23. What are the common causes of bottom odor? How to prevent underodour?
Common causes of underodour:
(1) The depth of aquaculture water is disconnected from the oxygenation capacity, resulting in insufficient dissolved oxygen in the bottom layer and odor in the bottom mud. For example, ponds with a water depth of more than 1.5 m only have waterwheel-type aerators, so the dissolved oxygen at the bottom of the pond is often insufficient.
(2) The amount of bait is large and the feed utilization rate is low. Under normal circumstances, shrimp can be eaten in about ten minutes, and excessive feeding causes shrimp indigestion, so that there is a large amount of residual bait or feces in the sediment, which is easy to stink.
(3) Sand bottom pond, due to the large sand particles, the relative surface area is small, the ability to adsorb harmful substances such as ammonia is poor, and it is easy to stink.
(4) The water is thin or aging pond, the algae photosynthesis is poor, not only the dissolved oxygen is low, but also the degradation rate of harmful substances is slow, and the sediment is easy to stink.
(5) Improper medication, such as the frequent use of disinfectants, the destruction of the self-purification ability of water bodies, and the accumulation of harmful substances such as ammonia nitrogen at the bottom.
(6) Often use zeolite powder, charcoal and other adsorption-based "bottom reform" products, resulting in a large number of harmful substances deposited in the substrate, the sediment is also prone to odor.
Ways to prevent underodor:
(1) Try not to raise shrimp on the sand bottom, or change the sand bottom to a sediment bottom.
(2) Bottom aeration, increasing the redox potential of the bottom sludge, and promoting the reproduction of beneficial algae are better ways to prevent bottom odor.
(3) The feeding method of a small number of meals is combined with appropriate stopping.
(4) Frequent feeding with micro-ecological preparations to improve the conversion rate of bait.
(5) Prevent blind medication.
(6) Replace adsorbent bottom modification products with degradable bottom modification products such as "bottom change 20" or "super sulfur bottom change".
24. What are the causes of shrimp swimming ponds? What countermeasures should be taken?
(1) Nutritional swimming pond.
Shrimp flocks have directional swimming ponds, sometimes in the middle of the water, sometimes on the surface of the water, and if some bait is thrown into the pond, many shrimp will stop feeding.
Countermeasures: At the seedling stage, it is recommended to release seedlings in fertilizer and water, and the microorganisms and algae in the water body should be cultivated as soon as possible, and the bait should be fed 2-3 times a day. In the process of breeding, the feeding amount should be flexibly adjusted according to the individual size of the shrimp, weather changes, water quality and substrate conditions, shrimp health status, the actual feeding amount of shrimp and other factors, so as to achieve reasonable feeding; In the middle and late stages, more artificial compound feed should be fed to meet the nutritional needs of shrimp.
(2) Shrimp stress ponds caused by mutations in environmental factors:
When high temperature, cold wave, heavy rain, strong wind, typhoon, due to the shallow shrimp pond, the polluted pool bottom is easy to be disturbed,
Sudden changes in physical and chemical factors or excessive toxicity factors in the water environment of shrimp ponds cause a large number of algae to die, the pond water suddenly becomes clear, or the composition of plankton changes (that is, "water transfer"), and the water quality deteriorates. In practice, it has also been found that if the rainy day lasts for more than 10 days, the sun is strong after the sun turns sunny, so that the water body suddenly thickens, this situation will also cause the shrimp to produce stress swimming ponds. In the pond where the pond appears, the pathogenic bacteria are concentrated at the bottom of the pond and are easily activated and proliferate in large quantities, while the shrimp are weak, which provides an opportunity for the pathogen to take advantage of the void and easily induce shrimp disease.
Countermeasure:
(1) On rainy days or 2 days before the typhoon, inject new water to increase the water level of shrimp ponds; Sprinkle a small amount of hydrated lime along the pond wall, soak the "Beneficial Algae Fertilizer Water Treasure" + "Amino Acid Fertilizer Water Paste" for 2 hours and then sprinkle the whole pool to maintain the balance of the bacterial phase and the algae phase during the wind and rain.
(2) During the rain, the aerator must be turned on sufficiently, and the amount of feeding must be reduced, and the "net detoxification" + "vitamin C sodium powder" must be sprinkled throughout the pool to detoxify and resist stress.
