Stanolone Powder,Raw Stanolone,Steroid Powder Qidi Chemical Co., Ltd. , http://www.czchemicals.com
Disease Prevention and Control in Mariculture (1)
First, seed selection choose robust, disease-free without injury, "Dingshui" strong seedlings; stocking specifications of seedlings have strong wind resistance, anti-wave and other adaptability; suitable for stocking specifications, grouper 10cm , Begonia canadensis 12cm, barramundi 8cm, red snap scorpion 7cm, pepper scorpion 7cm. Second, seedlings are disinfected and immunized throughout the entire breeding process. The disinfection and immunization of seedlings is the key to the success of breeding; because most seawater fish seedlings need to be imported at present, and due to the imperfect quarantine and disease prevention system of seedlings, the seedlings have passed long distances. Transport, it is inevitable to damage the body surface, and some even have pathogens. Therefore, fish species must be disinfected. Commonly used drugs include the following types: commonly used seed disinfection drugs and their concentrations. Note: At present, research on marine fish vaccines in China is still lagging behind. Japan's octopus vaccine against iridescent viruses has achieved better results. Effect. Third, seed domestication and feeding due to long-distance transport and changes in the new environment, seedlings within 2 to 7 days without feeding or rarely feeding; such as natural sea fishing or fishing sesame spot 5-7 days to eat less long-distance transport of white Seedlings 2 to 3 days poor feeding; it should be slowly adjust the feeding of fish, three meals a day, feeding evenly, take care of the weaker seed, the amount of feed in the fish have 3 to 4 percent full Can; seed after a period of "recovery", gradually increase the amount of food, feeding fresh fish without deterioration of the next, the amount of daily feeding is generally 30% to 40% of body weight, fish species have 7 to 8 into a full Yes, two meals a day, more in the afternoon than in the morning. In the hot season, the air pressure is low, and the water contains less dissolved oxygen. The fish can eat until it reaches 60% full. In order to strengthen the nutrition of fingerlings and increase the anti-stress ability, a variety of vitamins and minerals can be added to the food, especially vitamin C and vitamin E. After the fish fry are incubated in the middle and then the fish is raised, the survival rate can be improved. The survival rate of the barramundi and purple snapper after raising in the middle can be increased by 25% to 30%. Fourth, develop management 1. Adopt qualitative, quantitative, regular feeding methods. Qualitative: Feed fresh, unimpaired fish under the ground, ensure the quality of the bait, and regularly add vitamins and minerals to the bait. The vitamins and minerals are mixed with the binder first, then the bait is mixed and stirred from the meat grinder with the bait; the baits are periodically fed and the production method is the same as above to prevent diseases. Quantitative: The amount of daily feeding is different at each stage of the fish. It is appropriate to eat 80% of the fish. If the amount of fish fed is too high, the oxygen consumption of the fish is high. This high-density intensive culture method is used in cage culture. In the next, it is easier to cause oxygen deficiency; in the high temperature season, the pressure is low, and the water has less dissolved oxygen, and the fish can eat until 6-7 percent full. The food intake of fish varies depending on changes in water temperature, climate, seasons, etc. It is not static; the water temperature is low and the weather is less hot and less hot. Timing: During the hot season, when the weather is hot and the water temperature is high, it should be baited before sunrise or after sunset. At this time, the weather is cool, the water temperature is low, and the food intake of fish is large; in spring, autumn and winter season, the water temperature is relatively low. After the sunrise or before sunset, the water temperature is higher and the food intake is greater. 2. Day-to-day management Observe the daily activities of the fish and check whether the cages are non-destructive: test seawater pH value, dissolve oxygen, make records, analyze and predict the regularity of the disease; pay attention to seasonal changes and epidemics, and take preventive measures . Frequently clean cages, change the appropriate mesh as the fish grows to facilitate the exchange of water. V. Disease Prevention and Control 1. Viral Diseases 1) Infectious Hematopoietic Necrosis Pathogens: Infectious Hematopoietic Necrosis Virus; Symptoms; Mainly Infected Juveniles, Diseased Fishes Blackish, Sputum White, Liver White, Diseased Fish Refusing to Eat No good treatment measures, prevention has a certain effect. The author once obtained certain effects on the prevention of American redfish fingerlings (6-8cm). Prevention method: A20ppm povidone iodine soak 5 to 10 