Shrimp disease prevention

I. White spot syndrome virus (commonly known as white spot disease) [pathogen] white spot syndrome virus (WSSV), also known as white spot baculovirus, subcutaneous and hematopoietic tissue necrosis baculovirus, etc. [Popular] This disease has been in China since 1992. An acute infectious disease that is commonly occurring in shrimp culture areas in Southeast Asia. The disease occurs in various types of shrimp, and the disease size is more than 2 cm. The main infectious disease of the disease is shrimp and shrimp that have just died. Other wild shrimps, crabs, and planktonic crustaceans also carry the virus. They are potential infectious agents. Their transmission routes can be spread by shrimps, water, poisoned shrimp manure, crustaceans, etc. Some people found that bird droppings can also spread. It is mainly through feeding. The host or devoured by the virus contaminated bait after infection. Pond clear pond can completely kill most of the virus, the natural seawater in sunlight exposure to virus can survive 3-7 days, so when the water is not disinfected, it is best to stand for 7 days after use. In the production of shrimp ponds, there are two common conditions: one is that healthy shrimps are infected with highly virulent viruses, and water is the main reason; the other is shrimps with viruses that are affected by various Caused by reduced resistance of shrimp body, common causes are water quality mutations, medications and nets and other stress factors. The water temperature below 18C is a latent infection, and acute outbreaks above 20C. Tests for oral feeding of shrimps infected with the virus, 18 After an hour of empty stomach and stopping feeding, a red body appeared in about 36 hours, white spots appeared in the carapace about 48 hours later, and then began to die. In addition, some authors in Taiwan reported that even if there is white spot virus infection in shrimp, even the white spot virus is injected. Injection into the shrimp body will not cause the leukoplakia disease and cause death. This suggests that environmental factors and secondary infections are important causes of leukoplakia. Naturally occurring shrimp ponds can die in the high-temperature period after 5-7 days of death. Peak, the mortality rate is as high as 90%. In addition to the death of the virus, the lack of oxygen, secondary infection of bacteria, drug stimulation and water quality deterioration factors are often important reasons for aggravating the death of shrimp. [Symptoms] Shrimp first stop eating, slow action, Bounces weakly, swims slowly on the surface of the water or floats on the edge of the pool. It quickly dies. The diseased shrimp is reddish or fading. Typical shrimps have white spots on the inner surface of the carapace. White spots are particularly clear on the cephalothorax and are visible to the naked eye. The white spots are flower-like under the microscope, the outer periphery is more transparent, the pattern is clear, and the middle is opaque. The white spot of white shrimp is not obvious. The sick shrimp head breastplate is separated from the underlying tissue and is easily peeled off. The diseased shrimp is haemolymph haze, lymphoid organs and hepatopancreatic enlargement. In the initial stage of infection, the hepatopancreas is covered with a thin film and the hepatopancreas cannot be seen. , subcutaneous tissue, stomach, heart tissue lesions occurred. [Diagnosis] shrimp more than 2 cm, within a few days of death, severe incidence of high-temperature period, the appearance of the head on the chest and white shell surface symptoms, head thoracic easy to fall off. In the early stage of disease, when the symptoms of white spot are not obvious, peel the opening breastplate to observe whether the hepatopancreas can be seen. If it is covered with a thin film and can not see the hepatopancreas, it may already be on the pathogenesis. Anatomically dead shrimps haemolymph organs Turbidity, no coagulation, lymphoid organ enlargement, hepatopancreatic necrosis. Pathological sections were observed in larvae, stomach, lymphoid organs, and subcutaneous tissue cells of the diseased shrimp. Nucleus hypertrophy was observed in electron microscope. The cell's nucleus contains viral particles. The virus particles are ovoid, enveloped, negatively stained by the electron microscope, the complete virus particle is 375 nm at 157 nm, and the non-enveloped nucleocapsid is at 395 nm and 83 nm. Application PCR (polymerase) (Chain reaction) Technical examination of vitiligo virus is positive. Note the difference with leukoplakia caused by Vibrio infection. [Prevention] 1. During the onset of illness, do not enter