Hemicephalus

Alias: red-tailed catfish, paparazzi whale, pillow catfish, red-tailed cat.

Scientific name: half-headed dragon

Family and species: loach and catfish.

Origin: widely distributed in Amazon river basin.

Water temperature: about 25℃

Hardness: about 5

Ph value: about 6.

Food: I like to eat animal feed, especially small fish.

Temperament: grumpy (for small fish), gentle at other times.

This kind of fish is beautiful, slender, wide and flat. There are six pairs of white and noble beards above and below the mouth, one of which is longer and often stretches forward. This fish basically has three colors: gray-black back, white belly and orange tail fin. Moreover, the boundary is very obvious. The head and snout are very large. A white line extends from the snout to the tail. The tail and dorsal fin are carmine, and the other fins are blue-black, elegant. The upper part of the orbit is white, forming a semicircular white circle. The adult fish is 70 ~ 100 cm long.

This kind of fish is easy to raise, so it needs to be filtered and raised separately. Living well in neutral or weakly alkaline soft water, the water temperature is about 25℃, and there are live bait, fish and other bait. It swims gracefully during the day and easily flips up and down after turning on the light at night. Fu Gui catfish (catfish with red tail)-disease prevention 1, hemorrhagic disease: pathogen: initially thought to be caused by bacterial infection. Symptoms: At first, the sick fish swam alone on the water, head up, tail down and mouth open. When it was slightly frightened, it swam underwater and soon floated again. In the middle stage, the sick fish gather together in the running water; Near death, sick fish roll violently and swim around, often with sludge on their heads. Oral and nasal mucosal ulcer; Bleeding of fin and fin base, slight decay of fin tip, hyperemia and inflammation of body surface; Tearing open the skin, you can see the local punctate, linear or flaky bleeding of the muscle; The color of gill filaments becomes lighter, the mucus increases, and the terminal rot is missing. Due to severe anemia and bleeding, most sick fish have spots on their gills. The abdomen of sick fish is swollen, the anus of rich cat fish is red and swollen, the intestine is congested and inflamed, and there is yellowish or red ascites in the abdominal cavity; The liver, spleen, kidney and other parenchymal organs of some diseased fish have different degrees of punctate bleeding, and the gallbladder is often swollen and discolored. Epidemic situation: the disease mainly occurs at the seedling stage of 3~ 15 cm, and it is popular in pond culture and cage culture. It is popular from May to July. The water temperature is 24~28. Control method: (1) Spray the whole pool with bleaching powder with the concentration of 1 mg/L or strong chlorine essence with the concentration of 0.3 mg/L. Fish blood powder was fed on the same day, and mixed bait of100g was used for every ten thousand kinds of fish every day for five days. (2) continuously spraying for 3 days in a fish and shrimp safety pool with the concentration of 0.3-0.4 mg/L; And began to feed fish blood at the content of 3%~5% for 6 days. 2. gill rot: the pathogen needs to be studied. Symptoms and pathological changes: in the early stage, the gill filaments of diseased fish became weak, with a small amount of rot, increased melanin in tail and body surface, decreased food intake, and individual dead fish were seen every day. In the later stage, it can be seen that the diseased fish is black, sludge or bait residue is attached to the edge of gill filaments, most of which are rotted and missing, and the number of gill filaments increases sharply every day. The disease is prevalent from April to June. Control method: (1) Bleaching powder for external use: the concentration is 1 mg/L (adding 0.4~0.5 mg/L of crystal trichlorfon for the treatment of giant salamander cultured in cage), and spraying it in the whole pool or box. Strong chlorine essence: 0.3 mg/L (or quicklime 15~20 mg/L) overflows from the whole pool or box. (2) Furazolidone, for oral administration: every 100kg fish weight 10 ~ 20g, mixed with bait, and fed 1 time every day for 3 days. Yujunling: Add 200 grams of medicine to the bait every 100 kg, and feed it once a day for 3 days. 3. Erythroderma: The pathogen is bacteria, and the details need to be studied. Symptoms and epidemic situation: local or most of the diseased fish body surface is congested and inflamed. Mainly harmful to fish species, popular in June-July. Control method: The whole pond was sprayed with bleaching powder with the concentration of 1mg/L, and the mixed feed of sulfathiazole was fed, every 100kg fish 10g on the first day, halved from the second day to the sixth day, and fed continuously for 6 days. 4. White-headed white beak disease: the pathogen is bacteria. Symptoms: The snout and head of the sick fish lose their normal color and turn white, especially when observed in water. The disease mainly harms the 3-day-old Silurus meridionalis splashing water or the Silurus meridionalis seedlings with the height of 1~ 1.5 cm. Prevention and