minutes; B Povidone iodine and large yellow croaker and other anti-virus Chinese medicine binder mixed, fed with bait feed; C chloramphenicol 60 ~ 80mg + multi-vitamin / Kg of fish; feeding continuously for 5-7 days. 2) Lymphocystis disease Pathogen: Fish lymphocele virus: Symptoms: Single or clusters of rosary on the head, skin, fins, tail, and iliac crest of diseased fish. The color of lesions is from white to light gray to pink. The tumor can be slightly bleeding. It has little effect on the survival rate of fish, but it reduces the price of commodities. During the epidemic season, the disease can be seen at 18°C ​​to 30°C. Sea bass cobia 0.5 kg The disease is common, there is no good treatment, prevention methods: A20ppm povidone iodine soak 5 to 10 minutes; B povidone iodine mix in feed; C chloramphenicol 60 ~ 80mg + multivitamins / kg of fish; continuous feeding 5 to 7 days, once daily. 2. Fungal pathology Pathogens: water mould infections; Symptoms: diseased fish swim alone, do not eat, the body surface has a layer of "cotton", common cold species, barramundi, purple snapper, Grouper, etc.; popular season from December to next April. Control methods: A) Fresh water soaking for 5 to 10 minutes; B) Norfloxacin 50 mg/kg fish; C) Furazolid 60~80 mg/kg fish, continuously fed 4 to 6 days, once daily. Can cure this disease. 3. Bacterial Diseases 1) Gill Pathogens: Columnar Flexibacter bacillus; Symptoms: Diseased fish, black body, refusal to eat, outliers alone, slow swimming, increased mucus in the ankles, zygomatic arch, ankle defects, congestive inflammation, In severe cases, the lid is smashed into a round or irregular opening, commonly known as "open skylight"; sick fish died within 7 days. Seasonal replacement is prone to common diseases. Control methods: A) furazoliline 5ppm, freshwater soak 5 to 10 minutes; B) quaternary ammonium salt iodine 2 ~ 3ppm, freshwater soak 5 minutes; C) with chloramphenicol 40 ~ 70mg/kg fish; D) norfloxacin 50mg/kg of fish, serious can use enrofloxacin; continuous feeding 3 to 5 days once a day. 2) Pathogens of enteritis: Aeromonas pallidum; Symptoms: Weak appetite of the diseased fish, anal swelling, no food in the intestine, congestion and inflammation; Prevention and control methods: A) Feeding fresh fish without malodorous feed; B) Cast Feed allicin 30mg + sulfamethazine 50mg/kg fish; C) fed Triton 70 ~ 90mg/kg fish; D) oxytetracycline 100mg/kg fish, continuous feeding 4 ~ 6 days once a day. 3) Pathogen of ulcer disease: Mainly Vibrio; Symptoms: Diseased fish swim slowly, swim alone, eyes white, skin ulceration, generally in the body's trunk, lesions began to white, gradually congestion and inflammation, after lesions Become white. Common diseases are visible throughout the year. Control methods: A) Povidone iodine PVP-I20 ~ 30ppm soak 5 to 10 minutes or quaternary amine salt sulphon 2 ~ 3ppm soak 5 minutes; B) with tetracycline 70 ~ 90mg + multivitamin / kg of fish; C) fluoride Piperic acid 50mg + multivitamin / kg of fish, continuous feeding 3 to 5 days once a day. 4) The pathogen of the tail rot: Flexibacter bacillus; Symptoms: At the beginning of the tail shank, there is a small white point, which gradually expands and the entire tail shank rots. Hot season is common. Control methods with ulcer disease. 5. Parasitic diseases 1) Pathogen of spores of grouper: Caused by parasitism of sporozoites; Symptoms: There is no abnormality on the surface of the diseased fish, and the abdomen is swollen. The anatomy can be seen by connecting small black particles to form a large piece of “black matterâ€. "Pricking" the "black", the inside is white, microscopic examination, see a large number of sporozoites may be Pili, need further classification; "Black" can burst the abdomen of the fish, sick fish died; Grouper sporozoa disease has little effect on the survival rate of fish but affects market prices. Above 5cm fish species can be seen parasitic. At present, there are still no preventive measures, and care should be taken when selecting seeds. 2) Sea water echinococcosis, also known as the stimulating pathogen of secretable worms: Stimulation of secretive worms: Symptoms: Stimulation of Cryptosporidium parasitizes fish in tendons, fins, skin, mouth, etc. The body surface is full of white spots, also known as white spot disease, and it has a rapid infection rate and a high mortality rate. It can cause 80% of losses in 3 to 5 days. Water temperature 20 °C ~ 26 °C common disease. Brackish water ponds cultured yellow fins to prevent and treat the disease. Prevention methods: A) fresh water soaking for 10-15 minutes; B) 55% of the copper sulfate and ferrous sulfate 5/210ppm, freshwater soak 10-20 minutes; C) 5 to 10ppm of copper acetate, freshwater soak for 10 minutes; D) with the feeding of antibiotics , Norfloxacin 50 mg/kg of fish; E) Oxytetracycline 100 mg/kg fish or furazolidone 80 mg/kg fish, continuously fed for 2 to 4 days. 3) Trichoderma Pathogens: Trichomonads; Symptoms: Trichodins mainly parasitize in the axillae and body surface of fish; Small amounts, no effects, a large number of parasites, increased mucus production in diseased fish, slow swimming, difficulty breathing, causing death . Guangdong, Hainan, the disease can be seen throughout the year. The prevention and treatment methods are the same as those of sea cucumber scrapworm. 