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Overwintering techniques for freshwater pomfret fry
The freshwater pomfret (Piaractus brachypomus) is a freshwater aquaculture fish species introduced to mainland China for farming in the 1980s. Because of its good meat quality, fast growth, ease of extensive rearing and large market demand, it is deeply favored by the vast number of farmers. However, since the freshwater pomfret is a warm-water fish, its optimal growth
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Key points for overwintering management in the fry and fingerling culture of freshwater pomfret
The freshwater pomfret is a tropical fish species. Its main suitable growth temperature range is between 21-32°C, with the optimum range at 28-30°C. At a water temperature of 16°C, the pomfret only begins to eat a small amount; at 12°C, the fish's balance becomes disturbed; and at 10°C, it causes death. During the overwintering process, water temperatures that are too low
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How to prevent and treat saprolegniasis in freshwater pomfret during overwintering
1. Diseases commonly occurring in freshwater pomfret during overwintering. The most common fish diseases occurring in freshwater pomfret during overwintering are saprolegniasis, ichthyophthiriasis, trichodiniasis, chilodonelliasis, etc., especially ichthyophthiriasis, which can easily cause explosive death. The causes of various fish diseases are due to
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Overwintering management techniques for freshwater pomfret fry and fingerlings after being stocked into ponds
1. Overwintering pond preparation: area 600-1500 sq m, pond depth 1.5 m; the pond water in the Pukou District area of Nanjing is geothermal spring water, flowing into the pond in a slight current; the inlet pipe is 10 cm, and the mud at the pond bottom is 10 cm thick. After drying the pond and disinfecting it, fill with water. Each pond is equipped with two 3-kilowatt aerators. 2. Pomfret fry and fingerlings
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How to prevent and treat ichthyophthiriasis in freshwater pomfret during overwintering?
Ichthyophthiriasis is the second most common disease of freshwater pomfret during overwintering. Its incidence rate is lower than that of saprolegniasis, but the mortality rate per unit area is higher than that of saprolegniasis, and it can also lead to concurrent saprolegniasis. 1. Pathogen Ichthyophthirius multifiliis. 2. Symptoms On the body surface and
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Control methods for chilodonelliasis and trichodiniasis in freshwater white pomfret during the overwintering period
1. Pathogens: Chilodonella cyprini, Trichodina. 2. Symptoms: Both parasites attach to the skin and gills of fish, stimulating the secretion of large amounts of mucus, causing a pale blue film to form on the skin surface of diseased fish (chilodonelliasis) or a white film to appear on the fins, head, and body surface (trichodiniasis).
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Three Major Technical Measures for Safe Overwintering in Snakehead Fish Farming
Although the value of snakehead fish is now gradually being recognized by more people, and more and more people are farming snakehead fish, anyone who has raised snakehead fish knows that snakehead fish are suited to warm environments. Once winter arrives and the temperature turns cold, the management and feeding of snakehead fish becomes relatively
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What are the effective measures for keeping a flock of sheep safe through the winter?
To keep a flock of sheep safe through the winter, it is not only necessary to create good environmental conditions, but also to strengthen overwintering management. Specifically, the following measures should be carried out well: 1 Focus on grazing and build up autumn fat. After the beginning of autumn, the days are short and the nights are long, and there is not enough grazing time. Relying only on daytime grazing means the sheep cannot eat their fill, so grazing time should be appropriately extended. Before the frost, they should go out early and return late; after the frost, they should go out late and return late, so that every sheep can eat grass and eat its fill. After the autumn harvest, the flock should promptly be driven to fields where crops have been harvested, to graze on the stubble and pick up weeds and scattered grain. If this is done well, they fatten faster, and this is also an important aspect of seizing autumn fat. By combining these practices, the flock can quickly gain fat and regain condition, laying a good foundation for safely getting through the winter.
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How Turtles Overwinter and Key Points for Keeping Them
In a broad sense, "turtle" refers to the collective term for the order Testudines; in a narrow sense, it refers to species under the family Emydidae. The Chinese pond turtle (Chinemys reevesii) is also known as the golden turtle, grass turtle, mud turtle and mountain turtle. In animal taxonomy it belongs to the class Reptilia, order Testudines, family Emydidae, and is one of the common Testudines animals.
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How to Do a Good Job in Overwintering and Seed Stock Preservation for Tilapia in Earthen Pond Aquaculture
Tilapia, commonly known as: African crucian carp, non-crucian, Vietnamese fish, Nanyang crucian, etc. It originally referred to the fish species of the genus Oreochromis with Mozambique as the type locality: Mozambique mouthbrooder (scientific name: Oreochromis mossambicus). It is now the collective common name for several fish species of the genera Oreochromis and Sarotherodon in the family Cichlidae; in English they are collectively called Tilapia. It is now a freshwater aquaculture fish that is a key research and breeding target of the world's aquaculture industry, and is hailed as one of the main future sources of animal protein. It usually lives in freshwater, can also live in salt water with different salinity levels, and can also survive in shallow water in lakes, rivers, and ponds. It has strong adaptability, can reproduce even in small water areas, can even grow in rice fields, and has extremely strong adaptability to water with low dissolved oxygen. The vast majority of tilapia are omnivorous, often eating aquatic plants and debris.</p><p></p><p>There are many methods for overwintering and seed stock preservation of tilapia, but some are limited by resource conditions, with no hot springs or no warm drainage, and some have complex equipment and high investment. In order to explore a mass-oriented seed stock preservation method with low investment and simple equipment. Its main facilities and techniques are: </p><p>1. Construction of the overwintering pond: The tilapia overwintering pond should be built in a low-lying area that is sheltered from the wind and faces the sun, close to a river. In a place with solid soil, dig an earthen pond 4 m to 5 m long, 1 m to 2 m wide, and 2 m to 3 m deep. Water from the river channel can gradually seep into the earthen pond through the gaps in the soil layer, keeping the pond water fresh and the oxygen content sufficient. </p><p>2. Heat preservation facilities: Build a bamboo frame on the pond surface sloping toward the south, and cover the bamboo frame with two layers of plastic film, like a greenhouse for growing vegetable seedlings. The height between the pond surface and the film should be kept at about 0.1 m to 0.8 m; if the space is too large, it is not easy to keep warm. When the northwest wind blows, windbreak walls made of reeds or straw curtains should be made on the west and north sides of the overwintering pond. In frost and snow weather, straw curtains should be added over the film. If a cold wave invades and the temperature drops, 2 to 4 electric lights of 100 W to 200 W should be hung inside the plastic shed to raise the water temperature. In short, the pond water temperature should be kept at around 15°C to 16°C so that the fingerlings can safely pass the winter. </p><p>3. Putting fingerlings into the pond: Before the fingerlings are put into the pond, the overwintering pond should be filled with water and soaked for 3 days to 5 days to eliminate the effect of pollutants on the pond water. The time for putting fingerlings into the pond is generally in early November, and the water temperature should preferably be around 16°C; if too late, they are prone to cold damage. Before the fingerlings are put into the pond, they should be soaked in 4% salt water for 3 minutes to 5 minutes to disinfect the fish body and prevent infectious diseases. The density of fingerlings is 5 kg to 7.5 kg per cubic meter. </p><p>4. Overwintering management: During the entire overwintering period, specially assigned personnel should be on duty for management. At the same time, attention should be paid to changes in water temperature, changes in water quality, and the dynamics of the fish. </p><p>(1) Feeding: During the overwintering period, a small amount of feeding may be done, generally once every 10 days to 15 days, with the feeding amount at about 1% of the weight of the overwintering fingerlings, but when the water temperature exceeds 16°C, they can be fed once a day. Feed includes sugar dregs, rapeseed cake, etc. It should also be flexibly controlled according to the feeding situation so that the fish eat enough and eat well, in order to increase the overwintering survival rate and reduce losses.</p><p>(2) Lighting: Throughout the winter, as long as it is sunny, remove the straw curtains covering the heat preservation shed from 9:00 to 15:00 to let in light and raise the temperature. On snowy days, the snow on the frame should be swept off promptly to prevent the frame from being crushed and collapsing.</p><p>(3) Prevention and treatment of fish diseases: The overwintering period of tilapia is relatively long, and attention should be paid to observing whether there is fish disease. Once discovered, it should be treated promptly. During the overwintering period, saprolegniasis is the most common, mostly occurring after entering the pond and before leaving the pond. Saprolegniasis is a common disease caused by the attachment of fungi such as Saprolegnia and Pythium. With the naked eye, a grayish-white, soft, cotton-wool-like substance attached to the fish body can be observed. Injured fish bodies are highly susceptible to infection, and it occurs more frequently in winter and early spring. For treatment, alkaline green at a concentration of 0.1 mg to 0.2 mg/L or a copper sulfate solution at a concentration of 1 mg/L can be splashed over the whole pond, and it is effective. If pond oxygen deficiency occurs and fish gasp at the surface, more fresh water can be exchanged. </p>
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