(3) After rain, use "net detoxification" or "detoxification blue wave bay" + "algae fertilizer water treasure" to sprinkle the whole pond in small quantities, which can not only ensure that the water color is good and unchanged on rainy days and typhoon days, but also prevent the occurrence of hypoxia, floating head, bottoming and stealing death, so that the shrimp can stabilize the wind and rain days.
(3) Hypoxic swimming pond:
In the process of breeding, when the dissolved oxygen in the water body is insufficient, the shrimp will float in groups to the surface of the water with more dissolved oxygen to breathe oxygen, which is a phenomenon of hypoxia swimming pond (commonly known as floating head). Pond swimming due to lack of oxygen occurs at all stages of culture, due to the high density of pond culture, excessive bait, deterioration of pond water, dark or excessive water color, and is very prone to occur after thunderstorms in the evening. Swimming ponds mostly occur in the early hours of the morning, sometimes in the first half of the night, and even during the day. Farmers can be diagnosed according to the weather and water quality.
Countermeasures: (1) Immediately turn on the aerator to increase oxygenation. (2) The oxygenator is sprinkled on the concentrated place of the floating head. (3) Fill the pond with fresh water or use a sprinkler to spray water for oxygenation. (4) Stop feeding during the floating head, and then feed it after the dissolved oxygen condition has completely improved.
(4) Shrimp swim in groups on the surface of the water, have direction, and do not sink for a long time.
The content of organic matter, ammonia nitrogen, hydrogen sulfide, nitrite and heavy metal ions is too high, the dissolved oxygen of the water is low, and the water quality is poor. If it is not treated early, the immunity of shrimp will be reduced, and as soon as there is a bacterial viral infection, it will become sick and die.
Countermeasures: This kind of situation first uses "net detoxification" or "detoxification blue wave bay" detoxification and water transfer, and then "vitamin C sodium powder" + "algae fertilizer water treasure" mixed with the whole pool, after treatment according to this method, the shrimp not only do not swim in the pool, but also appetite, activity ability and so on will soon return to normal.
(5) The pH value is too high or too low, and the swimming pond caused by abnormal algal phase or bacterial phase.
When the pH value is lower than 6.5, the shrimp respiratory rhythm is accelerated, the metabolic frequency increases, and the acidic water can reduce the blood pH of the shrimp, and the partial pressure of oxygen in the blood is reduced, resulting in the dysfunction of hemoglobin in transporting oxygen, reducing its oxygen carrying capacity, resulting in hypoxia in the tissue, resulting in a swimming pond phenomenon similar to the occurrence of hypoxia in water bodies. When the pH of the water body is greater than 10, the gills of the shrimp are damaged, and the ventilator function is impaired, resulting in shrimp suffocation swimming pond.
Countermeasures: Many farmers neglect to regulate the pH value of pond water, resulting in the frequent occurrence of shrimp swimming ponds due to discomfort in pH values. Therefore, during the breeding process, the pH should be monitored daily. When the water quality is acidic, it should be treated with quicklime in time, and added several times according to the amount of 3-5 kg/mu; When the water quality is alkaline, drain 20-30 cm of pool water, return 20-30 cm of new water, and then "purify the spirit" or "detoxify blue wave bay" + highly concentrated composite spore water.
(6) Swimming pond caused by disease
Shrimp infected with diseases such as leukoplakia, fluorescent, rotten gills and so on can cause swimming pools. Sick shrimp in action is manifested as slow swimming or wild swimming on the surface of the water, swimming alone and not in groups, when artificial stimulation, slow response, sometimes whirling on the surface of the water or no directional upstream and downstream movement, some creeping or lying on the side of the shallow water; The most obvious feature is that shrimp swimming pond often has various typical pathological features on the body surface, gills, liver and pancreas, gastrointestinal and other tissues. Encountering this situation is a precursor to the occurrence of a large number of shrimp diseases, and should be closely observed, carefully examined for sick shrimp, and the right medicine is prescribed after diagnosis, so as not to cause greater harm. Countermeasures: When the day is bad or when the infection is mild, use the bacteriophage Vibrio preparation + "shrimp and crab AD calcium" for two consecutive days; At the same time, take antibacterial drugs internally and pour "vitamin C sodium powder" externally.
