Large-scale cultivation method for culter oxyculta fries

Abstract

The invention discloses a large-scale cultivation method for culter oxyculter fries, and belongs to the technical field of aquaculture. A circulating water treatment system is constructed, fry breeding is carried out, a series of means including microstrainer filtration, air floatation tank purification, biological purification, ozone disinfection, pure oxygen oxygenation and the like are used in the period, finally, water quality is improved, breeding density is increased, the disease incidence and the malformation rate are reduced, and the fry survival rate is increased. According to the method, water used in the seedling raising process is fully recycled, so that the loss of water heat is reduced, water resources are saved, the culture cost is reduced, and factory-like large-scale cultivation of the culter oxyculter seedlings is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of aquaculture, and in particular relates to a method for large-scale cultivation of Pseudoacanthus bream seedlings by utilizing a factory-scale circulating water system. Technical Background Pseudo-acanthus sphenodon Culter oxycephaloides ) belongs to the order Cypriniformes, family Cyprinidae, subfamily Cultrinae, genus Cultrinae Culter ). Also known as the similar pointed-head carp, duck-billed red tip, pointed-head red tip (Sichuan), duck-billed, and duck-billed fish (Shaanxi). The pseudo-pointed-head carp is distributed in the Yangtze River section from Yibin, Sichuan to Nanjing, Jiangsu. It is a species endemic to the Yangtze River, mostly in the middle and upper reaches, and 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. The pseudo-pointed-head carp mostly lives in the middle and upper layers of flowing water or deeper still water bodies. It mainly feeds on small fish and shrimps. 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 conditions, the natural population of the pseudo-pointed-head carp has decreased significantly, and the market is in a state of supply exceeding demand. Therefore, the development of the aquaculture industry of the pseudo-pointed-head carp is of great significance.

[0003] In recent years, China has conducted systematic research on artificial propagation of Pseudo-apex bream, breaking through the technical difficulties of artificial propagation and solving the problems of low induced fertilization rate, fertilization rate and hatching rate of artificial propagation. However, the large-scale cultivation technology of Pseudo-apex bream seedlings has not yet been realized internationally. The domestic seedling cultivation method is mainly pond cultivation. Due to the influence of the external environment, pond seedling cultivation has the following defects: first, the survival rate of seedlings is low, and the deformity rate of seedlings is high under traditional cultivation conditions; second, because the cultivation water body is generally small, the self-purification capacity is low, and the water quality control is relatively difficult, the cultivation density should not be too high, which is far from meeting the needs of the breeding industry, and has become a bottleneck restricting the sustainable development of the Pseudo-apex bream breeding industry. Summary of the invention

[0004] The purpose of the present invention is to provide a method for cultivating Pseudo-apex carp seedlings, aiming to solve the problems of low seedling cultivation density and survival rate, high deformity rate, etc. caused by traditional cultivation methods, so as to realize large-scale cultivation of Pseudo-apex carp seedlings.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions: A method for large-scale cultivation of Pseudoacanthus bream seedlings comprises the following steps: S1. Construct a circulating water treatment system; S2. Use the circulating water treatment system to cultivate seedlings. The construction of the circulating water treatment system includes the steps of microfiltration, flotation tank purification, biological purification, ozone disinfection, pure oxygen oxygenation, heat exchanger to adjust water temperature, etc. The seedling cultivation includes controlling the water temperature to maintain at 26-28°C, pH 7.0-8.5, dissolved oxygen content > 5 mg / L, NH3-N < 0.2 mg / L, and NO2- < 0.02 mg / L.

[0006] The biological purification is carried out through three different levels of biological filter materials. The first level of biological filter material is biochemical filter cotton and volcanic stone, which are used to remove larger biological suspended solids; the second level of biological filter material is biochemical balls and ceramic rings, which are used to remove soluble pollutants; the third level of biological filter material is bacterial house and coral bones, which degrade organic matter through microorganisms.

[0007] Wherein, the flotation tank purification is carried out by an aerator arranged at the bottom of the water body.

[0008] When the flotation tank is used for purification, flocculants are added to the water to promote the coagulation of tiny suspended organic matter.

