Observations on Cultured Channel Catfish Fish Foraging Behavior

Abstract

Harvestable, fed channel catfish, Ictaluruspunctatus were given access to two potential prey-fingerling Nile tilapia, Oreochromis niloticus and channel catfish in replicated 0.045-ha experimental, channel catfish production ponds. Three ponds were stocked in the spring with the fingerling Nile tilapia, which subsequently reproduced. Stomach contents were examined from subsamples of 50 channel catfish from each pond in October and results tabulated by catfish size group. An average of 19% of channel catfish in subsamples had consumed one or more 40-85 mm total length (TL) tilapia. Although mean frequencies of foraging did not significantly differ among catfish size groups, competition for feed pellets among size groups is hypothesized to have stimulated foraging and produced the greater foraging by smaller size groups when larger size groups were more abundant. The following spring, 90-200 mm TL fingerling channel catfish were stocked in six of the experimental channel catfish production ponds. No catfish fingerlings were found in stomachs from subsamples of 25 fish from each pond one month after stocking of fingerlings. However, a total of six fingerings (125-135 mm TL) from three ponds, seined with the larger catfish, sustained a large bite wound consistent with foraging behavior by catfish.

Key Words:

• Channel catfish
• Nile tilapia
• forage
• cannibalism