Since the beginning of last year's winter, several fish and duck breeding farms in Zengcheng have suffered from fish oxygen and poisoning accidents. The Municipal Bureau of Fisheries sent technicians to investigate the accident ponds, and there were no pollution sources from factories and mines in the surrounding areas. Some people suspected of being poisoned or The water in the pond water is deficient in oxygen, ammonia nitrogen, nitrogen nitrite, carbon dioxide, and hydrogen sulphide exceed the safe water standards for fishery and result in a large number of fish poisoning. During wintering, fish often cause direct death and major economic losses due to defects in the pond environment and poor management.
The author will introduce Zengcheng's common problems and management methods for controlling fish during wintering in recent years for reference by farmers.
First, common problems during wintering
1. During the hypoxia winter fish, although the amount of activity is reduced during feeding, it still needs some dissolved oxygen to maintain slow breathing. Dissolved oxygen in water is mainly supplemented by the photosynthesis of phytoplankton and the dissolved oxygen in the air. However, in the cold winter season, once the ice on the surface of the pond freezes with frost, the oxygen in the air cannot dissolve in the water. In particular, clear ponds are over-medicated before winter and the algae in the water are killed. The green plants in the water cannot use photosynthesis to make oxygen. In winter, most of the fish are concentrated in the bottom of the pond. If the water quality of the pond is poor, the fish is weak and it is more likely to cause the fish to lose oxygen and suffocate.
2. The ammonia, nitrogen, nitrous oxide, carbon dioxide, and hydrogen sulfide produced by the decomposition of silt, residual bait, livestock manure, and fish excrement at the bottom of the wintering pond are lost when they lose the phytoplankton that use them as a nutrient source. Harmful gas accumulates in water and poses a great threat to overwintering fish. Especially nitrite nitrogen, it will reduce the oxygen carrying capacity of the cells, reduce the fish's tolerance to hypoxia, resulting in fish poisoning and even a large number of deaths (sometimes the death of the whole pond). If the carbon dioxide content in the water exceeds 80 mg/l, the fish will suffer from respiratory difficulties, which will affect the metabolism and cause a large number of fish deaths.
3. Diseases The water temperature in winter is low, and fish diseases are relatively few; but some diseases can easily occur in the winter, such as parasitic worms such as small melon worms, myxozoans, etc., and hydromycosis is also a common fish disease in winter. Prevention and symptomatic treatment. Otherwise, it will easily lead to weight loss and death of overwintering fish.
Second, the management method during wintering
1. Before the clear pond is disinfected for winter, the pond will be completely dredged and disinfected, and the sludge at the bottom of the pond, residual baits, and weeds will be completely removed. Then, 250 kg of quick lime and 120 kg of tea bran per mu will be used. (Crush after soaking water for 30 hours Sprinkle) or bleaching powder 27 kg of water disinfection, kill bacteria, parasite eggs and wild fish and other harmful organisms, to create a good living environment for fish overwintering.
2, Fertilizer fertilizer water quality wintering pool requirements fertile, in order to heat insulation. According to the water quality conditions, some decomposed livestock manure can be used as base fertilizer and algae and other phytoplankton can be cultivated to enhance the oxygen-generating function of wintering pool water. During the winter, if the water quality is lean, you can apply 5 kg of urea per acre and 10 kg of phosphate fertilizer at noon on a sunny day to speed up fertility.
3. During the overwintering period, new fish are added at appropriate time. In addition to maintaining a high pond water level (2 to 3 meters is good) for oxygenation and warmth, new water should be injected periodically to supplement the dissolved oxygen in the water and reduce the concentration of toxic substances. Improve the winter survival conditions of fish. Normally, new water is added every 20 days. Each time, 20-30 cm water level can be filled. If the pool water deteriorates or deteriorates, a part of the old water (20-30 cm) can be drained, and then the new water can be injected 20-30 cm to maintain the general balance.
4, regular disinfection (15-20 days) to the pond were cast some lime (Mushi 40 kg) or bleaching powder (2 kg per mu of rice) and other drugs to improve the bottom, water quality and prevent diseases.
5. When the appropriate feeding water temperature is above 8°C, the overwintering fish are still feeding and growing. At this time, 1% to 1.5% of the concentrate feed (peanut bran, wheat husk, bean cake powder, etc.) should be fed according to the weight of the fish. Increase fish intake, enhance physical fitness, and help winter.
