Fish's memory is only seven seconds? Fish: You underestimate me!

The concept of "fish only have a memory of seven seconds" originally came from an advertisement, which mentioned that "goldfish only have a memory of seven seconds, so they don't get bored." It is said that people in Europe and the United States have read some historical documents about the cognitive ability of fish, and have accurately constructed relevant information to stimulate people's curiosity, such as providing interesting stories for children who are afraid of being put into fish tanks and suffer from depression. In addition, the saying "fish only have a memory of seven seconds" also appeared in Xu Zhimo's collection of poems, but this statement has no specific scientific basis, and people have overturned this statement through various experiments.

In fact, as early as 1965, American scientists conducted research on the memory of goldfish. Through bright light and electric shock stimulation, researchers trained goldfish to remember the "light-electric shock" stimulation cycle, allowing them to quickly escape from the bright light in subsequent experiments. This shows that goldfish have a memory of up to one month and can remember specific behavioral patterns. Similar experiments were also conducted on model organisms zebrafish, and similar memory results were found through the "light-food" stimulation method. In addition, some scientists have observed that farmed fish can retain memories of feeding stimuli for up to several years.

Fish, like humans, need to consolidate their memories

Goldfish have a certain memory ability, and if they are trained, their memory ability can be strengthened to a certain extent. It is similar to the process of human conditioned reflex. After a certain amount of training, they will make the same reaction under the same conditioned stimulation. So people conducted an electric shock experiment on goldfish. When they were released again after 20 seconds, they would appear afraid and dodge. After a month of testing, the goldfish still showed evasive behavior.

Fish memory can be inherited

An Australian research team has discovered that fish can pass on some information to their offspring through DNA methylation, including memories of environmental conditions and information that is detrimental to their survival. This means that many fish are born with some memories and can better adapt to the environment. Originally, as long as DNA methylation exists, memory can be maintained, but during animal fertilization and development, this gene will be cleared, while fish like zebrafish retain part of it. This intergenerational memory inheritance has also opened up new ideas for related scientific research. Perhaps the genetic rules of the future will be rewritten for it!