How to scientifically farm giant river prawns? A detailed explanation of the key technical points

The giant river prawn is a freshwater shrimp. It is rich in nutrients and has long been known as the king of freshwater shrimp. It is one of the three shrimp species with the highest farming volume, so it is a common food for residents in cities. Many farmers are preparing to farm giant river prawns, but they have been unable to proceed because they do not understand the technology. Now let us take you through the scientific farming technology for giant river prawns!

Giant river prawn farming technology

1. Installation of pond farming facilities for giant river prawns

1. Composition of the bottom microporous pipe aeration system: composed of a motor + fan + gas transmission pipe + aeration pipe, mainly including a blower, PVC water supply pipe, microporous aeration pipe, valve switch, etc.

2. For the blower, it is advisable to choose a Roots blower or a stacked blower, with an outlet air pressure of no less than 3500-5000 mm water column.

3. Power configuration: configure power according to different farming species. Under normal circumstances, for giant river prawn farming, each 15-20 mu of shrimp pond is equipped with one set of 2.2 kW power unit.

4. Equipment installation: fix a support on the pond embankment, install the motor and fan on the support, use Φ5OPVC water supply pipe for the main gas transmission pipeline, and match it with the outlet diameter of the blower, burying it underground along the pond embankment. Use ΦlO-15PVC water supply hose for branch pipes, connect them to the main pipe through a tee, and connect the branch pipes to strip-type or disc-type aeration pipes. The aeration pipes are coiled around strip-type or disc-type steel bar frames, and bricks and other aids are used to sink them to the bottom. For disc-type, place 4 aeration discs per mu on average. The in-situ water quality restoration facility uses aquatic plant-type filler. The bottom of the filler is tied to a square frame made of PVC pipe, and the square frame is fixed on the aeration disc. The length of the filler is best when it just floats out of the water surface.

2. Pond clearing and disinfection for giant river prawns

Before stocking giant river prawns, the shrimp pond should be cleaned and disinfected well. Newly opened shrimp ponds generally need to be exposed to the sun for 2-3 d before water is added, while old shrimp ponds should remove excess sludge (retain bottom mud about 10 cm thick). Both new and old shrimp ponds must be strictly disinfected. First, use quicklime to clear the pond and thoroughly kill all kinds of harmful organisms and wild miscellaneous fish in the water body. First drain the water (retain water 20-30 cm deep), remove sludge, and then disinfect with quicklime at 750-1 050 kg/hm2. After pond clearing, add water 7-10 d later. To prevent diseases and predators, the water must be strictly filtered when added.

3. Seedling cultivation

① Method of farming two crops of giant river prawns: from late March to early April, purchase early-bred giant river prawn seedlings and use plastic greenhouses for intensive cultivation, striving for the shrimp seed specification to reach 3 cm in mid-to-late June; from mid-to-late May, purchase giant river prawn seedlings for cultivation in dedicated ponds, and by around mid-August the shrimp seed specification reaches 3 cm for stocking in the later crop.

② Method of farming giant river prawns in the first crop and oriental river prawns in the later crop: from mid-to-late May, purchase giant river prawn seedlings for stocking; in early June, set up cages in the cultivation pond to stock ovigerous oriental river prawns, cultivate oriental river prawn seedlings in dedicated ponds, and by the end of September the shrimp seed specification reaches about 3 cm.

4. Feed feeding: feed special compound feed

For farming giant river prawns, mainly feed series compound feed, with an appropriate increase in small fish and shrimp. Feeding is mainly done once in the evening, accounting for about 70% of the whole day's feeding amount. During the day, feed is placed in deep-water areas; at night, it is placed in shallow-water grass clusters. Feed at fixed times, fixed locations, with fixed quality, and fixed amounts.

5. Water quality management for giant river prawns

Strengthening daily management is the key to the success or failure of farming. Regulate water level and water quality in a timely manner, and do a good job in disease prevention and control. For regulating the water level and water quality of farming ponds, keep the water level at 80-100 cm in the initial stage of seedling stocking, then gradually raise the water level as water temperature rises and individuals grow, until reaching the high water level of the pond, and maintain the water level at a relatively high level. Pay attention to observing water color concentration. When necessary, take water exchange measures, and regularly splash quicklime and microbial preparations to regulate and improve water quality.

6. Timely harvesting of giant river prawns

The market time for live giant river prawns is generally from the end of September to early November. The market time is relatively concentrated, and the market price is relatively low. If methods such as early seedling release and large seedling release are used to make the shrimp reach market specification early in early September or even at the end of August, this can not only advance the market time for live shrimp, but also increase the price of early-market shrimp by more than 20%. Harvesting methods include net fishing and pond draining, and harvesting tools include ground cages, dip nets, trawl nets, etc.