III. Prevention and treatment of common fish diseases during wintering
1. Saprolegniasis The disease is caused by the appearance of fungal parasite fish. Saprolegnia is most prevalent in late winter and early spring, and it is most likely to occur during the January-February period when fish species and adults (in particular, tropical and subtropical fish) enter the wintering period. When the fish is injured, the water fungal spores invade the wound, sucking up the nutrients in the fish skin to germinate and growing rapidly. One end of the hyphae absorbs like the roots in the skin tissue of the fish, and most of the rest is exposed outside the body surface. . The water hyphae hyphae appear as white or gray-white cotton wool fluttering in the water. After the fish parasitizes the hydromycosis, the mycelium absorbs the tissue nutrition in the epidermis of the fish, and the bacteria infects the wound to make the epidermal tissue necrotic and the fish gradually die due to the thinness. Control methods: (1) Care must be taken in fishing nets to avoid injury; (2) Use 3% to 4% of salt water, or salt and baking soda to make a mixture of 0.4 to 5 to 15 minutes. .
2. Myxosporidiosis This disease is one of the parasite diseases with the greatest harm to fish and the most widely distributed. Parasitic forms of cysts vary in size and form in different organs of fish. For example, Trichosporidium parasitizes in the muscles of the back of the head of a carp and forms nodules. The diseased fish loses its commercial value due to distortion. Control methods: 1 Thoroughly clear the pond with quick lime, with 150 kilograms per mu, to kill the overwintering spores at the bottom of the pond. 2 Fish species can be washed with crystal trichlorfon for 5 minutes and then splashed with 0.2ppm trichlorfon. 3 The ponds in the affected area were splashed with crystal trichlorfon and then baited with 4 grams of trichlorfon per 100 kilograms of fish and 2-3 kilograms of concentrated feed (yellow powder was good). The baits were fed and the three days were a course of treatment. (Note: Shrimp, crab, freshwater whitefish, sweet-scented osmanthus fish, etc. cannot be fed with trichlorfon medicinal baths and baits to avoid death from poisoning). 4 Add 2% to 3% 100 insect net (also known as spore net) in the feed, and feed it for 2 to 3 days.
3, oblique tuberculosis This disease is caused by the invasion of the clubworm. The temperature of the water suitable for the growth of the slugs is 5-18°C, and the optimum breeding water temperature is 5-12°C. Therefore, the 11-December of each year and the early spring of January-February are the epidemic seasons of the disease. Benthic larvae mainly attack the skin and skin of fish and use their mucus as a nutrient. When the fish is parasitized by oblique beetles, maggots and skin are destroyed, and mucus is secreted in large amounts, causing fish to breathe hard, the fish is thin, and the body surface is dark. Slow movement, then died. Control methods: 1 thoroughly clear the pond with lime disinfection, kill pathogens. 2 The diseased fish was soaked in copper sulfate (8 grams per ton of water) for 30 minutes. 3 Quanchiposa copper sulfate (0.5ppm) and ferrous sulfate (0.2ppm) mixture.
4, white spot disease caused by a large number of small melon insect parasitic fish disease. From the beginning of winter to the end of spring, when the water temperature is 15-20 °C, it is easy to cause the epidemic of poolfish white spot disease. The diseased fish was covered with a white film. After being parasitized by helminths, the pupa tissue secretes mucus in a large amount, congestes small pieces of hemorrhoids, causes hemorrhage or necrosis, and sticks together and erodes. When the parasite is parasitized in the eye, it can make the eyeball cloudy and white. The sick fish reacted slowly, swimming slowly and stopped feeding. Control methods: 1 Over-winter pool with lime clear pond to kill the small melon cyst. 2 When the fish are stocked, if they find that the small melon larvae use 0.3ppm Quanchiposa fish splash, use 2-3 days.
5, bubble disease The disease occurred in the past summer and autumn seasons, but in recent winters often occur during the winter. The reason is that after many years of cultivation, ponds with too much sludge or water, there is a lot of methane, ammonia nitrogen and carbon dioxide gas accumulated in the pool water. At this time, a large number of air bubbles appear in the water, so that the fish get bubble. Control methods: 1 Overwintering pond is thoroughly sterilized before putting fish into the pond. (2) Breaking some ice eyes around the ice in winter ponds is not only conducive to the emission of poisonous gases in the pond water, but also conducive to atmospheric air infiltration, which is more conducive to the photosynthesis of phytoplankton, increases the dissolved oxygen in the pool water, and improves the conditions for over-wintering. . 3 with 0.2-0.3ppm chlorinated water Quanchiposa, neutralize the organic matter in the oxidation of water.