(7) Physiological swimming pond
On the first and fifteenth day of the first month, when the moon is missing and the tide rises and falls, the shrimp will move frequently with the change of tide. This kind of swimming pond is not very strong, has a certain cycle and habituation, and at the same time appears molting phenomenon. Such swimming ponds belong to physiological swimming ponds, which are generally harmless, but they are in the molting stage, and the incidence of shrimp caused by insufficient dissolved oxygen should be prevented.
Countermeasures: Drainage of more than 30 cm when swimming in the pool, rapid addition of water to reset, stop feeding, promote the synchronous molting of shrimp, and sprinkle "shrimp and crab AD calcium" to promote growth; At the same time, oxygenation is increased to ensure that the pool water has sufficient dissolved oxygen.
25. How to deal with algal phase mutations ("inverted algae" or "water transfer")?
In the early stage of breeding, "inverted algae" appeared, which is the lack of nutrient salts in the water body, and the "beneficial algae fertilizer water treasure" + "amino acid fertilizer water paste" was mixed to soak and topdress the algae, maintaining transparency of about 30 cm. In the later stage of breeding, "inverted algae" appears, indicating that the water quality is aging, and the surface water should be drained 20 cm first, using "net detoxification spirit" or "detoxification blue wave bay", the next day "beneficial algae fertilizer water treasure" fertilizer water, while "changing the bottom 20" a small number of times to change the bottom, for 3 consecutive days, and add water to the original position.
26. How to deal with the death caused by the failure of the shrimp molting?
Some shrimp die before molting (molting), and some die after molting (physical exertion, soft shell does not harden).
Cause 1: Shrimp are infected with chronic diseases, eat less, have a weakened constitution, and physical exhaustion when molting, resulting in death.
Countermeasures: Sprinkle the whole pool with Vibrio phage preparation + "shrimp and crab AD calcium" and use it two to three times, while taking the antibacterial drug internally for three to five days, two to three times a day.
Cause 2: poor water quality, deterioration of substrate, pond water in a long-term low dissolved oxygen condition, or low dissolved oxygen at night, the content of harmful substances under the water is too high, shrimp are in a highly stressed state, powerless to molt.
Countermeasures: Use "Net Detoxification" or "Detoxification Blue Wave Bay" to transfer water in the morning, use "transsulfur bottom change" + "oxygenator tablet" to change the bottom in the afternoon, and use "shrimp and crab AD calcium" to sprinkle the whole pool the next day.
Cause 3: Calcium deficiency in feed or disorders in calcium metabolism in shrimp bodies, resulting in difficulty in molting.
Countermeasures: Strictly control the quality of feed, choose a high-quality feed with comprehensive nutrition, and sprinkle "vitamin C sodium powder" + "shrimp and crab AD calcium" in the whole pool.
Reason 4: Shrimp and crabs have algae attached to their bodies, and when ciliates parasitize, they will affect the molting shell.
Countermeasures: Use "transsulfur bottom change" + "rhubarb five-fold dispersion", and then use "vitamin power" + "shrimp and crab AD calcium" to restore physical fitness.
In view of the above reasons, in order to prevent the outbreak of molting, the following points should be noted:
1. "Vitamin power" + "shrimp and crab AD calcium" is often added to the feed.
2. Sprinkle "shrimp and crab AD calcium" in the water body once every half a month.
3. Commonly used "transsulfide bottom modification" to prevent ciliates.
4, high temperature season, especially in the middle and late stages, to maintain the water body has sufficient dissolved oxygen. At the peak of the molting shell, more oxygenation, water level should be reduced in an appropriate amount, less water replacement, to prevent excessive stress caused by molting.
27. How to set up the material table, how to deal with the dirty material table?
The feed table is a standard for us to test the shrimp feeding, but the feed table is sometimes inaccurate.
The main reasons:
(1) The material table is too small, at least 1 per acre.
(2) The material table is too dirty, the material table is dirty, reflecting that one is a waste of shrimp, and the bottom of the pool is also dirty, you can use the "sulfur bottom change" to change the bottom, even used two to three times, you can put it in the material table, the material table can become clean.
(3) The position of the table is not correct. Therefore, in order to accurately reflect the real situation of shrimp pond material, it is recommended to change the position frequently.
