Key Technical Points for High-Yield Mono-Culture of River Shrimp in Ponds
The river shrimp is widely distributed in rivers, lakes, reservoirs and ponds across our country. Also known as the river shrimp, its scientific name is the Japanese swamp shrimp (Macrobranchium nipponense), and it is a high-quality freshwater shrimp. Its flesh is tender, its flavor is delicious, and it is rich in nutrients; it is a high-protein, low-fat aquatic food product that is quite favored by consumers. So, if you want to achieve high yield in pond mono-culture of river shrimp, what are the key culture points?
1. Pond conditions
The area is 5-10 mu, the water depth is 0.8-1.5 m, the pond embankment is solid and does not leak, the slope is 1:(2-3), the pond bottom is flat and slopes slightly toward the drainage outlet, and the silt does not exceed 20 cm.
2. Preparations before stocking
① Pond disinfection with chemicals: 7-10 days before stocking, let in water to a depth of 20 cm, and use 100-125 kg of quicklime per mu, slaked with water and evenly splashed over the whole pond for disinfection, to remove wild miscellaneous fish and harmful organisms; ② Planting aquatic plants: varieties include Hydrilla verticillata, yellow silk grass, etc. The planting area accounts for 30-50% of the pond area. Fill with water and fertilize.
3. Water quality management
① Use microbial preparations: such as EM bacteria, photosynthetic bacteria, etc. From late August to early November, depending on the medication situation, use biological bacteria once every 15 days to improve the pond water environment. ② Microporous aeration: for every 20 mu, equip one 3 kw microporous aeration pump. In each pond, lay main pipes parallel to the two long sides, and install 6 disc-type microporous tube discs with a diameter of 1.5 m per mu of pond. The dissolved oxygen requirement is above 5 mg/L. When the dissolved oxygen in the shrimp pond is lower than 5 mg/L, turn on the aeration pump. Generally, the aeration time is from 12:00 to 16:00 in the afternoon and from 24:00 at night to 6:00 the next morning. On cloudy and rainy days or muggy days, additional aeration should be provided.
4. Feeding management
Mainly feed complete formula feed for river shrimp of different specifications at different stages, supplemented with rice bran and other feed in the early stage. Feed twice a day, with 1/3 in the morning and 2/3 in the afternoon. Adhere to the “four observations” (observe the season, observe the weather, observe the water color, observe feeding activity) and the “four fixeds” (fixed time, fixed location, fixed quality, fixed quantity). The daily feeding amount is 3-7% of the shrimp body weight. The specific feeding amount should be such that it is eaten up in 2-3 hours. The feed coefficient for the whole season is 1.5-1.8.
River shrimp are a species that is extremely intolerant of low oxygen. In summer and autumn, the early morning temperature is generally relatively low, especially after muggy thunderstorm weather, when the air pressure in the early morning is even lower. Generally, river shrimp gather at the pond edge to gasp for air. If medication is applied at this time, it will not only increase the concentration of the pond water, but the medication will also irritate the river shrimp, causing shrimp that already cannot withstand the hypoxic environmental conditions to suddenly suffer strong drug stimulation and immediately suffocate to death. This is the reason why medication cannot be applied in the early morning. So when is it more appropriate to apply medication? Generally, around 10 a.m. to 4 p.m. is more suitable. During this period, the dissolved oxygen content in the pond is relatively high, and as long as the medication is applied properly, there will absolutely be no problem. After applying medication, observe the activity of the river shrimp in a timely manner. If abnormalities are found, add clean water.