The author will introduce Zengcheng's common problems and management methods for controlling fish during wintering in recent years for reference by farmers.
First, common problems during wintering
1. During the hypoxia winter fish, although the amount of activity is reduced during feeding, it still needs some dissolved oxygen to maintain slow breathing. Dissolved oxygen in water is mainly supplemented by the photosynthesis of phytoplankton and the dissolved oxygen in the air. However, in the cold winter season, once the ice on the surface of the pond freezes with frost, the oxygen in the air cannot dissolve in the water. In particular, clear ponds are over-medicated before winter and the algae in the water are killed. The green plants in the water cannot use photosynthesis to make oxygen. In winter, most of the fish are concentrated in the bottom of the pond. If the water quality of the pond is poor, the fish is weak and it is more likely to cause the fish to lose oxygen and suffocate.
2. The ammonia, nitrogen, nitrous oxide, carbon dioxide, and hydrogen sulfide produced by the decomposition of silt, residual bait, livestock manure, and fish excrement at the bottom of the wintering pond are lost when they lose the phytoplankton that use them as a nutrient source. Harmful gas accumulates in water and poses a great threat to overwintering fish. Especially nitrite nitrogen, it will reduce the oxygen carrying capacity of the cells, reduce the fish's tolerance to hypoxia, resulting in fish poisoning and even a large number of deaths (sometimes the death of the whole pond). If the carbon dioxide content in the water exceeds 80 mg/l, the fish will suffer from respiratory difficulties, which will affect the metabolism and cause a large number of fish deaths.
3. Diseases The water temperature in winter is low, and fish diseases are relatively few; but some diseases can easily occur in the winter, such as parasitic worms such as small melon worms, myxozoans, etc., and hydromycosis is also a common fish disease in winter. Prevention and symptomatic treatment. Otherwise, it will easily lead to weight loss and death of overwintering fish.
Second, the management method during wintering
1. Before the clear pond is disinfected for winter, the pond will be completely dredged and disinfected, and the sludge at the bottom of the pond, residual baits, and weeds will be completely removed. Then, 250 kg of quick lime and 120 kg of tea bran per mu will be used. (Crush after soaking water for 30 hours Sprinkle) or bleaching powder 27 kg of water disinfection, kill bacteria, parasite eggs and wild fish and other harmful organisms, to create a good living environment for fish overwintering.
2, Fertilizer fertilizer water quality wintering pool requirements fertile, in order to heat insulation. According to the water quality conditions, some decomposed livestock manure can be used as base fertilizer and algae and other phytoplankton can be cultivated to enhance the oxygen-generating function of wintering pool water. During the winter, if the water quality is lean, you can apply 5 kg of urea per acre and 10 kg of phosphate fertilizer at noon on a sunny day to speed up fertility.
3. During the overwintering period, new fish are added at appropriate time. In addition to maintaining a high pond water level (2 to 3 meters is good) for oxygenation and warmth, new water should be injected periodically to supplement the dissolved oxygen in the water and reduce the concentration of toxic substances. Improve the winter survival conditions of fish. Normally, new water is added every 20 days. Each time, 20-30 cm water level can be filled. If the pool water deteriorates or deteriorates, a part of the old water (20-30 cm) can be drained, and then the new water can be injected 20-30 cm to maintain the general balance.
4, regular disinfection (15-20 days) to the pond were cast some lime (Mushi 40 kg) or bleaching powder (2 kg per mu of rice) and other drugs to improve the bottom, water quality and prevent diseases.
5. When the appropriate feeding water temperature is above 8°C, the overwintering fish are still feeding and growing. At this time, 1% to 1.5% of the concentrate feed (peanut bran, wheat husk, bean cake powder, etc.) should be fed according to the weight of the fish. Increase fish intake, enhance physical fitness, and help winter.
