Efficient culture technique of swimming crab

The meat of swimming crab is delicious, has high nutritional value and economic value, and is suitable for temporary fattening in seawater. The head and chest nail is fusiform, almost twice as wide as the length; the surface of the head and chest nail is covered with fine particles, with 2 transverse dikes and 3 verrucous protrusions; the forehead has 2 sharp teeth; the anterior edge has 9 sharp teeth, and the terminal teeth are long and thorny, protruding outward. The chelate foot is stout, the length is longer than the cephalothorax, the long node is prismatic, the male long node is longer, and the leading edge has 4 sharp spines.

Pond condition

Swimming crab culture pond with sand mud sediment is better, the pond area is 10-25 mu, the water depth is 1.5-2.0 meters, dig a ring ditch 4 meters wide and 0.5 meters deep around the pond, heighten the pond ridge 1.2 meters, each pond mouth is provided with a drainage culvert, each two rows of pond mouth to build a drainage channel; the pond had better choose the location where the tidal range is large, the tidal current is unobstructed, the salinity is more stable, and the pond is convenient to enter and drain. The most ideal is located in the intertidal zone, using the tidal range to receive water, and in places without such conditions, the water is lifted by a pump.

Stocking mode

The main results are as follows: 1. Preparation before stocking: after harvest of swimming crabs in autumn and winter, seal the gate and dry the pond. After drying, the bottom of the pond will be sloping ditches and ridges. In the middle and last ten days of March, 10 cm of water was collected with 60 mesh water net, 75 kg of quicklime per mu, and the whole pool was sprinkled with hydrated lime paste. After cleaning the crab pond, the content of calcium in the soil and water will increase, which is beneficial to the growth and development of swimming crab. After 50 cm of water, apply 20-25 mg / L tea seed cake to remove harmful fish.

2. Stocking quantity: according to the water exchange condition, water quality, water depth and feed supply status and technical level of the pond, 800-1000 young crabs at Ⅱ stage, 5000 young Penaeus chinensis and 50 kg shellfish such as clams are generally stocked per mu. It is best to separate the pond with a 20-30 mesh of rain flowers in the middle of the pond and separate male and female.

Daily management

1. Feed feeding: the amount of feed is closely related to the culture density, the size and temperature of swimming crab. In general, the daily feeding amount is 5-10% of the weight of the crab, twice a day. The amount of bait must be determined four times, that is, timing, quantity, fixed point and fixed quality. Fixed time, that is, 30% of the daily bait in the morning and 70% in the evening; quantitative, that is, the number and weight of swimming crabs should be measured regularly to determine a reasonable amount of bait; at a fixed point, the bait should be fed at a fixed place, and the bait will generally be scattered on the fixed slope around the pond; qualitative quality is to ensure the freshness and quality of the bait. Note that the amount of feeding is generally measured by the feeding situation of 3 hours after feeding, and it is adjusted in time. When the weather is dull or it rains heavily, bait should be cast less or not.

2. Regulation and control of water quality and water temperature: strengthen the management of water quality and persist in changing water. It is necessary to master the relationship between water color, transparency and water exchange. Before July, the transparency can be controlled at about 30 cm, and the daily water exchange volume is 10-20%. After July, the transparency of the pool water can be controlled at about 40 cm, and the daily water exchange volume is 20-30%. During the whole culture process, the water temperature is required to be 17-30 ℃.

Key points and matters needing attention in aquaculture management

1. Daily observation: daily observation should be strengthened. Biological observation was carried out every 15 days, the shell length, shell width and body weight were measured, and its growth was checked to measure the effect of culture. The hydration indexes of water temperature, salinity, pH value and dissolved oxygen are also measured and recorded regularly.

2. disease prevention and control: adhere to the principle of "prevention first, combination of prevention and control, comprehensive treatment", maintain good water quality, feed high-quality bait, and regularly mix vitamins during high temperature.

3. Separate stocking of female and male crabs is beneficial to the growth of female crabs, avoid the casualties caused by mating during molting, improve the survival rate and increase the feed coefficient. Male crabs can be caught and listed after mid-December.

4. Regular pond patrol: do a good job of anti-escape and anti-theft.