water to prevent the introduction of pathogenic virus and run away waterfowl. In order to prevent poisonous droppings from falling into the pond, 2. Oral Podcomb 8-10 g/kg material + "Viking Ning" 3-5 g/kg is taken orally during the onset of the disease, which has a good preventive effect. External use "three Huang Jing" 2-3PPM3. Long-term oral administration of "Yi-Ting Ling", often using "Di-An", "Shrimp Crab Saver" to change the end, increase oxygenation and other measures, can effectively reduce ammonia, nitrite The content of harmful substances, etc., to maintain the stability of water quality, greatly reduce the incidence of the disease. [Treatment] 1. Early onset (occurrence period, development period), reduce castration, oral administration of "Liver Baoda Kang" 8-10 g / kg material + "Vicinity" 3g/kg material, External use of "fish and happy" 0.3-0.4 g / cubic meter of water (in the evening) or "Diandan" (6-8 acres / bottle), depending on the water quality situation or use 2-3 times the next day. Bacterial infections may be preceded by a "powerful iodine" of 0.15-0.2 g/m3 water, followed by "Diam" or "Fuk Lok Le" and "Three Wong Semen" 2-3 PPM.2. Peak period), food, external use of "fish and happy" or "Diam" (in the same amount as above). External use "shrimp crabs tranquility" 1PPM3. In the late onset (recovery period), gradually increase the feeding, oral administration "Qingdusan" 8- 10 grams of kilograms + "three yellow powder" 3-5 grams / kilogram of material + "Viking Ning" 2-3 grams / kg of material; external "power iodine" 0.2-0.3 grams / cubic meter of water, use the next day " "Diamane" (the same amount as above), the latter used in conjunction or the next day 2-3 times. 4. Convalescence period, orally taking "Yi Tian Ling" 2-3 g / kg of material + "immunogenic agent" 5-10 g kg material , External use of "fish and shrimp Shule" to restore shrimp physique and water ecology. Ditao pull virus disease (commonly known as red body disease) [pathogen] Taura virus (TS V) [Popular] Taura virus (TSV) mainly invades Penaeus vannamei and Blue prawn (Penaeus scoparius), and affects most of the young larvae weighing 0.1-0.5 grams for 2 to 4 weeks. These viruses are usually pathogenic. Very strong virus, the cumulative mortality rate of up to 5% -95%, often occurs during the shrimp shelling, juvenile shrimp sub-acute to acute TSV infection, adult shrimp is mostly chronic, the mortality rate is not higher than 50 %, China's South American Penaeus vannamei have the disease in the main breeding areas, often causing the shrimp to die. The disease is transmitted, the route of transmission, the method of infection, the death of the disease see white spot virus disease. In addition, bird droppings have been confirmed to spread TSV. [ Symptoms Depending on the condition, it can be divided into acute, subacute and chronic. Acute, subacute: sick shrimp body is very weak, vigor, soft shell, digestive tract (empty stomach, jejunum), surface pigment diffusion, tail and Redness of the body surface, the prawns that survived after the onset of the disease showed irregular melanin distribution on the shell. The juveniles were mostly acute or subacute onset, and they reached the peak number of days of death. Chronic: The shell had no melanin pigment , But white spots are visible. Mortality is not high. Adult shrimps are mostly chronic and have a low mortality. Incidence lasts for more than one month. [Diagnosis] New diagnosis based on epidemic and symptoms. Observed by tissue section. Under the epidermis, appendages and muscles, etc., a slug-like black necrosis zone appears. In addition, white shrimp can be used to diagnose taras virus sensitively. The method is to inject the shrimp tissue slurry into the body of healthy white shrimp, in 1 - After 2 weeks, observe whether white shrimp has typical symptoms or tissue lesions of the virus. Confirm that virus examination is necessary. Commonly used PCR technique to diagnose quickly. Note that with white spot virus, bacteria and deterioration of water quality caused by red body disease Difference. White spot virus caused by red body in the early stages of acute onset, late white spot symptoms are not obvious, the incidence of death faster. White shrimp in South America, in particular, bleaching culture shrimp white spot is not obvious, if the head thoracic easily fall off, the shell is not soft , and microscopic examination of a small number of shrimp with white spots, can be temporarily caused by white spot virus. Bacteria (such as Vibrio, Aeromonas) caused by the early stages of the red body disease often surface dirt or ulceration The distribution of red spots is not uniform, and