Where did the belief come from that the memory of fish is 3 seconds? Unknown. But it is spread all over the world. And here in Russia, many people believe that fish – especially aquarium fish – are incredibly stupid. And how not to believe, if Pavel Volya himself, a perky humorist and resident of the Comedy Club, convinces of this. The video with his explanations is very popular on social networks. Got millions of views.
In fact, these “3 seconds” are a myth that extremely annoys ichthyologists. Recently, one of them – Culum Brown, a renowned specialist in the study of fish consciousness at Macquarie University in Australia – refuted the offensive fiction. And he told about experiments, which, on the contrary, testify to the outstanding mental abilities of the inhabitants of reservoirs and aquariums.
I will be a cichlid – I won't forget two weeks
Scientists at MacEwan University of Canada Dr. Trevor Hamilton and his student Erica Ingraham studied the behavior of aquarium cichlids – fish from the perciformes breed. They were trained for 20 minutes a day – they were given food in strictly defined places in the aquarium. They fed this way for three days. Then they were sent to another aquarium for 12 days, where they were not fed. Then they returned to the first aquarium. And they saw that the cichlids now and then swim up to the place from which they previously received food.
Conclusion: cichlids remember what they have learned for at least two weeks. Maybe longer. But certainly not 3 seconds.
Pisces remember people by sight
Ichthyologists from the University of Oxford and the University of Queensland have experimented with archer fish (Toxotes jaculatrix – striped archer or arrow fish or sniper fish, a squad of perchiformes). The test subjects surprised the scientists with their downright supernatural abilities. Believe it or not, they memorized people's faces and then recognized them among strangers.
For many years it was generally accepted that primitive creatures – like fish – cannot remember someone's face. Because this requires a large developed brain and, at least, a special section in it, specially designed to identify and recognize familiar features. In humans, for example, the so-called new cortex or neocortix, which is responsible for higher nervous functions, including thinking and speaking, specializes in this.
And recently, scientists decided to check whether such a complex mechanism is really necessary. Suddenly, in order to distinguish one person from another, it is possible without him?
In the test subjects, scientists recruited sprinklers, whose brains are not burdened by the neocortex.
But the fish themselves at the same time show both observation and ingenuity. They are able to recognize objects and estimate the distance to them. The sprinklers, possessing an unpretentious brain, purposefully spit a stream of water, knocking insects into their food with it. For which they are called snipers. The experimenters took advantage of this.
On screens above the aquarium, the scientists displayed images of human faces, two at a time. The trickle had to be released into one. For which the fish received a fly. In order not to think that she was spitting in vain.
The subjects were trained for several days. Then the face they used to spit at was placed among 44 others. The fish found it 81 times out of 100. The spitting accuracy increased to 86 percent after the color images were replaced with black and white.
– Remember the facial features, and then you can recognize them without the necortex, – made the logical conclusion Dr. Cait Newport (Dr Cait Newport), who led the research, published in Scientific Reports. Unfortunately, the experimenters did not report how long the fish remember the assimilated information. Well, for sure more than 3 seconds.
They recognize each other by their eyes
Researches similar to those that the British and Australians carried out with the sprayers were carried away by their Japanese colleagues. But they experimented with cichlids for about a year. They tried to understand whether the fish recognize each other, that is, whether they distinguish one relative from another. And if they do, then how. For us, it must be understood, all cichlids, as they say, look the same. So are the Japanese.
Eight males were tested. They were seated in pairs in four aquariums. In about a week, the fish got used to each other and stopped quarreling.
Then all the males were seated separately – in single aquariums. And they began to add a neighbor to each – not alive, but in the form of an image on the monitor, leaning against the wall of the aquarium. The image was a kind of chimera, composed of parts of seven other males. Specifically, the head of one was attached to the body of another – in all possible variants, among which were the following designs: a familiar head and a familiar body – according to the previous joint imprisonment, a familiar head – an unfamiliar body, an unfamiliar head – a familiar body, an unfamiliar head and body.
As a result, it turned out that the cichlids recognize each other. And recognizing, they distinguish their fellows by their heads. This takes them about half a second. A person needs about the same. To recognize a friend.
Scientists believe that the main distinguishing feature of cichlids is the eyes of congeners – it is in them that they look first. Just like people.
No, Pavel Volya is not right.
