelium outside the egg membrane. The external mycelium of Saprolegnia is very long (up to 5-10mm or even longer), so it is often called "ovum silk disease". Saprolegnia is the most important hazard to fish egg incubation.

[0003] Static water incubation refers to a method of placing fertilized eggs into or adhering to water for incubation and development by using incubation frames, adhesives (glue silk, palm leaves), etc. At present, the prevention and control of Saprolegnia in static water incubation of fish eggs mainly adopts drug soaking and increasing incubation water temperature. Drug soaking usually uses antibacterial drugs such as malachite green, potassium permanganate, etc. to inhibit the growth of Saprolegnia, but the residues of the drugs and the drugs themselves can cause harm to fish eggs, and the treatment of drug solution after soaking will cause environmental pollution to some extent, increasing the risk of aquaculture. Although increasing the incubation water temperature to above 25℃ can better control the occurrence of Saprolegniasis, the optimum incubation water temperature requirements of different types of fish are different, and blindly increasing the incubation water temperature may adversely affect the development of fish eggs, and a large amount of energy is consumed, which is not conducive to the realization of the goal of low-carbon fishery. SUMMARY

[0004] In order to solve the above technical problems, the purpose of the present application is to provide a low-carbon and environmentally-friendly method for removing Saprolegnia in static water incubation of fish eggs, so as to solve the problems of drug residues, high energy consumption and tediousness in the control of Saprolegniasis in the existing fish egg incubation process.

[0005] The technical solution of the present application to solve the above technical problems is as follows: a low-carbon and environmentally-friendly method for removing Saprolegnia in static water incubation of fish eggs is provided, which comprises the following steps in sequence:

[0006] (1) Object selection: before the artificial induction of the fish eggs of the fish to be incubated, select omnivorous fish, and the vertical length of the mouth slit of the omnivorous fish is 2-3mm larger than the diameter of the fertilized egg;

[0007] (2) domestication: put the hatching frame capable of floating freely on the water surface in the domestication pool, the mesh diameter of the hatching frame is 1 / 3-1 / 2 of the diameter of the fertilized eggs after absorbing water, put the omnivorous fish selected in step (1) into the domestication pool outside the hatching frame, then put the feed into the hatching frame, and supplement in time after feeding, and domesticate for 5-7 days;

[0008] (3) starvation: after the last injection of artificial induction of ovulation of the fish eggs of the parent fish to be hatched, stop feeding the hatching frame in step (2), and obtain the domesticated fish;

[0009] (4) artificial induction of ovulation and hatching: after the last injection of artificial induction of ovulation of the fish eggs of the parent fish to be hatched, the eggs of the female fish and the sperm of the male fish are collected respectively, artificial insemination is performed, the obtained fertilized eggs are evenly laid in the hatching frame which is sterilized in advance, and then the hatching frame is put into the hatching pool for hatching;

[0010] (5) removing Saprolegnia: when the fertilized eggs in step (4) develop to the gastrula stage, the domesticated fish in step (3) is put into the hatching pool outside the hatching frame, and the domesticated fish is taken out when the fertilized eggs develop to the pre-membrane stage.

[0011] The present application has the advantages of safety, low carbon, environmental protection, economy, simple operation, etc., and has a wide application prospect.

[0012] When the fertilized eggs develop to the gastrula stage, the unfertilized eggs gradually become white and deteriorate, and then Saprolegnia grows out of the mesh, the fish under the mesh pulls the mycelium, and then the whole bad egg is pulled out of the hatching frame, so as to remove the Saprolegnia eggs.

[0013] On the basis of the above technical scheme, the present application can also be improved as follows:

[0014] Further, in step (1), the omnivorous fish is carp, koi or crucian carp.

[0015] Further, in step (2), the area of the domestication pool is 3-5m 2 , the pool water depth is 0.9-1.2m, 90-110 tails of omnivorous fish are put into each domestication pool, 1-2 hatching frames are put into each domestication pool, the top surface of the hatching frame is open, and the four sides and the bottom surface are sealed mesh.

[0016] Further, the frame material of the hatching frame is wood or PVC.

[0017] Further, in step (2), the size of the incubation frame is (0.7-1) x (0.4-0.6) x (0.2-0.3) m. 3 .

[0018] Further, in step (2), the amount of feed put in each time is 0.4-0.6 wt% of the omnivorous fish body weight.

[0019] Further, in step (2), the feed put in has a particle size of 2-3 mm.

[0020] Further, in step (2), the feed put in has a particle size of 3 mm.

