Conditioning of a free operant in Octupus cyaneus Gray.

Operant conditioning was studied in six specimens of Octopus cyaneus Gray. An "arm-out-of-water" operant, in which the octopus inserted an arm up a feeding-tube breaking the water surface, proved susceptible to reinforcement schedules. An apparatus was developed that provided automated reinforcement and recording. Performance was studied under continuous reinforcement, fixed-ratio and variable-ratio schedules, and extinction conditions.