The head of the lion-headed goldfish was red for nearly a month and began to turn white. Now it's almost all white. Why?

That's leukoplakia. I am a large-scale farmer. Take a look at the breeding technology, hoping to be adopted and praised. The pathogen of white spot disease mentioned in this paragraph is caused by protozoa cucurbit invading the skin or gills of fish. It is a kind of ciliate in the protozoa of Cucurbita. Microscopically, the adult has a horseshoe-shaped nucleus. Young fish only have large round, oval or rod-shaped nuclei. Insects are soft and plastic, and their shapes are changeable. The disease is one of the most common frequently-occurring diseases of ornamental fish, which is characterized by rapid infection, wide epidemic and great harm. White spot disease is one of the most common parasitic diseases of fish, which mostly occurs in late autumn and early spring when the water temperature is low, and tropical fish of Cyprinidae and Cicadellidae are more susceptible to infection. White spot disease is also called melon disease. The gourd's body is spherical and covered with cilia, with a diameter of about 0.8mm, which is a small white spot visible to the naked eye. At the water temperature of 18-23℃, melons often parasitize under the skin, caudal fin and gills of fish, absorbing nutrients from fish tissues and stimulating fish to secrete a lot of mucus, thus forming white pustules on the surface of fish and spreading all over the fish. When tropical fish suffer from this disease, first of all, white spots appear on the fins, and the fish appear to be slow to move, floating on the water and rarely moving. Or often swim sideways and tickle quickly next to water plants and gravel. In severe cases, the fish will grow full of white spots, stop eating, lose weight, have difficulty breathing and even die. The course of disease is usually about 5~ 10 days. The formation of white spots is not spawning. It has a life cycle. When people see the salt particles on the fish, it is the stage when it is absorbed on the fish skin. In the meantime, it is drug-resistant. When it is full, it will separate from the fish and fall to the bottom of the tank. This parasite produces a protective film to form a capsule with 10 larvae (which can be seen with a magnifying glass of 40 times). White spot disease is caused by ciliate infection. At first, there will be some white spots on a certain part of the fish. After a few days, white spots will spread all over the body. They often lie motionless at the bottom of the aquarium, have no appetite, sometimes float under the water injection of oxygen bottles, and suddenly swim wildly. In the later stage, the fish secrete a lot of white mucus, and the fish often wipe the cylinder wall with their bodies, and when it is serious, a lot of scales fall off. The incidence of white spot disease is high and spreads quickly. It often occurs in early spring, rainy season and early autumn when the temperature changes greatly. The fish moved into the box or the water temperature changed too fast, which would cause white spot disease. Early detection and treatment of leukoplakia have a high cure rate. For example, in the later stage, due to the loss of appetite and physical decline of infected fish, it is easy to send out other diseases. At the beginning of the disease, the sick fish will rub hard objects with their bodies, hoping to get rid of the nasty pathogens. Many small white spots can be seen on the body surface, fins and gills of sick fish. Sick fish are thin, floating on the water or in the corner of the cluster, and rarely move. In the later stage, the body surface is covered with a white film, with increased mucus and dull body color. The occurrence environment of white spot disease has obvious seasonality, which generally occurs from 65438+February to June of the following year. When the water temperature is 14-25℃, it is the most suitable temperature for melon reproduction and the season of disease occurrence. However, when the water temperature is lower than 10℃ or higher than 28℃, the development of melon larvae stops or dies gradually. Early detection is the most important and the slightest symptom. You can pick up the fish and put it in warm water at 30~32℃, because the white spot bug can't grow at this water temperature. In addition, you can also use 10% salt solution to bathe 1000 kg of water for 3 days, and you can recover. Edit this treatment: no matter what medicine you use, you must first raise the water temperature to 30 degrees. We can make use of the method that the gourd is not resistant to high temperature to promote the spores produced on the surface of fish to mature rapidly, speed up their growth and make them fall off the surface of fish. Therapeutic drugs: 1. You can also soak in 5% salt water for a few days; 2。 Or soak in 2ppm methyl blue solution for 6 hours every day; 3。 The mixed treatment effect of 0.05ppm malachite green and 25ppm formaldehyde solution is better. 4。 Or soaking in quinine hydrochloride solution at 28-30℃ for 3-5 days; 5。 Or soak in two parts per million (2ppm) mercurous nitrate solution for 30 minutes; 6。 