One is to create a good environment for lobster growth. Lobster is a crustacean, similar to the crab, with a pair of particularly developed chelae, have the habit of digging holes to live in, generally near the water's edge of the bank to dig holes. Lobster like shade and fear of light, weak light or darkness when crawling out of the burrow, strong light, then sink into the water or hide in the burrow. According to the habits of lobsters, can be added in the river pond 50 cm high anti-escape net, to prevent lobsters from escaping. At the same time, the river pond simulates the ecological environment of the lobster under natural conditions, shallow planting of 10-15% of the pond side of the water plants, hidden objects, to create an environment for lobster habitat and shelling, to reduce mutual slaughter.
The impact of water quality on lobster production should not be ignored. Good or bad water quality directly affects the healthy growth and development of lobster, aquaculture process, the pool water ph value to maintain between 7.5-8.5, transparency of 30-40 centimeters, should be frequently refilled with new water, regularly sprinkle quicklime solution to regulate the water quality, to prevent the occurrence of disease and shelling attempts.
The second is reasonable feeding feed. Lobster in the case of hunger and insufficient food, will kill each other, so feeding must be sufficient. Lobster feed is plant and animal feed. Plant feed for wheat, watercress, rapeseed cake, etc., animal feed for miscellaneous fish, miscellaneous meat and animal offal. Usually according to the habits of lobster day and night and the density of shrimp in the pool to determine the feeding time, feeding volume and feeding methods. Otherwise, it will increase the feed plus cost, reduce the breeding efficiency.
Third, scientific fishing. In the lobster aquaculture process, young shrimp at a suitable temperature, under the condition of adequate feed, generally 60-90 days to grow to commercial specifications. March release of seedlings, June or so began to rotate catch, sell large and stay small. As a result of catching and retaining small, rotating catch and release, can improve the rate of return, sold at a good price, to achieve the purpose of high-yield and efficient.
Freshwater crayfish) culture technology
Freshwater lobster, the scientific name of Crayfish, also known as lobster, crayfish, red shrimp. The shrimp originated in the United States, during World War II from Japan into China, is now widely distributed in the middle and lower reaches of the Yangtze River. The shrimp is a temperate freshwater shrimp, adaptability, high reproduction rate, miscellaneous food, fast growth, disease resistance, high temperature resistance, low oxygen resistance, away from the water for several hours will not die. Shrimp meat flavor tender, nutritious, containing the body's essential 8 kinds of amino acids, while the fat content is low, and contains more of the original myosin and paramyosin, edible part of the higher. Favored by domestic consumers, the export volume is also increasing, sales and purchase prices are rising, breeding prospects and benefits are favorable.
Freshwater lobster live widely in freshwater lakes, rivers, ponds, ditches and rice paddies and other waters, benthic organisms, plankton and a variety of aquatic grasses are palatable bait, grow well in these waters. Juvenile shrimp live in shallow water or poolside, like burrowing, sometimes hiding in the gravel and water plants in the hiding place, usually dug in the large water surface perimeter of the shore of the clay more swampy rushes and grassy shoals and shoreline areas, shrimp holes are generally round, downward sloping, up to 30 centimeters or so deep and zigzagging direction is not the same. Freshwater lobster habitat is often a seasonal movement phenomenon, spring water temperatures rise, shrimp more activities in shallow water; summer is not warmer when moving to deeper water; winter overwintering in the hole. Freshwater lobster molting, growth and reproduction are also carried out in the cave to prevent injury, and the shrimp like shade and fear of light, weak light or darkness when climbing out of the cave. During the rainy season, the freshwater lobster often climbs onto land. The shrimp and has a strong ability to withstand hunger, generally can withstand starvation for 3 to 5 days; fall and winter seasons generally 20 to 30 days without food will not starve to death. The optimal temperature for feeding 25 ~ 30 ℃; water temperature below 15 ℃ below the activity is weakened; water temperature below 10 ℃ or more than 35 ℃ feeding significantly reduced; water temperature below 8 ℃, into the overwintering period, stop feeding. Freshwater lobster male shrimp life expectancy is generally 20 months, female shrimp life expectancy is 24 months.