4) Pathogens of the phylum Boletia: Pseudophagidae; Symptoms: The diseased fish is black, floating slowly on the surface of the water and swimming slowly, difficulty in breathing, increased mucus in the fins, fins, and skin. Irregular white spots appear on the body surface and the condition is serious. White spots become one, also known as white spot disease. Hot season is common. Control methods and small melon worms are the same. 5) refers to the etiological agent of the ringworm: refers to the ringworm; Symptoms: the insect body sinks slowly under the cage, breathing difficulties, cocoon swelling, sputum tissue damage, it is easy to cause gills, greater harm. It is more susceptible to the disease in hot seasons. The species that mainly parasitizes above 5cm. Control methods: A) Fresh water soaking for 15 to 20 minutes; B) Dipterex hanging bags, practice: use iron nails to hit two holes in the bottom of the enemy dipterex bottle, hang two bottles of trichlorfon diagonally in the cage; C) Combined with imidazole drugs + vitamin C + compound mineral elements 2 to 4 days; D) pay attention to the occurrence of gill disease, if any, control methods with the gill disease. 6) Benedeniasis Pathogen: Benedenia; Symptoms: Ingestion of sick fish is weakened, fish scales fall off due to parasitism of Bennetia, and skin ulcers, freshwater soaked sick fish, a large number of parasites fall off Some even reached thousands: fast infections and high mortality rates. In the popular season, from September to November, the water temperature is 21°C to 27°C. The control method is the same as that of the ringworm disease. However, we must pay attention to the occurrence of ulcer disease; if any, the prevention and treatment methods and ulcer disease are the same. 6. Diseases caused by algae Pathogens of amyloidosis: Trichoderma villus; Symptoms: When parasites are heavily parasitized, the diseased fish has many small white spots on the skin of the diseased fish, with increased mucus, difficulty in breathing, refusal to feed, and friction on the web. , easy to make sick fish infected with raging rickets and ulcer disease; the main damage to fish species, high mortality; common in the hot season. The prevention and treatment methods are the same as seawater melon worm disease. 7. Nutritional diseases are mainly caused by long-term feeding of stale chilled bait fish, causing fatty diseases such as fatty liver and yellow croaker. Preventive measures, feeding fresh fish, and often adding multidimensional food to bait , compound mineral elements. Sixth, summary and experience 1. At present, China's pathological research on marine fish disease is still lagging behind. Japan and Norway have injected vaccines to prevent marine fish disease long ago for production, and the diseases of marine fish in China rely mainly on antibiotics and chemical raw materials. Some Chinese herbal medicines are used for the discovery of unknown mechanisms or viral diseases, and there are no specific drugs; the use of Chinese herbal medicines has certain effects on the prevention and treatment of viral diseases. Relevant research departments should proceed with joint research to develop a broad-spectrum, high-efficiency, non-toxic and pollution-free “green fishery medicineâ€; develop a cell-level vaccine. It is of great significance to the healthy breeding of cages and the export of seafood in China. 2. Many aquaculture technologies draw on the experience of freshwater aquaculture; while the disadvantages of seawater cage culture are difficult to manage, difficult to handle, difficult to use, and different from freshwater aquaculture, a model suitable for marine aquaculture must be established. 3. The management level of farmers needs to be further improved. Farmers abused and abused drugs, and did not prescribe the right medicine. There were many people in the coastal aquaculture area. As a result, pathogen resistance was increased. Some farmers used the latest human drugs, such as Pioneer 6, and their doses were several times larger. Can not but worry. 4. To raise awareness of disease prevention of farmers who are “preventive, prevention-based, and prevention combinedâ€. Prior to the arrival of epidemic diseases, prevention work should be done to ensure early detection and early treatment so as to reduce the incidence of diseases. 5. When using drugs, pay attention to the fish's sensitivity to drugs, especially the use of insecticides, should do drug sensitivity test. The susceptibility of yellow croaker to copper ion and chloride ion at water temperature of 20°C to 30°C increased with the increase of water temperature.