Culture techniques of silver carp

Silver carp is a large-scale freshwater fish raised artificially. It grows fast, has few diseases and high yield. It is polycultured with grass carp and carp. Let's take a look at the cultivation techniques of silver carp

Silver carp growth and reproduction

The age of sexual maturity of silver carp was 1-2 years earlier than that of grass carp. Mature individuals are also smaller, generally more than 3 kg of female fish can reach maturity. The relative fecundity of female fish about 5 kg is about 40 - 50 thousand eggs/kg body weight, and the absolute fecundity is 200 - 250 thousand eggs.

Life Habits of Silver Carp

1. Silver carp belongs to pelagic fish. In spring, summer and autumn, most of the time they swim in the middle and upper layers of the water for food, and in winter they dive to deep water for winter.

2. It is a typical filter-feeding fish. Special structures on the gills filter plankton from the water. Main food: silver carp life-long to plankton for food, mainly eat plankton in the fry stage, up to 1.5 cm or more gradually to eat phytoplankton, and like to eat grass carp feces and put chicken, cow dung. Also eat soy milk, bean dregs powder, bran and rice bran, etc., more like to eat artificial micro-particle feed. Very interested in sour food, also has an appetite for bad food. Silver carp like to eat rotten food, often with grass carp with feeding silver carp eat grass carp feces, so there is a grass to raise three silver carp said. The diet of silver carp has obvious seasonality. In addition to plankton in spring and autumn, they also eat a lot of detritus bait; the lower the water level in summer, the greater their food intake; winter eat less and move less. Suitable for breeding in rich water. The length of the intestine is about 6-10 times the body length.

3. Appetite is proportional to water temperature. Silver carp likes high temperature, the most suitable water temperature is 23℃~32℃. In summer, the appetite of silver carp is the most vigorous. July to August in the north is a good time to fish silver carp, autumn equinox later, the weather is getting cooler, silver carp appetite has decreased, it is difficult to catch.

4. Lively disposition, like jumping, there is a habit of upstream, but the action is not very agile, relatively clumsy. Silver carp like fat water, individual similar often gather to swim to the middle and upper layers of the water, especially in the open water area with richer water quality.

5. Cowards fear disturbance. When disturbed or encounter network cable, they have jumped out of the water over the net and escape.

6. Fast growth and high yield. The age of sexual maturity of silver carp was 1-2 years earlier than that of grass carp. Mature individuals are also smaller, generally more than 3 kg of female fish can reach maturity. The relative fecundity of female fish about 5 kg is about 40 - 50 thousand eggs/kg body weight, and the spawning period is similar to that of grass carp. The eggs are laid in April to May every year, and the absolute number of eggs is 200,000 - 250,000. Egg floatability. The spawning period is similar to that of grass carp. Under the condition of pond culture, if the bait is sufficient, the fish can grow to 500~800 grams in the first year, the weight of the three-year-old fish can reach 3~4 kg, and in the natural river it can weigh 30-40 kg.

7. Low oxygen tolerance ability is very poor, water hypoxia immediately floating head, some will soon die.

habitat of silver carp

Lives in the upper layers of water. It often lives in rivers, lakes and their subsidiary waters.

Culture and utilization of silver carp

pond selection

Silver carp belongs to the fish culture category, which is kept in the ponds of carp, crucian carp, grass carp and bream, and is in a subordinate position. Its pond selection is completely consistent with the above-mentioned fish culture category applied for certification.

water quality requirements

The water quality requirements of silver carp are completely consistent with those of the main carp for which certification is applied.

Seed requirements

The seedlings must be inspected and quarantined before stocking, and the quality is pure, healthy and disease-free, and the specifications are neat. The stocking time is in the middle and late May.

pond rearing

1. fingerling

Fry stocking: in the middle and late May, when the pond water temperature is stable above 18℃, it is the appropriate time to put in. Silver carp fry are put in at a density of 3-5 fish per square meter.

Feeding management: fry into the pond, mainly to filter food plankton and feed debris.

Adult fish culture: specification and density of fish species, specification of overwintering fish species is 100-200 g/fish, stocking density is 0.4-0.5 fish/㎡.

Silver carp is a set of fish, carp out of the pond from the time of capture shall prevail.

2. winter management

Overwintering density: the overwintering density of adult fish and fingerlings in pressure pond is generally 0.3-0.6/㎡. Appropriate adjustments can be made according to pond conditions.

Overwintering fish body requirements: fish body should be free from disease and injury, fat and healthy.

Overwintering method: overwintering pond should be relatively clean, water retention is good, water depth under ice is maintained at about 1.5 meters, and the pond is divided into specifications: before freezing, use 90% crystal trichlorfon 1.5-3.0 kg per hectare. The amount of phytoplankton spilled in the whole pond should be maintained at 25-50mg/l. To maintain the transparency of the water surface, the snow on the ice surface should be removed in time, and the ice eye should be used to observe the water quality and fish activities.

Prevention and treatment of silver carp disease

1. In fry, fingerling net pulling, screening, transportation process should be carefully operated to prevent fish body injury.

2. Before entering the pond, fish fry are disinfected by immersion in 2.0% salt water for 5-10 minutes.

3. High temperature season, monthly bleaching powder or copper sulfate, ferrous sulfate mixture hanging bag method for food disinfection.

4. Regularly use microbial agents to regulate water quality and improve fish immunity.

5. Dead fish should be removed in time and buried deep.