the incidence of death is low. The use of disinfecting drugs has obvious effects. The red body caused by deterioration of water quality is not contagious, the course of the disease is not obvious, and often sudden large-scale disease occurs. After water quality deteriorates, it often induces or succeeds the virus or Bacterial infections. The true confirmation must be detected by the pathogen. When it is difficult to diagnose, it can be treated by leukoplakia virus disease infection. [Control] See white spot virus disease. Three yellow head virus disease [pathogen] yellow head virus (YHV) [Popular] Main Infection with white spotted prawns, Penaeus vannamei, can also be artificially infected, and no cases have been reported during production. This disease caused a large number of shrimp (grass prawns) in Thailand during the breeding season in 1991-1993. 5-15 g of prawns are susceptible to infection. The death rate is fast, and there is a large number of deaths in three days after the onset. The virus can survive in water for more than 72 hours. Hybrid shrimp and other crustaceans in the culture ponds can carry the virus. [Symptoms] The diseased shrimp and yellow head of the shrimp are yellow. Before the onset of disease, the prawns will be ingested in large quantities, and will not eat at all within one day. At this time, the diseased shrimp will begin to swim to the water surface of the culture pond and begin to die within a few hours. Pathological section The dense lymphoid organs, myocardium, sputum, hematopoietic tissue, connective tissues of the midgut, and intermittent tissues of the hepatopancreas appear in the body. The necrotic cells and the nuclei of the swollen cells are vacuolated. Lymphoid tissue, sputum Severe lesions of the head soft tissue suggest that these three tissues may be the site of the first infection of the yellowhead virus. [Diagnosis] According to the prevalence and symptoms of new diagnosis, further to observe the presence of inclusion bodies in the tissue section. The diagnosis of the need for electron microscopy or immunology. Other techniques are used to detect the infection of yellowhead virus. [Control] See white spot virus disease and controlled ecological breeding techniques to prevent disease and treat disease part. IV Hepatopancreatic parvovirus disease [pathogen] Hepatopancreatic parvovirus (HPV) [Pop] The disease mainly harms the Chinese shrimp, the Moji shrimp, the prawn can also be infected, and the P. vannamei infection has not been reported in detail. As a chronic disease, the larval stage is in serious condition and the mortality rate is generally 50%-90%. With the growth of the individual, the disease is reduced, and the broodstock is mostly hidden and infected. [Diagnosis] According to the prevalence and symptoms of shrimp disease, Diagnosis can be made of hepatopancreas smears stained with malachite green (0.05%) or histological section HE staining, microscopic examination of lesions in the nucleus inclusion body. [Control] See white spot virus disease. Five bacterial gill disease (commonly known as Black shank, jaundice, and red knot disease. [Virus] Vibrio, Pseudomonas, and Aeromonas etc. [Popular] This disease is common in all kinds of shrimp, water quality mutations, sediment odor or ciliate infection Post-infection. High temperature and prone to late breeding. Incidence rate of up to 30 or more, both sea and fresh water are seen. [Symptoms] disease shrimp head thoracodorsalis area is black or yellow, revealing the beginning of the breast silk texture fragile, swelling Increased mucus, many contaminants adhere to the tendon, from the tip to the base of necrosis, ulceration, and sometimes shrinkage and fall off. Microscopic examination ulceration at a large number of bacteria swimming, serious blood bacteria. Disease shrimp floating Water surface, slow swimming, unresponsive anorexia, and finally death, especially when the dissolved oxygen content in the pool water is insufficient, the diseased shrimp first die. [Diagnosis] Cut a small part of the cocoon, spread it with tweezers, and make an immersion film. Observe the condition of ulceration under low magnification microscope, and then use high magnification telescope to observe whether the bacteria in the silk can be diagnosed. Attention should be paid to differences between ciliates and scutellaria caused by deterioration of the ciliate, etc. There are bacterial infections due to ulceration, and deterioration may be caused by ciliates, etc. [Prevention] 1. Maintain water quality and prevent Abrupt water quality. 