The common mistakes in fish disease prevention and control

Sprinkle medicine in fish ponds

The prevention and control of fish disease is an important measure to improve the survival rate of fry and fry and the high and stable yield of adult fish. However, in the usual process of aquaculture production, many farmers misunderstand the prevention and control of fish diseases and use drugs at will, resulting in unnecessary losses.

1, light prevention and serious treatment: most agriculture and fisheries begin to use drugs after the fish get sick, often resulting in increased drug costs, undue losses such as dead fish. The prevention and treatment of fish diseases should be based on the policy of "prevention first, prevention is more important than cure". The prevention of fish disease should be "four determinations" and "four elimination". That is, feeding quality, quantity, timing, positioning. Sixiao is: fish pond disinfection, fish seed disinfection, water disinfection, feed, food, tool disinfection. Only by doing these can we control and avoid the occurrence of fish disease.

2. Don't ask about the cause of the fish. In order to grasp the incidence law of fish, we must first understand the causes of fish disease, and the causes of fish disease are very complex, there are both external and internal causes. If the PH value of the water environment of the fish is greater than 9.5 and less than 5.0, it will cause the death of the fish. for this reason, changing the pH of the water environment can alleviate the fish disease and treat it according to the condition. Some farmers do not analyze the etiology of fish, and the result will only get half the result with twice the effort.

3. prescribe the wrong medicine to the case. The type of fish disease is very complex, which can be divided into four types: skin disease, Gill disease, intestinal disease and other organ diseases. According to different pathogens, diseases caused by viruses, bacteria and fungi are called infectious diseases, and diseases caused by parasites are called invasive fish diseases. in addition, there are many kinds of fish diseases caused by enemies. If you do not prescribe the right medicine, all use bleach, strong chlorine, copper sulfate, quicklime and so on, not only can not cure the disease, but sometimes counterproductive.

4. Different fish are treated with the same medicine. If the species and size of fish are different, the dosage can not be the same.

5. Medication regardless of the size of the fish pond. After the disease of fish, in addition to the examination and diagnosis of diseased fish, it is sometimes necessary to sprinkle drugs according to the size of the pond and water quality, but many farmers do not make accurate calculation of fish disease drugs, resulting in too large or too small drug concentration in fish ponds, affecting the therapeutic effect.

6. The types of drugs have not been changed for many years. Practice has proved that the long-term use of a drug can sometimes cause drug resistance in diseased fish, and the effect will be better if it is exchanged. For example, the effect of alternate use of trichlorfon, 90% crystal trichlorfon and copper sulfate is better.

7. Use expired drugs. Each drug has a certain period of validity, and some farmers pursue to buy expired drugs cheaply or are reluctant to throw them away and continue to use them. As a result, they not only have no effect, but even produce toxic substances, often resulting in a large number of fish poisoning. Such "savings" really outweigh the gain.

8. Do not pay attention to the time and conditions of medication. When the temperature exceeds 38 ℃, the pest stops feeding, and the liquid sprinkled at this time volatilizes quickly and has no control effect. The correct way is to choose the morning and evening to give medicine at the right time. Another example is to disinfect fish in separate ponds, usually soaking in bleach or copper sulfate for 20 ℃ for 30 minutes, but it should be noted that the water temperature is 10 mi 15 min, otherwise the desired effect will not be achieved.

9. Do not pay attention to low residue. Some farmers only want to cure fish diseases and do not consider using high-efficiency and low-residue fish drugs. For example, in the treatment of melon disease, the conventional effective drug is mercurous nitrate, but mercury preparation is highly toxic and highly residual, and its use has been banned. Can be changed to Yuchongning, chilli powder, ginger slices and other prevention and control of melon disease, also have the same effect.

10. The use of drugs does not pay attention to economic benefits. Many farmers use drugs indiscriminately. In fact, fish diseases can sometimes be treated with the same disease or different diseases. Under the premise of ensuring the curative effect, the drugs used should also consider the effective amount of drugs, sales price and other factors to choose appropriate drugs, so as to minimize drug costs and improve economic benefits.