I raise seafood in a hotel in Shanghai. Every time I come here, many red crabs die the next day. Salinity is 1.05438+08; temperature is 15. Ask god to tell me how to raise them.

Red frost crab refers to the female crab that has been mated and fertilized. In June, 5438+10, stocking began in intensive culture ponds. When the ovary of Scylla serrata is fully mature, both sides of its carapace are filled with red cream, its breastplate is swollen, and the dots above its abdomen are red. The whole shell is brown or reddish brown, so it is called "red frost crab". At this time, it was harvested and listed, just before and after New Year's Day, and the benefits were extremely significant.

First, the construction of crab ponds. The general area is about 333 square meters, the height of the pool wall is about 1 m, and it is made of slate or brick. There is generally a fence around the pool wall to prevent escape, and the bottom is paved with coarse sand or gravel. It's best to lay slate on the bottom of the pool first, and the slate is close to each other without leaving gaps, and then sand 10cm is laid on the slate.

Second, stocking density. Generally, there are 2,000 mating egg-holding crabs weighing more than 250g per mu in intensive culture ponds.

Third, feed. Feed fresh fish, shrimp, shellfish and other animal bait, the daily feeding amount is 5% ~ 7% of the total weight, and the feeding should be fixed, with less feeding in the morning (about 20% of the total feeding amount) and more feeding in the evening (70% ~ 80% of the total feeding amount). When the water temperature drops to 10℃, water inflow should be stopped.

Fourth, grading feeding. Check the ovarian development of female crabs in time, and distinguish the quality grades (according to the degree of ovarian development, it can be divided into "female", "flower crab" and "cream crab") for grading feeding.

Fifth, adjust the water quality. The water depth is only 30-60 cm, so it is necessary to increase the change of water to maintain sufficient dissolved oxygen. Change the water twice a day and install the water pump. Do you want to pump fresh water at low tide and at 4-5 every morning? When you pour, the blue crabs often fight for new water. At this time, it is necessary to separate them in time with a bamboo rake.

Sixth, disease control. Molting failure is a common disease in mating and fertilizing female crabs. It has been observed that the crustacean hardening time of the mated female crab is as long as 2-3 days, and it is easy to be infected with germs. The oxygen consumption of mating female crabs increases, and female crabs are prone to suffocation and death due to lack of oxygen. Prevention and control methods. 1, improve the water environment, make the water clear and maintain a certain salinity (greater than the relative density of seawater 1.005). 2. Aeration with aerator or circulating water with water pump. 3. Don't feed the spoiled and moldy bait. 4, regular use of antibiotics according to 0.5-65438+/-0 ppm whole library. 5, found that sick crabs should be caught in time. At the same time, 2-3 ppm bleaching powder can be used for water disinfection to prevent the spread of diseases.

Seven, timely fishing. Check the ovarian development of blue crabs every 5- 10 days, and find that "red cream crabs" are selected and sold in time. If it is caught in time in March of the following year, it can only be sold as a "vegetable crab".