Breeding methods, disease prevention, treatment, feed and feed formula of freshwater shrimp (including how to clean the pond)

(1) Pond conditions: Macrobrachium nipponense has high oxygen consumption, is intolerant of low oxygen environment, is a benthic animal with poor swimming ability, and often likes to move at the bottom of the pond or on the shore. Therefore, the required area of the pond should not be too large or too small, generally 2-5 mu is appropriate, and it is best to be close to the large and medium-sized water surface, with sufficient water and fresh water quality. The pool water should not be too deep. Generally, 1- 1.5m is suitable for lighting and increasing dissolved oxygen. There should be a large and shallow beach foot on the slope of the pond to facilitate the feeding activities of freshwater shrimp. It is better to have a regular rectangle in the pond. The bottom of the pond is flat and easy to pull the net. The silt at the bottom of the pond is about 20 cm. Some aquatic plants can be planted by the pool for shrimps to inhabit and hide when molting.

The cleaning of shrimp ponds usually begins in early March, so as to drain the pond water, remove excessive silt, complete the ridging of the pond and check the inlet and outlet water. Expose the bottom of the pond, promote the decomposition of organic matter at the bottom of the pond and improve the fertility of the shrimp pond.

Before stocking the pond, the pond should be thoroughly cleaned and disinfected with croton or tea seed cake. The dosage of croton is 45 ~ 75 kg/ha, and shrimp can be released after 10. The dosage of tea seed cake is 600 ~ 900 kg/ha. After 7 days, the shrimp should be released. Before releasing shrimp, the water must be tested to prove that it is non-toxic.

(2) Larvae are kept in some shallow ponds or shallow water grass beaches, and shrimp can be raised separately, and the effect is also very good, but deep ponds and sewage ponds are not directly raised separately. At present, mixed culture of adult fish and freshwater shrimp or mixed culture of fish and freshwater shrimp is generally adopted in ponds. Macrobrachium nipponense cultured in ponds can be stocked from June to July with 40,000 to 50,000 per 667 square meters (2,000 to 5,000 per kilogram). In February 1 1 ~ 12, catch the big ones and keep the small ones, and then supplement a certain amount of young shrimps and raise them until May-June of the following year. If the pond is mixed with green shrimps, shrimp culture is the main method, and 20,000 to 30,000 young shrimps can be released every 667 square meters; Mainly fish farming, releasing 1. 1 10,000 shrimps every 667 square meters. If parent shrimps are stocked, 500 ~ 800 females and 300 ~ 500 males can be stocked every 667 square meters. The stocking time should be rainy, and if it is sunny, it should be in the early morning or evening. In the process of breeding, it was found that the polyculture larvae could be raised in different pools because of their too dense self-reproduction.

Attention should be paid to the following points when stocking shrimp species: ① The shrimp species released in the same shrimp pond have the same specifications and sizes, strong physique, no disease or injury, complete limbs, and can be fully stocked at one time; (2) The stocking time should be carried out in rainy days and in the morning or evening in sunny days to avoid direct sunlight and high temperature, which will affect the survival rate of shrimp fry stocking; (3) When raising shrimps, it is necessary to stick to the operation with water, and the movement should be light. It is not advisable to pile shrimps in containers.

(3) Bait and shrimp are omnivorous animals, which feed on rotten stems and leaves of aquatic plants, carcasses of fish and shellfish, and sometimes prey on benthic small invertebrates. In the case of pond culture, freshwater shrimps like to swallow all kinds of bait for artificially raised fish, such as rice bran, bran, bean cake, distiller's grains, bean curd residue, wheat flour, rice, silkworm chrysalis, mussel meat, snails, fish and so on. , especially earthworms. Shrimp's feeding ability is poor, so it can't prey on many fish and shellfish with lively swimming or hard shells, but only on those slow-moving annelids and animal carcasses deposited on the bottom of the water. In natural waters, this kind of food is less, and green shrimps often kill each other. In the case of artificial stocking, you can feed an appropriate amount of animal bait, such as snails, earthworms, silkworm chrysalis, dead fish and the internal organs of various animals to avoid killing shrimp.

