How to increase crab yield? Master these farming tips
Autumn is the season when crabs mature and hit the market. For farmers, the income from river crab ponds is their biggest concern. And the yield of river crab ponds directly determines this year's income, so how can you increase crab yield? Do the following and push crab yield up another notch!
I. How to increase crab yield
1. Enhance nutrition
The crab roe and crab paste inside the crab are the key factors determining the crab's weight. Generally speaking, the crab roe content of female crabs is slightly higher than that of male crabs, which is why the difference between female and male crabs is greater in weight than in body size. As the saying goes, autumn brings beautiful crab roe; crab roe and crab paste are also the main highlights people savor when tasting crabs, and the content and quality of crab roe and crab paste determine the quality of the crab.
The crab roe and crab paste inside the crab are the crab's gonads and hepatopancreas, and this is where the crab's nutrients are mainly stored. The crab's main source of nutrition is the protein fed by the farmer, so at the critical moment of the autumn harvest you must put in the effort and step up feeding of high-protein food.
But be careful not to blindly pursue high protein. There are two sources of high protein: animal-based protein food and plant-based protein food. For feeding crabs, animal-based protein food is generally used, as its digestion and absorption efficiency is higher and it is more conducive to the crab absorbing nutrients. This can be solved by feeding high-protein feed, feeding high-quality frozen fish, and so on.
2. Calcium supplementation
Increasing the molting multiplication rate of crabs is also key to raising yield. The calcium content in the water body can directly affect the timing and efficiency of crab molting. Crabs can absorb ionic calcium from the water, which can be understood as crabs being able to absorb calcium substances that dissolve in water. Some farmers spread lime to increase the calcium content in the water quality, but because lime's solubility is too low and it has a big impact on the water's pH value, the drawbacks outweigh the benefits, so this method is not recommended.
3. Dissolved oxygen
The oxygen content in the farming water is also crucial. If the dissolved oxygen index in the water quality does not meet the standard, even the survival rate is a problem, let alone the yield. In addition, the aquatic plant content in the water is also an important indicator of crab yield and survival rate. Aquatic plants not only provide good hiding conditions for crabs, but more than 80% of the dissolved oxygen also comes from aquatic plants. However, at night, aquatic plants begin respiration and will consume the oxygen in the water, so the aquatic plant content in the pond must also be well controlled, generally between 30%-50%.
II. Crab farming methods
1. Prepare the farming pond
The pond for farming crabs should have clear water quality, fairly abundant aquatic plants, and sufficient sunlight, generally 1-2 m deep. Before farming, clear the silt at the bottom of the pond, set up escape-prevention devices around it, and spread quicklime to do a good job of disinfection.
2. Select seed stock and release seedlings
When selecting seed stock, choose pure, high-quality varieties, and be careful to observe that there are no injured crabs, crippled crabs, or diseased crabs; choose crab seed stock that is well developed and robust. Before releasing the seedlings, let the crab seedlings go through a transition adaptation period. You can set up a temporary holding area in the pond, and after a period of time you can release the crab seedlings. The stocking density should be moderate, controlled at about 2000 per mu.
3. Feed the feed
During the process of farming river crabs, feed must be given regularly. Before the autumn harvest, you can feed high-protein meat-based material to strengthen nutrition, promote the development of the river crab's gonads and hepatopancreas, and make the meat more delicious.
4. Water quality management
Water quality is directly related to the crab's survival rate, so change the water and disinfect regularly, ensure the water contains a certain level of fertility, and adjust the water level according to changes in season, temperature, and weather.
The above are the key points of autumn field management for crabs and a brief introduction to farming methods. In addition, during the farming process, attention should also be paid to preventing the intrusion of pests and diseases to avoid unnecessary losses.