do fish have a memory longer than the supposed 3 seconds?
I
know they do! Mine react to strangers! If its me or someone who is over a lot (like my daughter) in the room, they go about their business like normal. If someone comes in and they have never seen them before, or only once or twice they all hide and peek out at them from inside their caves. Once that person leaves, as soon as the front door closes, they come out. Another example: one of my cats likes to tease them. Well, I have 5 cats and if any other cat lays in front of the tank my male Red Zebra ignores them. But, if my one cat lays down, he attacks her thru the glass, postures and is just totally wound up until she leaves! He does not do this to any of the other cats! Makes me wonder what the heck she did in the past LOL. So, not only can he see the cat thru the glass, he recognizes her!
My favorite time to watch my fish is after dark with all the lights but the tank lights off. I don't think they can see me as well that way, it turns the tank wall into a mirror of sorts. Its when it is like this that they attack themselves in the glass and get right up in my face to see me better
My son and I had an argument going one time. He insisted that the fish could not hear me. He was staying with me for a couple weeks and he noticed that every time I feed them or just watch them I talk to them. Can't help myself LOL. He insisted that they cannot hear me. But, after watching how they reacted to my voice, he conceded that they can hear me, but they can't understand what I am saying. I will give him that one hahaha
My Mbuna know that a small net means fry time too. When they see a small blue net over the tank above the water they all come to the top waiting. That is why when I add a new fish I have to be careful and put it in with my hand. If I use a net they will go after it, no matter its size.
I have discovered too that Cichlids are much smarter than community fish in these ways. In my planted community tank, it is only my Bolivian Rams who display a knowledge of strangers and such. The other tank mates, Tetras, danios, etc. do not show all these intelligent behaviors. I am not knocking these fish, I love my little guys, just stating my observations.