28. How to deal with hypoxia?
80% of the oxygen in the water body is produced by algae, 10% of the oxygen is about the aerator, and the remaining 10% of the oxygen is generated by the diffusion of the molecules in contact with the air in the horizontal plane and the addition of water and drainage in our daily management. 80% of the oxygen in the water body is consumed by algae, zooplankton and organic matter, and only 20% of the oxygen is used by shrimp. Therefore, the main reason for the lack of oxygen in water is caused by the aging of algae and too much organic matter. The next morning after hypoxia, it is necessary to use "net detoxification" or "detoxification blue wave bay" + "amino acid fertilizer water paste" in time to adjust water, in the afternoon with "over-sulfur bottom change" or "bottom change 20" to change the bottom, at night with granular oxygen oxygen, a small number of times to use two or three times, hypoxia symptoms alleviated.
29. In the evening, the shrimp jumped into the pond, the shrimp body was red, the eyes were bright and red, what was the reason for climbing the sand?
Shrimp farming to the middle and late stages, the density of shrimp becomes larger, the organic matter pollution at the bottom of the pond is aggravated, especially in the middle and late stages of the water temperature and high bottom fermentation is serious, resulting in low dissolved oxygen at the bottom, increased toxic substances, acidic bottom water, environmental degradation, easy to produce stress, so once stimulated by the outside world| (such as sound, vibration, light, etc.), the shrimp will jump out of the water. If the lack of oxygen at the bottom of the pond is not serious, the shrimp will have local jumping ponds at night; If the lack of oxygen at the bottom of the pond is severe, the shrimp will crawl in the upper water and crawl on the edge of the pond, and the shrimp will jump more severely. At this time, you can first use "net detoxification" or "detoxification blue wave bay" to detoxify and adjust the water in the morning, and then use "transsulfur bottom change" + "oxygenator tablet" to change the bottom, and use an oxygenator to oxygenate at night; According to the situation, you can sprinkle "vitamin C sodium powder" + "shrimp and crab AD calcium" at any time to alleviate symptoms.
30. Why are dead shrimp easy to die in the middle and late stages?
Shrimp in the growth process to continue to shell in order to grow, the more times the shrimp shell in the pond molting, the faster the shrimp growth rate, in our breeding environment, many shrimp shell is not a normal physiological cycle of shelling, many are because of stress and caused by abnormal shelling, so that the shrimp in the process of molting excessive consumption of energy, damage to the physique;
Ponds that do not often molt shrimp material accumulation, grow well, but not grow the largest, and frequent shelling of shrimp material energy accumulation is insufficient, although the growth is the largest, but the physique is also the worst; We can also find that the largest shrimp in the material table is often not the most beautiful shrimp, but those medium-sized shrimp have the best physique, which is why most of the deaths are relatively weak prawns who die first. In addition, this phenomenon shows that most shrimp are diseases of bacterial disease or sepsis caused by bacteria when they occur, not mainly viral diseases, and the death of viral disease shrimp is often dominated by small shrimp with poor resistance.
31. In the process of breeding, what is the reason why there are often shrimp shells floating at the tail of the wind?
This phenomenon, common in the middle and late stages of aquaculture, usually has two reasons for this phenomenon: (1) the pond bottom is seriously polluted, the pond bottom becomes dirty, hypoxia, the pool bottom is unstable, and the shrimp shell floats up during the convection process of water. (2) The shrimp shell lacks calcium phosphorus salts, the density of the shrimp shell is small, and the long-term physique is poor, the effective shell of the shrimp shell is insufficient, and the shrimp shell becomes lighter.
Countermeasures: Change the bottom with "bottom change 20" or "over-sulfur bottom change", once every other day, and use it 2-3 times. "Net detoxification" or "detoxification of Blue Wave Bay" + "lactic acid bacteria" water transfer, accelerate the metabolism of water substances, energy circulation, reduce water convection back to the bottom. At the same time, it is sprinkled with "vitamin C sodium powder" + "shrimp and crab AD calcium" to promote the absorption and utilization of calcium and phosphorus salt by shrimp.
22. There is a lot of foam around the aerator or the water streaks cannot be dispersed, what is the reason?
This kind of water body often occurs in the middle and late stages of the water body or after the inverted algae, this water body suspended particles more organic matter, more oxygen-consuming substances, the surface tension of the water body is large, then the circulation metabolism of the water body is not smooth, the general water color is dark, thick, mainly naked algae and cryptoalgae. Mainly due to (1) the increase in residual bait and manure brought about by the increase in feed feeding, which increased the organic matter in the pond. (2) The shrimp activity ability is strengthened or irritable due to discomfort, stirring the bottom mud, the organic matter at the bottom of the pond floats, increasing the content of organic matter in the water body.
