This short video shows how my aquarium fish learned to associate food with the sound of a feeder through classical conditioning.
The reason I can say this is that there is a brief delay from the moment I hit the button on the feeder to the moment the food enters the water, and the fish search for food as soon as I hit the button.
This leads me to think that the fish has become classically conditioned as they respond to the sound of the feeder and not the food itself. This is a conditioned response to a conditioned stimulus (the feeder).
The fish associate the sound of the feeder with food and reacts instinctively as if they are about to get food. They have learned this response through experience. I know this because they did not show this behavior before I had the feeder.
Notice the black fish that have not been classically conditioned yet. This is because I released them into the aquarium the same day as the video was recorded.
This small experiment is just one way of illustrating classical conditioning, a concept coined by Ivan Pavlov. Pavlov illustrated classical conditioning in his classic dog experiments (1927).
To support my findings of this experiment, one study found that gold fish can be classically conditoned (Gonzalez et al., 1962), and another study found that rainbow trouts can learn to operate a trigger to release food, which reflects operant conditioning (Landless, 1976).
So we might sum up by saying that even a fish can learn.
Let me know if you want more videos like this, perhaps with speech?