[0009] Among them, the seedling cultivation also includes feed management, including that the starting bait is mainly hatched Artemia, and when the Artemia is fed to the fish body length of about 1 cm, the compound feed is gradually fed for domestication, during which the proportion of feed is gradually increased, and the feed conversion is completed in 4-5 days; when feeding, the feed is fed three times a day in the morning, noon and evening, and the feeding amount is calculated according to the seedling weight, and the daily feeding amount is 3-5% of the body weight.

[0010] Wherein, the seedling cultivation is carried out under light-proof conditions with a light transmittance of 30%-50%.

[0011] Among them, when cultivating seedlings, measures should also be taken to prevent mutual harm and cross-infection of viruses due to size differences between seedlings.

[0012] The beneficial effects of the present invention are: The present invention determines the water quality and external conditions suitable for the growth of seedlings according to the living habits of Pseudo-apex carp, and circulates the aquaculture tail water, during which a series of means including microfiltration, flotation tank purification, biological purification, ozone disinfection, pure oxygen oxygenation, etc. are used to finally improve the water quality, increase the cultivation density, reduce the incidence of diseases and deformity rates, and improve the survival rate of seedlings. The present invention reduces the loss of water heat, saves water resources, reduces the breeding cost, and realizes the factory-scale cultivation of Pseudo-apex carp seedlings by fully recycling the water used in the seedling cultivation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1: Schematic diagram of the structure of the circulating water treatment system. In the figure: 1-breeding pond, 2-microfiltration pond, 3-air flotation pond, 4-biological purification pond, 5-circulation pump, 6-ozone disinfection pond, 7-intermediate filtration pond, 8-oxygenation pond, 9-heat exchanger.

[0014] Figure 2 : Schematic diagram of the structure of the biological purification pool. In the figure: 1-filter cotton, 2-volcanic stone, 3-biochemical ball, 4-ceramic ring, 5-bacteria house, 6-coral bone. DETAILED DESCRIPTION

[0015] The present invention is further described in detail below with reference to specific embodiments.

[0016] Example 1 The construction of circulating water treatment system The circulating water aquaculture process of Pseudoacanthus sphenodon includes six stages: microfiltration, flotation tank purification, biological purification, ozone disinfection, pure oxygen oxygenation, and heat exchanger to adjust water temperature. The aquaculture pond is composed of several circular fish ponds, each with an average effective volume of 3m 3 , with an average water depth of 1m. The water discharged from the breeding pond first passes through a microfiltration machine to remove large particle impurities and suspended solids (greater than 150 microns), and then through a flotation tank to remove tiny suspended solids (greater than 50 microns) and harmful gases. The water quality is regulated through biological purification, and ozone disinfection is used to prevent and control diseases and remove some heavy metal ions. Then, pure oxygen with a purity greater than 90% is added to increase the dissolved oxygen in the water. Finally, the water temperature is adjusted through a heat exchanger, and the treated water returns to the breeding pond for recycling. The specific operation process is as follows: (1) Microfiltration: The water discharged from the aquaculture pond is first filtered through a microfiltration machine to remove large particles and suspended solids (larger than 150 μm). This stage is mainly used to separate solid debris such as leftover bait and feces to prevent the decomposition of solid debris in the water, reduce the processing load of the circulating water treatment system, reduce the volume of the post-treatment system and reduce the system cost.

[0017] The microfiltration machine used in this process was purchased from Jiangmen Yumeng Fishery Machinery Co., Ltd. It is a solid-liquid separation equipment. Its working principle is to intercept solid particles in the water on the filter medium (usually a filter) through physical interception to remove suspended particles in the water and achieve the purpose of water purification.

