Biological bait disease prevention and control and multi-element nutrition fortification method for blue crab breeding

Abstract

The invention discloses a biological bait disease control and multi-element nutrient enrichment method for blue crab fry, which is applied to biological bait from zoeae to juvenile crabs of blue crab fry, and the technical scheme is characterized by comprising disease control and multi-element nutrient enrichment of rotifer and disease control and multi-element nutrient enrichment of artemia nauplii. According to the method, through multiple times of disinfection and multi-element nutrient enrichment of living body biological bait, especially rotifer and artemia nauplii, the situation that the juvenile crabs suffer from diseases due to the fact that the juvenile crabs prey on the biological bait with germs is prevented, meanwhile, according to the growth and development requirements of the juvenile crabs, nutrient substances in the biological bait are specialized, and good growth and development of the juvenile crabs are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of biological bait for blue crab seedling cultivation, and more particularly to a biological bait disease prevention and control and multi-nutrient enrichment method for blue crab seedling cultivation. Background Art

[0002] Preventing the occurrence of diseases during the breeding process of blue crab seedlings is a key step in seedling cultivation. Generally speaking, it is necessary to maintain a good external water environment, promptly kill pathogens carried by the crab seedlings themselves, and then prevent and control the secondary entry of pathogens. In particular, in terms of feeding live biological bait, it is necessary to ensure that the biological bait does not carry diseases into the pond. Secondly, it is also necessary to strengthen the nutrition of the crab seedlings to ensure their good growth and development and strong resistance.

[0003] The biological bait for crab seedlings mainly includes rotifers and Artemia nauplii. The existing rotifers and Artemia nauplii are generally cultivated directly in earthen ponds, carry many diseases and are insufficient in nutrition. The existing treatment method is generally to simply cultivate them for a period of time, enhance nutrition, and then feed them after disinfection. This method does not specifically enhance the nutrients required by blue crab seedlings. The nutritional enhancement effect on crab seedlings is general, and a single simple disinfection can only kill pathogens on the surface. It cannot effectively kill the pathogens remaining in the rotifers and Artemia, and they are still prone to carry diseases and affect the cultivation of crab seedlings. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a method for biological bait disease prevention and control and multi-nutrient fortification for blue crab seedling cultivation. Disease prevention and control are carried out by multiple disinfection of the biological bait, and at the same time, the bait is targetedly strengthened to ensure that sufficient nutrition can be provided to the blue crab seedlings.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: a method for controlling diseases and multi-nutrient enrichment of biological bait for blue crab seedlings, which is applied to biological baits from blue crab seedlings to crab larvae, including controlling diseases and multi-nutrient enrichment of rotifers and controlling diseases and multi-nutrient enrichment of Artemia nauplii;

[0006] The disease prevention and control and multi-nutrient enhancement of the rotifer include:

[0007] First rotifer disinfection reinforcement:

[0008] Pond disinfection: Add disinfected water to the pond, add rotifers, the density of rotifers is 80-120 per milliliter, add chlorella and microgreen algae to the water, the algae concentration is 400,000-600,000 cells per milliliter, and add appropriate amount of probiotics to the water; add vitamin B 120.1ug / L, vitamin D30.1ug / L, vitamin C1mg / L, to promote the growth and reproduction of rotifers; during the rotifer cultivation period, 10% of the rotifers in the siphon pond water are used for secondary disinfection and reinforcement;

[0009] Second rotifer disinfection and enhancement: The rotifers collected from the pond were disinfected with potassium permanganate solution (10 ppm) for 30 minutes, allowed to stand for 15 minutes to separate the impurities and dead worms that settled to the bottom, and then filtered with a 120-mesh net to filter out the impurities. The rotifers in the pond were transferred to a cultivation bucket with a rotifer density of 300-500 per milliliter. Bdellovibrio was sprinkled into the bucket, and 0.1 gram per milliliter of Schizochytrium and 500,000-1,000,000 cells per milliliter of golden algae were added to enhance the DHA content of the rotifers; 300,000-500,000 cells per milliliter of Nannochloropsis were added to enhance the EPA content of the rotifers; 100,000-200,000 cells per milliliter of Dunaliella salina were added to enhance the β-carotene content of the rotifers; and 100,000 cells per milliliter of Haematococcus pluvialis were added to enhance the astaxanthin content of the rotifers.

