Silver carp, also known as white chub, water chub, jumping chub, chub, etc., is one of the more desirable breeding of fine fish species, with fast growth, less disease, high yield characteristics, more mixed with grass carp, carp, for China's major freshwater aquaculture fish, enviously, we'll take a look at the silver carp common disease prevention and treatment techniques.

Gill rot

Characteristics of the disease fish body color black, away from the group alone, waste food. Gill filaments rot with mud, gill cover inner epidermis congestion, often corroded into a round transparent hole, commonly known as "open window". After the gill flap of grass carp was infected with mucococcus, the tissue in the lesion area showed different degrees of decay, ulceration and invasive hemorrhage. The disease can occur in farmed fish such as bluegill, grass carp and bighead carp, and is particularly harmful to grass carp. Water temperature below 15 ℃, generally rare, around 20 ℃ began to epidemic.

Preventive measures water depth of 1 meter per acre of water surface with bactericidal red 50 ml whole pool splashing, every 15 days to use 1 time. Or use 0.5% Fish Kang Le 2 added to the bait, every 15 days feeding 1 time. Before seedling stocking, use the seedling soaking agent diluted at a ratio of 1:5000, and then take a medicine bath for 3 to 5 minutes.

Treatment method water depth of 1 meter per acre of water surface with bactericidal red 100 ~ 125 ml whole pool sprinkling, with the use of fish Kangle 2 better, if the disease is serious or the emergence of violent disease, can be used to 1.5% fish Kangle 1 added to the bait feeding, 3 ~ 5 days for a course of treatment.

Chub tetrapod disease

Pathogenesis is characterized by chub tetrapod parasitism in the chub gallbladder caused by the chub tetrapod infection in June and July in the chub fry, the overwintering period is in metamorphosis in the body of the fish, and the formation of the first batch of mature spores late in the overwintering period, which is often associated with the disease of water molds, oblique tubeworms, resulting in the death of large numbers of diseased fish, and a small number of parasites with no obvious symptoms. In severe cases, it can cause the sick fish to lose weight, the body color becomes black, the eye circle is congested or the eyeball is protruding, the base of the fins and the abdomen is yellow, the liver is yellowish or pale, the gallbladder is very big, full of yellow or yellow-brown bile, and the intestines are full of yellow mucus, and the individual sick fish are full of water in the body cavity.

Prevention and treatment methods ① use lime to thoroughly clear the pond, can kill the spores in the silt at the bottom of the pond. ② Strict implementation of the quarantine system. ③ Strengthen feeding management. Enhance the resistance of the fish body. ④ found that the body of the disease in time to remove, buried in a place far away from the water source.

Vertical Scale Disease

Characteristics of the onset of the disease fish body surface roughness, part of the scales are flared in the form of a loose ball, the base of the scales edema, the internal accumulation of translucent or blood-colored exudate. The fins are rotted, the base of the fins are congested, the abdomen is enlarged, and the eyeballs are protruding. Sick fish swim slowly, breathing difficulties, abdomen upward, and die after 2 to 3 days. The disease mainly affects carp, crucian carp, grass carp and silver carp, and is prevalent in spring every year.

Preventive measures in winter after each pulling the net out of the fish, the water depth of 1 meter per mu of water surface with bactericidal red 50 ml whole pool sprinkling.

Treatment water depth of 1 meter per mu of water surface with bactericidal red 100 to 125 ml whole pool splashing, when the disease is serious, used 2 to 3 times, or in the bait to add 1.5% of the fish Kangle 1, used for 3 days.

Fingerling Disease

Characteristics of the disease pathogen is fingerling, when the disease is serious, the gill filaments of the sick fish are swollen, mucus increases, respiratory difficulties, which can cause a large number of deaths in the fry.

Control methods ① 90% crystal trichlorfon 0.3 ~ 0.7ppm whole pool sprinkling. ②Pour 130ml~170ml/mu/meter on the whole pool, and use it again every other day when the condition is serious.

Hexosporiasis

At the beginning of the disease, small white spots appear on the body surface of sick fish, covered with white mucus. With the development of the disease, the number of white spots is increasing, and the epidermis of the lesion part is gradually thickening, forming paraffin-like growths, which is similar to pimples, so it is called "pox disease", which mainly harms 2-year-old carp before and after the overwintering, and it occurs from fall to early winter and spring, when the water temperature is 10～15℃. In recent years, due to the development of high-density culture technology in the net box, this disease is becoming more serious, and the incidence rate is gradually rising.

Preventive measures after the beginning of spring, the water depth of 1 meter per mu of water surface with bactericidal red 50 ml or high-efficiency sterilizing iodine 200 to 400 ml diluted in the whole pool sprinkler, used once a week.

Treatment After the fish start feeding, add 0.2% super concentrated photosynthetic bacteria and 0.3% vitamin vc to the bait to improve the immunity of the fish.