[0021] Further, in step (2), the feed put in is Tongwei sinking artificial compound feed.

[0022] Further, in step (3), the feed in the incubation frame described in step (2) is stopped, and the fish is starved for 2-5 days to obtain domesticated fish.

[0023] Further, in step (3), the feed in the incubation frame described in step (2) is stopped, and the fish is starved for 2-3 days to obtain domesticated fish.

[0024] Further, in step (3), the feed in the incubation frame described in step (2) is stopped, and the fish is starved for 4-5 days to obtain domesticated fish.

[0025] Further, in step (4), the incubation frame is soaked and disinfected with 0.8-1.2 ppm potassium permanganate solution.

[0026] Further, in step (4), the number of fertilized eggs in each incubation frame is 20-25 thousand.

[0027] Further, in step (4), the size of the incubation tank is (4-6) x (1.2-0.8) x (0.5-0.8) m 3 , and 8-12 incubation frames are placed in each incubation tank.

[0028] Further, in step (4), the incubation frame is the same as the incubation frame in step (2).

[0029] Further, in step (5), the domesticated fish with strong constitution, active movement, no injury on the body surface, and uniform size are selected, soaked in 0.8-1.2 ppm potassium permanganate solution, and then placed in the incubation tank.

[0030] Further, in step (5), the number of domesticated fish placed for every 10 thousand fertilized eggs is 1-3.

[0031] Further, in step (5), according to the growth rate of Saprolegnia, the domesticated fish with poor efficiency is removed in time or supplemented.

[0032] The application also provides fish eggs hatched by the above method.

[0033] The application also provides application of the above method in hatching of fish eggs.

[0034] The application has the following beneficial effects:

[0035] The application can effectively remove water mold eggs generated in static water hatching, and is safe and simple to operate; the influence on the environment in the traditional removal process of fish egg water mold is reduced to zero; the method is green, low-carbon, environmentally friendly, power-saving and energy-saving, and can effectively reduce greenhouse gas emissions. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The technical route of Example 1 of the application is shown in the figure;

[0037] Figure 2 The domestication schematic diagram of the application is shown in the figure;

[0038] Figure 3 The mesh schematic diagram of the application is shown in the figure. DETAILED DESCRIPTION

[0039] The principles and characteristics of the application are described below in combination with the drawings, and the examples are only used to explain the application and are not used to limit the scope of the application. If the specific conditions are not indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not indicated by the manufacturer, they are all conventional products that can be purchased on the market.

[0040] Incubation conditions: the size of the incubation pool is a rectangular cement pool with a length of 5 m, a width of 1.5 m and a depth of 0.6 m, 10 incubation frames are placed in each incubation pool; the water temperature for incubation is 18℃, the pH value is 8.0, and the dissolved oxygen is 8.28 mg / L.

[0041] Incubation method: static water incubation.

[0042] Example 1:

[0043] A low-carbon and environmentally friendly method for removing fish egg static water mold, comprising the following steps in sequence (the technical route is shown in Figure 1 ):

[0044] (1) Object selection: before artificial induction of the fish eggs (mylonas fish eggs) to be hatched, select omnivorous fish koi with a body length of 13-16 cm, and the vertical length of the koi mouth slit is 4-5 mm;

[0045] (2) Domestication: place 2 incubation frames (size: 0.8x0.5x0.25m 3 ) that can freely float on the water surface in a domestication pool (area: 4m 2 , pool water depth: 1m); 3The incubation frame has an opening at the top, and the sides and bottom are sealed with mesh (see...). Figure 3 ), with a mesh diameter of 1.6mm, 100 omnivorous koi selected in step (1) were placed in the acclimatization pond outside the hatching frame. The next day, 3mm particle size artificial feed was added to the hatching frame at a rate of 50g / pond / time, and replenished in equal amounts after feeding. Acclimatization lasted for 6 days; (see Figure 2 )

[0046] (3) Hunger: After the last injection of spawning-inducing injection into the parent fish of the Chinese paddlefish, stop feeding into the hatching box in step (2) to obtain domesticated fish;

[0047] (4) Artificial spawning and hatching: After the last spawning injection of the broodstock of the red-lipped barb, wait until the female fish eggs begin to swim away (within 48 hours), collect the female fish eggs and the male fish sperm respectively, artificially inseminate, and gently stir the fertilized eggs with a feather until the fertilized eggs are dispersed into particles, and evenly spread them in the hatching frame (the same as the hatching frame in step (2)) that has been soaked and disinfected in 1ppm potassium permanganate solution in advance. The number of eggs in each hatching frame is 20,000, and they are placed in the hatching pond for hatching.

