Breeding technology-ZHONGKEHAI Recycling Water Aquaculture System(R.A.S)-第3页

Ecological and healthy breeding technology of Chinese mitten crab

4. Food habits: Chinese mitten crabs are omnivorous crustaceans. Their food habits have the characteristics of broad spectrum, cannibalism, gluttony and hunger resistance.
2. Salinity The salinity requirements of the first stage of flea-like larvae are higher than those of subsequent stages of flea-like larvae, and generally cannot be lower than 7‰; starting from the second stage of larvae, the salinity requirements decrease. Generally, the salinity can be reduced to about 5‰, and the metamorphosis can be smooth. The pool wall is preferably stone wall or cement board wall. When using quicklime to clean the pond, the dosage per acre of the dry pond is 75kg. On the one hand, it can kill harmful organisms. On the other hand, it can improve the water quality, increase the content of calcium ions in the water body, and promote the molting growth of Chinese mitten crabs. When using bleaching powder to clean the pond, first calculate the volume of the pond water, and use 20g of bleaching powder per cubic meter of water. Dissolve the bleaching powder required for the nursery pond with water, and then sprinkle it all over the pond immediately. Usually, crab seedlings can be released 5 days after the pond is cleaned. 3 to 5 days before planting seedlings, add new water to 60 to 80 centimeters, and then use Fertilizer and Water King/Fetilizer and Water Expert/Enoch Fishing Fertilizer/Bio Fertilizer Water Treasure + Water Treasure Nutrient/Freshwater Phytoauxin to fertilize and water. At the same time, you can use Black Elf/Water Adjuster/Nourish Water King/Enoch Bacteria King to adjust the water. 3. The desalination time of artificially bred crab fry must be five days, and the salinity should be less than three thousandths; the salinity of the water body at the natural crab fry fishing site should be less than five thousandths.
(1) From crab seedlings to young crab stages (weight increases from 6.5 mg to 2 grams, body length increases from 0.3 cm to 1.5 cm, molting eight times, lasting about 45 days), 100,000 to 200,000 crab seedlings can be released per mu.
① Plant-based feeds such as water peanuts, Hydrilla verticillata, Echinacea, Vallisneria and other natural aquatic plants, various vegetables such as pumpkins and watermelon rinds, and some cereal feeds;
2. Water quality management Chinese mitten crabs like to live in water bodies with fresh water, lush aquatic plants, sufficient dissolved oxygen, and abundant benthic organisms. The water temperature, dissolved oxygen, pH, sulfide nitrogen, ammonia nitrogen, plankton, and benthic organisms of the pool water are closely related to the habitat, growth and development of Chinese mitten crabs. (2) The pool water should be kept clear, fresh, and alive, with medium fertility, a transparency of about 30 to 50 centimeters, a dissolved oxygen requirement of more than 5 mg/L, and a pH value between 7.5 and 8.5; when water quality is abnormal, Enoch microbial preparations such as Tiao Shui Wang, Enoch Bacteria King, and Yujiabao should be used in a timely manner to improve the bottom quality and regulate the water quality.
(3) Be sure to keep the crab pond environment quiet and comfortable, and do not interfere too much with the feeding and molting processes of Chinese mitten crabs. Especially during the period when Chinese mitten crabs molt in large numbers, the crab pond environment must be kept quiet.