Or soak in 50-70 ppm mercury chloride solution for 5- 15 minutes, twice a day. After the white spots disappear, it will take a period of time to kill the small melon worms that are not attached to the fish. Mercury nitrate and malachite green are highly toxic products, which will do great harm to human body and easily cause cancer. Therefore, in the treatment of other diseases, it is not recommended and should be avoided. Malachite green is called basic green, with molecular formula of C23H26N2 and molecular weight of 346.4, which can be used as a green dye in industry. But fish diseases are also widely used (especially in fishing grounds), which can be used for a variety of fish ectoparasites and pathogens (including mold, bacteria, skin and gill fluke infections, etc.). ). Clinically proven effective diseases include white spot disease, water mold, filariasis, skin myxosis, etc. Mercury mercuric chloride is a kind of external medicine, and soaking is also a kind of external method, mainly to master the concentration and time. Only a few parts of the body can be wiped at the beginning, and all of them will be wiped at the later stage, so rubbing after dilution is the same as soaking. The rubbing is only partial and does not need to be diluted, because the rubbing is to fish out the fish first, so the fish should not be dehydrated for a long time. If it is diluted and put into the water immediately after rubbing, it will lose its efficacy and have little effect. So you can rub it locally, but don't dilute it. If it is all over the body, it should be soaked. Because it is difficult to wipe the cheeks all over the body, it is also difficult to operate. Careless operation can also cause trauma to the gills. Prevent editing this paragraph. Because melon worms are not resistant to high temperature, they will stop developing above 25℃, and when the water temperature rises to 28~30℃, they will die naturally. Therefore, for tropical fish with white spot disease, the treatment is not too troublesome. As long as the water temperature is kept at about 28~30℃, all the cysts on the fish body will fall off after one week. If drug treatment is supplemented at this time, the effect will be better. When taking medicine, 0. 1ppm mercurous nitrate can be used as a medicinal bath in the fish tank. For seriously ill fish, 2ppm mercurous nitrate or 0.5ppm malachite green solution can be used to invade and wash the sick fish for 2-3 hours. When the symptoms of sick fish disappear, fresh water should be replaced in time to avoid fish mercury poisoning for too long. To prevent this disease, just keep the water temperature above 25℃. When introducing new fish, it is generally possible to prevent the occurrence of white spot disease by soaking it in potassium permanganate solution or salt water for disinfection and then putting it into a fish tank. Usually, the water temperature is raised to 32℃, and the cure rate can reach above 90% by drug treatment. If treated in time, the cure rate can reach 100%. Soak in 1% saline or gentamicin for about 15 minutes, once a day for several days. Or soak in 2ppm methyl blue solution for 6 hours every day; Or soak in quinine hydrochloride solution at 28 ~ 30℃ for 3 ~ 5 days, and good results can be obtained. (1) When changing water, pay attention to the excessive temperature difference, which will cause the fish to catch cold, so that pests and diseases can take advantage of it and invade the fish. (2) Make full use of the weakness that cucurbits can die without looking for a host for 24 hours. The water for keeping goldfish should be exposed to the sun or allowed to stand for 2-3 days before use. This is one of the best ways to prevent melon diseases. (3) Spray the whole pool (tank) according to the ratio of 0.05-0. 1g mercurous nitrate per cubic meter of water, or when the water temperature is lower than 15℃, put 0.0 1g mercurous nitrate into 50kg of water, and the sick fish will be bathed for about 0.5 l, then washed with isothermal fresh water. However, it should be noted that mercurous nitrate is toxic and should be used with caution. In particular, the resistance of small fish to liquid medicine is weaker than that of big goldfish, so it is necessary to reduce the concentration of liquid medicine and shorten the soaking time appropriately. (4) Release 0.5- 1 ml of mercuric chloride (i.e. medical mercuric chloride) in 10 kg of water, and bathe the sick fish for 5- 15 minutes. If the color is ok, you can directly wipe the part or the whole body with mercuric chloride. After washing with fresh water, put it in clean fresh water for breeding, or sprinkle 3-5 (g) ml of mercury chloride according to L cubic meters of water (that is, l000 kg) to make the water concentration in the pool (tank) 3-5 mg/L. After 2-3 days, depending on the illness, you can use the above bath washing method once, and then use clean fresh water (light green water) for breeding. At the same time, prolonging sunshine time, raising water temperature appropriately, stopping eating and increasing oxygen can achieve satisfactory curative effect. (5) According to the characteristics that the gourd is not resistant to high temperature, when it is placed in the sun and the water temperature rises to 30℃, the fish is rubbed with mercuric chloride once, then washed with fresh water, fished out in clean, constant-temperature and light green water, fed, stopped eating in the sun 1 week, and then changed to fresh water to see the recovery. (6) Bathing sick fish with 0.3g or 0.4g malachite green solution for 2 hours per cubic meter of water (1000kg) in the water temperature range of 20-26℃ can kill cucurbits and is also safe for goldfish.