[0048] (5) Remove water mold: When the fertilized eggs from step (4) develop to the gastrula stage (48-72h), select healthy, active fish with no injuries on their bodies and uniform size from step (3) domestication. Soak them in a 1ppm potassium permanganate solution and place them in the hatching pond outside the hatching frame at a ratio of 2 fish per 10,000 fertilized eggs. Observe the growth rate of water mold every 5 hours. If the water mold increases too quickly, the number of koi can be increased appropriately to achieve a dynamic balance. When the fertilized eggs develop to the pre-hatching stage, remove the domesticated fish.

[0049] Example 2:

[0050] A low-carbon and environmentally friendly method for removing water mold from fish eggs during stagnant water incubation includes the following steps:

[0051] (1) Selection of target: Before artificially inducing spawning of fish eggs (sturgeon eggs) to be hatched, select omnivorous koi with a body length of 16-19cm and a mouth gape length of 5-6mm.

[0052] (2) Acclimation: In the acclimation pool (with an area of ​​3m²) 2 Place a hatching frame (0.7×0.4×0.2m in size) that can float freely on the water surface in a pool with a water depth of 0.9m. 3), the top surface of the incubation frame is open, the periphery and the bottom surface are sealed mesh, the mesh diameter is 2.0mm, 90 omnivorous fish Koi selected in step (1) are put into the acclimation pool outside the incubation frame, the next day, 3mm sinking artificial feed is put into the incubation frame at an amount of 70g / pool / time, and the same amount is supplemented in time after feeding, and acclimation is performed for 5 days;

[0053] (3) Starvation: after the last injection of artificial induction of sturgeon parents, stop feeding the incubation frame in step (2) to obtain acclimated fish;

[0054] (4) Artificial induction and incubation: after the last injection of artificial induction of sturgeon parents, when the female fish eggs begin to separate (within 12 hours), collect the eggs of female fish and the sperm of male fish, artificially inseminate, and gently stir the obtained fertilized eggs with a feather until they become dispersed granules, and then evenly spread them in the incubation frame (same as the incubation frame in step (2)) soaked in advance with 0.8ppm potassium permanganate solution for disinfection, with 23,000 eggs per incubation frame, and then put them into the incubation pool for incubation;

[0055] (5) Removal of water mold: when the fertilized eggs in step (4) develop to the gastrula stage (48-72h), select the step (3) acclimated fish with robust constitution, active movement, no injury on the body surface, and uniform size, soak them in 0.8ppm potassium permanganate solution, and then put them into the incubation pool outside the incubation frame at a ratio of 1 fish per 10,000 fertilized eggs, observe the growth rate of water mold every 4h, if the water mold increases too fast, the number of Koi can be appropriately increased to achieve a dynamic balance, and the acclimated fish is taken out before the fertilized eggs develop to the pre-membrane stage.

[0056] Example 3:

[0057] A low-carbon and environmentally friendly method for removing water mold during fish egg static incubation, comprising the following steps in sequence:

[0058] (1) Object selection: before artificial induction of fish eggs (Gymnocypris przewalskii eggs), select omnivorous fish Koi with a body length of 10-13cm, and the vertical length of the mouth slit is 3-4mm;

[0059] (2) Acclimation: put 2 incubation frames (1×0.6×0.3m 2 ) that can freely float on the water surface into the acclimation pool (area of 5m 3 ), the top surface of the incubation frame is open, the periphery and the bottom surface are sealed mesh, the mesh diameter is 1.0mm, 110 omnivorous fish Koi selected in step (1) are put into the acclimation pool outside the incubation frame, the next day, 2mm sinking artificial feed is put into the incubation frame at an amount of 40g / pool / time, and the same amount is supplemented in time after feeding, and acclimation is performed for 7 days;

[0060] (3) Starvation: After the last injection of the artificial spawning of the parent fish, stop feeding the fish in the incubation frame in step (2) to obtain the domesticated fish;

[0061] (4) Artificial spawning and incubation: After the last injection of the artificial spawning of the parent fish, collect the eggs of the female fish and the sperm of the male fish, and artificially inseminate the eggs. The fertilized eggs are gently stirred with a feather until they become dispersed granules, and then evenly spread in an incubation frame (the same as the incubation frame in step (2)) that has been sterilized with 1.2 ppm potassium permanganate solution. Each incubation frame contains 20,000 eggs, and the incubation is carried out in an incubation tank.