control methods: (1) Sprinkle Galla Chinensis decoction all over the pool water to make the concentration of the pool water 2-4 mg/L (2) Splash furazolidone all over the pool water to make the concentration of the pool water 0.2-0.5 mg/L..5. White dermatosis: the pathogen is bacteria. The diseased fish is white at first, and then spreads to the whole tail stalk and the second half of the body, which is obviously different from the first half, so the disease is also called white tail disease. The tail fin of seriously ill fish is rotten or incomplete. It mainly harms the southern catfish fry, with a body length of 3~6 cm, which is easy to occur at high density. Control method: (1) Spray bleaching powder with the concentration of 1 mg/L in the whole pond for 3-5 days. (2) Soak the sick fish in 2.5% salt water and a few drops of vinegar for 5~ 10 minutes. 6. Indian disease: the pathogen to be studied. The body color of the diseased fish is black, and the mucus on the body surface is obviously reduced. The lesions are located on both sides of the body surface and abdomen, and a few are in the back. At the beginning of the disease, the skin is ulcerated, congested and inflamed, and the muscles are oval and dark red spots, such as seals, and in severe cases, the muscles rot. A few cases were complicated with mullet disease and gill rot. The disease mainly harms the parent fish and backup parent fish of Silurus meridionalis, and there is no obvious epidemic season. The incidence rate is related to the nutritional status of fish, stocking density, fish damage and water quality environment. Prevention and treatment: (1) intramuscular injection of penicillin, with a weight of 20,000 international units per kilogram, and application of erythromycin ointment to the affected area. (2) The disease can be prevented by mastering the reasonable stocking density and keeping the water fresh (adding fresh water regularly or changing water appropriately, and splashing the whole pool with quicklime 15 ~ 20mg/L every half month or so). 7. Canker disease: pathogens need to be studied. The mouth of the sick fish is white, the mouth is swollen and white, the mouth cannot be closed, the beard is white or broken, and erythema appears on both sides of the fish. In severe cases, the epidermis at the erythema festers, exposing muscles. The disease mainly harms adult catfish and is prevalent from March to April. Control method: (1) Spray furazolidone 0. 1~0.2 mg/L in the whole pond, or soak sick fish 15~30 minutes at the concentration of 5 5~ 10 mg/L 0 mg/L. (2) Patients with serious illness can be injected with chloramphenicol 5mg/kg intramuscularly. 8. Tail rot: The pathogen is Aeromonas. The diseased fish festered from dorsal fin to anus in a large area, and the caudal fin was broken in severe cases. The disease mainly harms catfish seedlings of 2.5~5 cm. Prevention and treatment methods are the same as those of white mouth disease. 9. The pathogen of enteritis needs to be studied. In the early stage of diseased fish, the base of anal fin or each fin is red and swollen, and sometimes the anus is red and swollen. Almost all the dead fish are congested in the intestines. It mainly harms adult catfish, especially southern catfish that eats mixed bait or a lot of rotten fish pieces. It is popular from April to June. It can form complications with rotten gills. Control method: (1) Strengthening feeding management, keeping the water fresh and not throwing moldy or rotten bait are the key to prevent the disease. (2) After the onset of the disease, feed the mixed bait of 10 ~ 20g of furazolidone every 100 kg of fish weight, once a day for 3 days; Or every 100 kg of bait, add 40% Virulin (moroxydine hydrochloride) to the bait once a day 1 time for 4~5 days. When feeding, use 1 mg/L bleaching powder or 0.3 mg/L strong chlorine essence for disinfection, and sprinkle 1~3 times in the whole pool or box as appropriate. 10, Shui Mu: The pathogen is Shui Mu. The disease mainly occurs in the hatching stage of fish eggs, and it is more serious when the water temperature is below 19. Water mold first breeds on a few fish eggs, and then spreads to fertilized eggs, turning fish eggs into gray fluff balls, which is more obvious when observed in water. Emphasis should be placed on the prevention of this disease. During each incubation period, fish eggs 10~ 15 seconds were soaked in 67 mg/L malachite green solution every day for 2 days. Or spray malachite green solution with the same concentration on the incubation ring twice every morning and evening until the fry hatch. For fish eggs with mild water mold, malachite green solution with concentration of 67 mg/L can be soaked for 5~ 10 minutes, and Fu Gui catfish has certain curative effect. 1 1. Myxosporiasis: The pathogen is Myxosporidia. There are many small white cysts on the body surface of sick catfish. Microscopic examination revealed a large number of myxosporidia. It is popular from May to June. Control method: Use 0.3~0.5 mg/L crystal trichlorfon to spray the whole pond, and spray it 2~3 times as appropriate. 