Method for hatching fertilized eggs of myxocyprinus asiaticus

Abstract

The invention discloses a myxocyprinus asiaticus fertilized egg hatching method which is characterized in that myxocyprinus asiaticus fertilized eggs are hatched under the combination of a hatching device, and an aeration oxygenation system and a water quality monitoring system are arranged in the hatching device; the hatching method is a closed self-circulation hatching method, and specifically comprises the following steps: 1) hatching water source requirements; (2) the water quality requirement of hatching water is met; 3) artificial spawning induction and artificial fertilization of the parent fish; 4) fertilized egg debonding; 5) hatching flow rate and density; 6) water changing interval and water changing duration; 7) preventing saprolegnia and removing dead eggs; and (8) water quality indexes in the hatching process. The hatching device is combined with the core hatching method, the hatching density of the myxocyprinus asiaticus fertilized eggs can be greatly improved, the hatching rate is increased by 80% or above, water resources are saved, and labor is saved.

Description

Technical Field

[0001] The invention relates to the technical field of hatching fertilized rouge fish eggs, and in particular to a method for hatching fertilized rouge fish eggs. Background Art

[0002] The Chinese redfin mullet belongs to the class of bony fishes, the order of Cypriniformes, the family of Myristidae (or called the family of Aristolochiidae), the genus Myristolochia. There are 13 genera and 68 species of fish in this family, which are mainly distributed in North America. In Asia, only Aristolochia and Chinese redfin mullet are distributed. In addition to being distributed in Siberia, Aristolochia is also found in North America, and is found in both continents; while Chinese redfin mullet is only found in the Yangtze River and the Minjiang River in my country, and is endemic to my country and Asia. Therefore, the Chinese redfin mullet has extremely important scientific value in the study of fish systematics. The fish is large, grows fast, and has delicious meat. It is an important economic fish in the Yangtze River.

[0003] In the past 20 years, due to changes in the ecological environment, long-term overfishing, the continuous deterioration of the living environment and the impact of human activities, its natural resources have been severely damaged. It has been listed as an endangered species in my country. It is now a national second-level aquatic wild protected animal and its endangered level is vulnerable.

[0004] In order to protect and increase the number of this precious species, scientific and technological workers in my country's aquaculture industry have conducted extensive research on the artificial breeding technology of rosy barbel, which has now reached maturity. The hatching of rosy barbel fertilized eggs is one of the key factors in the success of artificial breeding of fish, and the hatching rate directly affects the recovery and proliferation of rosy barbel resources.

[0005] In summary, there are two ways to incubate the sperm and eggs of Chinese red snapper: still water incubation, flowing water incubation, and a combination of the two. Still water incubation is to move the mesh and palm sheets with fertilized eggs into a sterilized incubation pool and fix them so that they are suspended in the water and incubated in still water with oxygen. Flowing water incubation is to remove the fertilized eggs and move them into an incubation tank for stirring and incubation, or to use a Eugenics incubator for incubation. The combination of micro-flowing water and still water is either to incubate in still water first, and then move the mesh and palm sheets into the incubation loop for flowing water incubation 4 to 5 hours before the eggs emerge, or to use a hatching bucket for flowing water incubation first, and then transfer the eggs to indoor still water incubation 10 to 24 hours before the eggs emerge.

[0006] In summary, there are different methods for hatching fertilized eggs of rosy barb. A relatively successful case is to use a combination of micro-flow water and static water for hatching. Although this method can hatch fry, the operation is relatively complicated, time-consuming and labor-intensive, and cannot meet the needs of large-scale production. It also restricts the development of artificial breeding of rosy barb, and creates obstacles for the future artificial release of rosy barb to restore the natural resources of the fish. Summary of the invention

[0007] According to the above existing technical problems, the present invention provides a method for hatching fertilized eggs of rosy barb. The core hatching method is used in the hatching device to greatly improve the hatching density of fertilized eggs of rosy barb, increase the hatching rate to more than 80%, save water resources and save labor.