2. The bottom layer is inflated or changed with "bottom safety" to prevent bottom odor. 3. Prevent ciliates from occurring (see "Prevention of ciliate disease"). [Treatment] Oral and external use. 1. Mild infection: Oral administration" Liver Bao Dakang "+" Wei Xian Ning "to recover; external use "Diane", according to the water used or used 1-2 times the next day. 2. Severe infection: Oral "Sanhuang Jing" + "Wei Xi Ning" to heal External use "three Huang Jing", use the "bottom security" to change the bottom 12 hours after use. Use once or twice or every other day 1-2 times. If the water quality is poor or there is a phenomenon of "swimming pool", fish and happy or shrimp and crab can be used for peace. 3, recovery period: oral Yi Tian Ling + Wei Xi Ning, topical "fish and shrimp Shule" + Yi Yuan Sheng or fish and shrimp. The above dosages are used according to the instructions.. 6. Carapace ulcer (also known as black spot, brown spot) [pathogen] Vibrio, Pseudomonas, Flavobacterium, etc. [Popular] This disease is easy to use in adult shrimp culture. It is prevalent in ponds with aging, high-density culture, or foul odor in the substrate, heavy metal pollution, or shrimp malnutrition, and is also common in wintering broodstock, and is mainly caused by shrimp inadvertently during operations such as fishing, transportation, and sorting. , Shrimp injury, or jumping during the winter, the collision of injuries after the decomposition of chitin bacteria or other pathogens invade through the aircraft, causing ulcers, shrimp can make successive deaths, overwintering pool accumulation of mortality can be as high as more than 80%, the onset of the general During the middle and late wintering period, that is from January to March, the symptoms of the diseased shrimp occur on the surface of the carapace, resulting in the formation of dark brown depressions, which are mostly round or irregular, and have unstable parts of the ulcer, trunk and appendages. Can appear but with head breastplate and 1-3 abdominal segments With many back-sides, the prawn has a lot of dark brown spots on the body surface, so it is also called black spot or brown spot. When the depth of the ulcer does not reach the dermis, the prawns will collapse when they crust, and ulcers will occur when the prawns. Department of easy adhesion with the new shell, so that the skin is difficult, serious bacteria invade the internal tissue, causing the death of shrimp.[Diagnosis] based on the initial diagnosis of the epidemic and symptoms, pay attention to the distinction with the disease of the bacillus. Fusarium is mainly expressed in the cephalothorax Ulcers, and ulcers from carapace ulcers are relatively disperse: at the same time, silkworms and conidia are easily observed under the microscope in the case of Fusarium disease, and most of the crustacean diseases are sporty bacilli. Septicemia (commonly known as redleg disease, also known as vibriosis or aeromonas disease) [pathogen] Some species of the genus Vibrio in the seawater, some species of the genus Aeromonas in the fresh water. In shrimp farming areas, there are epidemic species. Infected with various types of shrimp, shrimps in China have morbidity and mortality rates of up to 90%. The high-temperature period is prone to occur. Some shrimp ponds almost died of shrimp in the whole pond within a few days after onset. Indigenous shrimp also suffer from this disease. The epidemic is closely related to the pollution at the bottom of the pool and the deterioration of water quality. Infestation of larvae can also lead to large numbers of deaths. 【Symptoms】 The diseased shrimp is reddened, especially in the swimming feet. The temporal area of ​​the cephalothorax is pale yellow. Observed by the thin haemolymph, blood cells become less, slow coagulation or coagulation. In the hemolymph, hepatopancreas, heart, cocoon and other organ tissues can be seen bacteria. Shrimp generally swim slowly in the pool, and some In the water rotation activities or up and down vertical swimming, stop feeding, and soon died.Some of the luminescent Vibrio infection, can be seen in all shrimp emit fluorescence.Sprouts larvae shrimp infection body color is opaque, swimming slow, poor phototaxis, acute Death, also known as larval vibriosis of prawns.[Diagnosis] According to the initial diagnosis of symptoms, if the shrimp is cultured at too high a density, the appendages will turn red for the time being, so the diagnoses must be examined under the microscope to find bacteria in the hemolymph. activity. Select the sick shrimp with obvious symptoms, puncture the throat and the first abdominal joint with tweezers, take the blood lymph, drop it onto a clean glass slide, and cover the cover glass to check the presence of bacteria. Or aseptically, take the hemolymph for bacterial isolation and culture. 