In September, the two festivals of white dew and autumn equinox were ushered in, and the whole country entered the season of summer and autumn conversion, as the proverb says, "After the white dew festival, the night is cold and hot", and the temperature difference between day and night is the characteristic of this period. After 6, 7 and 8 months of aquatic animal growth season, the breeding pond has accumulated a large amount of residual bait, feces, etc., and after continuous fermentation, it not only consumes the oxygen content in the water, but also causes the index of ammonia nitrogen and nitrite to increase. In the case of a large temperature difference in the pond water body, there will be convection up and down, causing harmful elements at the bottom of the pond to spread to all water bodies, which can easily lead to the occurrence of a variety of diseases of aquatic animals. In September, focus on the following aquatic animal diseases.
I. Disease prediction
(1) Diseases that may occur in fish
1, freshwater fish bacterial sepsis: can infect most freshwater fish, with a rapid course of illness, high mortality characteristics, especially the water temperature continues to be above 28 °C, after the high temperature season the water temperature is still maintained above 25 °C when the incidence is high, the disease can be spread through diseased fish, bacteria pollution of bait, utensils and water sources, birds prey on diseased fish can also cause the spread of disease between different breeding ponds, the country's freshwater fish farming areas need to focus on prevention and control.
2, koi herpes virus disease: mainly endanger carp and koi, the virus spreads rapidly, can infect carp and koi of all ages, resulting in a higher mortality rate, the appropriate water temperature of the disease is 23 ~ 28 °C (below 18 °C, above 30 °C will not cause death), mainly through the level of transmission. All carp and koi breeding areas need to focus on prevention and control.
3. Carp edema disease: mainly harmful to carp and koi, the water temperature of the disease is 7 ~ 28 °C, with the characteristics of acute onset and high mortality. The clinical symptoms of the diseased fish are lethargy, concave eyes, rotten gills, skin ulceration, etc., which are similar to the symptoms of koi herpes virus disease. All carp and koi breeding areas need to focus on prevention and control.
4. Bacterial enteritis disease: it is a high incidence of grass carp and bluefish, which can occur from fish species to adult fish, and carp and bighead carp also have a small amount of this disease. The water temperature above 18 °C began to circulate, and 25 to 30 °C is the peak of the epidemic, often complicated with bacterial gill rot disease, erythroderma, etc., resulting in a higher mortality rate. All grass carp and bluefish breeding areas need to focus on prevention and control.
5, wheel worm disease: is a large number of, a variety of wheel worm parasitized in the skin or gills of the fish body caused by the disease, mainly there are significant wheel worms, coarse spiny wheel worms, etc., is a more popular and harmful parasitic disease in China's fish farming production, fish farming areas throughout the country have occurred, in the continuous rainy weather to pay special attention to the outbreak of the disease.
6, anchor head loach disease: can cause harm to freshwater fish of all ages, especially to breeding fish the greatest harm, water temperature in 12 ~ 33 °C during the anchor head loach large number of reproduction, and cause disease, can be prevalent throughout the country, of which Guangdong, Guangxi and Fujian are more serious.
(2) Diseases that may occur in shrimp
1. Leukoplakia syndrome: the general water temperature is easy to erupt at 18 ~ 30 °C, and the main harm objects are Vannabin shrimp, Chinese shrimp, Japanese shrimp, etc., and the main coastal shrimp culture area needs to be key prevention and control. In addition, the main cultivation areas of Ke's original crawfish in Hubei, Jiangsu, Anhui, Jiangxi and other places also need to strengthen the prevention and control of the disease.
2. Dora syndrome: commonly known as red-tailed disease, which mainly harms Vanabin shrimp, occurs in the molting stage of shrimp, the sick shrimp do not eat or eat a small amount of food, the onset of shrimp tail fan redness, sub carapace skin appears punctate necrosis. It is usually prone to illness after a drastic change in temperature for 1 to 2 days, especially after the water temperature rises to 28 °C. All Vanabin shrimp farming areas across the country need to focus on prevention and control.
