Myth 4 of 10
4. Myth: the goldfish has a 3-second memory
Experiments show the opposite: goldfish learn tasks and remember them for months. They can associate a sound, a colour or a time of day with food.
Fish that learn tricks
In experiments at the University of Plymouth, in the United Kingdom, goldfish were trained to push a lever to get food, which only worked at a certain time of day. They learned and began to show up at the lever at the time it was active.
Other studies have shown that these fish recognise sounds linked to feeding time and keep reacting to them months later. Anyone with an aquarium usually notices this: the fish swim to the front of the glass when the person who feeds them approaches.
In 2022, researchers from the University of Oxford showed that goldfish can measure distances. They learned to swim about 70 centimetres along a channel to get food, and to repeat that distance.
The myth may come from appearance: the fish swims in circles in the tank and seems to explore everything as if for the first time. But a short memory is not the reason. A small, unstimulating tank, by the way, harms the animal's well-being.
Goldfish also distinguish colours and shapes and have been trained to recognise different signals when it's time to get food. They can even see part of the ultraviolet light, which is invisible to us.
Did you know? Goldfish live much longer than people imagine: with good care they pass 10 years, and there are records of individuals over 40.
