Capable of Pavlovian Learning
Fish are also capable of Pavlovian learning, just like dogs and many other vertebrates. That’s when an animal learns to associate a stimulus—like food—with a completely unrelated cue—like a bell.
For example, rainbowfish were able to associate a light turning on with food after about 14 repetitions. It takes rats about 40 repetitions before they learn a similar association. And the memories fish form last a whole lot longer than 3 seconds.
Lab experiments have shown that rainbowfish can remember the location of a hole in a net for a whole year—and given that they typically only live about 2 years in the wild, a year is a pretty long time. And not only do their memories last—some fish are really quick learners.