The Effect of Varying Biomass of Carryover Fish in Multiple‐batch Catfish,Ictalurus punctatus,Pond Production

The presence of carryover (fish >350 g stocked the previous year but not yet market size) channel catfish, Ictalurus punctatus, in multiple‐batch production ponds has been shown to affect overall production performance and costs. However, little attention has been paid to effects of varying biomasses of carryover fish in ponds. Twelve 0.1‐ha earthen ponds were stocked March 20, 2007, with 15,000 catfish fingerlings per ha (mean weight 31 g), and carryover fish at either 726, 1460, or 2187 kg/ha (mean weight 408 g, range 204–703 g) to compare the effect of three different biomasses of carryover catfish on the production performance of understocked fingerlings. Gross and net yields increased with increasing biomass of carryover fish. Growth and mean weight at harvest of fingerlings were significantly greater at the lowest biomass of carryover fish (<1460 kg/ha), but there was no difference between the medium and high carryover density treatments. Net returns were highest with the highest biomass of carryover fish, but fell by $688/ha in Year 2 because of slower growth of fingerlings in Year 1.