-
How to prevent and treat common diseases in river crab farming
I. Shell ulcer disease 1. Symptoms: Ulcerative lesions occur on the crab's exoskeleton. In the early stage, there are many brown spots on the shell, with each spot having a slightly reddish depressed center. In the late stage, the edges of the spots turn black, the ulcers in the center deepen, and the shell is eroded into holes, exposing muscle
-
Experience Sharing on Placing Fish-Rearing Cages in Flat-Bottomed Rivers
In flat-bottomed rivers with a water depth of more than 2.5 m and little year-round variation in water level, fish farming with cages works very well. 1) Generally speaking, a height of 50 cm between the cage bottom and the riverbed is sufficient. Leaving a gap between the cage bottom and the riverbed facilitates water flow, which first adds oxygen and second serves to exchange water ⟦4 <p>In flat-bottomed rivers with a water depth of more than 2.5 m and little year-round variation in water level, fish farming with cages works very well. </p><p></p><p>1) Generally speaking, a height of 50 cm between the cage bottom and the riverbed is sufficient. Leaving a gap between the cage bottom and the riverbed facilitates water flow, which first adds oxygen and second serves to exchange water and improve water quality. The height of the cage body can be 2.5-3 m. After this depth is immersed in water, 50 cm of netting is left above the water surface to prevent jumping fish from escaping. It is best to cover the top with netting to prevent birds from stealing and eating the fish. </p><p>2) It must be noted that the cage should be placed in a sunny spot, a place with a gentle flow speed, or a place with backflow. As far as the whole river channel is concerned, backflow areas are often places where fish gather; backflow areas have gentle flow speeds and abundant feed, making them very suitable for fish growth. </p><p>3) If the river channel is not deep, moso bamboo can be driven in as stakes, the cage tied with ropes, and marker lines indicating the cage's draught depth marked on the stakes, making it easy to adjust in time and stabilize the cage depth. Use slip knots for the ropes to make it easy to raise and lower the cage body. </p><p>4) For this fixed-type cage, tie straight strip-like objects along the top and bottom ropes of the cage body; for example, thin bamboo poles can be used for the top and bottom ropes, and iron bars can also be used for the bottom rope, stretching the entire cage flat and straight, avoiding folding of the netting in the water and reducing capacity. Install rings at the four corners of the cage. When in use, fit the rings at the four corners onto the bamboo stakes, and the formed cage will be firmly tied to the bamboo stakes and ready for farming. The rings can also be tied to the bamboo stakes, four on the top and four on the bottom, using pull ropes to control the entire cage body, following the rise and fall of the water level, and adjusting the draught depth of the cage body in time. In places with gentle flowing water, feed is most abundant. When the cage body is flat and straight, the fish are most comfortable. </p>
-
Sharing Experience in Northern River Crab Farming Management
The scientific name of the river crab is Chinese mitten crab (Eriocheir sinensis). Its flesh is delicious and nutritious, and it has certain medicinal value. Domestic market demand is large, economic returns are considerable, and farming prospects are broad. But we all know that the weather in the north in winter is much colder than in the south, so
-
Autumn River Crab Farming: Beware of Preventing River Crab Death
Autumn is the season when river crabs mature and are harvested, and it is also the peak period for river crab deaths. Therefore, strengthening autumn farming management of river crabs is the key to preventing autumn deaths of river crabs and improving river crab farming profitability. Preventing natural death. As the saying goes: when the west wind blows, crab legs itch.
-
Prevention and Treatment of the Hairy/Fuzzy Condition in Farmed River Crabs
During the growth of farmed river crabs, hair-like growths sometimes appear on the carapace and abdominal appendages, making the crab's surface very dirty, and causing slow movement, poor appetite, malnutrition, difficulty breathing, claws that do not pinch, and even death before molting. The cause of this condition
-
Experience and Techniques for Polyculture of River Crabs and Bass in Summer
This polyculture model of river crabs and bass fully utilizes the water body space, forming a composite ecosystem where fish and crabs coexist in a mutually beneficial relationship, reducing the disease rate, greatly improving the market quality of commercial crabs, and increasing farming income. The technical key points are summarized below:
-
Experience sharing on mixed culture of river crab and bass in ponds
1 Pond clearing and preparation After the pond is exposed to the sun, use 80kg of quicklime per 1/15 hectare to clear the pond and disinfect it, killing harmful organisms and pathogenic bacteria. 7d before stocking crab seedlings, fill with water to about 0.5m, apply 60kg of chicken manure per 1/15 hectare, cultivate plankton feed, and make the water color yellow-green, with transparency
-
Prevention and Treatment of Acute Poisoning in River Crab Culture
Acute poisoning in river crabs has two types of symptoms: 1) Toxic agents, because of their high invasion intensity, within a relatively short time pass through the gills and triangular membranes of the river crab, causing the rear edge of the crab's carapace to swell and split, producing a false "molting", or the triangular membranes to show abnormal red or black muddy conditions, or the crab's abdominal flap to open and droop, with the limbs becoming stiff and death occurring.
-
Five Key Points of the Nutritional Plan for River Crab Farming
1. Liver protection. The liver is an important metabolic organ of the river crab, serving functions such as detoxification, blood production and oxygen carrying, secretion of digestive enzymes, and absorption of nutrients. As the river crab molts and grows, the load on the liver increases, making it prone to lesions, which leads to a decline in constitution and immunity,
-
Five key points for autumn river crab farming
As the saying goes: when the autumn wind blows, the crab's legs itch. This saying indicates that once autumn arrives, crabs begin to come ashore, and coming ashore is generally a sign of sexual maturity. Therefore, this is a critical period in the year's crab farming, and a small detail can determine the success or failure of the farming. I personally believe that at this
条件筛选