【Control】 See rot disease. Eight, muscle necrosis (also known as muscle white cloud disease) (Country 9) [pathogen] Vibrio bacteria. [Population] occurs in all parts of the country. In recent years, high-density culture of Penaeus vannamei in parts of Guangdong and Guangdong has a high incidence of disease, and there are many dead shrimps in the evening, which is commonly known as the bottom-fall phenomenon. Onset ponds often have the following characteristics: 1 Changing the maximum water or increasing oxygen causes water flow too fast. The shrimp body is severely stressed: 2 The sediment quality is deteriorated and stinks, especially in the evening. The bottom of the pond is steep, and the shrimp cannot rest by the pool. 【Symptoms】 Abdominal muscles of shrimps, especially the abdomen, from the fourth to the sixth quarter, become white turbid and opaque. When severe, the necrotic area expands to the entire abdomen. Some diseased shrimps are accompanied by intense activity and swimming or jumping out incessantly. Water surface. [Diagnosis] Diagnosis based on symptoms and epidemic. Diagnosed should be bacteriological examination, pay attention to the difference between the stress and the white cloudiness caused by microsporidia. 【Prevention】 1. Do not make the pond slope too steep when building a new pond. The angle between the horizontal plane is not more than 30 degrees. 2. Use of controlled ecological breeding techniques to reduce water changes and improve the stability of the water body; Use a three-dimensional oxygenation to avoid local water flow due to oxygen increase. 3. Prevent bottom odor, Bottom inflatable or commonly used "bottom security" to change the end. 4. Oral incidence of oral administration "Liver Baoda Kang" 3-5 g / kg of material + "Yi source" 2 g / kg material + "Viking Ning" 3 g / Kilograms, better preventive effect. [Treatment] 1. With prevention 1.2.32. External: "Power iodine" 0.2-0.3 g / cubic meter of water, 12 hours after the "bottom security" change the end, the next day and then reuse Once.3. External use of “fish and shrimp Shule” 300-500 g/mu, with good results. 4. Internally: Fast-sterilizing "5-10 g/kg material or" liver Bao Da Kang "8-10 g / kg material +" Viking Ning "2-3 g / kg material until cured. Nine rotten eye disease [pathogen] is not 01 Vibrio cholerae, etc. [Popular] From July to October in the onset season, the most in August. Chinese shrimps, long-haired shrimps are often infected, and white shrimps also occur. The infection rate is generally 30-50%. Sporadic death , And seriously affect the growth. The disease is more common in the low salinity area of ​​the estuary, or does not carry out dredging disinfection of the bottom of the pool. The damage to the eyeball can also lead to rotten eye phenomenon. 【Symptoms】 The sick shrimp linger at the bottom of the pool. Move or swim in the water without direction, the eyeball is swollen, gradually turns from black to brown, and even ulceration becomes white, and severe eyeballs fall off. [Diagnosis] Visually observing eyeball ulcer, making ulcer tissue into water sheet, under high power microscope Observed, there are many short rod-shaped bacteria with power. 【Treatment】 See grub disease. Ten shrimp gut bacterial disease 【Pathogen】 A gram-positive bacillus. 【Population】 Mainly infected shrimp larvae, morbidity and mortality They reach 95% or more. They usually all die within 2-3 days after onset. They generally start from the zoea stage. Most of the larvae died during the larval stage of squid larvae. 【Symptoms】 The larvae have the same symptoms as vibriosis. There are no foods in the digestive tract under the microscope. Only light yellow colonies are present, and sometimes they are filled with the digestive tract. After eating, eating reduces the redness of the intestine. In severe cases, the stool is light yellow or has pus. Diagnosis: Diagnoses according to symptoms and prevalence. [Prevention] Internal and external use "Intestinal spirit" 3 g / kg of material +" Yi Tian Ling "5 g / kg material +" Yi Yuan Sheng "3 g / cubic meter of water, has a good effect. [Treatment] 1. The larvae during the incubation period of external use "Vicinity" 10 g / cubic meter of water + "Fish and shrimp Shule" 5g/m3 water, use it for 2-3 days and increase inflation. In severe cases, the topical use of "mycorrhizal net" 8-10g/m3 of water 2. After adult shrimp infection, orally Spirit "3 g/kg material +" Sanhuang San "2 g / kg material. Seriously when taken orally "Sanhuang powder" 3-5 g / kg material, once every 3-5 days, and external use "power iodine" 0.2 - 0.3 ml / cubic meter