As far as possible, adult shrimp culture uses artificial granular feed, such as special feed for Macrobrachium rosenbergii and prawn, or 40% animal feed and 60% plant feed are mixed and ground into slurry for feeding. If you make your own pellet feed, you can use 70% ~ 80% plant feed (bean cake, rice bran, etc. ) and 20% ~ 30% of animal feed (such as fish meal, silkworm chrysalis, fish and mussel meat, etc.). ), and add a small amount of bone meal, shrimp shell powder, trace elements, etc. The feed coefficient of freshwater shrimp: bean cake 0.96; Snail meat l.97；; Rice bran 2.08. In ponds where fish and shrimp are mixed, feed herbivorous fish feed first, then feed green shrimp feed, and throw it in the shallows beside the pond. Shrimp likes to be active at night, so feed it at night, or 1 time in the morning and evening. The daily feeding amount is 4% ~ 6% of the shrimp weight, which can be flexibly controlled according to the water temperature and eating situation. Moreover, feeding should be combined with splashing and piling, which is beneficial to feeding young shrimps.

(D) Daily management Water quality management during feeding period is very important. For example, if the dissolved oxygen in the pond is above 5 mg/L, the freshwater shrimp will eat very hard, and when it reaches 2.5 mg/L, it will not eat. If the dissolved oxygen drops again, it will float up and die. Therefore, every morning, we should patrol the pond, and when we find river shrimp crawling or floating on the shore, we should replenish fresh water and turn on the aerator. Fresh water should be replenished regularly, and 15cm fresh water should be replenished every 7- 10 days to keep the pool water fat, lively and cool. It is best to keep the transparency of pool water above 40 cm. In order to cultivate rich natural bait, adult shrimp culture ponds should be fertilized regularly. Pig manure and poultry manure are the best fertilizers, generally half a month 1 time, 50 ~ 100 kg per 667 square meters.

Shrimp is particularly sensitive to pesticides, so when applying new fish medicine, it is also necessary to do a toxicological test of shrimp first to obtain a safe concentration before releasing it. In addition, we should always pay attention to whether there are leaking holes in the pond embankment, and if there are, we should block them in time to prevent shrimp from escaping. Both water snakes and water voles prey on freshwater shrimps and should be driven away and killed. Pay special attention to installing a filter when entering the water to prevent fierce fish from entering the pond.

(V) Examples of shrimp culture in ponds From the overall level of aquaculture output, there is still a big gap between the aquaculture output of freshwater shrimp and that of fish. At present, the common freshwater shrimps are raised in ponds, and the yield of 667 square meters with high yield is only about 100 kg. The polyculture yield is generally only 10- 15 kg, and the high yield is only 25-50 kg. Here are some shrimp farming units and farmers with high output for reference.

The length of fisherman Luyou Village in Dongtang Town, Yuhang City, Zhejiang Province is 5.46 hectares in 1995, with a total output of 8,000 kg, a total income of 530,000 yuan and a net income of 4 1 10,000 yuan. He fed enough shrimp species to the compound feed produced by Ningbo and Xiaoshan Wenqiang feed processing plants at one time, and adopted the method of fishing all year round, catching large amounts and keeping small ones, and achieved good production results.

2. Jiangsu Wujiang Fisheries Research Institute and Wujiang Fisheries Bureau conducted a high-yield experiment on pond culture of freshwater shrimp in 1994. The shrimp pond of 0.233 hectares (water depth 1.5 m) produced 394.2 kg of shrimp, with a total output value of 23,652 yuan, a net output value of1265,438 yuan and an output value of 677 square meters. Their main experiences are as follows: ① Flying in a long pond; (3) The laying shrimps enter the pond for self-propagation, self-cultivation and self-cultivation; ③ Reasonable feeding; ④ Good water quality management.

