CATDOLL : CATDOLL: How to farm hairy crabs, including the conditions for farming

How to farm hairy crabs, including the conditions for farming

1. Pond treatment: clean up the excess silt at the bottom of the pond, sprinkle 100-125kg of quicklime per acre of pond, rinse the pond after 7 days, then dry the pond for 3-5 days and add water. 2. Stocking: Stock from the end of February to March every year, about 300 crabs per acre of pond, when stocking, the water depth is 1.5-2m and the temperature is 20-25℃. 3. Feeding: Feed twice a day, the daily feeding amount is 5-8% of the crab body weight, of which the feeding amount in the evening accounts for 70%.

1. Methods of breeding hairy crabs

1. Pond treatment

(1) Clean up the excess silt at the bottom of the pond (leaving only a 10 cm thick silt layer), then sprinkle 100-125 kg of quicklime per acre throughout the pond to clean and disinfect it.

(2) After 7 days, drain the water, dry the pond for 3-5 days, and then add water.

(3) Transplant an appropriate amount of aquatic plants that hairy crabs like to eat into the pond, with the area preferably being about one-third to one-half of the crab pond.

2. Free range

(1) Crab seedlings are released from the end of February to around March each year, with about 300 crabs released per acre of pond.

(2) Before releasing the crab seedlings, the crab bodies are disinfected, and then a fence is used to enclose an area of ​​water. The crab seedlings are placed in the fenced area to adapt to the environment. After 30 days, the fence is removed.

(3) When stocking, the water depth in the pond should be around 1.5-2m and the temperature should be around 20-25℃.

3. Feeding

(1) The daily feeding amount is about 5-8% of the crab's body weight. It is best if there is a little leftover bait from the previous feeding each time.

(2) Feed twice a day (8-10 a.m. and 5-6 p.m.), with the evening feeding accounting for 70% of the daily feeding amount.

(3) In summer, hairy crabs grow vigorously, so it is necessary to increase the amount of plant-based bait appropriately. In autumn, hairy crabs are in the fattening season, so it is appropriate to increase the amount of high-protein bait such as snail meat, animal scraps, and fish.

4. Management

(1) In summer, spray 2-3ppm superphosphate solution and 10-15ppm quicklime solution every 15-20 days to adjust the pH value of the water and supplement calcium (the interval between the two is 3-5 days).

(2) During high temperature periods, change the water every 3-5 days. The amount of water changed should not exceed one-third of the total water volume. The water level should be controlled at around 1-1.5m, and the water transparency should be controlled at around 35-40cm.

(3) Change water frequently in early autumn. As the water temperature drops, the frequency of water changes should be reduced. The water transparency should be controlled at around 45 cm and the water level should be controlled at around 1-1.5 m.

(4) The dissolved oxygen content in water should be kept above 5 mg/L as much as possible.

2. Conditions for breeding hairy crabs

The conditions for breeding hairy crabs are as follows:

1. The hairy crab breeding site should be sheltered from the wind, facing the sun, with convenient transportation and good environment.

2. There must be sufficient water sources near the hairy crab breeding site, and the water quality must be good, pollution-free, and drainage and irrigation must be convenient.

3. The breeding area should be about 5-10 acres. If the area is too small, the water quality will be unstable. If the area is too large, management will be inconvenient.

4. The depth of the breeding pond should be about 1.5m, and the depth of the breeding water should be about 1-1.2m.

5. The breeding pond is rectangular (long from east to west and narrow from north to south), with a length-to-width ratio of about 5:3 and a slope ratio of about 1:3 (which can effectively reduce the number of burrowing hairy crabs).

6. The breeding pond requires a wide bank, compact soil (loam is preferred), no water leakage, and the silt at the bottom of the pond should not exceed 5 cm.

Crab breeding methods and precautions?

October is the best time to eat river crabs. The crab meat is thick and yellow at this time. Many families eat 10 to 20 kilograms of crabs every year. The price of crabs is also rising. They are even sold by the piece, and the price of one piece is nearly 300 to 400 yuan. So today we are going to talk about the breeding techniques of river crabs.



1. Pond Preparation

First of all, we must choose a pond with a lot of aquatic plants and good light. It is best if there are no big trees nearby. Secondly, the water quality must be clean. After all these are ready, we should start to estimate our own breeding scale. Generally speaking, farmers choose three to eight acres. Then, when digging, they should not be too deep. A height of one meter and two is enough for crab ponds. Then, there must be a good drainage and irrigation system. Only with these can the normal growth of crabs be guaranteed. The pond mud also needs attention. It is necessary to choose the hard mud. Other muds are not good. The thick silt at the bottom of the pond cannot be left. It must be dug clean. Nets should also be placed around the crab pond to prevent these crabs from escaping if they are not careful. At the same time, in order to reduce some unnecessary losses, we must disinfect these crab ponds before each release of crab seedlings to prevent them from contracting diseases. The specific operation is to sprinkle the entire pond with quicklime for fifteen days before stocking, and disinfect the entire pond. The best amount per acre is generally 75 kilograms. Here we choose to use quicklime, which not only has a disinfecting effect, but also adds a lot of calcium ions to the water when it reacts with water. This makes the water in our pond very good and can provide crabs with more trace elements.