III. Prevention and treatment of common fish diseases during wintering
1. Saprolegniasis The disease is caused by the appearance of fungal parasite fish. Saprolegnia is most prevalent in late winter and early spring, and it is most likely to occur during the January-February period when fish species and adults (in particular, tropical and subtropical fish) enter the wintering period. When the fish is injured, the water fungal spores invade the wound, sucking up the nutrients in the fish skin to germinate and growing rapidly. One end of the hyphae absorbs like the roots in the skin tissue of the fish, and most of the rest is exposed outside the body surface. . The water hyphae hyphae appear as white or gray-white cotton wool fluttering in the water. After the fish parasitizes the hydromycosis, the mycelium absorbs the tissue nutrition in the epidermis of the fish, and the bacteria infects the wound to make the epidermal tissue necrotic and the fish gradually die due to the thinness. Control methods: (1) Care must be taken in fishing nets to avoid injury; (2) Use 3% to 4% of salt water, or salt and baking soda to make a mixture of 0.4 to 5 to 15 minutes. .
2. Myxosporidiosis This disease is one of the parasite diseases with the greatest harm to fish and the most widely distributed. Parasitic forms of cysts vary in size and form in different organs of fish. For example, Trichosporidium parasitizes in the muscles of the back of the head of a carp and forms nodules. The diseased fish loses its commercial value due to distortion. Control methods: 1 Thoroughly clear the pond with quick lime, with 150 kilograms per mu, to kill the overwintering spores at the bottom of the pond. 2 Fish species can be washed with crystal trichlorfon for 5 minutes and then splashed with 0.2ppm trichlorfon. 3 The ponds in the affected area were splashed with crystal trichlorfon and then baited with 4 grams of trichlorfon per 100 kilograms of fish and 2-3 kilograms of concentrated feed (yellow powder was good). The baits were fed and the three days were a course of treatment. (Note: Shrimp, crab, freshwater whitefish, sweet-scented osmanthus fish, etc. cannot be fed with trichlorfon medicinal baths and baits to avoid death from poisoning). 4 Add 2% to 3% 100 insect net (also known as spore net) in the feed, and feed it for 2 to 3 days.
3, oblique tuberculosis This disease is caused by the invasion of the clubworm. The temperature of the water suitable for the growth of the slugs is 5-18°C, and the optimum breeding water temperature is 5-12°C. Therefore, the 11-December of each year and the early spring of January-February are the epidemic seasons of the disease. Benthic larvae mainly attack the skin and skin of fish and use their mucus as a nutrient. When the fish is parasitized by oblique beetles, maggots and skin are destroyed, and mucus is secreted in large amounts, causing fish to breathe hard, the fish is thin, and the body surface is dark. Slow movement, then died. Control methods: 1 thoroughly clear the pond with lime disinfection, kill pathogens. 2 The diseased fish was soaked in copper sulfate (8 grams per ton of water) for 30 minutes. 3 Quanchiposa copper sulfate (0.5ppm) and ferrous sulfate (0.2ppm) mixture.
4, white spot disease caused by a large number of small melon insect parasitic fish disease. From the beginning of winter to the end of spring, when the water temperature is 15-20 °C, it is easy to cause the epidemic of poolfish white spot disease. The diseased fish was covered with a white film. After being parasitized by helminths, the pupa tissue secretes mucus in a large amount, congestes small pieces of hemorrhoids, causes hemorrhage or necrosis, and sticks together and erodes. When the parasite is parasitized in the eye, it can make the eyeball cloudy and white. The sick fish reacted slowly, swimming slowly and stopped feeding. Control methods: 1 Over-winter pool with lime clear pond to kill the small melon cyst. 2 When the fish are stocked, if they find that the small melon larvae use 0.3ppm Quanchiposa fish splash, use 2-3 days.
5, bubble disease The disease occurred in the past summer and autumn seasons, but in recent winters often occur during the winter. The reason is that after many years of cultivation, ponds with too much sludge or water, there is a lot of methane, ammonia nitrogen and carbon dioxide gas accumulated in the pool water. At this time, a large number of air bubbles appear in the water, so that the fish get bubble. Control methods: 1 Overwintering pond is thoroughly sterilized before putting fish into the pond. (2) Breaking some ice eyes around the ice in winter ponds is not only conducive to the emission of poisonous gases in the pond water, but also conducive to atmospheric air infiltration, which is more conducive to the photosynthesis of phytoplankton, increases the dissolved oxygen in the pool water, and improves the conditions for over-wintering. . 3 with 0.2-0.3ppm chlorinated water Quanchiposa, neutralize the organic matter in the oxidation of water.
Lactobacillus Crispatus,Crispatus Lactobacillus,Lactobacillus Crispatus Powder,Lactobacillus Crispatus Probiotic
Biodep Biotechnology Co. ,Ltd. , https://www.biodep.com