The yellow catfish (Pelteobagrus fulvidraco) is a bottom-dwelling omnivorous fish, with delicate flesh, rich nutrition and extremely high economic value, making it a farming species with great market potential. The yellow catfish has strong adaptability and a slower growth rate than cyprinid fish, but grows relatively fast for its own species; fry bred in the same year can reach market size in that same year, and the population yield is relatively high. Because artificial breeding technology is not yet mature, large-scale artificial farming faces certain difficulties, so carrying out polyculture has become imperative. Polyculturing yellow catfish in fish ponds has the following advantages: First, it can feed on low-value small miscellaneous fish and shrimp, residual feed of fish, organic debris, zooplankton, etc. in the pond, increasing the net yield of the pond. Second, the yellow catfish feeds on parasites such as Lernaea in the water, which can reduce the occurrence of fish diseases. Third, without affecting the yield of the main cultured species, adding 5 kg to 20 kg of yellow catfish per mu can increase the benefit by more than 100 yuan per mu. The polyculture techniques are introduced as follows:</p><p></p><p>I. Polyculture in adult fish ponds</p><p>Polyculturing yellow catfish in adult fish ponds places no strict requirements on the main fish species cultured in the pond. Ponds culturing the four major Chinese carps and ponds mainly culturing feeding fish (such as carp and crucian carp, tilapia, freshwater pomfret) can all be used for polyculturing yellow catfish. The pond area is 20 mu to 30 mu, the water depth is 2 m to 2.5 m, with sufficient water source, good water quality and convenient water injection and drainage. Generally, 40 to 50 yellow catfish are stocked per mu, with a size of 3 cm per fish to 4 cm per fish, which can increase the yellow catfish yield by 5 kg to 8 kg per mu.</p><p>II. Polyculture in broodstock ponds</p><p>Polyculture in broodstock ponds can not only make full use of the water space of the broodstock pond and improve the utilization rate of the broodstock pond, but the yellow catfish can also feed on some small wild fish in the broodstock pond that compete with the broodstock for food and consume oxygen. After the artificial breeding of broodstock is completed, stock 40 to 60 yellow catfish per mu, with a size of 2 cm per fish to 3 cm per fish, which can increase the yellow catfish yield by 6 kg to 10 kg per mu.</p><p>III. Polyculture in adult crab ponds</p><p>Polyculturing yellow catfish in crab ponds can make full use of the natural bait organism resources in the crab pond. Generally, the crab pond area is 30 mu to 50 mu, with a aquatic plant coverage rate of about 50%; after the crab seed is stocked, stock 30 to 50 yellow catfish per mu, with a size of 3 cm per fish to 5 cm per fish, which can increase the yellow catfish yield by 5 kg to 10 kg per mu.</p><p>IV. Polyculture in rivers and ditches</p><p>There are many low-value wild miscellaneous fish in rivers and ditches, and polyculturing yellow catfish can save artificial bait. Generally, stock 40 to 60 yellow catfish per mu, with a size of 2 cm per fish to 4 cm per fish, which can increase the yellow catfish yield by 6 kg to 12 kg per mu.</p><p>V. Polyculture in large water bodies</p><p>Polyculturing yellow catfish in large water bodies gives a high population yield, neither affecting the yield of the main cultured species nor requiring additional bait. Generally, stock 40 to 60 yellow catfish per mu, with a size of 3 cm per fish to 4 cm per fish, which can increase the yellow catfish yield by 8 kg to 15 kg per mu.</p><p>No matter which polyculture method is adopted, the following matters must be noted in farming management:</p><p>I. Maintain a relatively high dissolved oxygen level in the water body. The yellow catfish has relatively high requirements for dissolved oxygen in pond water, so polyculture requires fresh water quality and sufficient dissolved oxygen; during the growing season, new water should be added in a timely manner, and during the high-temperature season, water should be changed frequently; maintaining a slight water flow is even better.</p><p>II. Maintain a reasonable stocking density and stocking size. According to the bait organism biomass in the water body, scientifically and reasonably determine the polyculture ratio and stocking size; generally, 30 to 60 fish per mu is appropriate, with a stocking size of 3 cm per fish to 4 cm per fish. If the density is too high and the size too small, the market size cannot be reached by the end of the year.</p><p>III. After polyculturing yellow catfish in a fish pond, it is no longer suitable to polyculture other carnivorous fish, and yellow catfish should not be polycultured in ponds for farming freshwater prawns or freshwater crayfish.</p><p>IV. During the farming process, if the yellow catfish are found to be too small, it indicates that the natural bait organism biomass in the fish pond is insufficient; small miscellaneous fish and shrimp, summer fry of domestic fish may be appropriately added, or specially formulated artificial yellow catfish bait may be fed. When feeding artificial bait, the main cultured species should be fed first (put into the shallow water area), and then the yellow catfish (put into the deep water area). The yellow catfish has the living habit of hiding by day and coming out at night, so feeding should mainly be done at night.</p><p>V. When polyculturing yellow catfish in crab ponds, because the river crab and yellow catfish occupy the same water layer position ecologically, it is easy to cause competition for ecological position between the two. Therefore, sufficient natural bait organisms must be maintained in the crab pond, otherwise the yellow catfish rearing effect will be affected. In advance, 300 kg to 400 kg of spiral shells per mu can be put into the crab pond, along with some egg-bearing crucian carp and egg-bearing freshwater shrimp, allowing them to reproduce naturally for the river crab and yellow catfish to feed on freely.</p>