[0010] The third rotifer disinfection and reinforcement: Use formaldehyde or potassium permanganate solution for disinfection at a concentration of 10-15ppm for 30 minutes. After disinfection, use 200-300 mesh bags to collect the rotifers. After collection, rinse with disinfected water. Place the clean rotifers in a bucket, add probiotic solution to the bucket, and micro-aerate for 15 minutes before feeding.

[0011] The disease prevention and control of Artemia nauplii and multi-nutrient enhancement include:

[0012] Shelling Artemia eggs: Soak Artemia eggs in 5% sodium hypochlorite solution at a ratio of 1 gram of Artemia eggs to 5 ml of sodium hypochlorite solution. Add calcium hydroxide appropriately during soaking. When the eggs turn orange-red, rinse them and then add excess vitamin C to neutralize them. Then wash with disinfected water.

[0013] Artemia egg hatching: The temperature of the water environment for hatching is 30 degrees Celsius, the salinity is 25-30, and the pH value is maintained at 8.1-8.4;

[0014] Artemia nauplii enhancement: After hatching and breaking the membrane, collect them and transfer them to the enhancement tank for nutritional enhancement. Add 100-200ppm of Schizochytrium truncatum and 200,000-500,000 per milliliter of golden algae or Chaetoceros truncatula to the tank.

[0015] Further disinfection of Artemia nauplii: After strengthening, they are collected using 120-160 mesh bags, disinfected with potassium permanganate solution, rinsed with disinfected water, and then fed.

[0016] The present invention is further configured as follows: the disinfection and strengthening time of each of the first to third rotifer disinfection and strengthening is 12-16 hours.

[0017] The present invention is further configured such that the strengthening time of the Artemia nauplii is 12-16 hours.

[0018] The present invention is further configured as follows: the disease prevention and control and multi-nutrient fortification of the rotifer are applied to the biological bait feeding of crab seedlings in the flea stage 1 to flea stage 2.

[0019] The present invention is further configured as follows: the disease prevention and control of Artemia nauplii and multi-nutrient fortification are applied to the biological bait feeding of crab seedlings in the stage of larvae from 3rd stage to megalopause stage.

[0020] The present invention is further configured as follows: in the Artemia egg incubation step, 5-10 ppm of formaldehyde is added during the incubation process for disinfection.

[0021] The present invention is further configured such that: during the first rotifer disinfection enhancement, the pond is thoroughly flushed with a bleaching powder solution of 200 grams per cubic meter.

[0022] The present invention is further configured such that, in the first rotifer disinfection and reinforcement, probiotics are added by spraying a microbial preparation in the pool.

[0023] In summary, the present invention has the following beneficial effects:

[0024] The present invention performs multiple disinfections on various stages of rotifers and Artemia nauplii, and performs nutritional fortification during the disinfection process. Compared with the prior art which simply performs one-time disinfection and nutritional fortification, the present invention can effectively eliminate pathogens that may exist in the living biological bait, and basically avoids the problem of crab seedling diseases caused by feeding the biological bait. At the same time, according to the nutritional needs of crab seedlings, especially the relatively high unsaturated fatty acids required by crab seedlings, the biological bait is targeted with multiple nutritional fortifications to better ensure the nutritional needs of crab seedlings. DETAILED DESCRIPTION

[0025] The present invention is described in further detail below.

[0026] This embodiment discloses a method for controlling diseases and multi-nutrient enrichment of biological bait for blue crab seedlings, which is applied to biological baits from the zoeae to megalopause stage of blue crab seedlings, and includes controlling diseases and multi-nutrient enrichment of rotifers and controlling diseases and multi-nutrient enrichment of Artemia nauplii.

