CATDOLL : CATDOLL: How to farm crabs? How to farm crabs

How to breed crabs? How to breed crabs

1. You can put the crabs in a deeper basin. If there are too many crabs and one basin cannot hold them all, you can raise them separately. In order to prevent the crabs from escaping, it is best to cover the basin with a layer of gauze.

2. Put clean water in the basin. The water should not be deeper than the crab, so that its head can be exposed when it stands up. Otherwise, it will not be able to breathe due to lack of oxygen. However, the crab's shell should be submerged.

3. If you are worried that the crabs will escape if you keep them in pots, you can use plastic buckets. In the same way as in pots, do not put too much water in it and choose a bucket with a smoother inner wall.

4. Place the crab bucket in a ventilated and cool place. The temperature should be around 15 degrees. If you want to eat it after one or two days, you don’t need to feed it. Just use clean water.

5. If you want to raise the crabs for a longer period of time and prevent them from getting thin, you can feed them some small shrimps or small fish, and it would be best if you add some weeds.

6. If the crabs you want to raise are river crabs, you can just use clean water. If they are sea crabs, you need to put some salt in the water to make the water salty, closer to its growth environment.

How to raise seawater crabs in fresh water

1. Desilting and disinfection of crab pond

1. All ponds are mostly cleaned by drying the ponds (bottom mud does not exceed 15cm) and exposing them to the sun around the end of each year, and then cleaned with 100-100kg/mu of quicklime.

2. The dredging can be done thoroughly by using underwater dredges and other means.

3. Aerate the running water or use an aerator to ensure that the dissolved oxygen in the water is not less than 5 mg/L.

4. Make efforts to promote the use and feeding of photosynthetic bacteria and other microorganisms, which can effectively absorb toxic substances in the water and at the bottom of the water.

2. Adjust the stocking mode

1. Appropriate density.

Change from dense breeding to sparse release, generally releasing 500-600 crabs per mu, so that the river crabs have ample living and growth space.

2. Moderate specifications.

Generally, it is 100-200 crabs/kg, so as to ensure that the adult crabs meet the market specifications.

3. Release at the right time.

Change the winter release to spring release, usually from the end of February to the beginning of March, when the water temperature is between 8-12℃.

4. Raise them temporarily first and then release them into the air.

"Temporary rearing" is a necessary transitional stage before stocking crabs. Stocking crabs after temporary rearing can greatly increase the survival rate of crabs in the pond. Note that the length of temporary rearing time depends on the water temperature and the growth of aquatic plants in the pond.

3. Planting aquatic plants

1. The main purpose of planting aquatic plants

It plays a dispersing role, can make full use of the water body, and take advantage of the three-dimensional benign distribution of river crabs, that is, the upper, middle and lower water bodies are appropriately distributed.

2. Aquatic plant species

You can choose Elodea, Vallisneria, Hydrilla verticillata, etc., but Elodea is the best. It has high nutritional value, strong vitality, and can grow all year round.

3. Grass planting area

Generally, it is controlled at about 60% of the water surface. If it is too dense, a channel with a width of 3-5m should be opened every 10-15m to ensure that there is enough light at the bottom of the pool.

4. Planting time

It is usually chosen around the Qingming Festival, not too early or too late.

5. Planting method

Elodea and Hydrilla verticillata are mainly propagated asexually, using the method of cutting stems and cuttings, with a dosage of 25-30kg per mu; Vallisneria is mainly propagated by sowing, with a seed dosage of 0.1kg per mu.

4. Improve feeding aquaculture technology

Feed quality requirements are the material guarantee for the production of large and good crabs.

In March, when the water temperature reaches above 10℃, feeding begins. The bait mainly includes animal carcasses and their slaughtered scraps, clam meat, snail meat, shrimp, etc., as well as wheat, grains, cakes, and fresh aquatic or terrestrial grasses. Feeding must adhere to the principle of reasonable combination of fine, green and coarse.

From April to May, the water plants in the pond sprout, the biological baits multiply, and the newly released crabs are small and the water temperature is low, so the crabs do not feed very much. You can feed them less animal feed and more green and roughage. From June to October, the crabs gradually grow up, the water temperature rises, and the crabs feed more, especially from August to October, when the crabs grow fat and yellow, and their weight increases significantly, so you need to feed them more animal feed.

Feed once a day around dusk, with feed thrown in shallow water at the edge of the pond and multiple feeding tables set up. The amount of feed each time accounts for about 10-20% of the total weight of the crab, and can be increased or decreased appropriately depending on the season, water temperature, weather, feeding, and growth conditions. In addition, the following aspects should also be paid attention to in actual operation.

