Two behavioural responses were considered. In the first, rainbow trout were trained to press a trigger to obtain food, and in the second they were conditioned to respond to a sound signal in anticipation of food delivery. The trigger pressing, demand feeding, response was quickly learned and the pattern of feeding analysed. There was a dusk peak of feeding as well as appreciable nocturnal trigger pressing. Feeds were highly aggregated into bouts, more so in the case of groups of trout than with individuals. This suggests two behavioural mechanisms, one operating within individuals and a second social effect. The preferred time between trigger presses was 8–16 min. Total daily food intake could be controlled by adjusting the reward level per trigger press so that demand feeding was not necessarily ad lib feeding. Rainbow trout would respond to a sound signal of 100 Hz played for 30 seconds prior to a food delivery by showing a feeding type of behaviour in response to the sound only. Experiments are planned to try and use this sort of response to recall fish from a relatively free-swimming environment to a central point for feeding and eventual recapture.