preface
Multiple practices today show that shrimp farmers often use many probiotics with potentially high risks, increasing farming costs.
Therefore, there is a solution that many consider to be the "savior" and that has brought excellent farming efficiency, and that is the polyculture mode of shrimp and tilapia, thanks to the algae filtration mechanism of this fish.
Today, we will bring you knowledge about the polyculture mode of shrimp and tilapia to help you deepen your understanding and grasp more useful information.
First, learn about tilapia
1, tilapia is the name of a group of common freshwater fish, they can also live in brackish or brackish water environment, this fish mainly live in ponds, rivers, canals and other environments, tilapia is native to Africa and the Middle East.
2. Tilapia scales are purple, shiny, with about 10 parallel dark stripes from the back to the abdomen, adult tilapia can sometimes grow to about half a meter long and weigh nearly 4 kilograms, which is an easy fish to farm. Male tilapia grow fast and can weigh more than half a kilogram after 4-5 months of rearing.
Tilapia
3. The growth rate of male and female tilapia is different, tilapia lays eggs almost all year round, and the interval between the two spawning is about 3 weeks to 1 month.
4, tilapia in addition to temperature sensitivity, can survive or adapt to a variety of living conditions, tilapia in the yolk sac is absorbed, the fertilized egg in the mouth for a few days, until hatching into juvenile fish, this special hatching method, for the smooth reproduction of tilapia is very beneficial.
5. Tilapia usually eats organic humus, sediment, algae, and aquatic plants. In terms of fishing, they also eat foods such as crabs, snails, snails, peanut residue, etc.
Second, the benefits of mixed tilapia and shrimp culture
Whether intensive or semi-intensive, the polyculture of shrimp and tilapia offers the following advantages:
1. Improve the water environment;
2. Increase the oxygen content of water;
3. Reduce the damage caused by Taura syndrome and red tail disease;
4. Improve growth rate;
5. Reduce the growth of Vibrio bacteria in the water body;
6. Prevention and treatment of acute hepatopancreatic necrosis syndrome in shrimp;
7. Use the feed that shrimp have not been eaten.
8. Prevent the generation of pathogens and minimize the mortality of shrimp.
Effects of shrimp culture mixed with tilapia
Second, some methods of polyculture of shrimp and tilapia
1. Put directly into the pond where the shrimp is raised
Polyculture using male tilapia, when the shrimp reaches 3-6 g/m², the culture density is 30-40/m²; The fish size is 50-60 g/tail and the stocking density is 1/100 square meter.
2. Aquaculture in cages in shrimp ponds
The density of tilapia cages is 10 per m², the cage area is about 2% of the pond area, and farmers should clean the cages regularly so that the pond and the water in the cages are exchanged.
3. Aquaculture in sedimentation tanks
Tilapia is cultured at a density of 4-5 tails per square meter, and the fish are not fed during this time, but tilapia feed on dead shrimp, fish, aquatic animals and algae in the water.
This will help stabilize the water environment and reduce the spread of pathogenic organisms from outside.
Shrimp and tilapia farming – a model with great potential
4. Shrimp farming mode in rotation with tilapia
This form of shrimp culture, combined with tilapia, helps to improve pond bottoms, minimize waste accumulation and toxic gases, reduce chemical use, and limit diseases from farmed shrimp in the next season.
Third, some precautions when raising shrimp and tilapia
1. The conventional mode of shrimp and tilapia aquaculture is mainly applied to two common shrimp, namely: Penaeus monodon and P. monodon.
2. The breeding time of Penaeus monodon is generally relatively long, about 5 months, and the breeding density is about 20-30 / square meter. At harvest, the yield of Penaeus monodon is 3.0 to 3.5 tonnes/ha. For Penaeus vannamei, the rearing cycle will be shortened from 3 months to 3.5 months, with a higher culture density than Penus monodon, about 50-100 shrimp/m². At harvest, the yield is 6 to 10 tonnes/ha.
3. When preparing intensive shrimp ponds, cages should be designed in a low-lying place in the middle of the pond, accounting for 7%-10% of the pond area, and the mesh hole is 1cm to facilitate the discharge of feces and fish food through the mesh of the cage.
4. Only unisexual tilapia should be stocked to avoid fish spawning in the pond, and the size of the fish should be larger than the mesh size.
5. High-density shrimp ponds and intensive culture usually do not need to feed tilapia in cages, because tilapia eat the shrimp excrement concentrated by the rotation of the aerator, and clean the cages every 2 weeks.
6. Tilapia will help reduce the amount of nitrogen and phosphorus in the water, but they will release a lot of ammonia, and if too much, it will cause shrimp poisoning (weak growth, reduced disease resistance, disease-prone environmental conditions). Therefore, it is necessary to change the water of the pond regularly every month, changing 15%-20% of the pond water each time, and use probiotics regularly.
7. Shrimp often have a strong appetite in the evening and early morning, while tilapia has a strong appetite during the day. Therefore, shrimp should be fed before dawn and after dawn to avoid feed being ingested by fish, causing fish and shrimp to compete with each other, allowing tilapia to eat shrimp and eat the remaining feed and shrimp excrement.
8. Maintain the aerator and blower system to increase the dissolved oxygen content and prevent shrimp floating heads and accumulation of waste in the middle of the pond.
IV. Conclusion
With its algae filtration mechanism, tilapia is known as a "biological water purifier". Shrimp combined with tilapia culture mode helps farmers save breeding costs, ensure the water source of shrimp aquaculture, improve the pond environment, inhibit shrimp diseases, and help shrimp grow and develop stably.
In addition, tilapia can be harvested after a period of farming, helping farmers to have an additional source of income. Therefore, the combination of shrimp and tilapia farming model not only helps to increase the productivity of shrimp, but also brings double economic benefits.