of water. Eleven filamentous bacterial disease [pathogen] mainly mucorylase. [Popular] Filamentous bacteria are not only present in various shrimps and their various life stages, but also in the eggs of marine fish, and in other life stages of other marine crustaceans, as well as seaweeds can be found. In our country from Guangdong, A variety of prawns have been found on the Guangxi coast from the north to Liaoning, and some have caused the death of shrimp or larvae. The occurrence of filamentous bacteria has no obvious seasonality, but it mainly occurs in the high temperature of shrimp farming from August to September. Seasonal. [Symptoms] Filamentous bacteria adhere to the eggs of prawn, the body surface of the larvae, the larvae of the larvae, and the surface of the shrimp. The pods are black in appearance, and the mycelium is covered with a silky surface, with many primitives. Animals, algae, or dirt, etc., impede the breathing. Diseases of shrimps are difficult to molt and can cause death. [Diagnosis] When the shrimp is sick, cut a portion of the silk to make a water immersion film. The filamentous bacteria are larger, generally Can be seen under low magnification, but to confirm the diagnosis must be carefully observed under high magnification microscopy the structure of the hyphae, especially in the nursery larva sometimes attached to the tremblable algae, easy low frequency microscope with filamentous bacteria Confusion. Prevention] to maintain the quality of water and sediment clean, feed nutrition should be rich, appropriate feeding amount, prompt normal shrimp skin and growth, feeding density should not be too large. 【Treatment】 1. Quanchiposa 2.5 - potassium permanganate. 5 g/m3 water, change water after 12 hours. The disease during larval rearing can refer to shrimp gastro-intestinal bacterial disease. 2. Others see gill rot disease. 12 Fusarium wilt disease [pathogen] Fusarium. Mycelium is branched, Separated, reproductive methods are the formation of large conidia, small conidia and thick-film spores. Large conidia are sickle-shaped, hence the name Fusarium. [Popular] Fusarium is a relatively dangerous condition for shrimp, crabs Pathogenic fungi. Its host species and distribution areas are very extensive. China currently occurs mainly in the artificial winter broodstock. Shrimp breeding period occurs occasionally. [Symptoms] Fusarium more parasitic in the thoracic area, appendages, body In the tissues such as the wall and the eyeball, the tissues of the parasites are melanin-settling and appear black. The parasites cause symptoms of "black moles" in the ankles. The shells in the parasites are necrotic, blackened, disintegrated, and shed. [Diagnosis] According to the symptoms Newly diagnosed to distinguish bacteria , Water quality and malnutrition caused by black cockroaches, must take a little tissue from the lesion to make a water seal film, microscopic examination of mycelium and its conidia found, can be diagnosed. 【Prevention】 shrimp before clearing Can kill some of the conidia. The water source is used after being cleared. [Treatment] No effective drugs to kill the conidia 1. There is a certain amount of "potent iodine" for 0.3-0.4 ml/m3 water for external use. Effect. 2. Nursery pond with 20 million units/cubic meter of water nystatin, can inhibit the growth and development of fungi, reduce mortality. Thirteen microsporidia [pathogen] microsporidia, common microsporidium, Eight spores, Pili. [Popular] microsporidian disease in our country has been found in Shandong, Guangdong and Guangxi. Microsporidia is a common and more harmful disease in Guangdong and Guangxi, pond breeding Moji Prawns and hairy prawn, who are 6 cm or more in length, often suffer from eight spores, but they are often chronic types, that is, sick shrimps gradually weaken and emanate and eventually die. 【Symptoms】 Mainly infected with striated muscles, making the muscles white and turbid, opaque and loss of elasticity. Microsporidia infects the ovaries, making the ovaries swollen, white, opaque. In the tendon and subcutaneous tissue, many white tumorous masses appear. After being infected with Micronospermia, the Chinese prawns became white and opaque before the spores had formed. They began to die in large numbers. The ovary in the sternum of the shrimp after the infection of Murji shrimp was orange-red, and the orange color was particularly bright after soaking in formalin. The epidermis of pionid-infected shrimp is dark blue. [Diagnosis] You can get a new diagnosis from the above symptoms. Muscle necrosis, etc., can also make the shrimp muscles white. Therefore, when the diagnosis is made, the whitened tissue must be cut into smears or immersed pieces. The spores and their spore mother cells can be seen under a high magnification microscope and the diagnosis can be confirmed. However, in the early stages of the disease, diagnosis is difficult if the sporozoites have not yet formed. [Prevention] Shrimp ponds are thoroughly cleared of silt before stocking. When infected shrimp or dead shrimp are found, they should be removed and destroyed immediately to prevent swallowing by healthy shrimp or spores of microsporidia after the dead shrimp is spoiled and spread in water. 