CATDOLL : CATDOLL: What are the key ecological farming techniques for breeding freshwater shrimp in ponds?

What are the key ecological farming techniques for breeding freshwater shrimp in ponds?

Freshwater shrimp, scientifically known as Macrobrachium nipponense, belongs to the class Crustacea, order Decapoda, family Macrobrachium. It is large in size, has delicious meat and rich nutrition, and is a precious shrimp loved by people. Freshwater shrimp has become one of the main objects of freshwater aquaculture because of its fast growth, short breeding cycle and high economic value.

1. Pond conditions

Almost any fish pond can be used to raise shrimps. The area should not be too large, preferably 1 to 5 mu, with a water depth of 1 to 1.5 meters. The transparency of the pond should be maintained at about 40 cm, and the pH value should be 7.5. Shrimp have high requirements for dissolved oxygen, and the dissolved oxygen in the water must be above 5 mg/L. There should be less silt at the bottom of the pond, which should not exceed 20 cm. In addition, the water source of the pond should be sufficient, drainage and irrigation should be convenient, and there should be no pollution.

2. Pond cleaning

Before the shrimp fry are released into the pond, the pond must be strictly cleaned, excess silt removed, the pond embankment repaired, and a shrimp collection ditch about 3 meters wide dug in the pond to facilitate future fishing. Use 75-100 kg of quicklime per mu to disinfect the dry pond, and fill it with water after 4 days. When filling, use 80 mesh silk to filter the incoming water at the water inlet to prevent harmful organisms from entering. Before the shrimp fry are released, the pond should be fully fertilized to cultivate zooplankton and benthic organisms for the larvae to eat.

3. Shrimp fry stocking

Select healthy, complete and disease-free shrimp fry for stocking. There are generally two stocking methods, namely single stocking and mixed stocking. Single stocking is 60,000 to 100,000 1.5 to 2 cm young shrimp per mu. For mixed stocking, if fish are mainly for food, 20,000 to 30,000 young shrimp per mu; if fish are mainly for fattening fish, 10,000 to 15,000 young shrimp per mu. The per mu yield of fish should be controlled at 200 to 300 kg. The stocking time should avoid high temperatures and should be carried out before 9 am on a sunny day. The shrimp fry should be kept in water to prevent the shrimp from being injured.

4. Feeding and Management

1. Set up shrimp nests: In order to make full use of the water body, some submerged plants, such as Vallisneria, Hydrilla verticillata, etc., should be planted in the shallow water area of ​​the pond, and some water hyacinths should be planted on the water surface. Water plants generally occupy about 20% to 30% of the pond area, so that they can provide shade in the hot season, and the tender leaves of water plants can be eaten by shrimps, and can also be used as a hiding place for shrimps to live and molt.

2. Feeding: Shrimp are omnivorous animals. In the larval stage, they feed on plankton, and in the adult stage, they feed on the decayed stems and leaves of aquatic plants and the corpses of fish and shellfish. Therefore, the feed is generally based on plant baits such as bean cake, rice bran, distiller's grains, bran and large skin, and is appropriately matched with animal baits such as crushed snails, small fish, and fish meal. The mixing ratio is 6:4. You can also feed a compound feed with a crude protein content of more than 30%. The specific feeding method is to feed once in the morning and evening every day. The young shrimps that have just been put into the pond are small and have poor swimming ability. It is advisable to sprinkle the bait throughout the pond. When they are slightly larger, feed is thrown in a shallow water area with a depth of 50 cm, and in the evening, it is thrown on the edge of the pond. The daily feeding amount is about 10% of the shrimp's body weight, which increases or decreases according to the growth, feeding and weather conditions of the shrimp.

3. Daily management: Patrol the pond every day, observe changes in water quality and check whether the water inlet filter is damaged, and prevent harmful organisms from mixing in or shrimps from escaping. Shrimp require high dissolved oxygen. If the shrimps lie on the water plants by the pond or jump on the edge of the pond, it means that there is a lack of oxygen in the pond. Flush the pond or start the aerator in time. Generally, fill the pond every 5 to 7 days, and increase the water depth by 15 to 20 cm each time.