3. The first branch of East Taihu Aquaculture General Farm in Wujiang City, Jiangsu Province used 9. 133 hectares of fish ponds to polyculture freshwater shrimps (water depth 1.3 meters), and the total output of freshwater shrimps was 54 1 1.5 kg, with a shrimp output of 39.5 kg per 667 square meters; The profit of aquatic products was 382,000 yuan, of which 204,000 yuan was freshwater shrimp, accounting for 53.4%. Their main experiences are as follows: ① pond reconstruction; ② Thoroughly clear the pond; ③ Self-bred shrimp seedlings; ④ Reasonable feeding; ⑤ Manage water quality.

4. Multi-technology Station in Fangqiao Town, Yixing City, Jiangsu Province uses 1. 1 hectare shallow pond (water depth 1 meter) to polyculture freshwater shrimp, and catches 1.996 to 1.2 kg in dry pond, with a total fish yield of 51. Total output of freshwater shrimp 144.5 kg, and output of 667 square meters is 8.7 kg. Although the output of freshwater shrimp is not high, it accounts for 22.37% of the income (the total income is 43784 yuan, of which the income of freshwater shrimp is 9794 yuan).

Two. Fishing and transportation

/kloc-after 0/0, trawling can be carried out along the beach, and some prawns will be listed first. 1 10 months later, drainage fishing can be carried out according to the specific market demand. First, drain a part of the water in the pond, then catch some fish and shrimp by dragnet, then drain the water or leave a small pond, and finally catch all the shrimp. Shrimp can be stored in another pond until the following June.

(1) There are four main fishing methods for freshwater shrimp.

1. Dry pond fishing method This is the most commonly used method for catching shrimp in pond culture, that is, gradually dry the pond first, catch fish in time, then dry the pond, leave a small water storage area, and then catch shrimp with a small fishing net.

2. Trawl-wheel fishing method After 1 pond culture, the freshwater shrimp can be dragged along the pond by trawl. The width of the net mouth is 1.5 m, the height is about 30 cm, and the mesh is 24 meshes per square centimeter. It is best to drag it at night. Grasp the big and let go of the small.

3. The cage catching method is made of small bamboo chips, with a length of 18cm and a diameter of 8cm. Put bait in the cage, the bait is flour and rapeseed meal, knead it into strips, then steam it and cut it into small strips with a knife. L people can operate 400-500 pieces, put them into the shrimp pond at 6-7 in the morning, catch 1 time at night, and catch again 1 time the next morning.

4. the fishing method is to use nylon net, which is square. Tie an iron pendant under each corner with a mesh size of 40 cm square. Use two pieces of bamboo as claws, install a 1 float at the claw 1/2, and lift the float with nylon wires; The length of the line depends on the water level; Put a few small fish or mussels in the pot, and put them in the shrimp pond at night, fishing every 10 ~ 15 minutes/time.

(2) It is difficult to transport a large number of commercial shrimps alive, because shrimps are easy to die, which deteriorates the water quality and affects the survival of other live shrimps. Therefore, live transportation is only suitable for a small amount of transportation, and is usually used for the transportation of parent shrimps for breeding. There are the following methods:

Long trucks will tie an open canvas bucket to the truck, and the bucket will contain 1/2 ~ L/3 of water. When transporting prawns with the density of water storage per cubic meter 1 ~ 2 kg, the storage capacity can be increased if there is oxygen-increasing equipment during transportation.

2. Shipping can refer to the density of vehicles, but it is necessary to change water or add oxygen frequently on the way. If it is transported by living water boat (that is, there are access holes), pay attention to the water quality along the way, and do not enter the sewage river.

3. Nylon bag oxygen transportation In order to transport safely, double nylon bags are generally used, and nylon bags can be used to transport fry. Each bag can hold 1/3 water (6 ~ 8 liters). Tao of the Freshwater Fisheries Research Center made a detailed study on the live transportation of double-layer nylon bags.

The above experiments prove that the survival rate of live freshwater shrimps transported with oxygen in nylon bags can still exceed 60% even after a four-day journey as long as the shipment quantity is appropriate. This method is very suitable for the introduction of freshwater shrimp at home and abroad.