[0018] (2) Air flotation tank purification: The air flotation tank is used to remove tiny suspended matter (larger than 50μm) and harmful gases. The principle is as follows: the water body enters the air flotation tank after being filtered by a microfilter. A submerged aerator is installed at the bottom of the air flotation tank and air is introduced into the water, thereby generating a large number of tiny bubbles in the air flotation tank. These microbubbles attach to the suspended matter particles, causing the density to be less than that of water. The buoyancy principle is used to make them float to the water surface, and then the scum is scraped off by the scraping device, thereby achieving the purpose of solid-liquid separation and improving water quality. In this process, a small amount of flocculant can also be added to the air flotation tank to promote the coagulation of tiny organic suspended matter, making it easier for them to adhere to the bubbles and be removed. After actual measurement, the water quality indicators after purification in the flotation tank can basically meet the following requirements: nitrite (NO2-) concentration is lower than 0.05mg / L, ammonia nitrogen (NH3-N) concentration is lower than 0.50mg / L, dissolved oxygen (DO) is higher than 5mg / L, and the total number of bacteria is lower than 100 / mL. (3) Biological purification: The water body after being purified by the flotation tank enters the three-stage biological purification tank, and the biological purification effect of the water quality is improved through three different levels of filtration. The specific surface area of ​​the first-stage biological filter material is selected to be 100m 2 / m 3 The second-stage biofilter material has a specific surface area of ​​200m 2 / m 3 Biochemical balls and ceramic rings are used to remove soluble pollutants; the third-stage biological filter material is selected with a specific surface area of ​​220m 2 / m 3 The bacterial houses and coral skeletons provide a place for microorganisms to attach and grow, and degrade organic matter through microorganisms.

[0019] According to actual measurements, after three-stage biological purification, the NH3-N content in the water can be further reduced to below 0.2 mg / L, and the NO2- content can be reduced to below 0.04 mg / L.

[0020] (4) Ozone disinfection: By adding ozone to the water body, the purpose of disinfection, prevention of diseases and removal of some heavy metal ions can be achieved.

[0021] According to actual measurements, the NO2- content in water can be reduced to below 0.02 mg / L after ozone treatment.

[0022] (5) Pure oxygen oxygenation: Add pure oxygen with a purity greater than 90% into the high-efficiency dissolved oxygen tank to increase the dissolved oxygen in the water; use nano-microporous oxygenation tubes to increase oxygen content in the water to more than 5 mg / L. (6) Heat exchanger to adjust water temperature: The water temperature is adjusted by the heat exchanger so that the temperature is maintained at 26~28℃. The treated water returns to the breeding pond for recycling, completing the recycling process.

[0023] In order to provide a good growth environment for Pseudo-acanthopanax, the water flowing back into the breeding pond is required to have the following requirements: water temperature 26~28℃, pH7.0~8.5, dissolved oxygen content >5mg / L, NH3-N <0.2mg / L, NO2- <0.02mg / L. The above requirements can be fully met through the above circulating water treatment. (1) Circulating water system: When cultivating seedlings in circulating water, the water temperature must be controlled to maintain at 26-28℃, pH 7.0-8.5, dissolved oxygen > 5mg / L, NH3-N < 0.2mg / L, NO2- < 0.02mg / L. The number of cycles per day should be more than 10, and cultivation should be carried out in dark conditions. Sunshade facilities should be installed above the fish pond, and the light transmittance of the sunshade net should be 30%-50%.

[0024] (2) Feed and delivery: The main feed for the fish is hatched Artemia. When the Artemia is fed to the fish body length of about 1 cm, compound feed is gradually fed to acclimate the fish. When feeding, a small amount of compound feed is first fed, and then Artemia is fed, alternating until the fish are full. During this period, the proportion of feed is gradually increased, and the feed conversion can be completed in 4-5 days. Feed is fed three times a day in the morning, noon and evening. The feeding amount is calculated according to the weight of the seedlings. Generally, the daily feeding amount is 3-5% of the body weight. It can be adjusted in time according to the feeding situation of the fish. Observe whether the fish can finish the feed within 1 hour. If they can finish it, increase the feeding amount. Otherwise, reduce it appropriately, so that the seedlings do not actively grab food. (3) Fish body measurement: fish body parameters including body length, weight, body width, and total length are measured every 10 days, and the growth status of the seedlings is recorded. (4) Seedling screening: During the seedling cultivation process, seedlings of different sizes will be sorted. When the seedlings are 5-10 cm in height, screen them every 7 days; when they are over 10 cm, screen them every 15 days to prevent mutual injury due to size differences between seedlings.