[0027] Disease control and multi-nutrient enrichment of rotifers include:

[0028] First rotifer disinfection reinforcement:

[0029] First, disinfect the pond by thoroughly rinsing it with a 200-gram per cubic meter bleach solution. Then, add disinfected water to the pond. Disinfected water refers to water that has been disinfected to ensure that the pond and water itself are disease-free. Rotifers are then added to the pond at a density of 80-120 cells per milliliter. Chlorella and Nannochloropsis algae are added to the water at a concentration of 400,000-600,000 cells per milliliter. Appropriate amounts of probiotics and vitamins are also added to the water. By controlling the rotifer and algae densities, each rotifer is effectively nutrient-fortified. Chlorella and Nannochloropsis algae are rich in unsaturated fatty acids, particularly EPA and DHA, which are essential nutrients for crab fry growth and development. After nutrient enrichment, the rotifers provide these nutrients to the crab fry as a biological feed, ensuring their healthy development. Furthermore, the addition of probiotics allows the probiotics in the water to dominate, thereby inhibiting the growth of pathogens and eliminating them in competition. This approach essentially eliminates pathogens outside the rotifers.

[0030] Second rotifer disinfection and enhancement: transfer the rotifers in the pond into the cultivation barrel with a rotifer density of 300-500 per milliliter, sprinkle Bdellovibrio in the barrel, add 0.1 gram per milliliter of Schizochytrium, 500,000-1,000,000 cells per milliliter of golden algae, 300,000-500,000 cells per milliliter of Nannochloropsis, 100,000-200,000 cells per milliliter of Dunaliella, and 100,000 cells per milliliter of Haematococcus pluvialis; through the above settings, high-density disinfection and enhancement are carried out in the barrel, among which Bdellovibrio can parasitize and lyse pathogens, thereby clearing pathogens in the aquaculture water and aquatic animals and reducing pathogens, which further eliminates diseases in the rotifers. Schizochytrium and Chrysotrium are rich in docosahexaenoic acid (DHA, an important ω-3 polyunsaturated fatty acid) and γ-linolenic acid (GLA, an ω-6 fatty acid), respectively. DHA and GLA can effectively enhance the growth and development vitality of crab seedlings. By adding Schizochytrium and Chrysotrium to strengthen the diet, the content of DHA and GLA in rotifers can be significantly increased. By adding Dunaliella salina and Haematococcus pluvialis to strengthen the diet, the content of carotenoids and astaxanthin in rotifers can be significantly increased. The required nutrients can be further provided to crab seedlings in the form of biological bait to ensure their good growth and development.

[0031] The third rotifer disinfection reinforcement: disinfection is carried out using formaldehyde or potassium permanganate solution with a concentration of 10-15ppm and a disinfection time of 30 minutes. After disinfection, the crabs are collected using a 200-300 mesh net bag. After collection, they are rinsed with disinfected water and can be fed. Through the above method, after the first and second disinfections, the pathogens inside and outside the rotifers are basically eliminated. The last remaining pathogens are subjected to a final chemical disinfection before feeding. The residual pathogens are thoroughly eliminated by chemicals, achieving a good effect of disease prevention and control, and effectively avoiding the disease problems caused by the feeding of biological baits. At the same time, an appropriate amount of probiotic solution is added before feeding, and the probiotics mixed in the rotifers are directly ingested by the crab seedlings, promoting the absorption of nutrients and regulating the balance of intestinal microorganisms of the crab seedlings.

[0032] Disease control and multi-nutrient enrichment of Artemia nauplii include:

[0033] Artemia egg shelling: Soak Artemia eggs in 5% sodium hypochlorite solution, the ratio is 1 gram of Artemia eggs to 5 ml of sodium hypochlorite solution, add calcium hydroxide appropriately during soaking, wait until the eggs turn orange-red, rinse and then add excess vitamin C to neutralize them, and then wash with disinfected water; Artemia nauplii can be disinfected starting from Artemia eggs, so use strong alkali to directly remove the egg shell first to eliminate the pathogens that may be carried by the Artemia egg shell.

[0034] Hatching of Artemia eggs: After shelling, the eggs are hatched. The temperature of the water environment for hatching is 30 degrees Celsius, the salinity is 25-30, and the pH value is maintained at 8.1-8.4. Through the above environment, the Artemia eggs are kept in a suitable environment for hatching.