5. Scientifically regulate water quality

1. Water quality indicators

The water quality indexes are required to be 35-40cm in transparency, 5mg/L or above in dissolved oxygen, 7.5-8.5 in pH, and 0.2-0.5mg/L in ammonia nitrogen. The above water quality indexes can be tested clinically by using water quality test kits and other means, so as to take some measures (mainly simulating the natural ecological environment) to make necessary, beneficial and timely regulation of the water environment.

2. Pool water regulation

At the beginning of crab stocking at the end of February and the beginning of March, the water depth is controlled at 0.6-0.8m, from May to July the water depth is 0.8-1.0m, from August to October the water depth is controlled between 1.0-1.2m. In spring and autumn, change the water once a week, each time deepening 30-40cm. When changing the water, drain and fill at the same time, and the temperature difference of the water should not exceed ±5℃.

If there is a lot of silt on the bottom of the pond, the transparency is low, the water color becomes darker, the carapace of the river crab is dark black, rust appears on the abdomen, and the ends of the walking legs turn yellow, use 7.5-15kg of fresh quicklime per acre, dissolve it in water and sprinkle it throughout the pond. Use it 2-3 times in a row, with an interval of 5-7 days each time. This can adjust the water quality and increase the concentration of calcium in the water, which is beneficial to the growth of river crabs and the change of the color of their shells.

Additional information:

Things to note when breeding crabs:

1. Regularly visit the farm for observation

If you want to raise crabs well, the first thing you need to do is to check the farm regularly to see if they are alive and if the water quality has changed, so that you can take timely measures to solve the problem. This requires the farmer to be diligent enough to observe at least three times a day to see what happens in the morning, noon and evening.

If you want to raise crabs well, water quality is very important. Summer is the period of rapid growth for crabs, and the growth rate will increase a lot. In this case, we need to provide more feed. In this way, the excrement in the pond will increase, and clean water needs to be replaced in time, otherwise the crabs will not be able to grow normally.

2. Regular disinfection management

For disinfection, you can use bleaching powder. Many people who raise crabs have not noticed this. It is actually very critical, especially in summer when the weather is very hot. At this time, it is easy for bacteria to grow in clean water, so it is necessary to disinfect in time, about once every half a month.

3. Feed crabs reasonably and effectively

You need to choose feeding according to the weather and water quality. If the temperature is relatively high in summer, you can feed more. Those who know crabs may know that they generally grow rapidly in summer, and reproduce in summer. At this time, they need to have enough food, otherwise they will not be able to grow normally.

However, if the weather is cold in winter, there is no need to feed too much food, because crabs generally choose to rest in peace in winter.

4. Choice of crab feed

The choice of feed is also very important. Crabs need to be fed different feeds in different seasons so that they can grow normally. Feeding them with a combination of meat and vegetables will allow them to absorb better.

If they are all meat, they will grow too fast and affect their expansion. It is best to choose fresh food when feeding crabs, which can help them digest better. Crabs vary greatly in size, so they must be fed evenly, otherwise larger crabs may kill smaller crabs for food, which will greatly affect the yield in the end.

Reference source: Baidu Encyclopedia - Crab farming technology

You should bring back some sea water when you catch them, tap water contains chlorine, which is poison to them, so adding salt is useless.

Crabs are arthropods that breathe by filtering oxygen in the water with their gills. (When you eat crabs, you can see a few sponge-like things on the two sides of the front under the lid. These are gills.) In moist conditions, crabs can live for a while. But if it is dry for a long time, the gills will dry out and lose the ability to breathe. Because sea crabs live by the sea for a long time, their gills are adapted to the high-salt seawater and are not adapted to the low-osmotic pressure of fresh water.

Your crab died mainly because of difficulty breathing due to lack of oxygen. Although there is seawater, the oxygen in the seawater is not enough for it. (And you may have placed it in a sealed environment with seawater)

Are you going to keep it for a long time, or just for a few days for fun?

If you want to raise it for a long time, you should go to the aquarium store in the flower and bird market to buy salt that is specially made with sea water. The owner will teach you how to mix sea water.

If you are keeping it for a short period of time, just use fresh water and it will still work. Don't add regular salt randomly, as it contains iodine, and you don't know the ratio.

Yes, you can add some salt. It is best to mix sea crystal and water, use an oxygenator to epoxidize for 20 minutes, and then add crab roe.

Add some salt and expose it to the sun for an hour, and you can raise it.