[0008] To achieve the above object, the technical solution of the present invention is as follows:

[0009] A method for hatching fertilized eggs of mullet, comprising the following steps:

[0010] (1) Requirements for hatching water source: The water source for hatching comes from the water source pool. The water in the water source pool should be drained before use, and the pond should be thoroughly cleaned, excess mud should be removed, and it should be thoroughly disinfected with chlorine-containing lime at a dosage of 25 kg / mu. After ventilation and drying for 5 to 7 days, underground well water should be injected and fully aerated for 5 to 7 days.

[0011] (2) Requirements for hatching water quality: The hatching water quality should be fresh and transparent, with a pH value of 8.0-8.8, ammonium nitrogen <0.2mg / L, nitrite <0.05mg / L, sulfide <0.02mg / L, and it should be filtered through a double layer of 100-mesh silk sieve before use;

[0012] (3) Artificial induction of spawning and artificial insemination of broodstock: Artificial induction of spawning and artificial insemination of broodstock are used. 60 sexually mature broodstock ♀ and 20 ♂ are induced to spawn at one time. After the broodstock are injected with 3 injections, artificial egg collection and fertilization are performed according to the effect time.

[0013] (4) De-sticking of fertilized eggs: Wash the fertilized eggs repeatedly with clean water for 3 to 5 times, and the stickiness of the fertilized eggs will gradually disappear. At the same time, the semen and other substances wrapped and attached to the fertilized eggs will be cleaned until the eggs are crystal clear;

[0014] (5) Hatching flow rate and density: Before placing the fertilized eggs into the incubator, fill them with hatching water in advance, adjust the flow rate, and control the water flow at 0.15m / s. Then slowly pour the cleaned and debonded fertilized eggs into the incubator;

[0015] (6) Interval and duration of water changes: After the fertilized eggs are placed in the incubator, the closed self-circulating incubation method is used throughout the incubation process. The flow rate is adjusted by the self-circulating system of the incubator. The water needs to be changed 14 times during the incubation process. Each water change lasts for 2 to 6 hours, and the total water change time is 66 hours.

[0016] (7) Prevent Saprolegnia and remove dead eggs: Spray anti-Saprolegnia drugs four times during the incubation process, clean the screens in time, and remove dead eggs, moldy eggs, egg skins and dirt;

[0017] (8) Requirements for hatching water quality during the incubation process: The water temperature is required to be controlled at 17.2-20.7℃ during the entire incubation process; the pH value of the water quality is between 7.13 and 8.64, the dissolved oxygen in the water is 6.87-9.60 mg / L, the ammonium nitrogen is 0-2.67 mg / L, of which molecular ammonia is 0-0.13 mg / L, nitrite is 0-0.02 mg / L, and sulfide is 0-0.02 mg / L.

[0018] The incubation device is provided with an aeration and oxygenation system and a water quality monitoring system, and the aeration and oxygenation system and the water quality monitoring system are turned on when the fertilized rosy fish eggs are incubated.

[0019] Specifically, in step 6, the temperature difference before and after each water change is less than 0.8°C.

[0020] Beneficial effects of the present invention:

[0021] In the hatching method developed by the present invention, closed hatching is adopted in the whole hatching process, water is changed within a specified time, the external water comes from the hatching water, the water inlet and the drain of the hatching device are closed after each water change, and the self-circulation system in the hatching device is used to control the flow rate to 0.15m / s, which can greatly save water resources compared with "long-flow water" hatching or hatching in a hatching tank or hatching bucket;

[0022] The present invention utilizes the aeration and oxygenation system in the hatching device, and turns on the system during the entire hatching process, so as to realize the rapid increase of dissolved oxygen in the hatching water body, and reduces toxic and harmful substances such as ammonia nitrogen, nitrite, sulfide, etc. generated by organic matter in the hatching water body through aeration, and the water quality detection system in the hatching device realizes the continuous and automatic detection of the water temperature, dissolved oxygen and pH value of the hatching water body during the entire hatching process, and the hatching density can be fully improved in combination with the hatching technology of the present invention, thereby greatly improving the large-scale production of fertilized eggs of Chinese mullet;

[0023] The invention uses the drug for preventing and controlling water mold four times during the hatching process, which can effectively prevent the breeding of water mold in the mullet embryo and make the hatching rate of the mullet above 80%.