(3) Diseases that may occur in crabs
River crab enteritis: it is a common and frequent disease in river crab farming, especially in the rainy or high temperature season. The main causes of the disease are the deterioration of water quality, the deterioration of the substrate, and the lack of fresh food fed. All river crab farming areas need to pay attention to the prevention and control of the occurrence of this disease.
(4) Other types of diseases that may occur
1. Turtle intestinal hemorrhagic disease: also known as hemorrhagic intestinal necrosis, is a disease caused by hydrophilic aeromonas, which is widely prevalent in most turtle-raising areas in China, with the characteristics of rapid infection, fierce arrival, high mortality rate, and serious harm. The appropriate water temperature for the disease is 25 ~ 30 °C, and the turtle breeding area in southern China should pay closer attention.
2. Turtle mumps disease: in the early stage of the disease, a small number of turtles have leukoplakia symptoms on the dorsal carapace, which are easy to be ignored or misdiagnosed, and the diseased turtle has symptoms such as neck enlargement, body swelling, and organ bleeding. Gill adenitis is a disease that is quickly transmitted and has a high mortality rate. The disease mainly occurs during the growth period of juvenile and young turtles. The epidemic season is from June to September. The onset of the disease is most severe at water temperatures between 25 and 30 °C. All breeding areas should be strictly prevented and controlled.
In addition, freshwater fish generally farmed also need to pay attention to the prevention and control of gill rot disease, erythroderma, bacterial enteritis and ringworm disease. Tilapia needs to pay attention to the prevention and control of streptococcal disease and Luohu virus disease. Spotted catfish focuses on the prevention and control of catfish intestinal sepsis. Giant yellow croaker needs to focus on prevention and control to stimulate cryptonuclear worm disease. Shrimp also need to pay attention to the prevention and control of enteritis and vibriosis.
2. Prevention and control measures
(1) Adjust the water quality in a timely manner. Water can be changed and injected with new water to keep the pond water quality good and the dissolved oxygen sufficient. Appropriate use of microbial agents, water quality improvers and other methods to regulate water quality. The surface water temperature of the aquaculture pond in the south of China can still reach a higher temperature, and the excessive water temperature is not conducive to the growth of most cultured species, and the pond water level needs to be appropriately increased, which can make the water temperature suitable for the growth of aquatic animals and maintain the relative stability of water quality.
(2) Strengthen the management of feeding feed. It is necessary to ensure that the feed is fresh and does not deteriorate. After determining the amount of bait on a daily basis, the amount of feeding is reasonably arranged according to the weather, water temperature, water quality, fish eating, etc., so as to minimize the occurrence of residual bait, and the amount of bait is appropriately controlled during the treatment of fish diseases.
(3) Scientific use of aerators. Usually open the aerator for a period of time in the early morning of each day, and then open the aerator for 2 to 3 hours at noon to promote the exchange of water up and down, through the agitation of the aerator, so that the upper layer of dissolved oxygen high water body to the bottom layer, to ensure the balance of dissolved oxygen in the upper and lower layers of the entire pond. Frequently turning on the aerator can also break the temperature stratification of the water body, so that the farmed species are in the right temperature range.
(4) Appropriate supplementation of nutrition. The high temperature period is the high incidence period of aquatic animal diseases, and multi-dimensional, three-yellow powder, immune polysaccharides, etc. are added to the feed regularly to enhance the physique of aquatic animals and improve disease resistance.
1
Aquaculture disease prediction and forecasting in Guangdong Province
In September, there are more thunderstorms and typhoons in Guangdong Province, and the water temperature and temperature are higher, which is the high incidence season of aquaculture diseases, and it is necessary to do a good job in the prevention and control of diseases in advance. And we must pay attention to the wind and flood prevention measures, especially after the rainstorm, we must pay attention to the changes in various physical and chemical factors in the pond water quality, and timely regulation. Tilapia streptococcal disease, marine fish irritating cryptonuclear worm disease, shrimp acute hepatic and pancreatic necrosis syndrome (commonly known as "stealing death disease") are at the peak of the epidemic period, and the main breeding areas should strengthen the monitoring of these diseases, and take prevention and control measures in advance to prevent outbreaks.
