Key points of culture and management of Macrobrachium rosenbergii

Macrobrachium rosenbergii, also known as Malaysia prawn, is a kind of large freshwater shrimp with long arms, which is native to Indo-Pacific region, breeds in sea water and lives in various types of fresh or brackish waters. It has the characteristics of wide diet, fast growth, large size, delicious meat, rich nutrition and so on. It was introduced into China from Japan in 1976, and the scale of breeding has been expanding. Our city began breeding in 1995, the current farming area reached more than 200mu, the average yield per mu is 100kg, the average profit per mu is more than 1500 yuan, the benefit is very considerable. The culture techniques of Macrobrachium rosenbergii are introduced as follows:

1. Biological characteristics:

1. Morphological structure: the body of Macrobrachium rosenbergii is cylindrical. The head and chest is thicker than that of Penaeus chinensis, the abdomen is shorter, there are 5 pairs of steps, the swimming ability is poor, the body color is light bluish yellow, there are brown markings between. The second step of male shrimp is well developed, its length is 3 times of body length, its head is larger, and its abdomen is narrower than that of female shrimp. The head and second step of the female shrimp are smaller than those of the male shrimp. Macrobrachium rosenbergii is dioecious.

2. Living habits and eating habits; Macrobrachium rosenbergii belongs to aquatic benthos, does not like strong light, tends to dim light. Sleep during the day and go out at night, hiding in the bottom of the pool and under the hidden things during the day, less activity, but also eat bait, frequent activities at night, looking for food everywhere. Macrobrachium rosenbergii is an omnivorous animal, and the food composition is different at different stages of growth and development. In the case of artificial culture, compound bait, miscellaneous fish and shrimp and cakes can be fed.

3. Ecological habits

Macrobrachium rosenbergii is a kind of tropical shrimp, which requires high water temperature. The suitable temperature range is 18 ~ 34 degrees Celsius and the optimum water temperature is 28 ~ 31 degrees Celsius. The lowest critical temperature is 14 degrees Celsius and the highest critical temperature is 35 degrees Celsius. Macrobrachium rosenbergii is not tolerant to hypoxia and grows best when dissolved oxygen is more than 5 mg / L. when it is less than 3 mg / L, the shrimp floats. Macrobrachium rosenbergii is a widely salty shrimp, the range of adaptation is 10 ‰-30 ‰, the optimum growth salinity is less than 10 ‰, and the asphyxiation salinity is 33 ‰, which requires a PH value of 7mol / 8.5.

Second, preparation before stocking

1. Shrimp pond selection

Adult shrimp ponds should be built in places with good ecology, beautiful environment, sufficient water sources, convenient drainage and irrigation, fresh water quality, no pollution, drought, waterlogging and sunny ventilation. Semi-sediment is better at the bottom of the pool, and the transportation and power supply are convenient. We can use barren land to dig shrimp ponds or fish ponds and river ditches for culture, and we can also use brackish water such as coastal and lakes and prawn ponds with salinity below 15 ‰.

2. The area of shrimp ponds

Intensive culture or main culture pond generally 1 Macrobrachium rosenbergii pond area is too large, Macrobrachium rosenbergii easy to live on the edge of the pond, can not make full use of water space. If the newly dug pond is good with east-west, the length and width is 4:1 or 3:1, which is easy to operate, and the sunshine surface is large, which is beneficial to the growth of shrimp.

3. The depth of shrimp ponds

According to the living habits of Macrobrachium rosenbergii, the water depth of the intensive culture pond is 0.7 Macrobrachium rosenbergii, and the maximum depth of the intensive culture pond is not more than 1.5 meters, so that the light transmission layer is larger, which helps to increase the water temperature, enhance the photosynthesis of phytoplankton and increase the amount of dissolved oxygen in the water. At the same time, the shrimp body is exposed to sunlight, which is also conducive to the absorption of calcium and promote the growth of carapace.

4. Clear the pond and disinfect

The disinfection of shrimp ponds usually uses quicklime. There are two methods of disinfection: dry method and water. Dry disinfection is carried out within 20 days before the release of shrimp fry, that is, early May, and can be carried out at noon on a sunny day. The pool water should be discharged first, leaving about 10 centimeters of water at the bottom. One hundred and fifty kilograms of quicklime per mu. Disinfect with water 250 grams of quicklime per cubic meter of water. Newly dug ponds should also be disinfected, with 75-100 kg of quicklime per mu to increase the calcium content of the ponds. After disinfection, the ponds are generally injected with water of 70 Mel 100 cm in the 8 days before the release of shrimp fry, and filter screens are installed at the water entry to prevent wild miscellaneous fish and other enemies from mixing.

5. Applying basic fertilizer to cultivate water quality

Especially for the newly dug shrimp ponds, the bottom of the pond is poor in quality and the water quality is thin, so it should be fully fertilized. Cultivate abundant natural bait before the shrimp seedling goes into the pond, so that the shrimp seedling has enough bait after entering the pond, and chemical fertilizer or special powerful ecological fertilizer can be applied.

6. Set up concealment