It's often said that fish only have a three second memory - but new research may have blown that out of the water.
Scientists now claim to have found one particular breed of fish that can remember things for longer.
Canadian researchers trained the African Cichlids fish to go to a certain part of the fish tank to gather food.
They then took the fish away for 12 days.
When they put them back in the tank they found the fish remembered where to go to receive the food, proving that some fish have a longer memory than once thought.
Watch Hayley's report to find out more.