12, rotifer disease: the pathogen is rotifer and the species of rotifer. Rotifers are parasitic on catfish body surface and gill filaments. Parasitic on the body surface is often concentrated in the mouth, fins and other places of sick fish to form a layer of white clouds; Parasitic on gill filaments, they often gather in groups at the edge or gap of gill filaments, destroying gill tissues, causing gill tissues to rot in severe cases, exposing gill cartilage, and causing sick fish to die due to dyspnea. It is popular from April to June. Control method: (1) Dissolve and mix copper sulfate with concentration of 0.3 mg/L and ferrous sulfate with concentration of 0. 1 mg/L, and then scatter it in the whole pond. (2) 0.5 mg/L for catfish fry in pond and 2 mg/L for catfish fry in cage, spraying once a day for 3 consecutive days. 13, Trichinella spiralis: the pathogen is Trichinella spiralis. Trichinella spiralis is mainly parasitic on the gill filaments of catfish. In severe infection, mucus on gills increases, and the ends of gill filaments turn white and rot. The disease mainly harms 1~2 cm catfish seedlings, and it is prevalent from April to June. The control method is the same as wheel disease. 14, Cucurbitaceae: the pathogen is multi-chamber pumpkin. Root-knot nematodes are parasitic on catfish body surface and gill filaments. When a large number of parasites appear, fish flock and float on the water surface, without eating, and their body color is black. Visually, white vesicles appeared on the body surface and fins of the diseased fish, the color of gill filaments faded and mucus increased. In severe cases, a white film often appears on the body surface of sick fish, especially on the top of the head. High-density feeding is easy to happen and popular in May and June. Control method: (1) Soak the sick fish in formalin solution with concentration of 20 ~ 40mg/L for 20 ~ 30min. (2) Ginger and pepper mixture: 0.37 g of dried pepper and 0. 1 ~ 0. 15 g of dried ginger per square meter of water surface (depth 1 m), add water and boil for half an hour, then splash water with medicinal juice, once a day, for 3 days. 15. Immobilized ciliary disease: The pathogens are Colletotrichum, Colibacillus, Colibacillus, and Coccidium. The sessile ciliates mainly attach to the body surface and gills of catfish. In severe cases, the sick fish are thin and black, do not eat, and are slow to respond. The disease mainly harms catfish seedlings of 3~6 cm, and it is prevalent from May to June. Prevention and control methods: soak the sick fish with 3 mg/L copper sulfate for 2 hours, or spray the whole pond with 0.6 mg/L copper sulfate. 16. Onchocerciasis: The pathogens are Monosomiasis, Anchoraceae and Fu Gui Ancylostoma. The symptoms are reduced food intake, swimming alone in the water, slow response, shortness of breath, emaciation and black body color. Visually, the gill of the diseased fish is swollen, and the mucus in the gill filament is increased and there is dirt. Silkworms are mainly parasitic on catfish gills and also parasitic on catfish body surface, which mainly harms 7~ 10 cm larvae and is prevalent from May to July. Control method: (1) Spraying 0.2~0.3 mg/L crystal trichlorfon in the whole pond. (2) Soak the sick fish with 20 mg/L potassium permanganate for 30 minutes or with 3 mg/L crystal trichlorfon for 65438 0 hours. 17, Taenia solium: The pathogen is Taenia solium. Anatomical observation of the diseased fish shows that there is no food in the gastrointestinal tract and there is more yellow mucus in the intestine, so tapeworms are parasitic in the intestine. Control method: According to the life history of parasites and the breeding situation of Silurus meridionalis, the following control measures can be taken. (1) Daphnia should be fresh and refined. Before feeding, it should be filtered and washed to remove impurities and large crustaceans, and then soaked and disinfected with 0.03% salt solution to reduce or kill the intermediate host of tapeworm. (2) Soaking with trichlorfon before feeding water worms can also reduce the infection rate of tapeworms. 1 kg earthworm/1 g crystal trichlorfon, soaked until the earthworm shrinks. (3) crystal trichlorfon bait (100 kg bait +60 g crystal trichlorfon) once a day for 3 days. 18, crustacean diseases: the pathogen is China flea or anchovy flea or Japanese sole. These three crustacean diseases usually occur in the parents of Silurus meridionalis in ponds. The symptom is that fish swim uneasily on the surface of the water and erect their tail fins from time to time. The above parasites were found on the body surface and gills of fish by net capture. Prevention and control methods: the crystal trichlorfon solution is sprinkled all over the pond water to make the concentration of the pond water be 0.4~0.5 mg/L. 19. Nutritional fish disease: The disease is caused by single feed material, or lack of certain nutrients or spoilage of the feed. Symptoms are hepatomegaly, yellowing, ascites, enlarged gallbladder, black bile and pale pancreas. It is popular from March to May. Prevention and control methods: feed fresh miscellaneous fish and other animal bait; Improve the feed formula and increase the dosage of vitamins and mineral additives.