Countermeasures: "Net Detoxification" or "Detoxification Blue Wave Bay" + "Lactic Acid Bacteria" water transfer, using "change the bottom 20" or "over-sulfur bottom change" to change the bottom.
33. How to deal with high nitrite on rainy days?
Rainy days material metabolism energy flow rate is slow, algae metabolism rate slowed down, at this time high nitrite is mostly because the supply rate of nitrogen-containing compounds is greater than the water conversion and utilization speed, coupled with the lack of oxygen on rainy days, nitrite is difficult to be converted into nitrate, so it is difficult to reduce the accumulation of nitrite, if at this time forcibly reduce nitrite or forcibly transfer nitrite to the bottom of the pond, it is bound to break the original balance, causing water instability, resulting in disease.
Countermeasure:
(1) Reduce feeding or stopping (individual ponds with serious height). Reduce the supply of nitrogen-containing compounds and reduce the accumulation of nitrogen sources.
(2) Regular use of "net antidote" or "detoxification blue wave bay" to reduce the impact on shrimp caused by high nitrite.
(3) Frequent use of "persulfur bottom modification" + "oxygenator" to change the bottom, control the increase of nitrite at the bottom of the pond, and promote the conversion of nitrite into nitrate.
34. What problems will occur when adding materials?
If the feeding is too strong, the shrimp liver is easy to swell, easy to get enteritis, and at the same time, the burden on the liver will increase, the feces will increase, and it is easy to destroy the substrate and water quality. Therefore, when adding materials, adhere to the principle of less diligence and overtime,
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35. Shrimp death and prevention
Incidence:
"Death stealing syndrome", also known as "death syndrome", is also often referred to as "death stealing disease". It is mainly based on the fact that there are no obvious signs when the disease occurs, and the outbreak of the disease is the result of the comprehensive action of many factors, caused by pathogens, environmental stress, early nutrition of shrimp fry and other factors. Death syndrome is easy to occur in high-density shrimp ponds with deteriorating water quality and substrate, and the annual incidence time is generally in August to October, usually the water temperature is above 28 °C, and the breeding time is 60-80 days.
At the beginning of the disease, generally every day at the bottom of the pool, especially around the aerator can find several pounds of dead shrimp, as the water quality continues to deteriorate, the number of dead shrimp multiplied, in the molting period of the formation of a peak period of death, if not controlled, the phenomenon of death will continue until the shrimp harvesting season, or even harvest.
Causes:
First, there are pathogenic bacteria in the pond, with the increase of temperature, the amount of bait increases, the water quality is easy to deteriorate, the resistance of shrimp is reduced, and pathogenic bacteria multiply in large quantities, which in turn infects shrimp. Second, with the deterioration of the environment, shrimp are prone to stress response, once the shrimp resistance declines or is in the molting stage, if the environment continues not to improve, it will cause shrimp death.
Prevention and control methods:
(1) Management must be strengthened to prevent problems before they occur. Usually, attention is paid to the improvement of pond water quality and substrate. Regularly alternately use the "bottom change 20" or "over-sulfur bottom change" to change the bottom, timely decompose the bait and feces accumulated at the bottom, eliminate the production of toxic and harmful substances such as nitrite and hydrogen sulfide from the root, and also greatly reduce the possibility of the large number of pathogenic bacteria at the bottom of the pond. If the shrimp are dirty, consider whether there are ciliates attached.
(2) To enhance the resistance of shrimp, regularly sprinkle "vitamin C sodium powder" + "shrimp and crab AD calcium" to improve the immunity of shrimp.
(3) Enter the high temperature period, disinfect the shrimp pond regularly, and try to use a mild compound iodine solution. If you encounter sudden changes in the weather, sudden deterioration of water quality, etc., it is necessary to use "net detoxification" or "detoxification blue wave bay" to transfer water in time, and sprinkle "shrimp and crab AD calcium" in the water to improve the stress resistance of shrimp, minimize the casualties of shrimp, and prevent the production of soft shell dead shrimp.