First, the diagnosis of the disease
1. Freshwater aquaculture fish: prone to wheelworm disease, ringworm disease, anchorhead loach, bacterial sepsis, gill rot, enteritis, ulcer disease, nocardiosis and iridescent virus disease, etc., focusing on the breeding area of the province.
2. Grass carp: Fish fingerlings are prone to hemorrhagic diseases, focusing on the grass carp pond breeding area in the province.
3. Tilapia: prone to streptococcal disease. Focus on the aquaculture areas of western Guangdong and the Pearl River Delta.
4. Turtles: prone to mumps disease and red bottom plate disease, focusing on the breeding area of the Pearl River Delta.
5. Marine aquaculture fish: prone to irritating cryptonuclear worm disease and iridescent virus disease, focusing on coastal aquaculture areas.
6. Shrimp: prone to leukoplakia syndrome, hepatobatic necrosis syndrome, etc., focusing on high-density breeding areas such as western Guangdong and pearl river deltas.
2. Prevention and control measures
1. After a period of breeding, a large number of residual bait and excrement are deposited at the bottom of the pond, causing the deterioration of water quality, which is easy to induce various aquatic animal diseases. Appropriate use of microbial preparations, water quality improvers and other methods to regulate water quality, where conditions permit, water can be changed, filled with new water, keep the pond dissolved oxygen sufficient, do a good job in water quality regulation, maintain good water quality is the key measure to prevent diseases.
2, in the high temperature season, the maximum water temperature of the pond surface may reach about 34 °C, exceeding the normal growth of breeding species suitable water temperature, pond water temperature is too high is not conducive to the growth of most breeding species, in the high temperature season appropriately increase the pond water level, on the one hand, can obtain the appropriate water temperature, on the other hand can maintain the relative stability of water quality.
3, scientifically open the aerator, adhere to the early morning every day in time to start the aerator, noon and then open the 2-3 hours of aerator, promote the exchange of water up and down, through the agitation of the aerator, so that the upper layer of high dissolved oxygen water body to the bottom layer, to ensure the balance of dissolved oxygen in the upper and lower layers of the entire pond. The upper water temperature of the pond in high temperature weather is high, and the lower water temperature is low, and the phenomenon of water temperature stratification will occur, so another purpose of starting the aerator in high temperature weather is to break this delamination of the water body and keep the cultured species in the right temperature range as much as possible.
4, scientific adjustment of feed feeding amount and time, high temperature period at noon the upper water temperature increased significantly, so the morning can be fed early, afternoon and evening feeding, reduce the breeding caused by feeding caused by burns. The high temperature period is the high incidence period of aquatic animal diseases, and multi-dimensional, three-yellow powder, immune polysaccharides and other foods are added to the feed regularly to enhance physical fitness and improve disease resistance. With the great increase in the feeding volume of the farmed species, the growth rate is accelerated, and the water quality is easy to deteriorate during the high temperature period, the liver and gallbladder of the fish are under great pressure, so it is recommended to take hepatoprotective choleretic drugs regularly to increase the resistance of the fish.
Third, the prevention and control measures of major diseases
1. Prevention and stimulation of cryptonuclear worm disease: (1) The cage is reasonably set up so that the water flow exchange is smooth and the stocking density should be appropriate. (2) Feed artificial compound feed to reduce chilled fish and fresh fish as feed. (3) Freshwater soaking sick fish for 3 to 20 minutes. (4) Feeding multi-dimensional and immune enhancers and other nutrients to enhance nutrition and improve resistance.
2. Prevention of tilapia streptococcal disease: (1) reduce the feeding of bait, reduce the stocking density as much as possible, reduce stress factors and improve the breeding environment, increase the time to open the aerator, keep the pond dissolved oxygen sufficient, and conditionally reduce the water temperature appropriately. (2) Sprinkle microbial preparations and substrate improvers, adjust water quality, add multi-dimensional and immune enhancers to the feed to enhance physical fitness, and use less irritating disinfectants to disinfect the whole pool to control harmful bacteria in the water body.
