"Color observation" diagnosis and Prevention of Fish and Shrimp

After the disease of fish and shrimp, a certain part or organ of the body shows a unique color, which becomes the characteristic symptom of the disease. Animal medical workers define the name of the disease for disease differentiation and prevention, which is a common method in the field of animal medicine. The summary is as follows:

First, "red" diagnosis

The main results are as follows: (1) the red spot disease of eel is caused by Pseudomonas aeruginosa, which is mainly harmful to Japanese eel and European eel. Symptoms: punctate bleeding occurred in the lower jaw, operculum, chest fin base and abdominal body surface, and died within 1-2 days. Autopsy: punctate hemorrhage of peritoneum. Treatment: (1) tetracycline: 1 g / kg bait per day, fed twice for 3 days. (2) bleaching powder: according to the concentration of 1.3 mg / L pool water, remove the slag after dissolving, and sprinkle it all over the pool. Prevention: bathe the fish with 3% salt water for 5 minutes for 20 minutes before entering the pond.

(2) Red skin disease of fish is caused by Trichoderma fluorescens, and grass carp, herring and carp are susceptible to infection. Symptoms: small or large pieces of bleeding, inflammation and scale falling off on both sides of the fish and abdomen; in severe cases, bleeding at the base of the fins, decay at the end of the fins, hyperemia of the upper jaw and operculum, showing massive erythema, and died after 8 days and 10 days. Treatment: (1) bleach: 1 g / m3 of water, applied in the whole pond. (2) sulfathiazole sodium: 5g / 50kg body weight on the first day and 2.5g / 50kg body weight on the 2nd ~ 6th day. Prevention: before the fish enter the pond, use bleach 5g / L water body, soak for half an hour.

(3) the red body disease of Penaeus vannamei is caused by Taura virus, and Penaeus vannamei is vulnerable to infection. Symptoms: the body surface of acute patients is light red, and the tail fan and swimming feet are crimson. In chronic patients, black spots only appear on the surface of shrimp shell. Prevention and control measures: (1) bromochlorohydantoin: 0.5 mg / L water, sprinkled in the whole pool. (2) 50g of Radix Isatidis and 200g of Sanhuang powder, mixed with 100kg of bait and fed for a week.

(4) the red Gill disease of shrimp is caused by some vibrio, such as Vibrio anguillarum, Vibrio parahaemolyticus, etc. Symptoms: the Gill and appendages were red in the early stage, but red in the later stage, white on both sides of the shrimp body and turbid white on the abdomen. Treatment: (1) Oxytetracycline: 0.5 g / kg bait for 5 days. (2) bleach: 3 mg / L water, sprinkle disinfection in shrimp ponds. Prevention: (1) fresh water is often injected into shrimp ponds to improve water quality. (2) there is enough dissolved oxygen in the shrimp pond.

Second, "yellow" diagnosis

Shrimp yellow Gill disease: also known as shrimp yellow head disease, is caused by shrimp yellow Gill disease virus. Symptoms: the gills are yellowish and pale. Autopsy: the liver and pancreas were yellowish. Treatment: bromochlorohydantoin: 0.3 mg / L water, sprinkled in the whole pool. Prevention: antifungal poison: 0.5 mg / L water, sprinkled in the whole pool.

Third, "white" diagnosis

The main results are as follows: (1) White head and white mouth disease of fish is caused by myxococcus, which mainly occurs in grass carp, and other fish such as silver carp, bighead carp and herring occur occasionally. Symptoms: when in the water, the skin around the forehead, mouth and between the eyes fester slightly, showing white. After leaving the water, the symptoms are not obvious, only a few fish show white head and white mouth symptoms, and the mortality rate is high. Treatment: (1) Gingfengmycin: 25.0 g / 50 kg body weight, mixed with bait for 4 days. (2) Furazolidone: ① 5g / 50kg body weight, mixed with bait. ② 0.1g / cu m water, sprinkled all over the pond. Prevention: (1) keep the water in the fish pond clean. (2) reduce the stocking density.

(2) White skin disease of fish is caused by Trichoderma, which mainly harms silver carp and bighead carp, while eel seldom gets sick. Symptoms: White spots and white spots appear at the base of the dorsal fin and caudal fin, which gradually expand until the dorsal fin and the whole body are white. Some caudal fins are incomplete; sick fish stand upside down in the water, occasionally struggle to swim, die in 2-3 days, with a mortality rate of 10%-20%. Treatment: (1) carbendazim: 0.45 to 0.75 g / m3 of water, sprinkled in the whole pool. (2) bleach: 1 g / m3 of water, sprinkled throughout the pool. Prevention: (1) keep the water quality of the fish pond good. (2) do not injure the fish during operation.

(3) the white disease of fish is caused by water mold or cotton mold, which is mainly harmful to grass carp and other freshwater fish. Xing in Jinan City, Shandong Province has suffered from this disease. Symptoms: the bacteria invade from the wound, one end of the hyphae extends into the muscle, and the other end exposes the body surface. Exposed part of a large number of reproduction, branching, into a white cotton, the mortality rate is high. Treatment: (1) Malachite green 66g / cubic meter water, soak for 5 minutes for 10 minutes. (2) add 0.4 kg of sodium chloride and 0.4 kg of sodium bicarbonate per cubic meter of water, dissolve and bathe the diseased fish for half an hour. Prevention: (1) do not injure the fish during normal operation. (2) always keep the water body clean.

Fourth, "black" diagnosis

Black Gill disease of shrimp: it is caused by long-term lack of Vc and pollution of shrimp ponds. Symptoms: the Gill is light red at first, then dark red, and finally turns black, has difficulty breathing, and dies soon. Treatment: (1) change clean water in shrimp ponds immediately. (2) Vc100 mg, mix into 100g bait and feed. (3) Furazolidone: 2 mg / L water, immersed in bath, suitable for bacteria. (4) potassium permanganate: 10 mg / L water, sprinkled in the whole pool, suitable for fungi. Prevention: regular injection of new water into shrimp ponds to keep the water quality clean; regular disinfection; regular removal of sludge.