[0035] Artemia nauplii enhancement: After hatching and breaking the membrane, they are collected and transferred to the enhancement barrel for nutritional enhancement. 100-200ppm of Schizochytrium, 200,000-500,000 per milliliter of golden algae or Chaetoceros are added to the barrel; the Artemia is enhanced. Schizochytrium, golden algae or Chaetoceros play the same function as rotifer enhancement. The rich unsaturated fatty acids in different algae allow the rich unsaturated fatty acids in the Artemia to provide the crab seedlings with the nutrients they need for growth and development through the form of biological bait.

[0036] Furthermore, although the Artemia eggs are disinfected and shelled, in actual applications, pathogens still exist inside some Artemia eggs. Therefore, preferably, 5-10 ppm of formaldehyde can be added during the Artemia egg incubation process to ensure that any pathogens that may exist inside the eggs can also be eliminated.

[0037] Further disinfection of Artemia nauplii: After strengthening, the nauplii are collected in 120-160 mesh bags and disinfected with potassium permanganate solution. After disinfection, they are rinsed with disinfected water before feeding. Artemia nauplii are disinfected again before feeding to remove any remaining pathogens, achieving excellent disease control results.

[0038] Further as preferably, each disinfection strengthening time in the first rotifer disinfection strengthening to the third rotifer disinfection strengthening is 12-16 hours, and the time of Artemia nauplii strengthening is 12-16 hours; Its advantage is that, rotifer and Artemia nauplii are all significantly improved for the absorption of algae nutrients within the strengthening time of 12-16 hours, generally speaking, reach maximum value after 12 hours, therefore, to ensure good strengthening effect, get 12-16 hours to strengthen. Meanwhile, the strengthening time of 12-16 hours is suitable for large-scale production application, can reduce production cycle and improve efficiency while ensuring effect.

[0039] As a further preference, disease control and multi-nutrient enrichment of rotifers are applied to the biological bait feeding of crab seedlings in the flea stage 1 to flea stage 2.

[0040] As a further preference, the disease control and multi-nutrient fortification of Artemia nauplii are applied to the biological bait feeding of crab larvae from the stage of larvae 3 to megalopa.

[0041] The above-mentioned different biological baits are adaptively fed according to the growth status of crab seedlings at different stages, ensuring that the crab seedlings can be fed with disease-free biological baits fortified with multiple nutrients at different stages of their growth.

