DO GOLDFISH HAVE A MEMORY?

Goldfish are not stupid. They can remember things that matter to them and can be taught tricks. In one experiment a tank was divided into two halves with different coloured gravel, and the fish were fed only on one colour. When the gravels were switched, the fish would swim to the correct coloured gravel (in a different place) to be fed. I have seen video footage of a goldfish who was taught to swim through a hoop in return for titbits. Many goldfish will swim to the surface when they see or hear their regular feeder.