Freshwater lobster is generally the end of October to the following year between March mating eggs, different waters mating time varies, too early to mate eggs are often immature, too late is too ripe and aging eggs. Mating suitable water temperature of 22 ~ 25 ℃, the mating season is best not to catch, so that they hold eggs incubation, reproduction of offspring. Freshwater lobster mating in the spring, summer and fall, can spawn 3 ~ 4 times a year, the general body length of 7 ~ 10 cm, weighing 15 ~ 30 grams of the parent shrimp, the amount of eggs for 220 ~ 270, and the individual size is different, the amount of eggs for the difference is very large. Under normal circumstances, after mating and spawning shrimp need to have 1 ~ 2 months of incubation process (i.e., embryonic development), need to consume a lot of physical strength, and therefore need to strengthen the shrimp to hold the eggs of the nutrition and cultivation. Hold egg shrimp incubation of the appropriate water temperature of 22 ~ 27 ℃, incubation time of 6 ~ 10 weeks. Shrimp fry cultivation before the need to clear the pond disinfection, filtration into the water, and then apply organic fertilizer to cultivate natural bait organisms for shrimp fry feeding. General shrimp fry cultivation, stocking larval density of 15 to 20 million, such as "soybean paste" method of cultivation, the stocking density can be 16 to 18 million.
Two, lobster farming techniques
General culture of Japanese marsh shrimp ponds can be cultured lobster, ordinary ponds can also be cultured, and its seedling farming techniques and Japanese marsh shrimp is similar, including the preliminary preparatory work, feed and water quality management, etc., but pay attention to the habit of its hit the hole, and the need to strengthen the anti-escape measures. Lobster's tolerance is strong, breeding its high yield, the current market demand is also larger, the economic benefits of aquaculture is considerable. The most common shallow water type paddy farming as an example is described below, other farming methods can be referred to.
Three, rice paddy freshwater lobster
Rice paddy freshwater lobster farming is generally up to 400 to 500 kilograms per mu of production, high yield up to 600 kilograms. Rice paddy shrimp can be eaten in the field to consume fertilizer weeds and other aquatic organisms, not only saves the labor of weeding, but also eliminates mosquitoes and flies that harm people and animals. And shrimp in the rice paddy non-stop action, foraging, not only can help the rice paddy loosening, living water, aeration, increase the amount of dissolved oxygen in the field water, at the same time through the metabolism of a large number of feces, play a preservation of fertilizers, fertilizer effect.
1, the choice of paddy
Paddy freshwater lobster to choose sufficient water, not affected by droughts, floods, fresh water, pollution-free, fertile soil, good water retention, sunny paddy, some mountain streams or springs, although the water quality is relatively barren, the water temperature is relatively low, but if there is a longer process or through the paddy without shrimp, and then flow into the breeding of shrimp paddy, the temperature of water will be Increase, also suitable for shrimp farming.
2, the transformation of paddy fields
In order to facilitate production management and daily baiting, generally between the drainage area for a breeding block. From the inner 0.6 meters from the surrounding side of the ridge dug 0.5 ~ 0.6 meters deep, 1.0 ~ 1.2 meters wide circular flow buffer ditch, and all the soil turned over to the side of the ridge, so that the side of the ridge to reach a height of 0.8 ~ 1.0 meters, the top of the width of 0.6 ~ 0.8 meters. The ridge should be compacted, the inner slope should be leveled, and at the same time, the inside of the ridge top should be enclosed with plastic film to form a closed protective wall. The height of the fence on the ground is 0.4~0.5 meters, and the underground is buried in 0.1~0.2 meters. The upper and lower inlet and outlet should be set up to prevent the escape net.