(4) Control of the amount of bait. According to the weather, the amount of remaining bait, as well as dissolved oxygen and water environment, the amount of bait should be adjusted in time.
(5) If the chemical indicators such as nitrite and ammonia nitrogen of water quality are high, drain 20 cm of bottom pool water on the first day, fill part of the new water, and then sprinkle "net detoxification" or "detoxification blue wave bay" to divert water and detoxify. The next morning, use the "bottom change 20" to change the bottom, and sprinkle "vitamin C sodium powder" + "shrimp and crab AD calcium" in the afternoon to improve the immunity of shrimp.
(6) If the muscles of the dead shrimp are white and turbid, accompanied by carapace ulcers and broken whiskers, it is necessary to consider whether it is caused by pathogenic bacteria infection. Detoxification and water transfer should be accompanied by internal antibacterial drugs to control bacterial and viral infections.
36. Causes and countermeasures of shrimp red body
Cause 1 Stress red body
When various environmental factors in the water body change, such as temperature, pH, salinity, nitrite, ammonia nitrogen, weather mutations, shrimp in order to adapt to environmental changes, physiological changes in the red body, tentacles, tail fans, appendages, etc. redness. In addition, man-made fishing can also cause stress red bodies for shrimp. Especially in the hot and rainy summer, the weather sudden changes, after the rainstorm, a large amount of drainage water, etc. often causes the shrimp to have a stressed red body.
countermeasure
When the environment has a sudden change, such as after a rainstorm, after a sudden change in temperature, etc., timely sprinkle "vitamin C sodium powder" or "shrimp and crab AD calcium" in the water body to improve the anti-stress ability of shrimp, if the water body appears to pour algae, it is necessary to cooperate with the "beneficial algae fertilizer water treasure" at the same time. After fishing and draining water, it is necessary to supplement "vitamin C sodium powder" or "shrimp and crab AD calcium" in time to enhance the adaptability of shrimp to the environment, improve the vitality of shrimp, and prevent secondary bacterial and viral invasions.
Cause 2 Bacterial erythematous body
Mainly due to Vibrio parahaemolyticus infection. The appendages of diseased shrimp become red, especially the swimming feet, usually the body will become red, the shell will become hard, and the contours of the liver and pancreas are not clear. Sick shrimp have poor vitality, swimming slowly or at the bottom of the water, sometimes rotating or swimming vertically, unresponsive, anorexia.
countermeasure
Usually, it is necessary to strengthen the bottom reform of the pond, transfer water, and regularly disinfect to prevent the breeding of a large number of pathogenic bacteria. After the onset of the disease, the whole pool of compound iodine solution is sprinkled with disinfection, and then the "vitamin C sodium powder" or "detoxification blue wave bay" is used to divert water and detoxify. If you are seriously ill, you should take antibacterial drugs internally.
Cause 3 Viral red body
It is mainly manifested as the red whiskers, red tail and red body of the diseased shrimp, and the diseased shrimp eat less or no food, swim slowly on the surface of the water, and die quickly after being fished away from the water body. The carapace of the diseased shrimp becomes soft, separates from the muscles, is easy to peel off, and basically has no red legs. The contours of the liver and pancreas are very unclear, swollen, and eroded.
countermeasure
The key to preventing viral diseases lies in maintaining the stability of water bodies, improving the disease resistance of shrimp, and minimizing precipitating factors.
(1) In the high incidence season, do not drain the water when the nearby pond has the disease, drive away the water birds that stay by the pond, use the tools to disinfect in time, and do a good job in preventing infection.
(2) Do not use stimulant drugs, such as irritating disinfectants, insecticides, try to avoid incorrect medication.
(3) Regularly sprinkle "vitamin C sodium powder" + "shrimp and crab AD calcium" to enhance the disease resistance of shrimp, sprinkle "vitamin C sodium powder" or "detoxification blue wave bay" to stabilize water and detoxification, use "change the bottom 20" or "super sulfur bottom change" to change the bottom, and ensure that the dissolved oxygen is sufficient to reduce the precipitating factors.
(4) Appropriate reduction to reduce the infection of healthy shrimp in the pond.
The key to treating viral diseases is to keep the large number of non-diseased shrimp in the pond healthy, rather than to cure those sick shrimp that have been infected with the virus and are on the verge of death. Treatment is targeted according to the stage of onset of the viral disease.
