The types of cages are divided into closed cages and open cages according to the assembly method of the box body and whether there is a cover net. For cultivating filter-feeding fish or setting up cages in waters with large winds and waves, and setting up cages on water surfaces that need to overwinter, closed cages are generally used; in waters with small winds and waves, feeding fish or fish fingerlings generally use open-type cages. cage. According to the shape of the cage, there are rectangle, square, polygon and circle; according to the way of setting the cage, there are three types: fixed type, floating type and sinking type.
1. Fixed cage
Bamboo piles, woodpiles, or cement piles are used to nail the bottom of the water, the top of the pile is higher than the water surface, the arm is fixed on the pile, the upper part of the box is about 1 meter above the water surface, and the bottom of the box is 1-2 from the bottom of the water. Way. This type of cage can be set up in waters with strong wind and waves due to its relatively firm piles. However, the fixed cage cannot float with the change of the water level, and the effective volume of the box (the depth of the submerged water) will change due to the rise and fall of the water level. At the same time, since the cage cannot be moved, it is inconvenient for maintenance operations. In addition, the decomposition of fish feces and residual bait will cause great pollution to the water body of the cage, which often results in an ecological environment with low dissolved oxygen. Generally, it is rarely used.
2.Floating cages
Use a wider set of settings. Compared with fixed cages, they can be suspended on a buoyancy device or frame and float with the change of water level, which is effective.
Volume does not change due to changes in water level. This erection method is mainly suitable for reservoirs and lakes with deep water bodies and small waves. Because the cage is high off the bottom, it can also be transferred to the breeding site, which relatively reduces the water pollution caused by fish manure and residual bait, so it can always maintain good water quality conditions. The ability to float cages to resist wind and waves is poor, so it is advisable to add a cover net.
3. Sunken cage
The box is fully enclosed and the entire cage is submerged underwater. As long as the cage does not touch the effective volume of the water tank, the effective volume of the cage is generally not affected by changes in the water level. This kind of cage is more suitable for breeding filter-feeding fish. At the same time, the submerged cage can be used to solve the overwintering problem of warm water species when the water surface freezes in winter.