Wheelworm disease
(The peak season of the epidemic is April-August, and the suitable breeding water temperature is 18-28 °C.) ）
1. Pathological pictures:
Second, the cause of the disease:
Wheelworm disease is caused by the large number of wheelworms parasitizing the skin or gills of the fish, and microscopic fins can often see that the insect body is densely packed all over the fins. Wheel worms look at the felt hat on the side and round butterflies on the reverse side, and when they move, they are like wheels turning, so they are called wheel worms.
III. Symptoms:
When a small number of rotifers parasitize, there are no obvious symptoms, and when they are seriously infected, the sick fish is stimulated by the parasitism of the insect body, causing the tissue to become inflamed, secreting a large amount of mucus, and in severe cases, the gill tissue ulcerates. Sick fish infected with wheelworms have black body color, poor feeding, thin physique, swimming alone in groups, swimming slowly, and some swam wildly around the edge of the pool in groups, in the shape of "running horses". Sometimes the surface of the fish body is white, the mucus secretion on the gills of the fish becomes more, some fish will be whitened locally, the gill filament epithelial tissue of the fish body will grow, and the gill filament tissue will be swollen or destroyed.
IV. Medication and Treatment:
Each cubic meter of water with 0.7 g or 0.7 g copper sulfate and ferrous sulfate mixture (5:2) is evenly sprinkled throughout the pool, for fish ponds with severe wheelworm disease, it can be used continuously for 2-3 times. Note: Copper sulfate is more toxic, and the water measurement error and other reasons, so after taking the drug should pay attention to observe the activity of the fish, if found abnormal, the pond should be immediately replaced.
The diseased fish pond can be sprinkled evenly throughout the pond with 0.3-0.5 ppm of insects.
Each mu of water depth of 1 meter with maple poplar leaves 50-60 kg decoction juice evenly sprinkled throughout the pool.
Wheel ring net (the main component is ethylene bididithiocarbamate ammonium), a dose, per 1m3 water, 0.5 ~ 1g, the whole pool sprinkled once.
Each cubic body of water with 0.4 grams of matrine solution, diluted after dilution evenly sprinkled the whole tank 1-2 times.
Each mu of water depth of 1 meter with benzalkonium bromide solution 50-100g, diluted with water diluted whole tank sprinkled, mixed culture an 20ml dilution after the whole tank sprinkled.
Treat sick fish with a medicinal bath of 25 mg/L formalin solution for 15-20 minutes or a whole pool of formalin 15-20 mg/L.
Potassium permanganate 3g first medicinal bath after half an hour + dimethod 0.5g medicinal bath after 24 hours can kill the wheelworm to restore the fish to normal feeding.
V. Precautions for medication:
1. It is best to pour medicine on sunny days, take medicine in the morning or afternoon in summer, and avoid the high temperature at noon without medication. Do not take medication when it is raining or hypoxic.
2. After pouring the drug, the aerator must be started to prevent hypoxia floating head, especially poor water quality and seedling stage use.
3. When the pool water ammonia nitrogen or nitrite exceeds the standard, it should be used with caution. It is best to degrade before killing insects.
VI. Prevention:
1. Thoroughly clear the pond with quicklime or bleach powder before stocking.
(1) Disinfection with quicklime:
(1) Dry method of clearing the pond: first put the dry pond water or leave the bottom water depth of the fish pond about 7-10 cm, dig out several holes in the four corners and middle parts of the bottom of the fish pond, use block quicklime 120-150 pounds per mu of fish pond, put the block quicklime into the hole dug in advance to fully dissolve the water, and sprinkle the lime water on the bottom of the pond and the pond wall evenly when there is a condition, and when conditions permit, the bottom of the pond can also be turned over the next day, so that the silt at the bottom of the pond is fully mixed with the lime water, so as to enhance the disinfection effect of the pond. Generally, after 8-10 days, the medicinal effect of quicklime basically disappears, and you can inject water to release fish.
(2) Clear pond with water: For some ponds that cannot be completely drained, the method of clearing ponds with water can be adopted, that is, the pond is 250-300 kg of quicklime per mu/1 meter water depth, and the block quicklime and water are fully concentrated in the wooden barrel, and after it is not cooled, the whole pond is evenly sprinkled on the pond while it is hot. Usually, the medicinal effect of 8-10 natural lime disappears, and at this time, fry can be released into the pond for fish culture.
(2) Bleaching powder clear pond method: the pond per mu / meter water depth with chlorine 30% bleach powder about 27 pounds, with plastic or barrel water fully dissolved after the whole pond is evenly sprinkled, generally after 6-8 days after the pond can be stocked with fish fry for fish production.
Before stocking, soak in 10-20 ppm potassium permanganate solution for 10-30 minutes.
3. At a water temperature of 15 to 20 °C, each cubic meter of water is prepared with 8g of copper sulfate to make a solution, and the fingerlings are soaked for 10 to 20 minutes.
4. In the pond with a depth of 1 meter per acre, use 30 pounds of neem branches and leaves to tie into 4 bundles and soak evenly in the pond (if the pond is larger, you can tie several more bundles, the specific number of bundles depends on the size of the pond), change once a week, and use 3 to 5 times continuously.
Seven, compare the wheel worm and the oblique tube worm: