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Detailed Explanation of Key Points for Intensive Snakehead Farming Technology
The northern snakehead is commonly known as snakehead, spotted snakehead, ink-head fish, etc. At present, the main species farmed in China are the northern snakehead, the spotted snakehead and their hybrids. The northern snakehead is a valuable economic fish among the Channidae, with large individuals, fast growth, high yield and high economic value; its flesh is delicate and delicious
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Methods for the Prevention and Control of Fish Diseases in Rainbow Trout (Oncorhynchus mykiss) Reared in Brackish Water
Rainbow trout (Oncorhynchus mykiss) is a cold-water, euryhaline fish, noted for its delicious flesh and rich nutrition, with high economic value, and is one of the world's fine aquaculture species. Jingtai County is one of the most arid areas in central Gansu Province, lacking freshwater resources, but it has a certain flow
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What points should be noted in sturgeon fry rearing?
With the vigorous rise of sturgeon aquaculture, the price of commercial sturgeon keeps falling, and the profit margin is getting smaller and smaller. Improving the survival rate of sturgeon fry and fingerlings is one of the main means of increasing profits in sturgeon aquaculture. Farming sturgeon in the south generally requires southward relocation and acclimation, which
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How to prevent and treat white head and white mouth disease in farmed grass carp
In home fish summer fry nursery ponds, the skin pigment from the tip of the snout to the eyeball of diseased fish fades to a milky white color, the lips appear swollen, and opening and closing become impaired, thereby causing difficulty in breathing. White head and white mouth disease is one of the serious diseases harming summer fry fish species (grass carp, black carp, silver carp, common carp, etc.)
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Detailed explanation of large-mouth catfish farming technology, master the methods of catfish farming
I. Biological characteristics The large-mouth catfish is one of the fastest-growing and largest species among fish of the order Siluriformes, family Siluridae. Common individuals weigh 5-10KG, and the largest individuals reach 60KG. Its head is wide and somewhat flat, its eyes are small and its mouth is large, hence the name large-mouth catfish. Its upper and lower jaws are densely covered with fine teeth that curve inward like barbs, making it extremely difficult for prey to escape once bitten. Adult fish have two pairs of barbels, of which one pair of maxillary barbels is very long, while the other pair of mandibular barbels is very short and often hard to notice, but in the juvenile stage there are 3 pairs of barbels. Its dorsal fin is short and small, clustered, with no hard spines; the pectoral fin has a thick, sturdy hard spine with no obvious serrations on the outer side, but it feels rough to the touch; the anal fin is extremely long and connected to the caudal fin; the caudal fin is small, concave in the middle, and the upper lobe is longer than the lower lobe. The body color of the large-mouth catfish varies with the environment and the type of food. The back and sides of the body are mostly yellowish brown, bluish gray, or yellow-green, while the belly is grayish white, mixed with black spots, but without cloud-like patterns, and all fins are grayish black.</p><p></p><p>I. Pond main culture</p><p>1. Fingerling stocking To increase the survival rate and improve farming benefits, the large-mouth catfish fingerlings stocked must be above 8cm and uniform in size. For stocking density, stock 1000-1500 fish per mu at the 8cm-10cm size; stock 800-1200 fish per mu at the 10cm-12cm size, and polyculture 100-120 large-size silver carp and bighead carp fingerlings of 150g-250g in the pond to regulate water quality. 2. Feed feeding The large-mouth catfish is a carnivorous fish, mainly using live fish or chilled fresh fish and animal viscera as bait, but it can also be trained artificially to eat artificial compound feed. (1) Carnivorous bait: when stocking large-mouth catfish fingerlings, correspondingly stock slightly smaller carp, crucian carp and other fingerlings. Each day, still mainly use chilled fresh fish chunks, and pig lungs, cattle lungs and other animal viscera can also be fed. When these animal feeds cannot be guaranteed, artificial taming for feeding can be used to make them eat artificial compound feed, which can achieve relatively good results. (2) Artificial compound feed: the protein content of the compound feed is 41%-50%. When feeding, set up (2-4) feeding tables in each pond to make it easier to observe feeding conditions. 3. Daily management Patrol the pond 3 times a day in the morning, noon and evening to observe fish feeding and growth conditions, change the water once every 5d-7d, strictly prevent the large-mouth catfish from floating to the surface, and take corresponding preventive measures. II. Pond polyculture In adult fish ponds, broodstock ponds, or large lakes and reservoirs with abundant wild trash fish, depending on the abundance of forage fish, polyculture 15-30 large-size large-mouth catfish fingerlings of 8cm-10cm per mu. Without increasing feed input, without requiring special management, and without affecting the main cultured fish, 30kg-50kg of marketable large-mouth catfish (individual weight 1.5kg-3.5kg) can be produced in the same year. The technology for polyculturing large-mouth catfish in adult fish ponds is simple, with low input and high returns, but in production attention should be paid to: large-mouth catfish cannot be polycultured in the same pond with carnivorous fish such as mandarin fish and snakehead, and smaller-size large-mouth catfish cannot be stocked for polyculture; the size is best above 8cm.</p><p>III. Cage culture</p><p>1. Cages According to fingerling size, equip three types of cages with different mesh sizes: first-level fingerling cages, second-level fingerling cages, and adult fish cages. First-level fingerling cage: mesh 0.6cm-0.8cm, size 4mx4mx2m or 5mx5mx2m, single-layer warp-knitted knotless polyethylene open-top cage; second-level fingerling cage: polyethylene knotted open-top cage with mesh 1cm—1.5cm, size 4mx4mx3m or 5mx5mx3m; adult fish cage: mesh 2.5cm-4cm, size 4mx4mx3m or 5mx5mx3m double-layer polyethylene knotted closed cage. 2. Fingerling stocking Large-mouth catfish used for first-level stocking are most suitably stocked in early to mid-May each year. For stocking density, stock 500-600 large-mouth catfish fingerlings per m2 at the 4cm-5cm size. After 15d-20d of rearing, divide them by size into separate cages for rearing. At the 8cm-10cm size, stock 350-450 fish per m2. When they reach above 15cm, promptly transfer them to second-level cages and stock 250-300 fish per m2. When the fingerlings reach about 25g, transfer them to adult fish cages and stock 40-60 fish per m20.</p><p>3. Feed feeding In cages, feeding tables are set up to make it easier to observe fish feeding conditions and ensure full use of the feed. Generally, set up 1 feeding table per 1Om2, suspended inside the cage 20cm—30cm above the cage bottom. When the total length of the large-mouth catfish is 5cm-10cm, the daily feeding rate is 8%-10% of fish body weight; at total length 10cm-20cm, it can be adjusted to 4%-6%; when total length is above 20cm, the feeding rate is 1%-3%. Feed three times daily in the morning, afternoon and evening. Among these, slightly increase the feeding amount in the evening. The bait can mainly be wild trash fish, chilled fresh fish, and animal viscera, and artificial compound feed can also be fed through artificial taming. The method is: after the fingerlings enter the cage, first stop feeding for 1d-2d to make them feel slightly hungry, then each day place a small amount of attractant on the feeding table and slowly feed artificial compound feed. As the fish adapt to the artificial compound feed, correspondingly reduce the amount of attractant until the large-mouth catfish completely adapts to eating artificial compound feed. (1) Fingerling-stage feed formula: fish meal 42%, a-starch 15%, soybean meal 10.9%, peanut kernel meal 18%, yeast powder 3.3%, scallop powder 5.2%, fish oil 3.1%, premix 2.5%, crude protein content 35%. (2) Adult-fish-stage feed formula: fish meal 25%, wheat middlings 18%, soybean meal 18%, peanut kernel meal 18%, yeast powder 5%, fish oil 1.1%, corn 10.4%, compound amino acids 2%, premix 2.5%, crude protein content 35%. 4. Rearing management During the fingerling cultivation stage, cage sorting and screening should be done well. Regular cage sorting is a key measure to increase fingerling survival rate. Generally, during the fingerling stage, sieve all fish once every 15d-20d and rear them in separate cages by size. At 8cm-10cm, transfer them to second-level fingerling cages; when they reach about 25g, they can be put into adult fish cages for rearing. In daily rearing, the large-mouth catfish has sharp mouth teeth. When bait is insufficient or when it feeds on bait beside the cage, it easily bites through the netting. Usually, regularly check the cages for damage, regularly clean the feeding tables, ensure unobstructed water flow inside and outside the cages, regularly check the bait condition on the feeding tables, remove spoiled and deteriorated residual bait, and appropriately increase or decrease the feeding amount according to how much bait remains.</p>
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Experience Sharing on Placing Fish-Rearing Cages in Flat-Bottomed Rivers