Early onset: a small number of shrimp swimming ponds are found, and when a small number of shrimp in the shrimp net die, timely reduce or do not feed, and cut off the source of infection by feeding sick shrimp by fish. Taking or sprinkling "stress VC" to enhance the disease resistance of shrimp, oxygenators are used at night to prevent hypoxia death. If bacterial disease is complicated, use a mild disinfectant and change the bottom with "transsulfide bottom change" the next day.
Peak of incidence: The number of shrimp in the pond gradually increases, and when there are many dead shrimp in the shrimp net, the feeding is stopped and the aeration is changed.
In the later stage of the disease: there are fewer and fewer dead shrimp, appropriately increase feeding, take antibacterial drugs internally, sprinkle "stress VC" + "shrimp and crab AD calcium", and the next day "supersulfur bottom change" + "aerobic tablets" to change the bottom, prevent secondary infection, and continue to have 1-2 courses of treatment. After waiting until there are no dead shrimp, strengthen nutrition, diseased shrimp return to normal state, sprinkle "vitamin C sodium powder" or "detoxification blue wave bay" to stabilize water and detoxification, and appropriately sprinkle micro-ecological preparations to restore water ecology.
37. How to deal with shrimp white stool disease
Incidence:
In recent years, farmed Penaeus vannamei has appeared in the phenomenon of jejunal white stool, and it has shown a trend of spread year by year, and the harm is more serious. Most shrimp begin to appear jejunum, empty stomach, swimming pond phenomenon after the occurrence of white stool, and continue to worsen the symptoms of shrimp crawling to steal death.
Symptoms:
At the beginning of the disease, only the amount of food eaten is reduced, and as the disease worsens, a large amount of floating white feces appears in the downwind outlet of the pond, shrimp will be accompanied by jejunum, broken intestine, liver and pancreas appear atrophy, the appearance is blurred. The main pathological changes are manifested by proliferation of cells in the submucosa of the intestine, detachment of epithelial cells; The proliferative and fibrotic cell layer falls off as a whole and can fall off multiple times, forming multiple white stools.
Etiology Analysis:
It is initially caused by bacteria, but with the development of the disease, the effect is not very obvious to the middle and late stages of drug control. It can be judged that in addition to bacteria, its pathogenicity is also related to the pond environment, such as changes in water quality and feeding on spoiled bait
The damage to the digestive function caused by the occurrence and the inverted algae caused by weather changes are all factors that induce aggravation of the disease.
Prevention and control methods:
On the first day, stop the material, use "net detoxification" or "detoxification blue wave bay" to stabilize the water to detoxify, and after 2 hours, "transsulfide bottom change" + "aerobic tablet" to change the bottom.
The next day, the feeding was reduced by 20%, antibacterial drugs (treatment course of 3-5 days) were added to the feed, with the original solution of Clostridium butyrate, and the "vitamin C sodium powder" + "shrimp and crab AD calcium" was sprinkled.
On the third day, a mild compound iodine solution is sprinkled to thoroughly disinfect the water.
38. Causes and prevention methods of shrimp bubble disease
In summer and autumn or when the temperature changes suddenly after the rain, the water body is overweight, the bubble disease is divided into acute and chronic, and the occurrence of bubble disease at the seedling stage will cause direct harm and obvious symptoms; Bubble disease is easily overlooked, it keeps farmed animals in a state of sub-healthy stress, triggering a range of other diseases (such as stealing death), or when other diseases occur, the presence of bubble disease aggravates the extent of other conditions. During the high temperature period, it often happens to flip the pond due to bubble disease.
Microscopic examination can reveal (1) many gill filament bubbles in the tail fan, and even bubbles at the body joints. (2) There is a lot of pigmentation, and many blue spots. (3) Concurrent ciliates. (4) Soft shell, jejunum, liver atrophy much. The analysis of high dissolved oxygen saturation at water temperature causes dissolved oxygen stratification, the upper layer of dissolved oxygen is too much, the bottom layer is hypoxic, and the shrimp is susceptible to bubble disease, thus inducing other complications. Bubble disease leads to slow dehulling, soft-shelled shrimp more, resulting in liver atrophy, jejunum and empty stomach.