3. Prevention of acute hepatoppancreatic necrosis syndrome of shrimp: (1) Disinfect the bottom of the pond with bromine-containing preparations. (2) According to the different salinity, polyculture is carried out with grass carp, leather-bearded catfish, American redfish or cobia. (3) In order to reduce the pH of the digestive tract of shrimp, it is recommended to feed 1-2 times a day with lactobacillus fermentation.
Disease prevention and control methods should be implemented according to the actual situation of the farmed species, under the guidance of professional institutions or technical personnel.
2
Aquaculture disease prediction and forecasting in Jiangsu Province
In September, entering the "white dew" and "autumn equinox" festivals, the temperature and water temperature dropped, the water environment was suitable for fish growth, feed feeding entered the peak period, and the growth rate of fish accelerated. However, the temperature difference between day and night increases, the water in the breeding pond changes drastically, the dissolved oxygen in the water decreases, and the residual bait and feces in the breeding pond are generally more, which is easy to cause the deterioration of water quality, and aquaculture has once again entered a period of disease proneness. Fish that have reached the market specifications should be caught and marketed in a timely manner, the density of breeding should be reduced, the prevention and control of fish diseases should be done, and the risks of breeding should be resolved.
1. Fish bacterial sepsis, enteritis, gill rot, hepatobiliary syndrome: the main breeding areas of freshwater fish need to focus on prevention and control.
2. Parasitic diseases such as fish anchorhead disease, ringworm, crucian carp sporidium and so on: the main breeding areas of freshwater fish need to be prevented and controlled.
3. Crucian herpes virus disease: focus on Yancheng, Taizhou, Yangzhou, Changzhou areas.
4. River crab gill disease, enteritis disease, trembling disease, etc.: focus on Suzhou, Taizhou, Yancheng, Nantong and other areas.
5. Shrimp vibriosis, leukoplakiavirus syndrome, hepatobatic and pancreatic necrosis, etc.: focus on the main shrimp farming areas such as Yancheng, Suzhou and Nantong.
1. Fish bacterial gill rot disease, red skin disease: mixing three yellow powder, allicin and other prevention; taking antibacterial drugs internally during treatment, purchasing national standard fishing drugs in strict accordance with the prescribed dosage.
2. Crucian herpes virus disease: :(1) Before the epidemic of the disease, add appropriate immune enhancers to the feed for immunoprophylaxis. (2) For common parasites on fish bodies and pathogenic bacteria isolated from diseased fish bodies, highly effective drugs are selected by using the method of drug susceptibility testing. Avoid stressful irritation caused by repeated and extensive use of various drugs on the farmed crucian carp. (3) Regulate pond water quality through chemical drugs and microecological preparations to optimize the breeding environment. (4) During the illness period, "shock" therapy can be adopted, no water change, no spilling of external drugs, no internal antibiotics, reducing or stopping feed feeding, adding an aerator, and maintaining sufficient dissolved oxygen in the water body. And in the appropriate amount of antiviral natural plant medicines added to the feed, the disease can be gradually alleviated,
3. Crucian carp spore disease: thoroughly clearing the pond and killing oligochaetes in the water body is one of the preventive measures. Myxosporidosis focuses on killing radiosporidium in water bodies and the prespore stage after the body infects fish. Treatment can use the national regulations for aquaculture Chinese herbal medicine, freshwater fish per cubic meter of water body each use of 100 through the crowd scattering 3g whole pond sprinkling, continuous use for 5 days. Or choose the nationally prescribed aquaculture treatment with antiprotozoal drugs. In terms of feeding, choose high-quality feed and feed reasonably to ensure that crucian carp can be fully fed and grow healthily.
4. Fish hepatobiliary syndrome: attention should be paid to the reasonable feeding of feed, thickness and fine collocation, the addition of Vc, immunogly polysaccharides and other immune capacity, to avoid excessive feeding of bait, nutritional imbalance.
