Detailed Explanation of Key Technical Points for Chinese Mitten Crab Farming in 2019

In recent years, the Chinese mitten crab, as a mid-to-high-end aquatic product, has gradually opened up its sales and farming market, and it is currently one of the aquaculture projects encouraged and supported by the state. It is expected that the farming area for Chinese mitten crabs will further expand in 2019, so what are the key technical points for Chinese mitten crab farming? Below we will give a detailed explanation of this.

I. What are the growth habits of the Chinese mitten crab?

1. Cave-dwelling life

The Chinese mitten crab, also known as the Chinese river crab (Eriocheir sinensis), usually lives in caves and prefers clear, healthy water environments. It is very responsive to the outside world and likes light very much. It generally hides in aquatic plants during the day and comes out at night to look for food.

2. Water quality requirements

The Chinese mitten crab generally requires water quality with a pH of 7.5 to 8.5, and the suitable temperature is 15 to 30°C. Its requirement for dissolved oxygen in the water is similar to that of fish, about 3mg/L. If the water temperature is below 10°C, it will hide in caves to overwinter.

3. Food requirements

The Chinese mitten crab is very greedy and also fairly tolerant of hunger. Fish, shrimp, mussels, snails and insects are all foods it likes, and it also likes to eat various aquatic plants.

II. What are the key technical points for Chinese mitten crab farming?

1. Choose a suitable farming site and water source

When choosing a site, you should choose one with sufficient water sources, convenient drainage and irrigation, a relatively independent water inlet and drainage system, no pollution sources within a 3km radius, excellent water quality, and clay as the best geology. Escape-prevention facilities need to be set up around the farming pond.

The usually suitable pond area is 0.33 to 0.67hm2, and at the same time it is necessary to ensure that the pond water level is above 1.5m. In addition, a shallow shoal area should be set aside in the pond waters, accounting for about 25% of the total pond area.

2. Aquatic plants should be planted before releasing crab seedlings

The Chinese mitten crab usually likes to live in waters rich in aquatic plants and with clear water quality, and the amount of aquatic plants determines whether the Chinese mitten crab can grow healthily. Therefore, plants such as tape grass (Vallisneria) and elodea (Elodea) can be planted in the pond, and it must be ensured that these aquatic plants can cover more than 60% of the total pond area in the later stage of crab growth.

3. The seedlings of the Chinese mitten crab must be well selected

(1) A reasonable ratio of male to female crab seedlings should be chosen, basically maintaining the same number, which can promote the healthy growth of the Chinese mitten crab.

(2) The quality and size of the crab seedlings should be reasonably selected. Ones that are too large should not be chosen; it is best to choose ones around 100g, and for female crabs, relatively smaller ones should be chosen. When selecting seedlings, observe the external features of the Chinese mitten crab and be careful to remove seedlings with black bellies and yellowish backs.

As for the time to release crab seedlings, usually the effect of releasing crab seedlings in winter is clearly better than in spring, summer and autumn.

4. Pay attention to daily management

The Chinese mitten crab is an omnivorous animal. The release of bait should be proportioned according to scientific methods. A nutritionally balanced feed can help the Chinese mitten crab better adapt to the environment and increase its chances of survival. Small fish, small shrimp, river snails and other aquatic animals in the water will bring more nutrients to the growth of the Chinese mitten crab.

In addition to a balanced diet, routinely checking whether there are sick, dead from cold, or

broken-limbed Chinese mitten crabs in the pond is also important work to ensure the basic quality of the Chinese mitten crab.