The benefit of raising crabs in fish ponds is high.

It is a new breeding mode with low input and high output summed up by the author for many years to cultivate crabs in fish ponds, to adopt density to win, to carry out ecological breeding and to feed coarse instead of fine. Last year, the author successively invested 1000 yuan in fish seed fees and feed fees in a pond with a size of two mu. Results 70000 fire fillet fingerlings were produced with an income of 3000 yuan, 20000 one-year-old fish species, an income of 4000 yuan, and an income of 1000 yuan for 40 kilograms of adult crabs, with a total output value of 8000 yuan. excluding the cost, the net profit per mu was 3500 yuan, achieving the goal of low input and high output.

At the end of April, the pond was cleared thoroughly with 75 kg lime per mu. 250000 grass carp, silver carp and bighead carp fry, half grass carp silver carp and bighead carp fry were released on May 18, and 2000 bean crab fry were released on May 20.

One month after the fry went into the pond, the fry was fed with soy milk once a day. A month later, when the fry grew to 3-4 cm, the concentrate feed was stopped. From then on, all the fry were fed to Lausha (floating grass, also known as sesame duckweed). This kind of aquatic plant is small, the root system is only the size of hair, grass carp like to eat very much. At first, grass carp began to feed on the root system, and began to look for food in about a week or so. Grass carp excretes feces and can fertilize water, which can be eaten by chain bighead carp. Especially in the hot season of July, August and September, herbivorous fish are especially fond of eating, and river crabs are no exception. From mid-June to late September, a total of 7500 kilograms of ladyfish were fed. Grass is almost always in the pond, and grass carp grow very fast. Since October, when the resources of aquatic plants are less, they will all be fed with fresh chicken manure. There are a large number of undigested bait in chicken feces, as well as bean cakes, corn and other concentrate pecked by chickens in the feces, which are palatable bait for grass carp and river crabs. There is a principle in the feeding method: fish and crabs should be fed as much as they eat, so that the feed will not consume oxygen by fermentation in water. If there is too much bait for fish and crabs to find food at one time, it will ferment in the pond, oxygen consumption will affect the growth of fish and crabs, and in serious cases, it will cause flooding ponds. In the whole feeding process, 3000 kg of fresh chicken manure is fed, and the water quality of the pond is relatively fat, which is generally controlled at about 5-10 cm, which meets the requirements of water and fertilizer fish. In the past, books required the transparency of pool water to be 30cm to 40cm, which could not meet the requirements of high yield. In the process of feeding, insist on catching and releasing for many times. When the fish grow to the size of 3 cm to 5 cm, that is, fire slices, continue to catch and release, a total of 5 times, the initial catch of 70, 000 fire fish, income of 3000 yuan. The water in the fish pond fed with chicken dung is generally acidic, which will affect the growth of fish and crabs. Quicklime must be used regularly to regulate the water quality. Generally, the water depth per mu is 15 kg. The use of quicklime must be block ash, sprinkled with water throughout the pond, which can neutralize the acidity and keep the pond water neutral, which is very beneficial to the growth of fish and crabs. It can not only prevent disease but also purify the water quality and promote the healthy growth of fish and crabs.

After raising river crabs in ① fry pond, there are abundant bait for river crabs to find food in the pond. Captivity is often better than stocking alone. ② does not need to set up anti-theft facilities. ③ practice has proved that river crabs raised in fish ponds generally do not get sick and can be treated with less or no drugs. ④ crabs are caught within 15 days before and after the National Day, so don't take the effort to take care of them. ⑤ adult fish pond can also be imitated, the effect is very good, generally can increase the income of 200 million 300 yuan per mu.