1. The pond for breeding fresh shrimps requires sufficient water supply, fresh water quality, no pollution, and dissolved oxygen>5mg/L. The pond is rectangular, with loam soil from east to west, a flat bottom, 10~15cm of silt, and an area of ​​0.20~0.33hm2. It is required to install a 1.5kW aerator on the 0.20~0.33hm2 water surface. The microporous pipe oxygenation at the bottom of the pond generally adopts a three-stage gas supply of potato wheel main pipe, inflation pipe, and microporous pipe, which can be centralized gas supply or divided into pools.

In Gaochun District, Nanjing City, Jiangsu Province, Gucheng Lake crabs are a major pillar industry for local farmers to get rich. Residents of Huashan Village in the area mostly make a living by breeding hairy crabs. Especially in the years when the crab market is good, good quality crabs are hard to come by. Wu Shengbao is one of the many crab farmers, but when talking about the market situation in the past two years, he is somewhat helpless. In recent years, the consumption enthusiasm for hairy crabs has been high, and farmers have been enthusiastic about raising crabs, resulting in a large-scale breeding and oversupply, and the price is somewhat depressed.

Green shrimps are more adaptable to growing in a clean and comfortable water temperature environment. If the temperature of the pond is relatively high and not very clean, they may not survive.

The silt at the bottom of the pond should be less and should not exceed 20 cm. In addition, the water source of the pond should be sufficient, the drainage and irrigation should be convenient, and there should be no pollution. When filling the water, the water should be strictly filtered with 80 mesh silk at the water inlet to prevent the entry of harmful organisms. Before stocking the shrimp fry, the pond should be fully fertilized to cultivate zooplankton and benthic organisms for the larvae to eat.

What are the requirements for water quality management in pond shrimp farming?

Strengthening the management of shrimp pond water quality and creating a good ecological environment are important measures to achieve high yields of shrimp farming in ponds. Specifically, the following four aspects should be mastered:

(1) Manage the water quality of shrimp ponds according to the requirements of water environment conditions for the growth and development of freshwater shrimp

Freshwater shrimps are crustaceans that require the dissolved oxygen in the pond to be above 5 mg/L, the pH to be 7-8, the water transparency to be around 40 cm, the silt at the bottom to be around 10 cm, the organic matter content to be low, and the water to be fresh and lively. During the shrimp farming process, strengthen the monitoring and regulation of water quality, maintain good water quality, and promote the growth of freshwater shrimps. (2) Manage the water quality of shrimp ponds according to the changing laws of the main water quality factors

Dissolved oxygen is an important factor in water quality. The main sources of dissolved oxygen in water are: first, photosynthesis of green plants; second, dissolving oxygen in the air into water through wind diffusion; third, supplementing oxygen in water through artificial measures. The consumption of dissolved oxygen in water is: first, oxygen consumption by aquatic organisms; second, wind diffusion, which returns dissolved oxygen in water to the air; third, oxygen consumption by the decomposition of organic matter in the pond. The diurnal variation of dissolved oxygen in water is: in clear weather, due to the photosynthesis of green plants, a large amount of oxygen is released, and the dissolved oxygen in water reaches saturation around noon, while at night, the photosynthesis of green plants stops, aquatic organisms consume a lot of oxygen by breathing, and organic matter decomposes and consumes oxygen. The dissolved oxygen in the shrimp pond is at the lowest level before dawn, so it is easy to cause hypoxia in shrimps at night and early morning. In addition, the water quality of the shrimp pond can also cause hypoxia in the shrimp pond through irregular fertilization and the death of a large number of algae, or continuous rainy weather. Pond inspections should be strengthened, attention should be paid to changes in water quality and dissolved oxygen, and oxygenation measures should be taken in time to avoid hypoxia accidents and losses.

The pH change of shrimp ponds is mainly caused by the metabolites of anaerobic bacteria and the organic acids produced by the decay of leftover bait. In addition, factors such as acid rain can also cause changes in the pH of pond water. The transparency of shrimp pond water is mainly determined by the amount of suspended matter in the water, especially algae. Usually brown or oily green is better, and the transparency is about 40 cm. Water quality management should be strengthened according to the diurnal changes of these factors. (3) Manage the water quality of shrimp ponds according to the seasonal changes of fishing time.