The yellow catfish (Pelteobagrus fulvidraco) is a benthic omnivorous fish with tender flesh, rich nutrition and extremely high economic value, making it a highly marketable aquaculture species. The yellow catfish has strong adaptability, and although its growth rate is slower than that of cyprinid fish, it grows relatively fast for its own species. Fry bred in the same year can reach market size within that year, and the population yield is relatively high. Because artificial breeding technology is not yet mature, large-scale artificial farming faces certain difficulties, so polyculture is imperative. Polyculture of yellow catfish in fish ponds has the following advantages: First, it can feed on low-value small miscellaneous fish and shrimp, residual feed of fish, organic debris, zooplankton and so on in the pond, increasing the net yield of the pond. Second, the yellow catfish feeds on parasites such as anchor worms (Lernaea) in the water, which can reduce the occurrence of fish diseases. Third, without affecting the yield of the main cultured species, adding 5 kg to 20 kg of yellow catfish per mu can increase the benefit by more than 100 yuan per mu. The polyculture techniques are described below:
I. Polyculture in adult fish ponds
Polyculture of yellow catfish in adult fish ponds has no strict requirements for the main fish species in the pond. Ponds raising the four major Chinese carps and ponds mainly raising feeding fish (such as common carp, crucian carp, tilapia, freshwater pomfret) can all be used for polyculture of yellow catfish. The pond area is 20 mu to 30 mu, with a water depth of 2 m to 2.5 m, abundant water sources, good water quality and convenient water filling and drainage. Generally, 40 to 50 yellow catfish per mu are stocked, at a size of 3 cm to 4 cm per fish, which can increase the yellow catfish harvest by 5 kg to 8 kg per mu.
II. Polyculture in broodstock ponds
Polyculture in broodstock ponds can not only make full use of the water space of the broodstock pond and improve the utilization rate of the broodstock pond, but the yellow catfish can also feed on some small wild fish in the broodstock pond that compete with the broodstock for food and consume oxygen. After the artificial breeding of broodstock is completed, 40 to 60 yellow catfish per mu are stocked, at a size of 2 cm to 3 cm per fish, which can increase the yellow catfish harvest by 6 kg to 10 kg per mu.
III. Polyculture in adult crab ponds
Polyculture of yellow catfish in crab ponds can make full use of the natural bait organism resources in the crab pond. Generally, the crab pond area is 30 mu to 50 mu, with a aquatic plant coverage rate of about 50%. After the crab seed is stocked, 30 to 50 yellow catfish per mu are stocked, at a size of 3 cm to 5 cm per fish, which can increase the yellow catfish harvest by 5 kg to 10 kg per mu.
IV. Polyculture in rivers and ditches
There are many low-value wild miscellaneous fish in rivers and ditches, and polyculture of yellow catfish can save artificial bait. Generally, 40 to 60 yellow catfish per mu are stocked, at a size of 2 cm to 4 cm per fish, which can increase the yellow catfish harvest by 6 kg to 12 kg per mu.
V. Polyculture in large water bodies
Polyculture of yellow catfish in large water bodies yields a high population yield, neither affecting the yield of the main cultured species nor requiring additional bait. Generally, 40 to 60 yellow catfish per mu are stocked, at a size of 3 cm to 4 cm per fish, which can increase the yellow catfish harvest by 8 kg to 15 kg per mu.
Regardless of which polyculture method is adopted, the following points must be noted in breeding management:
I. Maintain a relatively high dissolved oxygen level in the water body. The yellow catfish has relatively high requirements for dissolved oxygen in pond water, so polyculture requires fresh water quality and sufficient dissolved oxygen. During the growing season, new water should be added in a timely manner, and during high-temperature seasons, water should be changed frequently; maintaining a slight water flow is even better.
II. Maintain a reasonable stocking density and stocking size. According to the bait organism biomass in the water body, scientifically and reasonably determine the polyculture ratio and stocking size. Generally, 30 to 60 fish per mu is appropriate for polyculture, with a stocking size of 3 cm to 4 cm per fish. If the density is too high and the size too small, the market size will not be reached by the end of the year.
III. After yellow catfish are polycultured in a fish pond, it is no longer suitable to polyculture other carnivorous fish, and yellow catfish should not be polycultured in ponds for freshwater prawns or freshwater crayfish.
IV. During the breeding process, if the yellow catfish are found to be too small, it indicates that the natural bait organism biomass in the pond is insufficient. Small miscellaneous fish and shrimp, summer fry of farmed fish may be appropriately added, or artificial specially formulated yellow catfish bait may be fed. When feeding artificial bait, the main cultured species should be fed first (put into shallow water areas), and then the yellow catfish (put into deep water areas). The yellow catfish has the habit of resting by day and coming out at night, so feeding should mainly be done at night.
V. When yellow catfish are polycultured in crab ponds, because the river crab and the yellow catfish occupy the same water layer ecologically, competition for the same ecological niche is likely to occur. Therefore, sufficient natural bait organisms must be maintained in the crab pond, otherwise the rearing effect of the yellow catfish will be affected. Beforehand, 300 kg to 400 kg of river snails per mu can be put into the crab pond, along with some egg-bearing crucian carp and egg-bearing freshwater shrimp, allowing them to reproduce naturally for the river crab and yellow catfish to feed on freely.