Growth, yield, dressout, and net returns of bighead carp Hypophthalmichthys nobilis stocked at three densities in catfish Ictalurus punctatus ponds

Alternative fish species that can be cultured together with catfish Ictalur us punctatus provide an opportunity to diversify catfish farms. A 2-yr stud y was conducted in 0.10-ha earthen ponds to evaluate the effect of bighead carp (BHC) stocking density on growth, yield, dressout yield, and net retur ns. Initially, bighead carp (average weight of 22 g) were stocked at rates of 380, 750, or 1,130 fish/ha in ponds with catfish. Catfish were cultured under commercial conditions by stocking catfish at a density of 12,500/ha, aerating nightly and feeding at an average rate of 82 kg/ha per dr Stocking rates for 2-yr-old fish were reduced to 77, 260, and 435/ha in the second growing season, There were no significant differences among treatments (P > 0.05) in summer growth of bighead carp in either year. Bighead carp stocke d at 1,130 fish/ha hart significantly higher yields than those stocked at 3 80/ha, but did not reach minimum market size of 2.2 kg during the first yea r (P less than or equal to 0.05), There were no significant differences (P, 0.05) in catfish growth, yield, survival, or feed conversion ratios due to the bighead carp stocking densities. Partial budget analysis indicated tha t net benefits were positive for all three treatments over a range of preva iling prices of bighead carp. Bighead carp production in catfish ponds is e conomically feasible over a wide range of prices. Given the market risk of producing smaller fish at the higher density, the medium density Is the pre ferred stocking density of fingerling bighead carp in catfish ponds.