In order to facilitate shallow irrigation of rice paddies, sunshine, fertilizers, pesticides or fishing, it is necessary to excavate shrimp ditches and shrimp pools in shrimp rice paddies. Shrimp ditch can be excavated after rice planting, its opening method should depend on the shape of the field, the size of the area and the direction of the drainage outlet. If the rice field is small, can be opened into the "field" shape; such as long and large fields, can be opened into the "well" or "field" shape, ditch width and depth of 0.3 ~ 0.4 meters respectively. Shrimp pond can be opened at the intersection of shrimp ditch or the corners of the field, and shrimp ditch. Shrimp pool generally 1.0 meters square depth of 0.8 ~ 1.0 meters.
Shrimp paddy rice paddy to open a good inlet and outlet, the location should be selected in the paddy field relative to the two corners of the ridge, the breeding process inlet and outlet can make the whole paddy water flow. Inlet and outlet should be set up to block the fence, to avoid escaping shrimp.
3, shrimp stocking
Stocking time: Whether it is the year the shrimp species, or holding the eggs of the pro-shrimp, should strive for an "early" word. Early release can extend the growth period of shrimp in the paddy field, but also to take full advantage of the paddy field fertilizer cultivated by a large number of natural bait resources. Conventional stocking time is generally in November each year or the end of March of the following year.
Stocking density: 30 to 40 kilograms per mu of paddy rice paddies stocked with egg-holding shrimp. You can also wait until April to May of the next year to stock young shrimp species, per mu of paddy rice by 1.2 ~ 1.5 million tails put. Attention to hold eggs shrimp should be directly into the periphery of the ditch to feed overwintering, seedlings green and then lure shrimp into the paddy field growth. General culture and release culture mode has the following two:
(1) summer stocking: to stock the year artificially bred baby shrimp. Stocking time for July to September. Each mu of shrimp ditch stocking juvenile shrimp 1.5 to 20,000 tails.
(2) winter stocking: usually in December, per mu of shrimp ditch stocking 3 cm of shrimp species 1 ~ 1.5 million. Conditional places can carry out two seasons of shrimp farming, July to October to raise a season of green shrimp, December to the following year, May to June to raise a season of freshwater lobster.
4, feeding management
(1) baiting: rice paddy shrimp should also be timed, positioning, quantitative and qualitative baiting. Early in the day divided into morning and afternoon feeding; late in the evening at 6:00 pm more feeding. Feeding bait species are mostly small mixed fish, snail meat, mussel meat, earthworms, animal offal, silkworm pupae, with corn, wheat, barley flour. Can also feed the right amount of plant feed, such as water hyacinth, water turnip, water duckweed. Daily feeding feed amount of 3-5% of the weight of shrimp. Usually adhere to diligently check the shrimp's eating situation, the day of feeding the bait in 2~3 hours was eaten, indicating that the amount of bait is insufficient, should be appropriate to increase the amount of bait, such as in the next day there are still remaining, then the amount of bait should be appropriately reduced.
(2) removal of pests: rice paddy shrimp more pests, such as water centipedes, snakes, waterfowl, eels, water rats and so on. In the early days of shrimp, rice plant stems and leaves are not luxuriant, the field water surface gap is larger, at this time the shrimp individual is also smaller, weaker activity, the ability to escape from the enemy is poor, easy to be attacked by the enemy. At the same time, freshwater lobsters need to molt every once in a while to grow, in the molt or just molt, the most likely to become the enemy's palatable bait. To the harvest period, due to the shallow field water drainage, shrimp may crawl around, the target will be bigger, but also easy to be birds and animals predators. In this regard, it is necessary to strengthen field management, and timely repellent enemy pests. In addition, when the shrimp stocking, but also prohibit domesticated ducks under the field ditch to avoid losses.
(3) field ditch management: shrimp stocking, good management of field ditch is very important