After the appearance of bubble disease, the aerator is first turned on to accelerate the escape of supersaturated gases in the water body. Sprinkle "Net Detoxification" or "Detoxification Blue Wave Bay" + "Vitamin C Sodium Powder" + "Shrimp and Crab AD Calcium". "Net detoxification" or "detoxification of Blue Wave Bay" can break the surface tension of the water body, promote the release of gas into the air, "vitamin C sodium powder" + "shrimp crab AD calcium" anti-stress, enhance the physique of shrimp, the condition can be gradually alleviated. After the symptoms of bubble disease disappear in the second weather, disinfect with a compound iodine solution to prevent secondary bacterial infection.
39. Methods of prevention and treatment of soft shell disease.
The symptoms of penaeus vannamei soft shell disease are that the carapace is thin and soft, the shell is close to the flesh, sometimes there is water under the shell, the carapace is rough, and the sick shrimp is thin and weak, and the vitality is poor. Soft-shelled shrimp are not resistant to transportation and have low commodity value.
The causes of the disease are: (1) the feed fed is not comprehensive in nutrition, the proportion of calcium and phosphorus is unbalanced, or the feed feeding amount is insufficient for a long time, which is the main reason for the soft shell disease of South American white shrimp. (2) Improper use of certain pesticides directly leads to soft shell disease. (3) The content of heavy metal ions in the water body is too high, and the water quality deteriorates in the middle and late stages.
Solution: (1) Strictly control the quality of feed, choose a high-quality feed with comprehensive nutrition, and do not feed moldy expired feed.
(2) Add vitamin power and "vitamin C sodium powder" to the feed, and feed fresh feed appropriately. Depending on the specific situation of shrimp feeding, increase the amount of feeding.
(3) Strengthen water drainage, regularly apply bacillus, EM bacteria and other microbial live bacteria preparations, and often use active black soil to improve water quality and substrate.
40. Common diseases of shrimp gills.
In farming, the shrimp gills are an important indicator organ when shrimp occur, and the occurrence of many diseases will be manifested in the gills of shrimp. Today, I will share with you the analysis and prevention and control methods of gill diseases such as black gills, rotten gills and green gills of Penaeus vannamei.
Several common gill problems with shrimp:
1. Black gills: mostly caused by bacterial infections. Most of the gills of shrimp are black or tan. Microscopic examination can show clumps of filamentous bacteria attached to the gills or appendages, and most of the shrimp after bacterial infection do not eat or eat less.
2. Yellow gills: mostly caused by ciliate attachment. Shrimp can not be fed for a period of time, the shrimp body is rough, the starting table is fast away from the water when the side of the carapace is fluorescent, yellow feet, gill yellow, it is possible to start ciliates, as soon as possible microscopic examination to determine.
3. Green gills: mostly dead algae adhering to the gills after pouring algae can easily lead to green gills. Shrimp have difficulty breathing, and juvenile shrimp or shrimp with poor physique can lead to acute death due to lack of physical strength.
4, rotten gills: rotten gills is the most serious manifestation of Penaeus vannamei, generally because of Vibrio, aquaculture water quality and substrate pollution intensified, algae death leads to a large number of pathogenic bacteria multiplying, shrimp gill attachment increases, so that its gill tissue is damaged, rotten gills appear.
Prevention and control methods of shrimp gill disease:
1. Open the full aerator, increase the oxygenation, and ensure that the dissolved oxygen is sufficient.
2. Where there is a storage pond, water can be added appropriately, increasing the dissolved oxygen of the water body and regulating the water quality.
3. Divert water to reduce ammonia nitrogen and nitrite, keep the water quality refreshing, the pH value is stable in the relatively normal range, take the plate yellow loose liver protection internally, enhance the resistance of shrimp, help the detoxification and detoxification of the shrimp liver and pancreas, and solve the gill problem caused by the deterioration of shrimp water quality.
4, regular small number of multiple bacteria + fertilizer + algae seeds, the early bacteria less fertilizer, the later bacteria more fertilizer less, can be used 4-5 days once or once a week, the pond water is not enough fertility especially in the weather before the supplement of fertilizer bacteria.
5. Regular use of rhubarb pentaxer powder internal administration + sprinkling, effectively prevent ciliate parasitism, inhibit water bodies, shrimp body Vibrio, and promote the healthy growth of shrimp.