The memory of a goldfish…is actually good?!

A fundamental quality of all humans is that we are flawed. We are not perfect beings (which is okay!) and we each have our weaknesses. Some struggle with maths, some dislike sharing and others may have a bad memory. You might even say people in that last group have the memory of a goldfish. But exactly how scientifically accurate is this widely used analogy? 

Carassius auratus, more commonly known as goldfish, is a freshwater fish and common household pet notorious for having a 3-second memory. Sadly, we are here to tell you this is a myth. Science has shown consistent evidence that goldfish are intelligent creatures capable of interesting cognitive functions.

Goldfish distance perception and memory

A 2022 study by researchers at Oxford University examined distance perception in goldfish. The fish were trained to swim along a tank covered in vertical stripes. Researchers then studied whether the fish could complete the swim if the striped pattern was altered. The study found goldfish could remember how far to swim by using visual cues and spatial frequency, even if the background patterns were altered. These findings indicate goldfish have better distance perception and memory skills than previously thought.

Goldfish visual perception

An American study from 2022 investigated visual perception – specifically object constancy – in six goldfish. Object constancy is the ability to recognise an image of a known object even if it has been rotated. Researchers presented goldfish with pictures of turtles and frogs at different viewing angles and studied how the fish responded. They found goldfish were able to recognise the images at all angles and there were no significant differences in recognition ability between the angles. This study demonstrates the strong object recognition and memory skills of goldfish.

Goldfish navigation

A 2021 study from Israeli researchers investigated navigation and directional skills in goldfish by training them to drive a vehicle (yes, you read that right!). Researchers developed a Fish Operated Vehicle (FOV), a wheeled platform that detects fish movements and positions and moves itself in response. Goldfish were tasked with ‘driving’ the FOV to reach a target in the tank. Researchers found goldfish were able to reach their target despite differing starting points and could avoid dead-ends and correct any navigational mistakes. These findings suggest goldfish can learn and remember routes even when presented with navigational challenges.

These three studies (and countless others dating back as early as 1965 and 1966) paint a different picture of goldfish to what we know. Goldfish are smart creatures capable of learning and higher cognitive functions. All in all, it’s safe to say the memory of a goldfish is actually good and anyone with a bad memory should not be likened to a goldfish. It’s okay, at least you can still say people who struggle to see are ‘blind as a bat’ – or can you?

Knowledge is power,

The Science Advocate

References:

https://academic.oup.com/book/10753/chapter-abstract/158864925?redirectedFrom=fulltext

https://royalsocietypublishing.org/doi/10.1098/rspb.2022.1220

https://www.mdpi.com/2076-2615/12/14/1797#B2-animals-12-01797

https://www.pnas.org/doi/epdf/10.1073/pnas.54.3.788

https://www.pnas.org/doi/epdf/10.1073/pnas.55.3.555

https://www.sciencedirect.com/science/article/abs/pii/S0166432821005994?dgcid=author#fig0005