4. If wooden barrels, canvas barrels or other containers are transported in barrels, 2.5 kilograms of live shrimp can be transported per/kloc-0.00 kilograms of water. If oxygenation measures are taken, the transportation time can exceed 24 hours. If the transportation time is short (3 ~ 5 hours) and the water temperature is below 65438 05℃, plastic boxes (or iron boxes) can also be used for shallow water shipment, with about 500 pieces per square meter, and the water depth in the container should be just above the shrimp body. If the distance is close, the temperature is low and the transportation volume is not large, bamboo baskets (or plastic baskets) can also be used for transportation. You can first put a layer of fresh water plants or brown leather in the basket, wrap a layer of shrimp, and then cover it with water plants. Sprinkle water regularly on the way to maintain a certain humidity and the survival rate is also high.

Third, other farming techniques.

(1) Shrimp culture in cages Using rivers, lakes, reservoirs and other open waters or waters with running water for shrimp culture in cages, the production effect is good, mainly because these waters have good water quality and sufficient dissolved oxygen, which is very suitable for the growth of freshwater shrimp. It is a kind of intensive culture method with less investment, quick effect and high benefit, and has broad development prospects.

1. It is very important to choose the position of shrimp culture in cage structure. It is important to note that there is no industrial sewage flowing into the upstream, and the water depth is not less than 2 meters. You can also choose areas with small winds and waves in the tributaries of lakes and reservoirs for convenient management. To avoid the places with many traffic arteries, the pH value of water body should be 7 ~ 8.5, and the contents of nitrate and nitrite should not be higher than 20mg/l and 0. 1mg/l respectively. Cages are usually rectangular and made of polyethylene nets. Each cage has an area of 20-30m2, a cage height of1.5-2m, a water depth of1-1.5m, and a surface cage height of 0.5m.. Some aquaculture units use cages with specifications of10m x 6.6 x1.3m and mesh size of 24 meshes/cm2. Because of the strong climbing ability of the freshwater shrimp, it is necessary to add an escape prevention net at the upper end of the cage, with a height of 0.4 m and a mesh 196 mesh/cm2. When the breeding scale is large, 5 cages can be hung in 1 row, with the box spacing of 4-5 meters and the row spacing of 5-6 meters.

2. Shrimp can be cultured in cage twice a year, in summer 1 crop. Shrimp species overwinter in March-April, the specification is per kilogram 1000-2000, and the stocking density is 80- 1000 per square meter. Autumn 1 crops will be ready in mid-July. The stocking specification is 2000 ~ 5000 heads per kilogram, and the stocking density is per square meter 150 ~ 180 heads. Shrimp farming needs water, directly or in the morning and evening on cloudy days. The specifications of shrimp species in the same cage should be unified and sufficient at one time. 3-5 square meters of floating plants such as water hyacinth and Eichhornia crassipes are kept in each cage as hidden places for shrimps to inhabit, which can reduce the mutual damage of shrimps when molting. The roots of tender floating plants can be used as supplementary green feed for freshwater shrimps.

3. Feeding management

(1) Shrimp culture in cages is basically artificial. Therefore, the quality and quantity of feed are very important, and animal feed is even more necessary. The feed is preferably a compound feed containing more than 35% protein, and rice bran, bean cake, miscellaneous fish, snail meat, earthworm, etc. Feed should be put into the whole box twice a day (where there are management conditions, it can also be used several times in small quantities). Generally, 2/3 of the daily feed can be used in the morning 1 time, and 5 times in the afternoon is 1/3 of the daily feed.

(2) In daily management, it is necessary to clean the net clothing of the cage frequently to maintain the permeability of the net clothing and keep the water exchange smooth. It is necessary to regularly remove the residual feeding dirt at the bottom of the box to prevent it from affecting the water quality. Always check whether the cage is damaged to prevent the invasion of enemy creatures such as water rats and water snakes.