[0025] (5) Rapid detection of viral neuronecrosis: During the seedling cultivation process, the seedlings should be sampled and tested regularly. The test is to analyze the samples taken using a test kit. Once a positive sample is found, the seedling pond should be isolated to prevent cross infection.

[0026] From June to October 2024, the same batch of Pseudoacanthus sphenocephalus fry were cultivated in the breeding ponds of Hubei Xinyun Agricultural Development Co., Ltd. and the circulating water system of the breeding base of the College of Fisheries of Huazhong Agricultural University. The feed and other breeding management were the same as above. 10,000 fry were selected from each group after they were hatched in the incubator for about 5 days and reached the level of swimming for breeding. The specifications of the pond breeding pool were 15m 3 5,000 fry were placed in each pond, and a total of more than 4,000 fry with a body length of 10-15 cm were cultivated in the two ponds. The survival rate of the fry was only about 40%, and the deformity rate was about 3%.

[0027] The circular fish pond of the circulating water system is 3m 3 2,000 fry were placed in each fish pond, and a total of more than 8,000 fry of Pseudo-acanthopanax bream with a body length of 10-15 cm were cultivated in the five fish ponds. The survival rate of the fry was over 80%, and the deformity rate was less than 1%.

[0028] The present invention realizes the large-scale cultivation of high-quality seedlings of Pseudo-apex bream. This is the first time in China that a factory-based circulating water system is used to cultivate Pseudo-apex bream seedlings, proving that the innovatively developed factory-based circulating water system seedling cultivation method is feasible and reliable. In addition, the present invention has the advantages of high breeding density, low cost, high survival rate, and low deformity rate, and is of great significance to the future development of the Pseudo-apex bream breeding industry.

Claims

1. A method for large-scale cultivation of Pseudoacanthus striata seedlings, characterized in that The following steps are involved: S1. Construct a circulating water treatment system; S2. Use the circulating water treatment system to cultivate seedlings. The construction of the circulating water treatment system includes the steps of microfiltration, flotation tank purification, biological purification, ozone disinfection, pure oxygen oxygenation, heat exchanger to adjust water temperature, etc. The seedling cultivation includes controlling the water temperature to maintain at 26-28°C, pH 7.0-8.5, dissolved oxygen content > 5 mg / L, NH3-N < 0.2 mg / L, and NO2- < 0.02 mg / L.

2. The method for large-scale breeding of Pseudoacanthus bream seedlings as claimed in claim 1, characterized in that: The biological purification is carried out through three different levels of biological filter materials. The first level of biological filter materials are biochemical filter cotton and volcanic rocks, which are used to remove larger biological suspended matter; the second level of biological filter materials are biochemical balls and ceramic rings, which are used to remove soluble pollutants; The third-level biological filter material is bacterial house and coral skeleton, which degrades organic matter through microorganisms.

3. The method for large-scale breeding of Pseudoacanthus bream seedlings as claimed in claim 1, characterized in that: The flotation tank purification is carried out by an aerator arranged at the bottom of the water body.

4. The method for large-scale breeding of Pseudoacanthus bream seedlings as claimed in claim 3, characterized in that: When the flotation tank is used for purification, flocculants are also added to the water to promote the coagulation of tiny suspended organic matter.

5. The method for large-scale breeding of Pseudoacanthus bream seedlings as claimed in claim 1, characterized in that: The seedling cultivation also includes feed management, wherein the starter bait is mainly hatched Artemia. When the Artemia is fed to the fish body length of about 1 cm, the compound feed is gradually fed for domestication. During the period, the proportion of feed is gradually increased, and the feed conversion is completed in 4-5 days. The feed is fed three times a day in the morning, noon and evening. The feeding amount is calculated according to the seedling weight, and the daily feeding amount is 3-5% of the body weight.

6. The method for large-scale breeding of Pseudoacanthus bream seedlings as claimed in claim 1, characterized in that: The seedling cultivation is carried out under light-proof conditions with a light transmittance of 30%-50%.

7. The method for large-scale breeding of Pseudoacanthus bream seedlings as claimed in claim 1, characterized in that: When cultivating seedlings, take measures to prevent mutual harm and cross-infection of viruses due to size differences between seedlings.

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