[0042] Furthermore, in the first rotifer disinfection and strengthening, a microbial preparation is sprayed in the pool to add probiotics. Among them, the microbial preparation may include but is not limited to Bacillus, yeast, photosynthetic bacteria and lactic acid. These probiotics can not only inhibit the growth and development of pathogens, but also assist the growth and development of live baits such as rotifers. For example, yeast can decompose organic matter in the water body, produce vitamins and amino acids, and provide nutrition for farmed animals. Photosynthetic bacteria can use light energy to carry out photosynthesis, produce oxygen, increase dissolved oxygen in the water body, and improve water quality. At the same time, they can also decompose organic matter and reduce the accumulation of ammonia nitrogen and nitrite. Therefore, the use of microbial preparations to add probiotics can achieve multiple goals at one stroke, and provide good help for disease prevention and control and multi-nutrient strengthening of biological baits.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the design concept of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling diseases of biological bait and multi-nutrient fortification for blue crab seedlings, which is applied to biological baits from blue crab seedlings to crablets, characterized in that: Including disease control and multi-nutrient fortification of rotifers and disease control and multi-nutrient fortification of Artemia nauplii; The disease control and multi-nutrient fortification of the rotifer include: The first rotifer disinfection reinforcement: Pond disinfection: add disinfected water to the pond, add rotifers, the density of rotifers is 80-120 per milliliter, add Chlorella and Microchlorophyll to the water, the concentration of algae is 400,000-600,000 cells per milliliter, and add appropriate amount of probiotics to the water; at the same time, add vitamin B120.1 ug / L, vitamin D30.1 ug / L, and vitamin C 1mg / L to the water; during the rotifer cultivation period, 10% of the water in the pond is siphoned daily for secondary disinfection reinforcement; Second rotifer disinfection and strengthening: The rotifers collected from the pond were disinfected with potassium permanganate solution (10ppm) for 30 minutes, left to stand for 15 minutes to separate the impurities and dead worms that sank to the bottom, and further filtered the impurities with a 120-mesh net. The rotifers in the pond were transferred into a cultivation bucket with a rotifer density of 300-500 per milliliter. Bdellovibrio was sprinkled in the bucket, and multi-nutrient strengthening was performed: 0.1 gram of Schizochytrium per liter and 500,000 to 1,000,000 cells per milliliter of Chrysotrione were added to strengthen the DHA content of the rotifers; 300,000 to 500,000 cells per milliliter of Nannochloropsis were added to strengthen the EPA content of the rotifers; 100,000 to 200,000 cells per milliliter of Dunaliella were added to strengthen the β-carotene content of the rotifers; Haematococcus pluvialis was added to strengthen the astaxanthin content of the rotifers; The third rotifer disinfection and reinforcement: Use formaldehyde or potassium permanganate solution for disinfection, the concentration is 10-15ppm, the disinfection time is 30 minutes, and after disinfection, use 200-300 mesh bags to collect them. After collection, rinse them with disinfected water, place the clean rotifers in a bucket, add probiotic solution to the bucket, and micro-aerate for 15 minutes before feeding; The disease control and multi-nutrient fortification of Artemia nauplii include: Artemia egg shelling: Soak Artemia eggs in 5% sodium hypochlorite solution, with a ratio of 1 gram of Artemia eggs to 5 ml of sodium hypochlorite solution. Add calcium hydroxide appropriately during soaking. When the eggs turn orange-red, rinse them and then add excess vitamin C to neutralize them, and then wash them with disinfected water. Artemia egg hatching: The temperature of the water environment for hatching is 30 degrees Celsius, the salinity is 25-30, and the pH value is maintained at 8.1-8.4; Artemia nauplii enhancement: After hatching and breaking the membrane, collect and transfer to the enhancement barrel for nutritional enhancement. Add 100-200ppm of Schizochytrium, 200,000-500,000 per milliliter of golden algae or Chaetoceros into the barrel; Further disinfection of Artemia nauplii: After strengthening, they are collected using 120-160 mesh net bags, disinfected with potassium permanganate solution, rinsed with disinfected water, and then fed.

2. The method for biological bait disease control and multi-nutrient enrichment for blue crab seedling cultivation according to claim 1, characterized in that: The duration of each disinfection and strengthening from the first disinfection and strengthening of rotifers to the third disinfection and strengthening of rotifers is 12-16 hours.

3. The method for biological bait disease control and multi-nutrient enrichment for blue crab seedling cultivation according to claim 1, characterized in that: The Artemia nauplii strengthening time is 12-16 hours.

4. The method for biological bait disease control and multi-nutrient enrichment for blue crab seedling cultivation according to claim 1, characterized in that: The disease prevention and control of rotifers and multi-nutrient fortification are applied to feeding biological baits of crab seedlings in the 1st to 2nd stages.

5. The method for biological bait disease control and multi-nutrient enrichment for blue crab seedling cultivation according to claim 1, characterized in that: The disease prevention and control of Artemia nauplii and multi-nutrient fortification are applied to feeding biological baits of crab seedlings in the stages of larvae 3 to megalopa.

6. The method for biological bait disease control and multi-nutrient enrichment for blue crab seedling cultivation according to claim 1, characterized in that: In the Artemia egg hatching step, 5-10 ppm of formaldehyde is added during the hatching process for disinfection.

7. The method for biological bait disease control and multi-nutrient fortification for blue crab seedling cultivation according to claim 1, characterized in that: In the first rotifer disinfection enhancement, the pond was thoroughly flushed with a 200 g / m3 bleach solution.

8. The method for biological bait disease control and multi-nutrient enrichment for blue crab seedling cultivation according to claim 1, characterized in that: In the first rotifer disinfection enhancement, the probiotics are added by spraying the microbial preparation in the pond.