[0024] By using the incubation device and the incubation technology developed in conjunction with the present invention to incubate fertilized rouge fish eggs, the entire incubation process is convenient, simple and efficient to operate, thus laying a foundation for rouge fish breeding and indoor factory-based incubation. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be further described in detail below in conjunction with specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] Step 1, artificial induction of spawning and artificial insemination of broodstock: When the water temperature of the broodstock breeding pond stabilizes at 14°C in spring, the broodstock can be artificially induced to spawn. After three drug injections, eggs are collected and artificially inseminated in a timely manner according to the effect time.

[0028] Step 2, because of the characteristics of rosy barbel fish eggs, the mature rosy barbel eggs are orange-yellow, nearly spherical, and sinking eggs, with a weight of 165 per gram. After the eggs are fertilized, they swell in water to form a perivitelline space, which is filled with translucent "colloids". At this time, the fertilized eggs have weak viscosity and form egg masses, so it is necessary to debond the fertilized eggs, and clean the semen and other substances wrapped and attached to the fertilized eggs with clean water. After washing 3 to 5 times, the viscosity gradually disappears until the eggs are crystal clear, and the egg diameter after water absorption and expansion is 3.6 to 4.0 mm, and then the fertilized eggs are placed in the hatching ring in the hatching device.

[0029] Step 3, requirements for the water source and water quality of hatching, the hatching water must be filled in the hatching device in advance, the hatching water requires fresh water quality and high transparency, the pH value of the water quality must be tested, the pH value is 8.0-8.8, wherein ammonium nitrogen is less than 0.2mg / L, nitrite is less than 0.05mg / L, sulfide is less than 0.2mg / L, and the water can be used after double filtration through 100 mesh silk sieve. The hatching water source comes from the water source pool. When using the water source pool, the pool water must be drained, the pond must be thoroughly cleaned, excess mud must be removed, and the water must be thoroughly disinfected with chlorinated lime at a dosage of 25kg / mu. After ventilating and drying for 5-7 days, underground well water is injected and fully aerated for 5-7 days.

[0030] Step 4: Incubate the fertilized eggs:

[0031] First, adjust the flow rate before placing the fertilized eggs into the incubator, and control the flow rate at 0.15-0.18 m / s;

[0032] Secondly, the debonded and cleaned fertilized eggs are placed in the incubation device, and the incubation density is 600,000 / m 3 After the fertilized eggs are placed in the incubator, the self-circulation mode in the incubator is turned on, and the oxygenation system and water quality monitoring system are turned on at the same time. The aeration system is turned off during each water change and turned on after the water change is completed until the fry are sold.

[0033] Step 5, water change frequency and water change duration:

[0034] The first water change is 30 hours after the fertilized eggs are placed in the incubator. This water change takes 3 hours.

[0035] The second water change is 30 hours after the first water change, and the duration of this water change is 3 hours;

[0036] The third water change is 42 hours after the second water change, and the duration of this water change is 3 hours;

[0037] The fourth water change is 28 hours after the second water change, and the duration of this water change is 8 hours;

[0038] The fifth water change is 17 hours after the second water change, and the duration of this water change is 4 hours;

[0039] The sixth water change is 30 hours after the second water change, and the duration of this water change is 3 hours;

[0040] The 7th water change: 25 hours after the 2nd water change, this water change takes 2 hours;

[0041] The 8th water change: 19 hours after the 2nd water change, this water change lasts 6 hours;

[0042] The 9th water change: 18 hours after the 2nd water change, this water change lasts 6 hours;

[0043] The 10th water change: 18 hours after the 2nd water change, this water change lasts 6 hours;

[0044] The 11th water change is 18 hours after the 2nd water change, and the water change lasts for 6 hours.

[0045] The 12th water change: 18 hours after the 2nd water change, this water change lasts 6 hours;

[0046] The 13th water change is 18 hours after the 2nd water change, and the water change lasts for 5 hours.

[0047] The 14th water change: It is 18 hours after the 2nd water change, and this water change lasts 5 hours.

[0048] Step 6. During each water change, the temperature difference should be maintained at 0-0.8℃. Too large a temperature difference will affect the hatching rate.

[0049] Step 7, the first medication is administered 1 hour and 20 minutes after the fertilized egg enters the egg; the second medication is administered immediately after the first water change is completed; the third medication is administered immediately after the second water change is completed; the fourth medication is administered immediately after the fourth water change is completed, wherein the dosage of the medication is the same each time.

