How much water do you put in crayfish?

It is hard to get shrimp in summer, which shows the popularity of crayfish. Crayfish taste delicious and high nutritional value, but crayfish culture methods are not well understood. If crayfish are full of meat, water quality management is very important. Xiaofeng Xiaobian will introduce what problems should be paid attention to about the water for raising crayfish.

How much water do you put in crayfish?

Don't drown the shrimp with water. It is best to expose one-third of the head on the outside! This is more suitable for oxygen absorption and conversion, but the water level must not be lower than the shrimp itself, the specific water level height can be determined according to the actual situation.

Crayfish is a kind of freshwater economic shrimp, which is very popular because of its delicious meat. Because of its omnivorous, fast growth and strong adaptability, it forms an absolute competitive advantage in the local ecological environment. The range of food intake includes aquatic plants, algae, aquatic insects, animal carcasses, etc., and kill each other when food is scarce. Crayfish has become an important economically farmed species in China in recent years. In the process of commercial breeding, we should strictly prevent escape, especially into the inaccessible original ecological water body. It causes destructive harm to the ecological competitive advantage of local species.

Water quality management of crayfish culture

1. Fertilization

In addition to applying basal fertilizer to improve water quality before putting crayfish seedlings, shrimp ponds should also apply certain fertilizers according to the changes of water quality to ensure the supply of zooplankton in the water. Topdressing is mainly based on rotten organic fertilizer, less chemical fertilizer, especially ammonium bicarbonate. In the application of topdressing, it is necessary to apply less and frequently, and the amount of fertilizer should not be too much each time, so as to control the water quality. Generally apply once a month, each time the amount of fertilizer per mu is about 100 kg, the amount of topdressing should be adjusted according to season, weather, temperature, water color and so on. In general, due to low water temperature and slow decomposition of organic matter in spring and autumn, the amount of fertilizer application can be increased appropriately; in summer and other high temperature seasons, the amount of fertilizer application should be reduced. Give more in sunny days, less in cloudy and rainy days, and no muggy weather before thunderstorm. Fertilization should also look at the water color, generally the pond water is grass green, tea brown and non-turbid water is good water, when its transparency is less than 30cm, do not apply fertilizer, apply fertilizer in time when more than 30cm, if the water color is dark brown or the water surface accumulates yellowish green bloom, it should be fertilized after changing water.

2. Regulation of water quality

In the process of crayfish culture, when the temperature is low in early spring, the water level can be lowered and the water depth can be kept at a depth of 30-60 cm to make the water temperature rise quickly. In the future, with the gradual rise of the temperature, the water level can be gradually increased. During the hot summer season, keep the water depth at 1.5-2 meters. If the water level is too low when the temperature is high in summer, it will accelerate the gonadal development of crayfish, cause the precocity of shrimp, and cause the individual of commercial shrimp to be too small. In general, during crayfish culture, new water should be injected every 10-15 days when the temperature is low, and once every 7-10 days in summer to keep the amount of dissolved oxygen in the water above 5 mg / L.

Where there are conditions, an aerator should be installed so that the low amount of dissolved oxygen in the water can be replenished in time during summer high temperatures, rainy days and sudden weather changes. Shrimp ponds should choose air compression aerator and spray aerator, which has the advantage of not being afraid of slapping and stirring the water body to avoid damage to shrimp. And impeller aerator and water wheel aerator at the same power, than spray aerator to the water area swirling range, easy to damage shrimp, the use of this aerator must be kept at a depth of more than 1.5 meters.

If a large number of crayfish are found climbing out of the water when the weather is clear during the day, it is proved that the lack of oxygen should be filled with new water in time. At ordinary times, we should often observe the changes of water quality, so that the water quality can be kept in a state of fertilizer, activity, tenderness and freshness for a long time.

Fertilizer: refers to a large amount of phytoplankton in the proper concentration of water color and conducive to shrimp digestion. The general transparency is 25-35 cm, and the water color is tea brown or grass green.

Live: refers to the continuous change of water color and transparency with the intensity of sunlight. This is mainly due to the alternation and vitality of the dominant populations of phytoplankton in the pond. Fishermen often say that "early Qing and late green", "early red and late green" and "half red and half green" all refer to this change. If there are wisps of spray like clouds interlaced with yellow and green in the pond, there are too many indigestible algae in the water, which is a sign of deteriorating water quality, so the water should be changed in time. In addition, the activity of pond water varies not only at different times of day, but also periodically every 10-15 days, which means that beneficial algae populations are in a virtuous circle of continuous utilization and growth.

Tender: refers to water and fertilizer but not old. There are two main signs of old water, one is yellow or yellowish brown, the other is white. The emergence of these signs is due to the deterioration of water quality caused by the large number of indigestible cyanobacteria in fish and shrimp or the aging and death of algae cells.

Shuang: refers to the fresh water quality, the water color is not too strong, and the transparency is 25-35 cm.

How many seedlings are suitable for crayfish culture?

The specific stocking density depends on the environmental conditions of culture, the conditions of water sources, the level of breeding and management, the sources and specifications of seedlings, the sources of bait, and so on. In short, according to local conditions, flexible release of seedlings. If you are your own young shrimp, the specification is 3-4 cm, 14000 Mu 15000 pieces per mu.

Among them, the yield per mu is expected to reach 200 kg according to the previous output for many years, combined with their own breeding conditions and measures. It is estimated that the survival rate can be calculated at 40 per cent, and according to the market specifications needed for breeding, it is generally 30 per kilogram, so you can calculate how much you want to breed in a major change.

How to cultivate crayfish with fertile water

The main results are as follows: 1. Crayfish are reclusive animals. Fertilizing water before releasing seedlings and controlling the transparency of the water body in advance can provide a stable growth environment for shrimp seedlings that have just entered the pond.

2. It can effectively control the growth of moss and land, prevent shrimp seedlings from being wrapped in moss after entering the pond, and the dissolved oxygen in water is relatively good, which is beneficial for shrimp seedlings to adapt to the pond environment quickly.

3. Through the reproduction of algae and fungi, the nutrients of the pond can be absorbed in advance to avoid the adverse effects of potential harmful indexes such as ammonia nitrogen, nitrite, phosphide and so on.

4. Many farmers are used to throwing snails before releasing seedlings. Fertilizer and water just before releasing seedlings can provide rich bait for snails. Snails grow well and become excellent bait for crayfish.

5. Good organic fertilizer can be used as both fertilizer and material through fermentation process. Fertilizer and water indirectly replenish bait to the pond before seedling release, and shrimp seedlings can be eaten after entering the pond.

6. It can promote the growth of aquatic plants, and the good growth of aquatic plants can provide a better hiding place for shrimp seedlings.

To sum up, shrimp culture still has requirements for water quality, and water quality can directly affect the yield of shrimp, which is related to the interests of farmers, so good water quality management is an important part of shrimp culture.