My fish can tell me apart from other people, AND they see and recognize their food container. No one believed me, so we did tests. Walking into and out of the room, sitting on opposite sides of the tank, passing around the food container, etc.
We figured out they can tell their "mommy" from other people, and will prefer to hang out by me, unless the food container is out- then the guy holding the food container is king. They will go greet anyone new walking in, no matter what (probably looking to see if the new guy's got some snacks), but once everyone settles down they will congregate closest to me, no matter where in the room I sit. If someone else takes out their food- syonara mama- but the minute we put away the food container, they are right back at my side.
We figured out they can tell their "mommy" from other people, and will prefer to hang out by me, unless the food container is out- then the guy holding the food container is king. They will go greet anyone new walking in, no matter what (probably looking to see if the new guy's got some snacks), but once everyone settles down they will congregate closest to me, no matter where in the room I sit. If someone else takes out their food- syonara mama- but the minute we put away the food container, they are right back at my side.