[0050] Step 8, because fertilized eggs are heavier than unfertilized eggs, they often float on the water surface, so the fertilized eggs placed in the incubator need to promptly remove dead eggs, moldy eggs and dirt in the ring channel, and wash the ring channel screen in time, which can effectively prevent the mullet embryo from breeding water molds and make the mullet hatching rate more than 80%.

[0051] Step 9, when the water temperature is 17.2-18.9°C, with an average water temperature of 18.2°C, the fertilized eggs begin to hatch after 124 hours of incubation, and all the fry have hatched after 164 hours. It takes 20 hours from the beginning of hatching to half of the fertilized eggs hatching, and 40 hours from the beginning of hatching to the end.

[0052] Step 10, when the water temperature is 18.3-20.7°C, with an average water temperature of 19.3°C, the fry will all swim horizontally after 200 hours after hatching. If it takes 364 hours to incubate from the time the fertilized eggs enter the ring, the fry will start swimming horizontally after about 15 days.

[0053] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the implementation mode. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the embodiments shown and described here. The present invention may also have various changes and improvements, which fall within the scope of the invention claimed for protection. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for hatching fertilized eggs of mullet, comprising the following steps: (1) Requirements for hatching water source: The water source for hatching comes from the water source pool. The water in the water source pool should be drained before use, and the pond should be thoroughly cleaned, excess mud should be removed, and it should be thoroughly disinfected with chlorine-containing lime at a dosage of 25 kg / mu. After ventilation and drying for 5 to 7 days, underground well water should be injected and fully aerated for 5 to 7 days. (2) Requirements for hatching water quality: The hatching water quality should be fresh and transparent, with a pH value of 8.0-8.8, ammonium nitrogen <0.2mg / L, nitrite <0.05mg / L, sulfide <0.02mg / L, and it should be filtered through a double layer of 100-mesh silk sieve before use; (3) Artificial induction of spawning and artificial insemination of broodstock: Artificial induction of spawning and artificial insemination of broodstock are used. 60 sexually mature broodstock ♀ and 20 ♂ are induced to spawn at one time. After the broodstock are injected with 3 injections, artificial egg collection and fertilization are performed according to the effect time. (4) De-sticking of fertilized eggs: Wash the fertilized eggs repeatedly with clean water for 3 to 5 times, and the stickiness of the fertilized eggs will gradually disappear. At the same time, the semen and other substances wrapped and attached to the fertilized eggs will be cleaned until the eggs are crystal clear; (5) Hatching flow rate and density: Before placing the fertilized eggs into the incubator, fill them with hatching water in advance, adjust the flow rate, and control the water flow at 0.15m / s. Then slowly pour the cleaned and debonded fertilized eggs into the incubator; (6) Interval and duration of water changes: After the fertilized eggs are placed in the incubator, the closed self-circulating incubation method is used throughout the incubation process. The flow rate is adjusted by the self-circulating system of the incubator. The water needs to be changed 14 times during the incubation process. Each water change lasts for 2 to 6 hours, and the total water change time is 66 hours. (7) Prevent Saprolegnia and remove dead eggs: Spray anti-Saprolegnia drugs four times during the incubation process, and clean the screens in time to remove dead eggs, moldy eggs, egg skins and dirt; (8) Requirements for hatching water quality during the incubation process: The water temperature is required to be controlled at 17.2-20.7℃ during the entire incubation process; the pH value of the water quality is between 7.13 and 8.64, the dissolved oxygen in the water is 6.87-9.60 mg / L, the ammonium nitrogen is 0-2.67 mg / L, of which molecular ammonia is 0-0.13 mg / L, nitrite is 0-0.02 mg / L, and sulfide is 0-0.02 mg / L.

2. The method for hatching fertilized eggs of myxocyprinus rubripes according to claim 1, characterized in that The incubation device is provided with an aeration and oxygenation system and a water quality monitoring system, and the aeration and oxygenation system and the water quality monitoring system are turned on when the fertilized rosy fish eggs are incubated.

3. The method for hatching fertilized eggs of myxocyprinus according to claim 1, characterized in that In step 6, the temperature difference before and after each water change is less than 0.8°C.