【Treatment】 There is currently no treatment. Fourteen-fixed ciliate disease [pathogen] Pathogens belong to many species in the suborders of the order Fixaea. The body is mostly inverted bell-shaped. The front end is the mouth plate, which has cilia or straws, the back end has a handle, handle The basal part is attached to the substrate. Some stalks are dendritic and some stalks are retractable. [Popular] The distribution of scat-like ciliates is worldwide, and shrimp farms and nurseries in coastal provinces, autonomous regions and municipalities in China Farms often occur. The main pathogens during the nursery period are the bell insects and polychaetes. During the rearing period, the main pathogens are poly-degraded insects. The disease is most common in granular organic matter, small green algae, and most often in live water. Prone to occur. Its spread is by hairy larvae. 【Symptoms】 The body adheres to the surface of the shrimp and the crustaceans of the appendages, and to the prawns of the prawns, even to the eyes. When the body surface is mass-produced, the naked eye It is seen that there is a layer of gray-black fluffy hair. In severely infected shrimp, the cocoon filaments are covered with parasites and often coexist with filamentous bacteria or other protozoa, and some unicellular algae are also adhered between the parasites. , organic debris and dirt, etc. Yellow or black, so some people also called "yellow pupa" or "black pupa." Swimming is slow, feeding capacity is reduced, growth and development stop, can not molting, it will promote the fixation of ciliate attachment and proliferation, the result will be Cause death of shrimp. [Diagnosis] From the appearance of symptoms can be newly diagnosed, but the diagnosis must be cut silk or scrape attached to the body made of water immersion film, the body can be seen under the microscope. Diseased larvae can be used as a whole to do water Dipping tablets for microscopic examination. 【Prevention】1. Maintain water quality, prevent water from changing, do not use chemical fertilizers, and reduce the proliferation of small algae. 2, increase oxygenation, small meals, proper external use of live bacteria, do not use granular organic fertilizer. 3, often use "bottom security" to change the bottom, can effectively reduce ciliate disease. 【Treatment】 When there are few ciliates, no treatment is needed. When the quantity is large, follow the law: 1, "Bottom", continuous or interval multiple use, the effect is good. 2, Quanchiposa 0.3 ~ 0.4 ml / cubic meter of water "power iodine" has a certain effect, after the use of enhanced oxygen, 24 hours later with "Di" change the end. Fifteen bubble disease [Cause] Algae photosynthesis is too strong, resulting in oversaturation caused by courage. [Popular] The sunny days at the beginning of seeding, or the peaks of algae after a water quality change, or after a few days of killing, are prone to occur. There is a high incidence of temperature rise in spring. It is often the main cause of sudden death of shrimp. 【Symptoms】Sick shrimp often floats on the surface of the feng shui during the high temperature from noon to the afternoon. There are often bubbles on the body surface and appendages. Check for no other symptoms. The water is darker and there is often foam on the water. [Diagnosis] There were many deaths during the day from noon to afternoon, the water color was thicker, the shrimp floated on the water surface, there were no bubbles or no other symptoms, and the dissolved oxygen in the water was oversaturated. The PH value was high. 【Prevention】1. After entering the clear pond, the influent water is best to enter part of the “old water”, which is rich in biological species. At the same time, it is not necessary to use chemical fertilizers and water to prevent the over-breeding of certain kinds of algae. 2, old ponds should be properly dredging, do not apply large amounts of fertilizer to avoid the algae before the peak of the pond. When the water is too fat, part of the "old water" or water containing zooplankton may enter. 3, regular use of "Bottom security" to change the bottom, to prevent water changes, do not kill ciliates. 