Seawater specific gravity and salinity conversion table

Seawater specific gravity and salinity conversion table

2015-04-03 admin 38763

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 8332

Crab Apartment was selected into CCTV-7's "Science and Technology Garden" 11th Special Program - A Collection of Field Wisdom

2026-03-30 admin 2512

The feature film "Crabs in a Box" introducing our company's "Crab Apartment" is expected to be broadcast on CCTV-7's "Science and Technology Garden" column at 18:30 on August 22 (this Thursday). Pleas

The feature film "Crabs in a Box" introducing our company's "Crab Apartment" is expected to be released at 18:30 on August 22 (this Thursday)

2026-03-30 admin 5607

Chitin ranks sixth among the top ten health foods in the world announced by the World Health Organization (WHO)!

Chitin ranks sixth among the top ten health foods in the world announced by the World Health Organization (WHO)!

2. Regulate blood lipids, improve blood thickening, and resist cardiovascular diseases.
4. Can regulate blood sugar and reduce the onset of diabetes

2012-03-09 admin 1782

Method for producing soft-shell crabs from Portunus trituberculatus

Method for producing soft-shell crabs from Portunus trituberculatus

2014-03-03 admin 1639

【Soft Shell Crab】--from Baidu Encyclopedia

Appearance characteristics
In short, soft shell crabs are rich in nutrients and can be eaten all over the body. They contain 18 kinds of amino acids. In addition to water, the nutritional content of soft shell crabs is 14.0g of protein, 2.5g of fat, 0.8g of carbohydrates, and 14.2m of zinc per 100g.

2011-10-26 admin 1484

The State Council issued financial and taxation policies and measures to support small and micro enterprises

The State Council issued financial and taxation policies and measures to support small and micro enterprises

Strengthen loan supervision and end-user monitoring to ensure that it is used for the normal production and operation of small and micro enterprises. Promote the establishment of new rural financial institutions on the basis of prudent supervision, guide small financial institutions to increase service outlets, and extend institutions to counties and townships within their jurisdiction. The meeting required all regions and relevant departments to regard supporting the healthy development of small and micro enterprises as an important task, conscientiously formulate relevant policies and measures, and implement them effectively.

2014-08-02 admin 462

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

2014-03-03 admin 847

soft shell crab

2011-10-04 admin 2108

Factory-based recirculating aquaculture system will be an important model for future aquaculture

Factory-based recirculating aquaculture system will be an important model for future aquaculture

2011-09-08 admin 2196

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 2069

The largest bathing beach in Qingdao is blocked by Enteromorpha

On July 15, 2011, Enteromorpha was covered with Qingdao No. 1 Bathing Beach, and many tourists were "swimming" and playing in the Enteromorpha.

2014-08-02 admin 497

Zhejiang: Marine fish are cultured in water towns, and groupers are produced in factories

2014-08-02 admin 1318

Shandong Peninsula Blue Economic Zone

Shandong Peninsula Blue Economic Zone

2014-08-02 admin 851

Qingdao Jiaozhou Bay Cross-sea Bridge officially opened to traffic

China Broadcasting Network News The Voice of China will broadcast a special live broadcast of "Across Jiaozhou Bay" from 10:00 to 10:30 and 11:00 to 11:30 today (June 30), taking you to experience the opening of the Qingdao Jiaozhou Bay Cross-Sea Bridge and Undersea Tunnel. The highest - a 60-meter precast concrete box girder weighing 2,050 tons can be hoisted to a height of 58 meters, which is the maximum height of similar box girder installations at home and abroad.

On the morning of June 30, the world's longest cross-sea bridge - Jiaozhou Bay Bridge in Qingdao, Shandong Province, and the longest undersea tunnel in China - Qingdao Jiaozhou Bay Tunnel will be officially opened to traffic.

2014-08-02 admin 817

zebrafish

Zebrafish, also known as blue striped fish, striped fish, and zebra daniorerio, is native to India and Bangladesh.

2010-05-17 majifen 696

Introduction to artificial breeding methods of zebrafish

2014-03-03 majifen 3426

Model organism zebrafish

Model organism zebrafish

2010-05-17 majifen 950

Research progress on zebrafish as a model organism in the causes of human diseases

2010-05-17 majifen 487

Zhongkehai opens 400 national service hotline!

The company has opened a 400 national service hotline!

2010-06-07 majifen 483

Xenopus laevis: the frog prince among model organisms

Xenopus laevis: the frog prince among model organisms
"Xenopus" is Latin, meaning "special foot". The hind feet of Xenopus are well-developed, with five toes and well-developed webs. Among them, the inner three toes have keratinized claws at the end, so it is named Xenopus; "laevis" means "smooth", which refers to its smooth skin. But its love words are not uttered through the vocal sac, because our prince has no vocal organs common to this animal. During this period, the researchers who studied Xenopus were mainly researchers from museums and zoos in London, England, and the specimens used in the research were all imported from Africa. Due to this use, Xenopus laevis was also exported to various parts of the world from its native southeastern Africa during this period, and breeding groups of Xenopus laevis were established in Europe, the United States and other places. Although Spemann discovered the organizer in 1924, no breakthrough was made in the study of the molecular mechanism of the organizer's action for a long time. This may be the world's first cloned animal. What is more interesting is that the activity of MPF in oocytes changes with the cell cycle. It is most active before the oocyte undergoes meiosis; and when the oocyte divides, the activity of MPF also disappears. It also has the experimental embryology research advantages of Xenopus, such as hormone-induced spawning and large egg production.

2010-05-17 majifen 872