How long can fish remember things?

This may be one of the most frequently asked questions about fish, and the most controversial, sparking much debate.


The scientific theory behind testing a fish's memory span is that, once a fish has learned a new skill, it could be observed to be repeated - or not, and otherwise forgotten. If a fish repeats the new skill, it will have utilised memory. If it has utilised memory, it will be possible to measure how long it can remember to perform the new skill.


In 2009, a fifteen-year-old Australian schoolboy helped debunk the the myth that a fish has a memory span of only 30 seconds by activating a beacon before feeding time and seeing how the fish responded. After a period of recognising that the beacon signified "food", the beacon was removed and brought back again a week later, to which the fish responded in the same way. Scientists now collectively believe that a fish's memory span can last up to 5 months!


It is also believed that the method can be tested by anyone by simply wearing the same colour clothing, like a bright yellow jumper, at feeding time. This can prompt your fish to associate the colour with being fed if carried out regularly. You can also provoke a 'colour recognition response' by feeding them when flicking your lights over from white to blue (if you have them!) observing how they head for the surface when the blue light is activated. This method has proven that fish still associate certain things with colour even after a break of anywhere up to 5 months. Maybe this is why they always swim away when I put my green fish net in the water...?

So, if someone says that fish only have a 30 second memory, you can inform them that it has been scientifically proven that fish can remember things for up to 5 months!


Writer: Luke Williams