Gill mold

Characteristics of the onset of the disease fish do not feed, slow swimming, gills are congested and hemorrhagic, gill flap a little congested, lose the normal bright red and pink or pale, serious gill filaments necrosis, affecting respiratory function, resulting in death of sick fish.

Prevention and treatment methods ① Thoroughly clean and disinfect the pond, keep the water clean and prevent water quality deterioration. ② Cultivate the water quality need to Shi fermentation heat of organic fertilizer, should not be raw Shi. ③ morbidity pond should be quickly refilled with fresh water to improve water quality, or transfer the sick fish to fresh and clean water in the pond. ④ 20-30 mg / l of quicklime sprinkled throughout the pond, can reduce the content of organic matter in the water, improve water quality.

Printing disease

Pathogenesis is characterized by Aeromonas hydrophila and Aeromonas mildans, and the sick fish have nearly round red spots on the body surface behind the dorsal fins, and the scales at the foci are detached, and finally ulcers are formed and even bones or internal organs are exposed.

Prevention and treatment methods ① Because the feces of herbivorous animals (such as cattle, sheep, etc. feces) is the breeding place of Aeromonas bacteria, so the fish pond must be mixed with quicklime and fully fermented, rotting hot before applying to prevent the pathogen from entering. ② When the fish species pass through the pond, 2% of salt water can be used to dip and wash for 5-10 minutes, which can effectively prevent this disease. ③When sick, use bacteriophage 0.5ppm or dibromohydantoin 0.3ppm to splash the whole pond.

Water mold disease

Morbidity characteristics commonly known as white mold, skin mold. Operation, transport inadvertent fish injury, or low temperature caused by frostbite, or parasites, bacteria and other infections caused by the primary lesions, mold spores from the fish body wound invasion, sucking nutrients in the skin, in the injury lesions at the rapid reproduction, spreading and expansion, grow into cotton wool-like mycelium. The mycelium adheres to the wound tissue, causing skin ulceration and tissue necrosis, and with the expansion of the lesion, the fish swim abnormally, loss of appetite, and death of the disease. The disease occurs in the low water temperature season below 20℃, and is most prevalent in early spring and late winter. Dense wintering ponds, spring pond water is thin or in a hungry state of fish susceptible to the disease.

Preventive measures before the fish fry into the pond with fry soaking agent diluted at a ratio of 1:5000, drug bath for 3 minutes, into the pond with bactericidal red at a depth of 1 meter per mu of water surface 50 ml dosage of the whole pond sprinkler.

Treatment water depth of 1 meter per mu of water surface with bactericidal red 100 to 125 ml, splashing the whole pool.

Iodine vesicular disease

Pathogenesis characteristics of this disease, also known as chub madness disease, mainly occurring in a foot of age chub, can cause a large number of deaths, the fish did not die due to the meat flavor and loss of commercial price. Diseased fish is very thin, head and tail small, body color is dull without luster, spine to the back of the bend, so that the tail upward, away from the group in the surface of the wild swimming rush or spinning circle, from time to time to jump out of the water, and then back into the water, repeated many times, and finally died, died when the head is often drilled into the silt. After dissecting the abdomen, the liver and spleen are seen to be atrophied, and the abdominal cavity is filled with water, and the brain is dissected to reveal the brain, which is visible as a white granular cyst, and the sporocysts are removed, and a large number of spores are visible under the microscope.

Prevention and treatment of this disease emphasizes prevention. ① Use lime or lime nitrogen to thoroughly clear the pond, kill the spores in the silt, in order to reduce the occurrence of this disease. ② In the winter piece of stocking before, available potassium permanganate solution (500 grams per cubic meter of water) immersion 30 minutes, or lime nitrogen solution (500 grams per cubic meter of water) immersion 30 minutes, can kill 60% to 70% of the spores. ③ June to September, at the trophic stage of the pathogen, can be used trichlorfon (content 90%) at 0.5 grams per cubic meter of water body water concentration of the whole pool sprinkled, every half a month, can reduce the infection rate.

Two-line tapeworm

Pathogenesis characteristics of the diseased silver carp from the outside, the abdomen is enlarged, locally raised, early spring ice melt after the body is obviously thinning, the abdomen is enlarged more obvious, abdominal muscle is extremely thin, squeeze the abdomen, schizothoracic larvae can be drilled from the pectoral fins. Most of the sick fish died in the net and transportation, only a small portion of the survival, two-line tapeworm susceptible hosts are mainly silver carp species, and carp species infected species to the tongue tapeworm cleistothecia predominantly.

The most common type of tapeworm in the world is the ligular tapeworm Schizothoracin larva.

Swimming Bladder Disease

The disease is characterized by a darkening of the fish's body color, unresponsiveness, loss of swimming balance, head downward, and an enlarged belly with the tail exposed.

The method of prevention and treatment of such dead fish should be immediately fished out and destroyed, and in the onset of the fish pond with antibiotic bait feeding, once a day, even feeding three times the effect is better, the harm is heavier pond thoroughly clean pond, the specific method is to turn over the pond mud, disinfected with bleach or quicklime, and change to other varieties of fish.