5. Shrimp and crab ciliate disease: appropriate water change, bait, keep water quality, substrate clean, can prevent the occurrence of ciliate disease. If there are many parasites on the surface of shrimp and crabs, the whole pond of tea seed cake with a concentration of 10-15 grams per cubic meter can be sprinkled.
6. Black gills of river crabs: do a good job of water quality regulation, feed fresh bait, fine roughage reasonable collocation; appropriate amount of mixing multi-dimensional, immune polysaccharides and other effective disease prevention to enhance anti-stress ability and disease resistance.
3
Aquaculture disease prediction and forecasting in Hubei Province
Hubei Province entered the late summer and early autumn period in September, and the temperature difference between morning and evening was large. At this stage, the water temperature is suitable for the growth of aquatic animals, and the incidence and mortality rate of fish diseases will also be reduced.
1． Grass carp, silver carp, bighead carp, crucian carp, bream and other conventional fish are prone to gill rot, enteritis, red skin disease, printing disease and bacterial sepsis, and the main area of concern is the aquaculture area of Hubei Province.
2． Grass carp, silver carp and crucian carp are prone to wheelworm and ringworm disease, and the main area of concern is the aquaculture area of Hubei Province.
3. Yellow eels are prone to hemorrhagic diseases and enteritis diseases, and the main areas of concern are the main breeding areas such as Xiantao, Jianli and Honghu in Hubei Province.
(1) Preventive measures:
1． Strengthen the patrol of the pond and pay close attention to the dynamics of the fish.
2． Pay attention to adjusting the water quality, changing the water or filling it with new water at the right time.
3． Sprinkle the whole pool with quicklime once a month, with an average water depth of 1 meter and 15-20 kg of quicklime per acre.
4． Timely open the aerator to increase oxygenation and improve water quality.
5． Improve water quality with microecological agents.
6. Strictly do a good job of "four certainties".
(2) Prevention and control methods
1． For grass carp and other conventional fish bacterial gill disease, enteritis, erythroderma, bacterial sepsis, treatment of external use: chlorine dioxide, a one-time amount, per 1m3 water body 0.3 ~ 0.5g whole pool sprinkling. Internal administration: florfenicol, once, per 1 kg of body weight fish mixed feeding 15 ~ 20 mg feeding, 1 time a day, continuous use for 3 to 5 days.
2. Control measures for grass carp, silver carp, crucian carp wheelworm and ringworm disease: sprinkle with 0.7g/m3 copper sulfate and ferrous sulfate (5:2) mixture throughout the pond.
3. Treatment of yellow eel hemorrhagic disease: florfenicol or thiamphenicol can be used, 15 to 20 mg per 1 kg of body weight fish mixed and fed, once a day, for 3 to 5 days. Yellow eel enteritis can be fed with thiamphenicol, 7g per 1 kg of feed, during the epidemic season, once a day, for 5 days.
4
Prediction and forecasting of aquaculture diseases in Sichuan Province
September will enter the autumn "white dew" and "autumn equinox", the temperature in Sichuan Province gradually dropped, is expected to be between 18 °C and 33 °C, the water load force reached a peak, bait and metabolite deposits are more, pathogens are easy to breed, easy to induce aquatic animal diseases. In the event of heavy rain, strong convection and other disasters, it is easy to cause water quality mutations, hypoxia flood ponds or ammonia nitrogen nitrite poisoning, etc., feeding management should be strengthened and precautions should be taken in advance.
First, be vigilant against diseases
1. Grass carp: prone to gill rot, red skin disease, enteritis disease, Chinese flea, anchor head loach disease, etc.
2. Silver carp: prone to bacterial sepsis, enteritis, rotten gill disease, printing disease, Chinese gill, anchor head flea disease, etc.
3. Carp and crucian carp are prone to bacterial sepsis, gill rot, ringworm disease and so on.
4. Largemouth catfish and perch are prone to rotting skin disease, ulcer disease, ringworm disease, etc., spotted forktail catfish intestinal sepsis, spotted forktail catfish "infectious socket disease", columnar disease, etc.
The above diseases need to be paid great attention to in all breeding areas, seed breeding farms and points in the province.
1. Strengthen water quality management. Timely filling with new water, starting to increase oxygenation; sprinkling quicklime, microecological preparations and other measures to improve water quality. Adhere to the morning, middle and evening patrols of ponds, pay close attention to changes in weather, aquaculture water bodies, and fish activities, prevent the impact of disasters such as heavy rain, lightning, mudslides, etc., strengthen flood prevention and escape prevention facilities, and disinfect water bodies and the surrounding environment after heavy rains.
2. Scientific breeding. Feeding high-quality feed, feed nutrition should be balanced and reasonable, can be an appropriate amount of vitamins and add immune enhancers, improve the disease resistance of the fish body, master the amount of feeding, do not use mildew feed, control the density of breeding.
3. Do a good job in epidemic prevention and medication. Actively grasp the prevention of fish diseases, remove residual feed in a timely manner, and regularly disinfect aquaculture water bodies, feeding platforms, breeding tools, and the surrounding environment. Found dead fish fish fished out in time, there are conditions to do laboratory pathogen testing and drug resistance experiments, once the disease is found, targeted scientific specifications of medication to ensure the quality and safety of aquatic products.
3. Therapeutic measures
1, bacterial sepsis, external use: per cubic meter of water, 1 g of chlorine lime (bleaching powder) or bleach powder essence (effective chlorine 60% ~ 65%) 0.3 ~ 0.5 g, the whole pool is sprinkled, or rhubarb, 2.5 ~ 3.7 g per cubic meter of water, first the rhubarb is soaked with 20 times the weight of 0.3% ammonia water to improve the effect, and then sprinkled with the whole pool with water slag, 1 time in 15 days. For internal administration: florfenicol or thiamphenicol, 15 to 20 mg per kilogram of body weight, once a day, for 3 to 5 days.
2, rotten gill disease, erythroderma, printing disease, enteritis disease: external use: 8% bromoclohydantoin, 0.2 to 0.3 grams per cubic meter of water, the whole pool is sprinkled, once in 15 days; or 10% povidone iodine, 0.5 to 1 ml per cubic meter of water, the whole pool is sprinkled, once in 15 days. Internal administration: Flufenicol, thiamphenicol or enrofloxacin and other sensitive drugs are mixed and fed according to the instructions.
3 Spotted forktail catfish cylindrical disease: keep the aquaculture water body clean, control the stocking density, reduce stress is an important preventive measure, per kilogram of body weight, deoxyoxycycline 20 to 30 mg or florfenicol 10 to 20 mg, continuous use for 5 to 7 days.
4. Ringworm disease: ringworm disease: 90% crystalline enemy worms, 0.5∽0.7 grams per cubic meter of water, sprinkle the whole pool, after 7 days, sprinkle again; or ivermectin, 0.4 grams per kilogram of body weight, mixed and fed, once a day, for 3∽5 days.
5. Chinese loach disease: chlorine-containing lime (bleaching powder), 15 grams per cubic meter of water, with water about 30 cm of clear pond, or copper sulfate ferrous sulfate compound (5:2), 70 mg per cubic meter of water, soak for 20 to 30 minutes before stocking.
6, anchor head loach disease: 90% crystal enemy insects, 0.3 to 0.7 grams per cubic meter of water body, the whole pool is sprinkled, can kill the larvae of the anchor head flea in the pool, generally every 1 month must be used continuously 2 to 3 times, the number of days each interval depends on the water temperature, when the water temperature is high, the number of days apart is small, and vice versa; or masson pine needles, 37.5 grams per cubic meter of water, mash out the juice, the whole pool is spilled; or with fresh leafy pine branches, 115 grams per cubic meter of water, tied into several bundles in the fish pond.
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Reprint Statement
Source | National Aquatic Technology Extension Station, Guangdong Provincial Aquatic Animal Disease Prevention and Control Center, Jiangsu Provincial Aquatic Animal Disease Prevention and Control Center, Hubei Provincial Aquatic Animal Disease Prevention and Control Center, Sichuan Provincial Aquatic Technology Promotion Station, please indicate the source.
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