Introduction to giant river prawns

The giant river prawn belongs to the family Palaemonidae. It is native to the Indo-Pacific region and lives in various types of freshwater or brackish water areas. Since the 1960s, it has successively been introduced for farming in some countries and regions in Asia, Europe, the Americas, etc. In 1976, it was introduced to China from Japan, and mainly promoted for farming in more than l0 provinces (municipalities, autonomous regions) in the south, with Guangdong developing the fastest. Every 100 grams of shrimp meat contains 20.6 grams of protein, 0.7 grams of fat, and also contains various vitamins and trace elements essential to the human body. It is a high-protein nutritious aquatic product. For fresh consumption, it can be cooked as braised large prawns, pan-fried white shrimp, sauteed shrimp sections, pipa large prawns, stir-fried shrimp, etc. For processing, it can be made into dried shrimp, shelled dried shrimp, and other seafood products.

Morphological characteristics of giant river prawns

The body is plump and greenish brown. Each abdominal segment has one pair of appendages, and the appendages at the tail become a tail fan. The cephalothorax is thick and large, and the abdomen gradually becomes thinner backward. The cephalothorax includes 6 head segments and 8 thoracic segments, surrounded by one shell. The abdomen has 7 segments, each surrounded by a shell. Each segment has one pair of appendages, with great variation. From front to back, they are two pairs of antennae, 3 pairs of mandibles, 3 pairs of maxillipeds, 5 pairs of walking legs, 5 pairs of swimming legs, and 1 pair of tail fan. Adult males are generally larger than females. The largest male can reach a body length of 40 cm and weigh 600 grams; females can reach a body length of 25 cm and weigh 200 grams. The second walking legs of males are especially large and azure blue.

Dietary contraindications for giant river prawns

1. The shrimp line on the back of the shrimp is undischarged waste from the shrimp. If eaten, it has a muddy fishy taste in the mouth and affects appetite, so it should be removed.

2. Shrimp that are red in color, soft in body, and have lost their heads are not fresh. Try not to buy them. Spoiled and deteriorated shrimp must never be eaten.

3. Pay attention when eating shrimp together with some fruits. Shrimp contains relatively rich nutrients such as protein and calcium. If eaten together with fruits containing tannic acid such as persimmons, hawthorns, pomegranates, grapes, etc., it will not only reduce the nutritional value of protein, but tannic acid and calcium will combine to form calcium tannate, which irritates the gastrointestinal tract and causes discomfort, resulting in symptoms such as vomiting, dizziness, diarrhea, and abdominal pain.

4. When eating seafood, it is best not to drink large amounts of beer, because that will produce excessive uric acid and cause gout. When eating seafood, it should be paired with dry white wine, because the fruit acid in it has bactericidal and fishy-removing effects.

5. The back of the shrimp being greenish black is a sign of freshness. Generally, shrimp with hard shells, intact heads, firm and curved bodies, and large size taste relatively delicious.

6. People allergic to shrimp and those with allergic diseases, such as allergic rhinitis, allergic dermatitis, and asthma, should eat with caution.

7. When preserving small dried shrimp, to prevent the shrimp from drying out and oxidizing, try to put the shrimp into black plastic bags or sealed containers for refrigerated preservation.

How to remove the internal organs of giant river prawns

1. Hold the shrimp body

2. Use scissors to cut off one third of the shrimp head, at the starting point of the vertical line protruding in the middle of the head, including the eyes;

3. Lift off the shell of the shrimp head;

4. You will see two lumps of black/green/brown matter. Keep the part close to the shrimp body and remove the part close to the front end;

a. If the paste and internal organs are distinct, remove them conventionally;

b. If the internal organs have already been pulled off when removing the shrimp head shell, there is no need to bother;

c. If the paste is relatively large and covers the internal organs, lift part of the paste and remove the covered internal organs.

5. Cut open the back of the shrimp and remove the shrimp line;

6. Cut the overly long whiskers and legs shorter, keeping a part to absorb flavor.

Giant river prawns grow quickly and are an economically important shrimp species, the first choice for artificially farmed shrimp. When large quantities of giant river prawns are on the market, prices will fall. To avoid the market peak, they can also be harvested early. At present, the market price of giant river prawns is relatively good, so as long as the farming technology is mastered, the risk is generally not too great.