2014-03-07 admin 1453

Seawater specific gravity and salinity conversion table

2015-04-03 admin 38758

River crab breeding technology

River crab breeding technology
Adult crabs prefer a water environment with clean water and greater transparency, with overgrown aquatic plants and abundant food. River crabs are most suitable for growth. Currently, most crabs are cultured in ponds, lakes, rivers and rice fields. Therefore, for pond cultivation of river crabs, great efforts must be made to plant aquatic plants. The main types of aquatic plants include duckweed, Azolla, water hyacinth, water lily, Hydrilla verticillata, hornwort, Vallisneria, water peanut, etc. Pay attention to disinfection and damage prevention when transplanting.
6. Daily management
Look at the weather: Feed more when the weather is sunny, feed less on cloudy and rainy days. In hot and muggy weather, you can stop feeding before there is no wind and showers. In foggy days, feed after the fog subsides.
Quantitative: "If a fish does not eat for one day, it will not grow for three days." The same is true for river crabs. This requires determining the feeding amount according to the size, density, different seasons, weather, and activity conditions of the river crabs. Generally, the daily feeding amount is 8-10% of the body weight of the crabs in the pond. A small feeding amount can only maintain life. Exceeding the appropriate time range will also affect growth and increase the feed coefficient.

Pay attention to frequent water changes to keep the water level stable. Change the water once a week in spring and every 3 days in summer. If the high temperature persists, change the water every day. In autumn, the weather is hot and muggy weather often occurs, and the water quality is easy to deteriorate. Pay special attention to water changes. Change the water once every 2 days. The water change accounts for 1/3 of the entire water area.
The water quality is required to be fresh and pollution-free, with convenient water intake and drainage, sufficient water sources, and compliance with national fishery water standards.
After the medicinal properties of the clear pond disappear, the pond water should be kept at 20-30cm. After the water temperature gradually rises, aquatic plants can be planted. For ponds planted with submerged plants such as Hydrilla verticillata and Vallisneria, due to their late germination, it is necessary to set up a water peanut (Hydrophylla philodendron) strip 1 meter away from the edge of the pond, with a width of 2 meters, as an auxiliary measure to absorb water body fertility, regulate water quality, improve river crab habitat, avoid enemy molting sites, and provide shade and cooling.

　　The main types of fertilization include: fermented and sterilized organic fertilizers and inorganic fertilizers such as superphosphate and dicalcium phosphate. The first is to adjust "new", that is, add new water, once every 5-7 days, and change the water once every 10 days and a half. In high-temperature seasons, add 20-30cm of water every day, and change the water once every 3-5 days.
The water depth is controlled at 0.5-0.6cm from March to May, 1.2-1.5m from June to August (the water level may be deepened appropriately in high temperature seasons), and stabilizes at around 1m from September to November. As the stocking density of crab seedlings in our county continues to increase and the breeding output continues to increase, the ecological environment and water quality regulation of crab ponds have been paid more and more attention by the majority of farmers. Practice has proved that in the crab breeding process, the full use of microecological preparations has obvious effects on improving the ecological environment of crab ponds, regulating water quality, improving crab immunity, preventing diseases, and promoting growth. When purchasing, farmers must carefully read the main strains contained on the label, the main mechanism of action after being put into water or mixed with erbium and fed, and use them in a targeted manner.
1. Under natural breeding conditions, there are many factors that will affect the effectiveness of microecological preparations, such as weather, water temperature, water quality, water body fertility, and the type of breeding. The effects vary greatly.
Water peanuts can also induce some live bait to be eaten by river crabs, such as water worms and small fish, shrimps, snails and aquatic insects among annelids.

Second, a "cluster" of vines must be formed in the pond. It should not be a few water pods together, but clusters together, otherwise the above effect will not be achieved.

2014-03-03 admin 8328

Method for producing soft-shell crabs from Portunus trituberculatus

2014-03-03 admin 1637

Pollution-free food Technical specifications for the breeding of Portunus trituberculatus NY/T 5163-2002

2014-03-03 admin 845

The role of ultraviolet germicidal lamps in aquaculture

The role of ultraviolet germicidal lamps in aquaculture
Ultraviolet rays are very effective in killing water bacteria that cause fish diseases, such as white spot bacteria, which can be killed in three seconds under ultraviolet irradiation. If used for pond sterilization, considering the attenuation of UV lamp radiation, in order to ensure the sterilization effect, it is recommended that users replace the UV lamp every 8 to 10 months.

2014-03-03 admin 2065

Introduction to artificial breeding methods of zebrafish

2014-03-03 majifen 3418

Breeding technology

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