Operant conditioning of spitting behaviour in the archer fish (Toxotes jaculator)

Abstract

The archer fish, Toxotesjaculator, has the ability to knock insects out of the air by spitting at them. Although many studies have been done using the archer fish, it has never been considered from the operant conditioning perspective. In the wild the fish does not always get the prey at which it spits. Therefore, it is possible that a Variable Ratio (VR) schedule of reinforcement is involved in the spitting process. In an effort to understand this behaviour, one must first demonstrate operant conditioning with the spitting response. This hypothesis was tested in the laboratory with three fish in three indentical tanks, each with a target apparatus, an automatic food dispenser; all were attached to a PET computer to control the schedules and to record responses and reinforcements. All three fish were successfully shaped to spit at the target and all came under control of a Continuous Reinforcement (CRF), a Variable Ratio 3, 5, 8, and 10 schedule of reinforcement. I also found that the fish showed greater resistance to extinction following a VR 10 schedule relative to CRF. The results of this experiment suggest operant learning principles can be used to control the spitting behaviour of the archer fish.