The life span of green shrimp is not long, generally for a year, the shrimp hatchlings in June, after October that year, that is to grow into commercial shrimp; shrimp hatchlings in September, in May of the following year to grow into commercial shrimp. Limpet shrimp need more than 20 times a lifetime of shelling growth, to develop and mature.
Green shrimp spawning period for May-September. Suitable water temperature of 18 ℃ or more, the optimal water temperature of 22-28 ℃. At a water temperature of 25-28 ℃, the incubation period of only 14-15 days, at a water temperature of 19.5-20.5 ℃, the incubation period of 22-23 days. The newly hatched larvae are called flea-like larvae, which can jump and swim in the water, and develop into baby shrimps, also called shrimp fry, with a body length of about 1 centimeter after 9-14 times of shelling.
Second, shrimp breeding nursery
The first peak of shrimp reproduction in late May to early June, each large female shrimp carrying about 2-3 thousand eggs, generally 30,000 per city catty of the female shrimp can be littered with shrimp. As a female shrimp, required body length of 5 centimeters or more, male and female shrimp ratio of 2-3:1. conditions, it is best to choose the rivers and lakes in the wild shrimp as the parent for breeding.
Green shrimp nursery pond, an area of 0.5-2 acres is appropriate, the water depth of about 1-1.5 meters or so, easy access to water and drainage, adequate water supply without pollution. Pond disinfection according to conventional clearing, lime 150 kg / mu, or chlorine system machine or tea seed cake clearing, dosage 1-2PPM. clearing, filtering off the key to the success or failure of shrimp farming off.
Nursery ponds holding eggs shrimp stocking generally have two methods: holding eggs shrimp straight into the pond to engage in breeding, about 15 pounds per acre, to be shrimp fry basic hatching with shrimp cages to trap the parents out of the pond; holding eggs shrimp raised in the pond in the mesh box, each box to put the parents of 1-2 pounds per acre to put about 10 pounds of parentage. (Net box specifications 100 × 70 × 50 cm).
Nursery mainly rely on fertilization, in the release of holding eggs shrimp at the same time, the pool water fertilization. Throughout the nursery period, the pool water transparency control between 20-30 cm, PH value control in 7-8. Fertilizer can be applied organic fertilizer or add the appropriate amount of nitrogen, phosphorus fertilizer, but also can be splashed with soybean milk, splash pig's blood and so on. Fertilizer at the same time, but also need to pay attention to the dissolved oxygen of the water, to prevent hypoxia in the water, so you need to add new water at the right time, so that the pond water to keep both fat and live. Mastering the peak of zooplankton reproduction and production in the pond and flea-like larvae synchronization is the key technology for the success of the nursery.
The nursery period of about 25-30 days, according to the production requirements of the successive pieces of breeding adult shrimp.
Split seedling catching can first use the light trapping method, flushing water trapping method, and finally pulling the net method. Regardless of which method, the seedlings must be quickly put into the pre-prepared set of seedlings in the net box, and then over the number of sub-culture.
Third, adult shrimp farming
Pond conditions
Shrimp farming pond area can be large or small, the requirements are not stringent, but the requirements of high-yield people, then the area of 10 acres is good. Pond ridge to mud ridge is good, and the greater the slope ratio the better. The depth of water is about 1.5 meters, the bottom of the mud and sand is good, not more than 20 centimeters of silt.
Water source and supporting equipment
Requirements for year-round water sources, especially between May and November, the water required to be sufficient and pollution-free. Electricity facilities are complete, oxygenator, water pump complete supporting.
Shrimp stocking
Mu put shrimp seed is generally 6-8 million tails / mu, depending on the quality of seedlings, specifications and requirements of the yield, conditions, feeding management level and other flexible control. At the same time in the shrimp stocking, you can partner with the summer flower fish species or winter piece of fish species. Together with the fish species are mostly chub, chub. Summer flower fish species mu put 500 or so, white chub ratio of 1:2 or 1:1. winter piece of fish mu put 100 or so, white chub ratio of 1:2. usually shrimp mu yield 50-100 kilograms, fish mu yield 60-80 kilograms.
