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What to Do When the Leaves of Large-Leaf Gardenia Turn Yellow? Causes and Solutions
[Gardenia Leaves Turning Yellow] What to Do When the Leaves of Large-Leaf Gardenia Turn Yellow
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Large-size river crab breeding technology promotion project in the Yellow River Delta passes acceptance
Large-size river crab breeding technology promotion in the Yellow River Delta passes acceptance
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Nearly all of his 100,000 large yellow croakers were wiped out, yet he still refused to back down
Nearly all of the 100,000 large yellow croakers were wiped out, and even that did not scare him off
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Large yellow croaker
(1) Morphological characteristics: The body of the large yellow croaker is elongated and laterally compressed, with the dorsal and ventral margins forming a broad arc, and the caudal peduncle slender. Body length is 3.5-4.2 times body depth and 3.4-3.8 times head length. Head length is 3.9-5.0 times snout length and 3.-5.7 times eye diameter. Caudal peduncle length is 3.4-3.8 times caudal peduncle depth. The dorsal surface and upper sides are yellowish brown, the lower sides and ventral surface golden yellow, the dorsal and caudal fins grayish yellow, the pectoral and pelvic fins yellow, and the lips orange-red. The head is laterally compressed, large, pointed and blunt, with well-developed mucous cavities. The snout is bluntly pointed, larger than the eye diameter. The snout folds are complete, not
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Many difficulties in large-scale farming of yellow catfish, polyculture models work better
The yellow catfish is a benthic omnivorous fish, with tender flesh, rich nutrition and extremely high economic value, making it a farming species with great market potential. The yellow catfish has strong adaptability and grows slower than cyprinid fish, but grows relatively fast for the species itself; fry bred in the same year can reach marketable size within that year, and the population yield is relatively high. Because large-scale artificial farming currently faces certain difficulties, carrying out polyculture has become imperative. Polyculture of yellow catfish in fish ponds has the following advantages: first, it can feed on low-value small miscellaneous fish and shrimp in the pond,
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What are the prevention and control methods for abdominal distension and ulceration disease in large yellow croaker?
(1) Pathogen According to reports from Japan, it is Vibrio alginolyticus; but another source says it is Edwardsiella. (2) Symptoms The stomach sac of diseased fish is especially swollen and enlarged, and in some fish the dorsal and ventral walls rupture from the swelling, with the entire stomach sac detaching from the fish body. Large numbers of diseased fry float scattered on the water surface, unable to feed, spin in circles for several days, then sink and die. Larvae at 15-20 days of age are most susceptible, showing a peak mortality period. (3) Prevention and control methods Increase the water exchange rate, improve the rearing environment, avoid feeding Artemia nauplii alone, feed copepods earlier, strengthen the nutrition of larvae and juveniles, and strictly control water quality.
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Prevention and Control Methods and Technical Key Points for Common Diseases of Large Yellow Croaker
I. Cryptocaryon irritans disease (white spot disease) Symptoms: A large number of small white spots appear on the body surface. In severe cases, the fish body is covered with a layer of white film. Due to the destruction caused by the parasites, secondary bacterial infection is triggered, resulting in inflammation and necrosis of the fish epidermis, scales easily falling off, fin rays rotting and splitting. When parasitizing the gills, it destroys the gill filaments, and after bacterial infection, it causes gill rot. When the parasites invade the fish's cornea, it causes inflammation and blindness. Diseased fish have reduced appetite, become thin, and swim erratically. The parasites can be identified by microscopic examination. Prevention
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Prevention and Control Methods and Technical Key Points for Protozoan Diseases in Large Yellow Croaker
(1) Pathogen: Cryptocaryon irritans (Crypjocaryonirrions). (2) Symptoms: Small white spots appear on the body surface and gills of diseased fish. These small white spots are white vesicles formed by the parasitism of the parasite, irritation of the host, and the secretion of large amounts of mucus and proliferation of epidermal cells in the surrounding tissues. In severe cases, the body surface tissues are destroyed. If bacteria invade, it can cause skin inflammation, scale loss, fin membrane rot and splitting, corneal damage, and blindness. The diseased fish ultimately die due to loss of appetite,
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A Detailed Guide to the Main Diseases of Large Yellow Croaker and Their Prevention and Treatment Methods
I. Bacterial Diseases 1. Vibriosis Pathogen: Vibrio parahaemolyticus. Symptoms: The appearance of ulcers on the body surface of diseased fish is the typical feature of this disease. In the early stage, there are petechiae, ecchymoses, and irregular red patches on the body surface, mostly seen on the abdomen and tail. In severe cases, there is bleeding and ulceration of the lower jaw, congestion and redness at the fin base, missing fin rays, and rotting of the caudal peduncle muscle, forming hemorrhagic ulcers. The liver, spleen, kidney, and intestine are all congested, the liver is enlarged and earth-yellow in color, and there is pale yellow mucus in the intestinal tract. Microscopic examination of the tissue at the lesion site reveals slightly curved bacteria. Epidemiology: This disease
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What are the treatment methods for several diseases of large yellow croaker?
I. White spot disease (cryptocaryoniasis) 1. Pathogen: Cryptocaryon irritans, also known as "marine fish ichthyophthirius," belongs to the ciliate class of the phylum Ciliophora. The body is oval or spherical, with uniform cilia over its entire surface. 2. Symptoms: The parasite mainly infests the body surface, gills and fin rays of the large yellow croaker. In the early stage of the disease, white spots are visible to the naked eye on the caudal and pectoral fins of the diseased fish, and as the disease progresses they gradually spread to the body surface and gills, with the increasing white spots forming a film, commonly known as "white spot disease." The diseased fish are restless, either swimming in circles along the pond walls, or
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