[0062] (5) Removal of water mold: When the fertilized eggs develop to the gastrula stage (48-72 h), select the domesticated fish in step (3) that are healthy, active, have no injuries on the body surface, and have uniform specifications. After soaking in 1.2 ppm potassium permanganate solution, place 3 domesticated fish per 10,000 fertilized eggs in the incubation tank outside the incubation frame. Observe the growth rate of water mold every 8 hours. If the water mold grows too fast, replace the koi fish appropriately to achieve a dynamic balance. Remove the domesticated fish before the fertilized eggs reach the pre-membrane stage.

[0063] Comparative Example 1

[0064] A method for removing water mold eggs in static water incubation of fish eggs, comprising the following steps in sequence:

[0065] In step (1), select omnivorous koi fish with a body length of 20-23 cm, and the koi fish has a vertical length of 7-8 mm at the mouth slit.

[0066] The rest is the same as Example 1.

[0067] Comparative Example 2

[0068] A method for removing water mold eggs in static water incubation of fish eggs, comprising the following steps in sequence:

[0069] In step (2), the mesh diameter is 2 mm.

[0070] The rest is the same as Example 1.

[0071] Comparative Example 3

[0072] A method for removing water mold eggs in static water incubation of fish eggs, comprising the following steps in sequence:

[0073] In step (5), place 7 domesticated fish per 10,000 fertilized eggs in the incubation tank outside the incubation frame.

[0074] Comparative Example 4

[0075] A method for removing Saprolegnia sp. in static water hatching of fish eggs, comprising the following steps in sequence:

[0076] In step (5), when the fertilized eggs develop to the gastrula stage, the hatching frame is taken out from the hatching pool one by one every day, put into another container with a size of 1m x 0.8m x 0.4m, 50L of malachite green solution with a concentration of 5mg / L is added, soaked for 10min, and then put back into the hatching pool for continuous hatching, and the soaking is continued for 3 days, i.e. no domesticated fish is put in. The rest is the same as example 1.

[0077] Comparative example 5:

[0078] A method for removing Saprolegnia sp. in static water hatching of fish eggs, comprising the following steps in sequence:

[0079] In step (5), when the fertilized eggs develop to the gastrula stage, the hatching frame is taken out from the hatching pool one by one every day, put into another container with a size of 1m x 0.8m x 0.4m, 50L of potassium permanganate solution with a concentration of 15mg / L is added, soaked for 10min, and then put back into the hatching pool for continuous hatching, and the soaking is continued for 3 days, i.e. no domesticated fish is put in. The rest is the same as example 1.

[0080] Comparative example 6:

[0081] A method for removing Saprolegnia sp. in static water hatching of fish eggs, comprising the following steps in sequence:

[0082] In step (5), when the fertilized eggs develop to the gastrula stage, the single hatching pool is heated by a 3000W heating rod for 24h to keep the water temperature at 20℃ until the fry is hatched, i.e. no domesticated fish is put in. The rest is the same as example 1.

[0083] Test example:

[0084] I. The Saprolegnia sp. inhibition rate, hatching rate, deformity rate and cost (drug or electricity) of fish eggs after removing Saprolegnia sp. in examples 1-3 and comparative examples 1-3 are detected, and the results are shown in table 1.

[0085] Table 1 Comparison of various indexes of examples 1-3 and comparative examples 1-3

[0086]

[0087] As shown in table 1, examples 1-3 and comparative examples 1-3 have little difference in Saprolegnia sp. inhibition rate, deformity rate and cost, but due to the unsuitable selection of the parameters of fish mouth slit, hatching frame mesh diameter and domesticated fish quantity in comparative examples 1-3, the difference in fry hatching rate is significant.

[0088] II. The Saprolegnia inhibition rate, the hatching rate, the deformity rate and the cost (medicine or electricity) of the fish eggs after removing Saprolegnia of Example 1 and Comparative Examples 4-6 were detected, and the results are shown in Table 2.

[0089] Table 2 Comparison of various indexes of Example 1 and Comparative Examples 4-6

[0090]

[0091] As shown in Table 2, the Saprolegnia inhibition rate and the hatching rate of Example 1 are not obviously different from those of Comparative Example 4, but the deformity rate of Comparative Example 4 is significantly higher than that of the method of the present application; Comparative Example 5 cannot achieve the effect of the method of the present application in all indexes; and Comparative Example 6 has similar deformity rate to the method of the present application, but the Saprolegnia inhibition rate and the hatching rate are significantly lower than those of the method of the present application, and the cost is significantly higher than that of the method of the present application. Therefore, the method of the present application can effectively remove Saprolegnia eggs, has high hatching rate and low deformity rate, and has the characteristics of high efficiency, energy saving, low carbon and environmental protection.

