New culture technology of green crab how to raise fresh water of green crab

In fact, many delicacies are produced in autumn, compared with the crabs in seafood. You must know a lot about green crab, it often appears in our lives. At present, green crab has also become a craze in the breeding industry, but if you want to bring certain economic benefits, it is necessary to master certain culture techniques.

A new culture technique of green crab

1. Crab seedling selection: at present, the main sources of green crab seedlings are natural seedlings in the sea area and industrial artificial cultivation of seedlings (the technology of industrial production of seedlings has not been fully popularized, and the sources of seedlings are still very few). Should choose strong shell hard, carapace is turquoise, the specification is neat, the body is intact without damage, fully complete (especially a pair of chelate feet and swimming feet can not be missing one and injury), sensitive response, strong vitality, rapid crawling, no pathological changes of the health vaccine.

2. Site selection: green crab culture ponds (ponds) should be selected and built in the middle and high tide areas where there is no industrial and agricultural production wastewater, no toxic substances, no pesticides and domestic sewage pollution, fresh sea water, strong self-purification capacity of water exchange, stable physical and chemical factors, large tidal range, calm inner bay and a certain amount of land-based fresh water.

3. Escape prevention facilities: the inner side of the pond dam must be made of anti-escape fence (which can be made of cement sheet, bamboo fence, hard plastic sheet and other materials), and the height of the facility should be more than 50 cm higher than the highest water level in the pond. The upper end of the facility board and barrier should be tilted slightly to the pond, and the setting must be tight and firm to effectively prevent the green crab from escaping.

4. Feeding ratio: the feeding amount during the culture period should be flexibly controlled according to the water temperature, tide, water quality and the activities of green crabs. For example, the green crab feeds vigorously when the water temperature is above 15 ℃ and reaches the peak at 26 ℃. If the water temperature is higher than 30 ℃ or lower than 13 ℃, its food intake decreases obviously.

5. Adjust the salinity: when the salinity of the sea water in the pool is too low or too high, it is necessary to change the water in time, especially in the rainy season or during the rainy season, when the proportion of sea water in the pool is too low, the upper gate should be opened in time to discharge the low specific gravity water in the upper layer of the pool, and then the high specific gravity seawater in the middle and lower layers will be included in the most exciting part. For the difficulty of natural water intake in the construction of high beach, the middle and lower sea water can be extracted by lifting pump.

How to raise green crab in fresh water

Green crab is a marine crab. Due to its long-term survival at the seaside, its gills adapt to the high salt water, but not to the fresh water with low osmotic pressure. It is not suitable to use fresh water for aquaculture. It is recommended that we still use seawater for aquaculture according to its growth habits. However, if you breed for a few days, you can directly use fresh water or the aquarium shop in the flower and bird market to buy that kind of salt that specializes in preparing sea water, and the shopkeeper will teach you how to match it.

What food does green crab eat?

The eating habits of green crabs are very miscellaneous, mainly animal food, and the food composition is mainly molluscs and small crustaceans. Gastric contents often appear bivalve shell margin, twisted part fragments, gastropod snail, incomplete spiral shaft, square crab stump and cephalosternum fragments. It often feeds on beach worms, small fish and shrimp, and sometimes plant stem and leaf fragments are found in the stomach. Artificially cultured green crabs have no strict choice of bait, small miscellaneous fish, shrimp, small shellfish (blue clam, Xun's muscle clam, snail, etc.), bean cake, peanut cake can be eaten, have the habit of killing each other, often prey on soft-shell crabs that have just been shelled.

Mixed culture technique of green crab

1. Shrimp. Such as Penaeus chinensis, Penaeus vannamei, Penaeus Monodon, Penaeus vannamei, Penaeus chinensis, Penaeus chinensis and Penaeus vannamei. The stocking specification of shrimp seedlings requires that the seedlings of more than 3 cm after temporary culture are generally about 1000-2000 per mu, and the growth rate is faster than that of shrimp ponds on the tide. When the water temperature is suitable, the catch can begin after one month.

2. Fish. The main species are: mullet, barracuda, black sea bream, catfish and so on. The condensed organic matter in the pond is the excellent bait for these fish, and the amount of seedlings ranges from 20 to 500 per mu.

3. Class. Mixed culture of green crab and Gracilaria (called asparagus in Taiwan) is more common in Taiwan. Mixed culture of appropriate amount of algae can absorb a large amount of dissolved organic matter and increase the dissolved oxygen in the water body, which is more conducive to the growth of green crabs and other economic animals in the pond.

At present, the prospect of green crab in the market is still very good, good breeding can naturally bring people more optimistic economic benefits. However, the green crab belongs to the sea crab, so we should master the main points of its culture when raising it.