Shrimp culture in paddy field

1. Selection and arrangement of paddy fields Some paddy fields with fresh water and convenient management should be selected for the cultivation of freshwater shrimp. Combined with farmland improvement, the ridge can be reinforced and raised, and the height of the ridge is required to reach 30 ~ 50 cm, which is about 25 cm higher than the normal water level. Dig a fish ditch in the shape of a "field" or "well" in the field, with a width of 50 cm and a depth of 30 cm. Dig a fish tank at the intersection of fish ditch or the four corners of the field and near the water inlet of paddy field, with the width of 160 cm and the depth of 100 cm. The total area of ditches and chutes accounts for 6%-8% of the paddy field area.

2. Generally, young shrimps are released after transplanting (throwing) seedlings 1 week, and the specification is 2000-5000 per kilogram, and 667 square meters are released1000-0/000. Parent shrimps can also be released at the end of June and the beginning of July, allowing them to reproduce, feed and nourish themselves. Generally, there are 500 to 800 females in 667 square meters. 300 ~ 500 male shrimps. Fish and shrimp can also be mixed in rice fields, silver carp is the best fish species, while bighead carp, which has similar feeding habits to freshwater shrimp, is not suitable. Fish farming is also done after sowing single-season rice or double-season rice. In winter, fish can be put before planting in paddy fields to prolong the growth period of fish. Shrimp can also be stocked in two seasons: the first season can be stocked in early May and caught before the end of July; The second season can be stocked at the end of July and fished at the end of the year. The stocking time is cloudy or morning and evening.

3. Feeding management

(l) Feed is basically similar to pond culture and cage culture. At present, rice bran is often used as the main feed for shrimp culture in rice fields, together with 20% animal feed such as fish meal or snail meat. It is generally believed that feeding pellet feed has the best effect. According to the life characteristics of freshwater shrimp, feeding should be carried out in ditches, and the feeding amount is about 2%-3% of the total weight of shrimp all day, and the feeding time can be 5 pm, or 1 time in the morning and evening. Because shrimp fry eat plankton, manure, compost or mixed compost should be applied to rice fields, not human manure or inorganic fertilizer. In case the fertilizer efficiency is too fast and the water quality deteriorates.

(2) Careful use of pesticides and field inspection should attach great importance to the impact of pesticides, try to use pesticides with high efficiency and low toxicity, and strictly control the safe dosage. Before pesticide application, the accumulated water in the field should be deepened by 7 ~ 10 cm to reduce the harm of pesticides to fish and shrimp. When applying pesticide, the nozzle should be horizontal or upward, and the drug should be sprayed on the rice leaves as much as possible. Spray powder directly when the dew is not dry in the morning, and spray water after the dew is dry. It is not advisable to apply it before it rains. Because green shrimp is particularly sensitive to pesticides, it is easy to kill people. Therefore, special care should be taken when using pesticides. It is necessary to insist on leaving early and returning late, regularly check the ridges and fish-stopping facilities, and solve problems in time when found; To keep the water depth and keep the drainage system unblocked; Pay attention to the weather forecast and do a good job in flood control, escape prevention, enemy harm prevention and illegal arrest prevention.

(3) Catch shrimp cultured in rice fields in time. When the shrimp reaches a certain specification, it can be caught in time, by hand, by chute or in dry land. Shrimp can also be transferred to fish ponds or cages to continue farming.

Fourth, disease control.

Shrimp is not easy to get sick, and the main causes of death are the deterioration of water quality and careless operation. At present, there are two common shrimp diseases, namely gill rot and red disease.

(-) gill rot

[Pathogen and Disease] The pathogen is bacteria. The gill filaments of diseased shrimp are black and partly moldy.

【 Prevention method 】 It is necessary to regularly remove the residual feed and dirt, inject new water, and maintain a good water environment. Treatment: the dosage of bleaching powder per cubic meter of water 1 g, spread in the whole pond.

(2) Polycythemia

【 Symptoms 】 At the beginning of the disease, the tail stalk of the diseased shrimp was red, then the red range gradually expanded to the whole abdomen, and finally it spread to the head and chest and died. This disease is mainly caused by careless operation when fishing young shrimp and young shrimp.

[Prevention and treatment methods] There is no effective treatment at present, and prevention should be given priority to.

There are many shrimp farms all over the country. If you don't know where you are, you can ask at the local nursery.