[0092] The prior art mainly adopts the following two methods to control Saprolegnia during the incubation process:

[0093] The first method: when the fertilized eggs develop to the gastrula stage, the incubation frame is taken out from the incubation pool one by one, soaked in the medicine solution for 5-10 min, and then put back into the incubation pool for continuous incubation. Generally, different fish eggs need to be soaked for 1-3 times to control the development of Saprolegnia. This method is complicated, requires a large amount of manpower and material resources, and the medicine will remain in the fish body and the environment, which has great safety hazards.

[0094] The second method: during the whole incubation period of the fertilized eggs, the incubation water temperature is heated by a heating rod or a boiler to inhibit the growth of Saprolegnia. This method not only consumes a lot of energy, which is not conducive to the development of the environment and economy, but also the unsuitable incubation temperature will have an adverse effect on the development of fish eggs.

[0095] The method of the present application can effectively remove Saprolegnia eggs, has high hatching rate and low deformity rate, and has the characteristics of high efficiency, energy saving, low carbon and environmental protection.

[0096] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for removing ichthyophthirius multifiliis from fish egg static water incubation water in a low-carbon and environmentally friendly manner, characterized in that, Comprise the following steps in turn: (1) object selection: before the artificial spawning of the fish eggs to be hatched, select omnivorous fish, the longitudinal length of the mouth slit of the omnivorous fish is 2-3mm larger than the diameter of the fertilized eggs; (2) domestication: put the hatching frame capable of floating freely on the water surface into the domestication pool, the mesh diameter of the hatching frame is 1 / 3-1 / 2 of the diameter of the fertilized eggs after water absorption, put the omnivorous fish selected in step (1) into the domestication pool outside the hatching frame, then put feed into the hatching frame, and replenish in time after feeding, domesticate for 5-7 days; (3) starvation: after the last injection of the artificial spawning of the fish eggs to be hatched, stop feeding the hatching frame in step (2), and obtain the domesticated fish; (4) artificial spawning and hatching: after the last injection of the artificial spawning of the fish eggs to be hatched, collect the eggs of female fish and the sperm of male fish respectively, artificially inseminate, and evenly spread the obtained fertilized eggs in the hatching frame which has been sterilized in advance, then put it into the hatching pool for hatching; (5) remove water mold: when the fertilized eggs in step (4) develop to the gastrula stage, put the domesticated fish in step (3) into the hatching pool outside the hatching frame, and remove the domesticated fish when the fertilized eggs develop to the pre-membrane stage.

2. The method for removing fish egg static water hatching water mildew according to claim 1, characterized in that, In step (1), the omnivorous fish is carp, koi or crucian carp.

3. The method for removing fish egg static water hatching water mildew according to claim 1, characterized in that, In step (2), the acclimation pond area is 3-5 m 2 , the pond water depth is 0.9-1.2 m, 90-110 omnivorous fish are put into each acclimation pond, and 1-2 hatching frames are put into each acclimation pond, the top of the hatching frame is open, and the periphery and bottom are sealed mesh.

4. The method for removing fish egg static water hatching water mildew according to claim 1, characterized in that, In step (2), the amount of feed put in each time is 0.4-0.6wt% of the body weight of the omnivorous fish.

5. The method for removing Saprolegnia from fish egg static water hatching water according to claim 1, characterized in that, In step (4), the hatching frame is soaked and sterilized with 0.8-1.2ppm potassium permanganate solution.

6. The method for removing Saprolegnia from fish egg static water hatching water according to claim 1, characterized in that, In step (4), the number of fertilized eggs in each hatching frame is 20-25 thousand.

7. The method for removing Saprolegnia from fish egg static water hatching water according to claim 1, characterized in that, In step (5), select the domesticated fish with strong physique, active movement, no injury on the body surface and uniform size, soak them in 0.8-1.2ppm potassium permanganate solution and then put them into the hatching pool.

8. The method for removing fish egg static water hatching water mildew according to claim 1, characterized in that, In step (5), the number of domesticated fish put into the hatching pool for every 10 thousand fertilized eggs is 1-3.

9. The application of the low-carbon and environmentally friendly method for removing water mold during fish egg hatching according to any one of claims 1-8 in fish egg hatching.

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