【Treatment】 1. Accelerate the aerator oxygenation rate, or external "fish and shrimp Shule" to expose oxygen, and part of "Old water" or water containing zooplankton controls algal overgrowth. 2. Spill yellow mud (100 kg/mu) to make water "turbid" and reduce transparency. In severe cases, 0.2-0.3 ml/m3 of water is externally applied. "New Wei off" Quanchiposa, the use of "Diane" the next day to change the bottom. Sixteen soft shell disease [Cause] may have the following reasons: 1. Water or feed lack of phosphorus and calcium caused by 2. Irregular and frequent Shell. [Popular] Penaeus vannamei, Penaeus monodon, Chinese prawns all see this disease occur. New ponds excavated, high-density culture ponds prone to occur. 【Symptoms】 Shrimp carapace is thin and soft, shell and muscle seem to be separated, Some diseased shrimps have water under the shells, and some shells are rough. The diseased shrimps are 1-2 cm smaller than the healthy shrimps in the same pool. Diseased shrimps are weak, inactive, and are easily eaten by the same type of food. Diagnosis Mainly rely on the feeling of hand, gently squeeze the shrimp shell, there is a thin feeling, and there are shells and muscles The feeling of separation. Microscopic examination shrimp organs generally do not have other pathogens and symptoms, but some people found that most of the disease shrimp hepatopancreas with small sample of virus, but has not proved to be the primary pathogen. 】 1. Feed nutrient comprehensive, add shrimp powder and calcium dihydrogen phosphate or water in the feed often spill "living calcium" or superphosphate has a certain preventive effect. 2. Newly dig ponds, should maintain a certain degree of water body, Saline-alkaline ponds should be properly reduced PH value. The emergence of soft shell disease shrimp pour "vigor" can improve the status of soft shell. 17 aflatoxin poisoning [pathogen] compound feed and its raw materials such as bean cake, peanuts and other very wet It is easy to produce Aspergillus flavus. These Aspergillus flavus produce aflatoxin, and fish and shrimps are poisoned after eating such feeds, which can cause death. [Popular] No matter what type of prawns, when, where, just feed moldy feed Aflatoxin poisoning can occur. [Symptoms] The main symptoms and pathological changes after prawn poisoning are necrosis and inflammation of hepatopancreas, pancreas organs and hematopoietic tissues. In acute and subacute poisoning, hepatopancreas regardless of epithelial tissue Bad Necrosis starts from the center of hepatopancreas and progresses to the end of the tube. When chronic poisoning occurs, there is obvious blood cell inflammation between the tubes. As the disease progresses, hepatic pancreatic ducts are gradually encapsulated and fibrosis. The necrosis of the orbital epithelial cells in the gill organs and glands is performed from the proximal end to the central vein with mild inflammation of the blood cells. [Diagnosis] The initial diagnosis can be based on histopathological examination revealed hepatopancreas necrosis, inflammation and atrophy, and Check whether the feed or its raw materials are moldy, if necessary, analysis can confirm. 【Prevention】 is mainly to pack feed and its raw materials, preservation and transportation should be moisture-proof. Moldy feed can not be fed, add "Qingdu scattered" in the feed And "Vicinin" has a certain therapeutic effect. 18 vitamin C deficiency disease [pathogen] is fed a lack of vitamin C (ascorbic acid) or vitamin C content of the bait. At the same time there is not enough algae in the shrimp pond, it is easy Occurrence of the disease. [Population] Various shrimp larvae and juvenile shrimps are susceptible to vitamin C deficiency. [Symptoms] Diseased shrimp lacking vitamin C in the abdomen, head chitin and appendage chitin layer Below, especially at the joints or near the joints, blemishes, as well as black spots on the walls of the foregut and the posterior intestine, there is blood cell inflammation near the darkened tissue. Shrimp is usually anorexia, abdominal muscles are opaque. In general, secondary bacterial sepsis are infected later. [Diagnosis] According to shrimp body surface symptoms can be used for the initial diagnosis. Definite diagnosis should also understand the feeding conditions, check the vicinity of the joint epidermis, the foregut and hindgut intestine wall, eyelid and palate. [Prevention] bait The addition of "Vincinin" 3-5g/kg material can prevent the occurrence and development of this disease, and increase the dosage appropriately when the disease is heavy.

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