In flat-bottomed rivers with a water depth of more than 2.5 m and little year-round variation in water level, fish farming with cages works very well. 1) Generally speaking, a height of 50 cm between the cage bottom and the riverbed is sufficient. Leaving a gap between the cage bottom and the riverbed facilitates water flow, which first adds oxygen and second serves to exchange water ⟦4 <p>In flat-bottomed rivers with a water depth of more than 2.5 m and little year-round variation in water level, fish farming with cages works very well. </p><p></p><p>1) Generally speaking, a height of 50 cm between the cage bottom and the riverbed is sufficient. Leaving a gap between the cage bottom and the riverbed facilitates water flow, which first adds oxygen and second serves to exchange water and improve water quality. The height of the cage body can be 2.5-3 m. After this depth is immersed in water, 50 cm of netting is left above the water surface to prevent jumping fish from escaping. It is best to cover the top with netting to prevent birds from stealing and eating the fish. </p><p>2) It must be noted that the cage should be placed in a sunny spot, a place with a gentle flow speed, or a place with backflow. As far as the whole river channel is concerned, backflow areas are often places where fish gather; backflow areas have gentle flow speeds and abundant feed, making them very suitable for fish growth. </p><p>3) If the river channel is not deep, moso bamboo can be driven in as stakes, the cage tied with ropes, and marker lines indicating the cage's draught depth marked on the stakes, making it easy to adjust in time and stabilize the cage depth. Use slip knots for the ropes to make it easy to raise and lower the cage body. </p><p>4) For this fixed-type cage, tie straight strip-like objects along the top and bottom ropes of the cage body; for example, thin bamboo poles can be used for the top and bottom ropes, and iron bars can also be used for the bottom rope, stretching the entire cage flat and straight, avoiding folding of the netting in the water and reducing capacity. Install rings at the four corners of the cage. When in use, fit the rings at the four corners onto the bamboo stakes, and the formed cage will be firmly tied to the bamboo stakes and ready for farming. The rings can also be tied to the bamboo stakes, four on the top and four on the bottom, using pull ropes to control the entire cage body, following the rise and fall of the water level, and adjusting the draught depth of the cage body in time. In places with gentle flowing water, feed is most abundant. When the cage body is flat and straight, the fish are most comfortable. </p>
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Why Does Shrimp Farming Lose Money? Real Case Analysis
In order to summarize the experience and lessons of crayfish farming, the author recently surveyed more than 20 shrimp farming ponds covering nearly 1,000 mu in the urban area. According to the survey statistics, in 2011, 80% of shrimp farmers made a profit, with an average profit of 750 yuan per mu, and the highest reaching 1,050 yuan. But nearly 20% of farmers suffered losses.
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What are the points to note when stocking freshwater crayfish?
In recent years, crayfish have become a darling of the dining table, with their value multiplying. It is predicted that the crayfish market will not become saturated within the next 5 years, and crayfish farming is rapidly expanding in various places. After several years of production practice, the author believes that the following points should be noted when stocking crayfish:
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Detailed Explanation of Key Technical Points for Monoculture of Snakehead in Ponds
Snakehead is now a relatively well-developed project in the past two years. In previous years, the market price of snakehead remained in a sluggish state. As people's awareness and understanding of snakehead have grown, more and more people enjoy eating snakehead and have come to know its value. Therefore, snake
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How to prevent and treat saprolegniasis in pufferfish? A detailed explanation of prevention and treatment techniques for common diseases in aquaculture
1. Causes Saprolegniasis, also known as water mold disease or white hair disease, is mainly caused by fungi such as Saprolegnia or Achlya invading through wounds on the fish body surface resulting from careless operations such as netting, transport, pond transfer and artificial breeding of broodstock with induced maturation and spawning, or from net-cage fish farming causing abrasions on the fish body surface, or from parasites damaging the fish body surface.
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