Operant responding in Siamese fighting fish (Betta splendens) as a function of schedule of reinforcement and visual reinforcers.

Siamese fighting fish were trained to emit an operant response that was reinforced by the opportunity to view a motion picture film image of another fish. Performance under various schedules of reinforcement was examined. When reinforcement followed every response and when reinforcement was delivered after every second response, the number of responses per session was higher than during operant level or during extinction. Reinforcement delivered following intervals of no responding (differential reinforcement of other behavior) markedly decreased responding. Light from a projector without film was found to be as effective a reinforcer as film reinforcement. Responding when projector light reinforcement followed every response was maintained at approximately the same level as that obtained under film reinforcement. Responses per session decreased when only the light was delivered on a differential-reinforcement-of-other-behavior schedule. The behavior of the fish during presentation of the film was markedly different from their behavior while the projector light was being presented.