siamese fighting fish koiThe existing experiments hence tested mirror presentation as a reinforcer of operant responding by female Bettas. Each of four aquariums was housed in a small room that was acoustically and visually isolated from the handle equipment. Ambient light in the room was programmed on a 12 hr light/dark cycle. During each session, the ambient light was on. Temperature and humidity in the room were held constant. An instance of the equipment is diagrammed in Figure 1 all letter references in this description are to this figure.