Prevention and Treatment Methods for Common Diseases in Sturgeon Farming

Bacterial enteritis in sturgeon

1. Symptoms and causes: This disease is caused by bacteria. The symptoms are bleeding in the abdomen and mouth, redness and swelling of the anus, and emaciation of the fish.

2. Prevention and treatment method: Feed medicated bait containing 0.2% furazolidone, and continuous feeding for 5-6 days can cure it.

Sturgeon swollen mouth disease

1. Symptoms and causes: This disease occurs more frequently in the larval stage of the Amur sturgeon (Acipenser schrenckii). It is caused by bacteria, mainly due to feeding spoiled bait. The symptoms are swelling of the mouth, congestion around it, redness and swelling of the excretory pore, inability to move, and sometimes accompanied by saprolegniasis.

2. Prevention and treatment method: Promptly remove diseased fish, clear away residual bait, replace with fresh water, regularly disinfect the feeding table, and ensure the quality of the feed.

Trichodiniasis in sturgeon

1. Symptoms and causes: The pathogen is Trichodina. Because too many pathogens parasitize the fish body and gill rakers, the fish becomes weakened, swims sluggishly, stops feeding, and grows slowly, with massive mortality in severe cases.

2. Prevention and treatment method: Soak in 5% saline water for about 1 hour, then rear in flowing water for a relatively good effect; in addition, soaking in a 15%-25% formalin solution can also be used, but copper sulfate must not be used.

Chilodonelliasis in sturgeon

1. Symptoms and causes: The pathogen is Chilodonella. When the pathogen parasitizes the fish body, oral cavity, and gills in large numbers, it causes the diseased fish to become restless, with a blue-gray membranous appearance on the body surface and increased melanin in the oral cavity and eyes.

2. Prevention and treatment method: There is currently no effective treatment. The main measure taken is to transfer the diseased fish to a flowing-water pond for rearing, which can reduce the mortality rate to below 4%.

Trypanosomiasis in sturgeon

1. Symptoms and causes: The pathogen is Trypanosoma. The diseased fish moves sluggishly, its body bends in the water into an “L” or “S” shape, often lies at the bottom, cannot feed, and its body color is dark and lusterless. Sometimes it spins rapidly up and down in the water. If not treated promptly, it will die within 3-5 days after onset.

2. Prevention and treatment method: The main treatment is to add 20-40 international units of penicillin G ammonium salt to 5 kg of water for medicated bathing, once a day for 2 hours each time; the dosage is 40 international units on the first two days and 20 international units from the third day onward, and it can be cured in about 7 days, with an early cure rate of up to 100%.

Ichthyophthiriasis in sturgeon

1. Symptoms and causes: This disease is also called white spot disease. The pathogen is Ichthyophthirius multifiliis. The symptoms are: with the naked eye, large numbers of spots can be found outside the gill filaments and fin rays, and in severe cases the spots appear in patches. The diseased fish gradually becomes emaciated, its swimming ability weakens, and it becomes restless and agitated, with reduced appetite. Under a microscope, the white spots appear as thick blister-like shapes covered with a white mucous layer. Because Ichthyophthirius multifiliis invades the skin and gill tissues of the fish and uses the fish's tissue cells as nutrition, it causes tissue necrosis, obstructs respiration, and ultimately leads to death.

2. Prevention and treatment method: Soaking in a formalin solution at a concentration of 50 g per cubic meter of water has a certain effect; during seedling rearing, raising the water temperature above 25 degrees C, preferably to 28-30 degrees C for control, is more effective.

Paraergasilus disease in sturgeon

1. Symptoms and causes: The pathogen is Paraergasilus. This disease occurs more frequently in the Chinese sturgeon (Acipenser sinensis). The pathogen parasitizes the fin base, anus, nasal cavity, pharynx, and esophagus of the fish, and is most commonly seen in the gill arches and oral cavity.

2. Prevention and treatment method: Generally, manual removal of the pathogen is used, and antibiotic ointment is applied to the affected area; or the diseased fish is placed in 5% saline water for 1-2 hours, which also has a relatively good effect.

Gas bubble disease in sturgeon

1. Symptoms and causes: The cause is excessive microbubbles in the rearing water, especially supersaturation of nitrogen and oxygen (above 10 ml/L), which causes microbubbles to form in the fish's intestines, gills, muscles, and other tissues. The small bubbles then merge into large bubbles. The diseased fish swims slowly and weakly, floats to the surface, and swims along the pond edge. In severe cases, many bubbles arranged in a linear pattern can be seen with the naked eye inside the two groove clefts on both sides in front of the mouth. Under microscopic examination, the gills are whitish, mucus between the gill filaments increases, there are many small bubbles, the gill filaments are intact, the liver is relatively pale, there is food in the stomach, and there are food, yellow mucus, and bubbles in the intestine. There are no other external symptoms, and it appears to die as if from blood loss; some show blood throughout the entire head, redness and swelling around the mouth, and inability to close the mouth. This disease is highly harmful.

2. Prevention and treatment method: The main preventive method is to improve water quality conditions, eliminate supersaturated gases in the water, and supplement with medicated bait treatment.

Gyrodactyliasis in sturgeon

1. Symptoms and causes: The cause is feeding undisinfected water fleas. This disease mainly occurs at the seedling stage. The mouth area and gills of the diseased fish are congested, and the fry appear to gasp at the surface due to oxygen deficiency.

2. Prevention and treatment method: Soaking the fish in crystalline trichlorfon at a concentration of 0.25% has a relatively good effect.

Hemorrhagic disease in sturgeon

1. Symptoms and causes: This disease mainly occurs in the larval stage of sturgeon. It is caused by Aeromonas bacteria and is extremely contagious, with rapid onset, fast spread, and very high mortality.

2. Prevention and treatment method: During seedling rearing, disinfect with drugs such as chlorine dioxide or furazolidone every 5-10 days, regularly add antibacterial drugs to the feed for prevention, and add B vitamins such as vitamin C and vitamin E to the feed to improve immunity.