2. Precautions for crab seedlings

Then when we choose crab seedlings, we must choose those strong crabs with very good growth conditions. The simplest way to check these crabs is to see if their two claws and eight legs are defective. Generally speaking, intact crabs have very good quality. Secondly, the size must be similar. If there is a big difference, it will not be good for the subsequent breeding. In this way, after we do a good job of the preliminary work, we can guarantee the quality and survival rate of the crabs to a certain extent. Then when we release these crab seedlings, we don’t rush to release them. We first enclose an area in the crab pond as a temporary breeding area, which is about one-fifth of the entire crab pond. The purpose of this is to let them adapt to the pond first and then remove the temporary breeding area. At this time, we should pay attention to the density. Generally speaking, about 2,000 crabs are released per acre, and the time we choose is around the beginning of spring.



3. Feed usage for river crabs

When we are breeding river crabs, we must use some feed in moderation, because the natural food collected by these crabs in the crab pond is definitely not enough for them to thrive, and the yield will not be too high. So at this time we have to use feed to help them. Generally speaking, after we put the crab seedlings in the crab pond, we will start to prepare to put in feed when the water temperature reaches 11 degrees Celsius. When putting in, we should pay attention to putting in fine feed in the early stage, in the middle stage we put in coarse feed, and in the later stage we just use meat feed. Specifically, the early, middle and late stages are in each season. In spring, we will choose to feed them a small amount of paste feed, and in summer we will feed them plant-based feed. When we enter the best season for crabs in August, we are ready to start feeding them meat feed with meat. The purpose of doing this is to allow their gonads, that is, the yellow part, to develop to the fullest before they are fully mature, so that not only the crabs are bigger, but also the meat will be more delicious.



4. Precautions during breeding

Because our river crabs have extremely high requirements for water quality, our work on water quality must be put in the first place. First of all, before releasing the crab seedlings, we need to ensure that the water in the crab pond has a certain degree of fertility, and this degree can only be more, not less. Therefore, during our breeding process, we must add water at least once a week, and when the temperature rises, we must also add water to them, using the method of raising the water level to ensure that the temperature of the water layer below is not too high. There is a standard that in July, the water level at this time must be at least 1.5 meters, and the frequency of water changes must also change with the increase in temperature. Generally speaking, we have to change the water at least once every half a month in May and June, and once a week in July and August. After the temperature gradually drops, our frequency will gradually return to normal. And every time you change the water, you don’t have to drain the entire pond, just replace about 30% is enough, and the work of quicklime cannot be interrupted, the frequency is about every 15 days.

Note:

1. The pond must have good drainage and air permeability. In order for crabs to thrive, the conditions of the pond must first meet the growth conditions. While choosing clay, sand and other soils with good ventilation, convenient drainage and unpolluted water quality, you must also pay attention to the depth of the water in the pond and the slope of the pond. Please note that the depth of the pond must be maintained at about 0.6-1.5 m. If the pond is not tilted too fast, it will be detrimental to the nighttime water release activities of crabs. If conditions permit, you can choose to make holes artificially. Plant aquatic plants well. Aquatic plants are related to the production of river crabs, so it is necessary to plant aquatic plants well. There are many kinds of aquatic plants such as duckweed, water hyacinth, black fish algae, potatoes, etc.

2. Be careful not to let the crabs run away. Crabs are easy to escape when they are raised in ponds, so measures must be taken to prevent them from escaping. Depending on the breeding conditions, you can use plastic film, cement board, etc.

3. The pond should be disinfected and cleaned. The purpose of cleaning and disinfecting the pond is to prevent crabs from growing better and getting sick. Using quicklime to disinfect before putting in the seedlings can improve the structure of microorganisms at the bottom of the pond and kill harmful organisms.

4. Select and stock the crab seedlings. The crab seedlings of crabs are related to the quality of crabs, so you must choose healthy, lively and neat crab seedlings. Pay attention to the stocking density and temperature when stocking the seedlings. You can't just put the newly bought seedlings into the pond. Soak them several times and put them into the pool after getting familiar with them. The survival rate is higher.

5. Feeding. When breeding crabs in ponds, they are mainly fed with artificial feed, so choosing the right feed is the key. Generally, small fish of animal origin can be chosen. Aquatic plants, bitter herbs, etc. of plant origin can be chosen; commodities include cereals, potatoes, etc.

6. Crab black gill disease. When crabs are suffering from black gills, if it is mild, the gills will turn dark gray and black, and if it is severe, the entire gill will turn black, and they will be unable to breathe and their reactions will become sluggish. Generally speaking, due to differences in water environments, it is more common in the later stages of crab growth.