In the early stage of shrimp fry stocking, the water depth of the shrimp pond can be maintained at about 0.8 meters. August and September are both hot weather and the peak growth season for freshwater shrimp, so the pond should be filled with water to a depth of 1.2 to 1.5 meters. The water quality in autumn is very easy to change. Depending on the water quality of the shrimp pond, water should be added or replaced once every 7 to 10 days. The amount of water replacement should not be too large, generally around 1/4. Or start the aerator regularly to add oxygen to the shrimp pond. Normally, if the water quality is found to be too rich or too concentrated, add or replace water in time to adjust the water quality. (4) Manage the water quality of the shrimp pond according to weather changes

Keep listening to weather forecasts and patrol the ponds in the morning and evening to observe changes in the water quality of the shrimp ponds. Take appropriate measures based on the weather, water quality and shrimp activity to maintain good water quality.

Strengthening the management of shrimp pond water quality and creating a good ecological environment are important measures to achieve high yields of shrimp farming in ponds. Specifically, the following four aspects should be mastered:

(1) Manage the water quality of shrimp ponds in accordance with the requirements of water environment conditions for the growth and development of freshwater shrimps. Freshwater shrimps are crustaceans, and require the dissolved oxygen in the pond water to be above 5 mg/L, the pH to be 7-8, the water transparency to be around 40 cm, the silt at the bottom of the pond to be around 10 cm, the organic matter content to be low, and the water quality to be fresh and lively. During the shrimp farming process, strengthen the monitoring and regulation of water quality, maintain good water quality, and promote the growth of freshwater shrimps.

(2) Manage the water quality of shrimp ponds according to the changing rules of the main water quality factors. Dissolved oxygen is an important factor in water quality. The main sources of dissolved oxygen in water are: first, photosynthesis of green plants; second, wind diffusion, dissolving oxygen leaking from the air into the water; third, artificial measures to supplement oxygen in the water. The consumption of dissolved oxygen in water is: first, oxygen consumption by aquatic organisms; second, wind diffusion, which returns dissolved oxygen in the water to the air; third, oxygen consumption by the decomposition of organic matter in the pond. The diurnal variation of dissolved oxygen in water is: in clear weather, due to the photosynthesis of green plants, a large amount of oxygen is released, and the dissolved oxygen in the water reaches saturation around noon. At night, the photosynthesis of green plants stops, aquatic organisms consume a lot of oxygen by breathing, and organic matter decomposes and consumes oxygen. The dissolved oxygen in the shrimp pond is at its lowest level before dawn. Therefore, it is easy to cause hypoxia in shrimp at night and early morning. In addition, the water quality of shrimp ponds can also cause hypoxia due to irregular fertilization, the death of a large number of algae, or continuous rainy weather. Pond inspections should be strengthened, attention should be paid to changes in water quality and dissolved oxygen, and oxygenation measures should be taken in time to avoid hypoxia accidents and losses. The pH change of shrimp ponds is mainly caused by the metabolites of anaerobic bacteria and the organic acids produced by the decay of leftover bait. In addition, factors such as acid rain can also cause changes in the pH of pond water. The transparency of shrimp pond water is mainly determined by the amount of suspended matter in the water, especially the amount of algae. Usually tea brown and oily green are better, and the transparency is about 40 cm. Water quality management should be strengthened according to the day and night changes of these factors.

(3) Manage the shrimp pond according to the seasonal changes in fishing seasons. In the early stage of stocking shrimp fry, the water depth of the shrimp pond can be kept at about 0.8 meters. August to September is both a hot weather and the peak season for the growth of freshwater shrimp, so the pond water should be filled to a depth of 1.2 to 1.5 meters. The water quality is very easy to change in autumn. Depending on the water quality of the shrimp pond, water should be added or changed once every 7 to 10 days. The amount of water changed should not be too large, generally about 1/4. Or start the aerator regularly to add oxygen to the shrimp pond. In normal times, if the water quality is found to be too rich or too concentrated, water should be added or changed in time to regulate the water quality.

(4) Manage the water quality of the shrimp pond according to weather changes. Keep listening to weather forecasts and patrol the pond in the morning and evening to observe changes in the water quality of the shrimp pond. Take appropriate measures based on the weather, water quality and shrimp activity to maintain good water quality.

This article is from: China Agriculture Press "Green Development and Green Plant Protection"