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Is the memory of fish really only 7 seconds long

Is the memory of fish really only 7 seconds long we often say that the memory of fish is only seven seconds, and we often say that the memory of human is poor. So is the memory of fish really only seven seconds? How does the memory of fish come from? How long does the memory of fish last? Let's take a look at it together!

I don't know what's the reason, the saying that "fish's memory is only 7 seconds" is widely spread, but almost all about fish!

Memory research tells us that fish's memory is far more than 7 seconds. On the Internet, there is a saying that is very popular: 'as early as a long time ago, someone told me: the memory of fish is only 7 seconds, after 7 seconds, it will not remember what it used to be, and everything will become a new beginning. So, in that small fish tank, it will never feel bored. 'it's no problem if we simply regard this passage as a fairy tale, but many people regard it as a scientific fact. On many Q & A websites, there are questions about whether this passage is scientific.

In fact, if we take "fish have seven seconds of memory" as a scientific conclusion, many questions will arise. Can the memory ability be accurate to seconds? If the average memory of a fish is 7 seconds, isn't the memory of some stupid fish only 2 or 3 seconds? When these "stupid" fish bite a bite of food, will they forget what is in their mouth?

Fortunately, as an early species of vertebrates, fish has a very unique evolutionary position, so there are many scientific researches on fish memory. Although there are different kinds of fish as experimental materials and different experimental methods and specific purposes, almost all studies on fish memory show that fish memory is far more than 7 seconds. (this article is edited and collated by, reprinted and noted with source, original link:

As early as the 1960s, when chemistry began to intervene in neurobiology, people had already studied the memory ability of goldfish. In 1965, researchers at the University of Michigan did an experiment with goldfish. They put the goldfish in a long fish tank, and then they shoot a light at one end of the tank. After 20 seconds, they release electric shock at the light end of the tank. Soon, goldfish formed a memory of the shock. When they saw the light, they would swim to the other end of the fish tank to avoid the shock before the shock was released into the water. The scientists who designed the experiment found that with proper training, the goldfish could remember the technique of avoiding electric shock for up to a month.

In addition to goldfish, another famous ornamental fish, paradise fish, also has strong memory ability. When this kind of fish meet a strange goldfish in the pool, they will swim around curiously and look at the new strange neighbors until they lose interest. If paradise fish and goldfish meet in the water tank for the second time, they will soon find that they are old acquaintances and lose interest in exploration. Experiments have found that such a memory can be maintained for at least three months.

Soon, scientists found that zebrafish, a model organism in biological research, is also a quite intelligent animal, which can perform various tasks. In 2002, researchers at the University of Toledo, Ohio, tested zebrafish memory. During the training, they will give zebrafish a red light as a signal before feeding. After 10 days of training suspension, zebrafish still remember that the red light signal indicates the time for eating. In the laboratory, zebrafish can also quickly learn how to walk the maze [6], search for food according to the sound signal [5], remember the shape of the predator, and avoid electric shock according to the prompts. (this article is edited and collated by, reprinted and noted with source, original link:

Interestingly, zebrafish and human memory have similarities. For these small fish, too much pressure will make them unable to remember things, and distraction will also reduce learning efficiency [8]. The memory ability of zebrafish will gradually decrease with aging. Long term memory is not impossible. Can fish have more powerful memory ability? For example, to remember a story for several years? Relevant academic research is very limited, because many kinds of fish can't even live that long, and several years is too long for a graduate student who is eager to publish a paper. However, there are some unofficial observations that show that some fish may have long-term memory.

Charles W. Eriksen, a professor of psychology at the University of Illinois at Champaign, once noticed that his neighbor always shakes the jar before feeding the fish, while the fish in the pond will gather in all directions after hearing the sound of the fish shaking in the jar.

Inspired by this phenomenon, Eriksson decided to make a rather simple practice. He keeps some catfish in his own fish pond. Every time he feeds them, Eriksson shouts "fish fish!". After months of training, when Eriksson yells, 19 catfish will come to him. The next summer, Eriksson repeated the process again, this time, a total of 16 fish followed his orders.

It's been five years since Eriksson returned to his fish pond. But he still decided to test whether his own catfish had preserved the previous memory. So Eriksson came to the pond again and shouted 'fish! Fish!'. To his surprise, even before he had time to put the fish food into the water, nine fish had already swam over. The next day, the number of catfish he called increased to 13. Eriksson described the experiment in a letter to colleagues as a reference for fish's memory ability.

Tony J. pitcher, a fish scientist at the University of British Columbia in Canada, also described an experiment in his book fish cognition and behavior. In his lab, two different colored tubes were placed in the goldfish pond. Only when goldfish choose the right color can they get food. After a period of training, the colored tubes were removed. A year later, when the researchers put the tube into the pool again, the goldfish immediately chose the tube with the color of food available. (this article is edited and collated by, reprinted and noted with source, original link:

Eriksson's observations and pitcher's experiments suggest that fish are likely to have memories of up to a year to several years. Given that most fish live only a few years, their memories are quite long-lasting. In addition, some studies have shown that the reason why the famous migratory fish salmon can return to their birthplace in adulthood is that they form a memory of the smell of their young living environment.

Why do fish have memory ability? This problem is very complex, and many studies only preliminarily reveal some possible reasons. If juveniles were given the scent of phenylethanol, they would remember it until adulthood. Studies have shown that the expression of a gene called Otx2 in olfactory epithelium cells of juvenile zebrafish exposed to phenylethanol has increased significantly. Moreover, the gene remains at a high level even after zebrafish reaches adulthood. Interestingly, if the juveniles were exposed to other odors, the expression of Otx2 gene would not continue to increase, which suggests that Otx2 is likely to be a molecule that enables zebrafish to remember the special smell of phenylethanol.

The rumor was shattered In other countries around the world, the idea that fish only have 7 seconds (or 3 seconds) of memory is also widespread. According to Ashley ward of the University of Sydney, the claim comes from an advertisement. But maybe it's because of the long history. It's hard to find the exact source. Ward also believes that early zoologists used overly complex methods to test the memory ability of fish. These tasks suitable for human intelligence test are obviously too difficult for fish, so the experimental fish left a bad record, which may be one of the reasons for this rumor. All in all, studies of fish memory have shown that fish's memory is much longer than seven seconds. The saying "fish's memory is only 7 seconds, never bored" is just a legend despite its beauty.

The famous TV program "rumor terminator" of American exploration channel has also done this rumor topic, but the saying in it is that "goldfish's memory is only 3 seconds". Jamie Hyneman and Adam savage, two hosts of the show, designed a simple maze, and then put the goldfish at the beginning of the maze, and the fish food at the end of the maze. After training, these goldfish will start from the starting point to find the final food more quickly, and obviously remember the right route. The final conclusion of the show is that the memory of goldfish is far more than three seconds.