Winter stocking of hairy crab seedlings has many advantages; here's how to raise hairy crabs well

The hairy crab is a type of river crab, widely distributed along China's long coastline from the Liao River in the north to the Pearl River in the south, with the Yangtze River system producing the largest yields, the most delicious taste and very rich nutrition. Generally speaking, hairy crab specifically refers to the Chinese mitten crab of the Yangtze River system. Hairy crab farming requires little investment and yields high returns, making it a good path to prosperity. In recent years, hairy crab farming has developed rapidly, and many farmers naturally assume that spring is more suitable for stocking hairy crab seedlings, but this is not the case. The advantages of stocking hairy crab seedlings in winter are mainly reflected in the following aspects.

I. Advantages of stocking crab seedlings in winter for hairy crab farming

1. Low price

Every year from mid-October to mid-November is the period when large numbers of crab seedlings are caught, transferred to ponds for concentrated overwintering and sold. During this period, buying seedlings is inexpensive, generally about 1 yuan each, while in spring, crab seedlings sell for 2 to 3 yuan each.

2. Safe transport

Newly caught crab seedlings have rich fat reserves in their bodies, are strong and robust, and have strong adaptability and resistance. Moreover, at this time the temperature difference between north and south is only 5°C to 10°C, and the air humidity is high, making handling easy, management simple and transport safe and reliable. In contrast, crab seedlings after overwintering are weak and have poor resistance; combined with the large temperature difference between north and south, they are prone to various diseases, have a low transport survival rate and require more demanding transport conditions.

3. High survival rate

In winter, because the water is clean, bacterial and viral activity weakens, and the stocked crab seedlings have fewer chances of being infected by various pathogens. In spring, however, crab seedlings suffer invasion by various pathogens that cause disease, reducing the survival rate.

4. Long growth period

Crab seedlings stocked in spring have a growth period of only just over 6 months; after deducting the adaptation period, the growth period is even shorter, making small size and low yields hard to avoid. Stocking crab seedlings in winter generally extends the effective growth period by 1 to 2 months, with notable effects on increasing size, raising yields and boosting returns.

II. Hairy crab farming techniques

1. Plant water plants well

In hairy crab farming, the first step is to plant water plants well. Water plants are one of the natural foods of hairy crabs, can effectively purify water quality, and are also places for hairy crabs to rest and escape from predators. Algae are the main type. An appropriate amount of field snails can also be added. For more on planting water plants, you can read the article "Planting and Maintenance Techniques for Water Plants in Crab Farming Ponds."

2. Reasonable stocking

Before stocking, the crab seedlings must be disinfected and separated evenly by size. When stocking, use enclosure netting to release them within the water area, and only remove the netting after the crabs have adapted to the environment for 1 month. Generally, crab seedling stocking should follow the principles of "three suitables" and "one temporary holding." That is, suitable density, suitable timing, suitable size, and temporary holding first followed by release. When stocking, the water must not be too deep; 1.5-2 m is appropriate; a temperature of 20-25 degrees is most suitable.

3. Stocking density

In an environment with abundant water plants and fresh water quality, generally about 300 seedlings per mu are stocked, giving the hairy crabs ample space to live and grow. Crab seedlings are generally stocked from the end of February to March each year. If stocked too early, overwintering losses will be heavier; if too late, water temperatures rise, some river crabs molt, and this will affect the survival rate after entering the pond.

4. Daily pond patrols

Morning pond patrols mainly check whether there is leftover bait, so as to arrange the day's feed; midday pond patrols mainly measure water temperature and observe water color conditions and pond water changes; evening and nighttime pond patrols mainly observe the activity and feeding conditions of the river crabs, so that measures can be taken promptly when problems are found.