Trainning a fish

what species are capable to be traind and are more friendly?please advise.thanks.

If memory still serves me after all these years, it seems like one of the on line aquarium shops sells a fish training gadget. Angelfish are my favorites, and they certainly learn when they are about to be fed or netted. The first time you net an angelfish, it's fairly easy, but all subsequent attempts are anticipated. They say that Discus exhibit more intelligence than most aquarium fish, and that partially supports the idea that larger species have larger brains. Almost any aquarium fish, though, will learn about feeding routines.