What mainstream models of leech farming exist today? An analysis of common farming methods

Article source: http://www.shuizhi315.com/

    I. Environment and conditions for artificial leech farming:
   Leech farming does not require heavy labor. In the Yellow River and middle and lower Yangtze River regions, as long as there is an adequate water source and feed that leeches suck - snails and river mussels - can be caught oneself or purchased, farming is possible (except in seawater), indoors or outdoors, in front of or behind the house, in old factory buildings, on wasteland, in fish ponds, etc. The farming area can be large or small.

   II. Farming models and stocking numbers:
     1. Semi-artificial cage pond farming: Using excavated wasteland, or low-lying old ponds and fish ponds, for cage farming. The cage width is C--D m, the length is unlimited, the cage height is A m or more to prevent flooding, and the water depth is kept at 80 cm or more. (This farming method makes harvesting convenient and is currently the commonly adopted farming method, but if the mesh count is too low, small seedlings get pinched to death, and if the mesh count is too high, the excrement of field snails and leeches clogs the mesh during farming. Water quality regulation becomes the biggest problem, and yield also fluctuates high and low from year to year.)
    2. High-density industrialized soilless artificial leech farming: Using the area in front of or behind the house, old factory buildings or old cement yards, gardens, wasteland, or places near lakes with convenient water sources, build cement ponds for soilless three-dimensional farming. The pond specification is B m--C m wide, the pond depth is 100 cm, the length is unlimited, and the farming area can be large or small. A sewage discharge outlet is made at the bottom of the pond, and a flood-control outlet is made on the pond wall at a height of 80 cm from the pond bottom. (This farming method disrupts the leeches' original natural survival characteristics. Whether the leech seedlings can survive high temperatures is the decisive factor for this model, but regulating water temperature during the high-temperature weather in June and July is a fundamental problem. Anyone with a bit of common sense understands that in summer above 35 degrees, the cement gets scorching hot, and changing the water 24 hours a day is only a drop in the bucket. This method means high input and low output. Building one mu of cement ponds costs 60,000, and under the theoretical condition of stable production for four years can the cost be recovered. It is a farming method provided for reference only.)
   3. Imitation-ecological earth pond leech farming: Use farmland to dig farming ponds (ditches) in a (dish) shape, B·C m wide, A·AB m deep, length unlimited. With an east-west orientation, leave a management walkway A·AB m wide between ponds (ditches). Old ponds and fish ponds can be renovated for farming, and anti-escape equipment is all that is needed. The water depth in the pond is kept at 50·100 cm. (This farming method imitates the natural living habits of leeches in all respects, while the ditches and walkways facilitate daily management and observation. It is suitable for large-scale farming with low input and high output. It is currently the most ideal farming method.)