The Effect of Understocking Density of Channel Catfish Stockers in Multiple-Batch Production

Abstract

A multiple-batch study was conducted using stocker catfish (0.09 kg/fish) and carryover fish (0.39 kg/fish) to look at the effects of different stocker densities on fish production. Twelve 0.1-ha ponds were stocked with 7,400; 11,120; or 14,825 stockers/ha, and equal weights of carryover fish (2,268 kg/ha). Fish were fed once daily to apparent satiation with a 32% protein floating feed and aerated with a single 0.37-kW electric paddlewheel aerator. No significant differences were detected for gross, net, and net daily yields, growth (g/d), or survival. Sub-marketable yield (<0.57 kg) increased as stocking density increased. However, marketable yields (≥0.57 kg) were not affected by density. Carryover fish in high-density ponds had a significantly lower (P < 0.05) mean weight at harvest, but mean stocker weight was not different across densities. Economic analysis found breakeven prices increased and net returns decreased with increased stocking density when sub-marketable fish were not considered as revenue. The study indicated the possibility that stockers compete with large carryover fish, particularly at higher densities.

KEYWORDS:

• channel catfish
• Ictalurus punctatus
• stockers
• production
• costs
• multiple-batch

This material is based upon work supported in part by the State of Arkansas 1890 Matching funds for the UAPB Aquaculture/Fisheries Center, under project AFC02CE. Special thanks to the faculty, staff, and students at UAPB and ARS for help with stockings, samplings, and harvest. Thanks to Nathan Stone, David Heikes, Peter Perschbacher, and David Bouras for edits and helpful advice.