Structure and layout of the cage: it can be made into a cage of 1m× 1m× 1m with a mesh of 3cm. The bottom of the box is made of dense mesh cloth into a disc-shaped bottom net with a side height of 20 cm to prevent bait loss. A trap lamp is installed at the top 50 ~ 30 cm of the fully enclosed cage, and a black plastic inclined sleeve or black iron pipe with a diameter of 10 cm is set at one corner of the net cover as a bait feeding pipeline. Phyllostachys pubescens (diameter 10 cm thick) is used as the whole frame of the cage, and the top of the cage is made into a hat slightly larger than the box cover, which is used to shield the tilapia in the box, avoid human interference from outside, avoid animal interference, and protect the fish from eating safely. In the dark environment, the activity of fish is greatly reduced, which is conducive to growth. Cages are 2 ~ 3 meters apart and arranged in zigzag.
First, tilapia culture technology
Seed release time: fish can be released when the water temperature is about 24℃. When the water temperature is lower than 20℃, it is easy to frostbite fish. Therefore, sowing after the temperature is stable at 20℃ is beneficial for fish to start eating early.
Stocking density: tilapia with a tail weight of about 40 grams, with 330 ~ 550 species per square meter in cages.
Feeding method: the fish that just entered the box should be tamed with a small amount of palatable bait, and fed stably after a few days, 4 times a day. The water temperature of 28 ~ 32℃ is the golden water temperature for tilapia to eat, so it needs to be fed more. It is the key point of disease prevention to mix Chinese herbal medicine into bait. During the flying season, uncover the net cover at night, turn on the light to lure insects and feed the fish, and add the net cover during the day. It is most useful for fish to eat insects, so it doesn't hurt the fish or get sick. The net cover creates a dark environment, and fish can't stop growing when the water is good.
Second, overwintering technology
Tilapia is a tropical fish and can't tolerate low temperature. When the water temperature drops below 12℃, it will gradually die. In general, tilapia can overwinter naturally in a few areas in southern China, and other areas need to take measures to help overwinter. According to the production experience, tilapia has the following safe wintering methods.
1, hot spring water overwinters.
The area of the wintering pool should be determined according to the water temperature, flow rate, topography and production scale. The water depth of the wintering pool should be1.5-2m, and the water inflow and water outflow should be similar to maintain a certain water temperature and depth. If the hot spring water temperature is very high, it should be cooled to a certain temperature through the reservoir and then injected into the wintering pool. This wintering mode and wintering density are higher. At the same time, due to the high water temperature and sufficient water, the breeding of parent fish can be strengthened, the gonadal precocity of parent fish can be promoted, and breeding and seedling raising can be carried out in advance.
2. The remaining hot water in the factory will be used for winter.
Using the cooling water discharged from some factories, you can directly overwinter in the cooling pool or build an overwintering pool. The area of the wintering pool depends on the cooling water temperature and flow rate, and the water depth should be1.5-2m. The waste steam from some factories can also be used to adjust the water volume of the temperature regulating pool as needed, and can be introduced into the wintering pool for heat preservation and wintering. This wintering method can make use of heat source conditions according to local conditions, with low cost and good wintering effect.