I have kept most fresh and salt water aquarium fish that have been in Australia.
My fish knew me as the food guy and would take food from me without any issues. In my last house I had a couple of tanks in the loungeroom and the fish could see my bedroom door from where they were. When I opened my door they would all swim to the side of the tank closest to my door. As I walked past the tanks they would swim along next to me waiting for food. When other people walked past the fish ignored the people and kept doing whatever they were doing. Same deal when other people came out of my room, the fish just ignored them.
In 1997 I went to Geraldton to study aquaculture. Before I left I asked one of my sisters to feed my fish for me. I took her into the fish room and showed her how to feed them. I got her to feed them each day for a week before I left (I was with her when she was doing this). A few months later I came back from Geraldton and there were no plants or algae left in the tanks and the fish were right up at the front glass begging for food. I fed them and later on had a chat to my sister to see how things went. It turned out she tried feeding them for the first few days but the fish wouldn't eat anything she offered them, so she stopped feeding them. The fish went without food for 2 months. Fortunately I had a lot of aquatic plants in the tanks before I left and there was algae on the glass. The fish were also well fed before I left and they lived off their fat reserves and the plants and algae in the tank. But they were definitely hungry when I got back. I lost about 30 fish from that and they were either babies or specialised feeders (nightfish). All the other fishes were fine, just hungry and happy to see me.
I'm pretty sure there's a thread on here somewhere about fish intelligence.