⒋ feeding management
Feed
To shrimp pellet feed, supplemented by small mixed fish, frozen seafood mixed fish, snails, clams, mussels, pupa powder, fishmeal, soybean dregs, oilcake, gluten and so on.
Feed feeding no less than two times a day, preferably three times, once in the morning for the total amount of 1/3, the evening for the total amount of 2/3, the morning cast in the deep water, the evening cast in the shallows, in the deep water set up a number of activities at the food table, to check the amount of food and growth.
planted green
In the shrimp pond around the pool water junction must be planted green, planted green varieties of cabbage, revolution grass, water hyacinth. Seed green area of about 1/4 to 1/3 of the area between the deepest also need to set up a number of mesh to increase its climbing space, in addition to the pond can be placed on bamboo branches, branches, shrimp balls shrimp broom and other habitats hiding things, to do a good job of this, there is hope for a high yield.
Daily management
Daily inspection of the pond no less than twice, especially in the evening. Pond inspections can detect changes in water quality and flooding omens in a timely manner. Under normal circumstances, the amount of food intake can reflect the water dissolved oxygen and water quality is good or bad, suggesting that we should take appropriate management measures, water change, open the oxygenator or fertilization. In the sudden change in climate, when found above the water plants, shrimp, shrimp, etc. shows that the flooding of the pond is imminent, should be immediately into the water, open the oxygenator, splash oxygen powder and other first aid measures.
In the routine management, sunny days every afternoon to open the oxygenator 0.5-1 hours. On rainy days, turn on the oxygenator for 3-4 hours in the evening or at night every day. Splash lime slurry regularly, usually once every 15-20 days, with a dosage of 10-15 kg/mu each time. When you need to apply fertilizer, it is best to match a certain proportion of phosphorus fertilizer.
In short, raising adult shrimp, pool water. Transparency requirements of about 30 centimeters, the second head of fat, relatively thin in the middle, dissolved oxygen cloudy days not less than 2mg / l, can always keep the pool water fat, live, tender, cool.
Careful fishing: adult shrimp fishing in the usual ground shrimp cage trapping, shrimp ball shrimp broom trapping and other methods, the end of the year a pull net cuttings, and finally dry pond clearing.
Density is too large
The prawns have a strong reproductive capacity, July shrimp stocked that year can hold eggs breeding seedlings, a large number of autumn breeding seedlings and the original pool of green shrimp to compete for food, space, mutual influence, mutual constraints, resulting in the final shrimp specifications into small, poor quality, can not be sold at a good price. Therefore, the control of excessive fall breeding shrimp seedlings, is to enhance the quality of green shrimp, one of the effective ways to increase the benefits of aquaculture. Commonly used control measures in production are as follows.
Postponement of seedling time
Gray shrimp breeding and water temperature is closely related to the stocking of shrimp seedlings to avoid the highest temperature of the year in July, and selected in early August, you can greatly reduce the chances of shrimp seedling breeding.
Put chub
Chub is a filter-feeding fish, shrimp in the metamorphosis before the trevally larvae is also one of the chub's filter-feeding objects, in the shrimp pond put specifications for the 20 ~ 30 tails / kg of the chub species, can effectively regulate the density of shrimp fry.
Artificial fishing in addition to holding the egg shrimp
Peanut is the ideal habitat for shrimp, most of the peanut hiding in the peanut is to hold the egg shrimp, and therefore can be used to catch the appropriate amount of holding the egg shrimp, can effectively reduce the distribution of shrimp fry density.
Stocking of high-quality shrimp fry
Precocious maturity is one of the factors of high breeding frequency of shrimp, and precocious maturity is often a poor quality shrimp fry inherent characteristics, and thus the production of shrimp advocated to the original farm to buy high-quality shrimp fry stocking, can not be greedy for trouble or in order to save the cost of breeding self-propagation, inbreeding.