Chemical and visual control of feeding and escape behaviors in the channel catfish Ictalurus punctatus

Abstract

Channel catfish, maintained individually in aquaria with dark substrate, responded to visual stimuli from above with escape behavior and to amino acid stimuli with feeding behavior. Feeding behavior was composed of a) appetitive patterns, such as barbel movements, orienting posture, and search swimming and b) consummatory patterns that included a halt in swimming, turning, snapping-biting, ingestion, mastication, and swallowing. The conditioning procedure, which consisted of 90 s presentations of a single amino acid followed by a food reward, influenced the duration and speed of the search swim. Swimming behavior was quantified by counting the number of turns greater than 90°. Catfish turned 40–75 times to the conditioned stimuli, l-proline and l-arginine, but only 20–40 times to the nonconditioned stimuli. Olfaction rather than taste was involved in the conditioned response to l-proline because the highest possible contact concentration (3 × 10 −6 M) of l-proline within the stimulus eddies was at least 30 times lower than the estimated l-proline electrophysiological taste threshold (>10 −4 M).