Do fish really have bad memories?

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There are some common misconceptions in the world yet few animals are as misunderstood as the fish. If you think about some of the phrases we associate with fish we clearly have a poor view of them. If a friend drinks too much we say that they were “drinking like a fish” which doesn’t make any sense considering a fish doesn’t even drink water. Sometimes we call people “odd fish” when they are strange yet it is harsh that we include fish in this view. Finally, we often say to someone who has a poor memory “you have the memory of a (gold)fish”. This again is incredibly harsh as it turns out fish have pretty good memories!

The myth that fish have bad memories has been around for a very long time. If you ask most people how long a fish or even a goldfish remembers things for, the majority of people would say three seconds. The majority of people would be wrong. Even large blockbuster movies try to poke fun at the humble fish. Think of Dory in the movie Finding Nemo. She informs the others that she has a very poor short term memory. While it is possible that some fish have terrible memories (maybe Dory really did) the majority of fish do not.

The first question is why do we believe that fish have such terrible memories and where does this view come from? There are three likely explanations. The first is our traditional view of evolution. We like to look at fish as primitive creatures and something that we are far more superior to. However, fish are actually an animal with a rich history and have been evolving in some shape or form for roughly the same amount of time as humans. The second explanation is that we like to eat fish so we tell ourselves that they are not that clever as it makes us feel better. As the famous Nirvana lyric suggests “But it’s ok to eat fish because they don’t have any feelings”. The third explanation and the one that may explain the three-second rule is that we like to keep some fish in small bowls. We have come to the belief that this is ok because it takes about three seconds for a fish to get from one side of a small bowl to the other. If they have long memories this could be seen as torture.

Well, studies now show that they have much longer memories. A study as far back as 1994 showed that goldfish can remember certain things for at least three months. Not only this but they were able to tell time. The fish were given a lever that if they pushed it during a single hour of a day they were rewarded with treats. The fish soon learned the importance of this hour and were happy to play along. A study in 2017 showed that guppie fish can solve mazes with 6 route decisions to make.

Fish may even have one advantage over us. As we live our lives on one horizontal plane of existence we tend to things of space in terms of a flat idea. Fish move and operate in three dimensions so are far better at perceiving the world in 3D. It was once thought that only primates used tools but fish have now been found to use them often. Some hit shells off rocks to get what is inside. Others use leaves as a mode of transport for their babies. One fish even shoots water out of its mouth to the sky to shoot flies out of the air!

All in all, it is clear that fish are far more intelligent than we previously thought. The three-second memory myth can be completely ruled out and whether Kurt Cobain was right about their lack of feelings certainly requires another investigation. If that is enough to stop people putting fish in tiny bowls or eating them for dinner? Only time will tell.