In fact, if we regard "fish's memory has seven seconds" as a scientific conclusion, many questions will arise. Can memory be accurate to the second? If the average memory of fish is 7 seconds, then some stupid fish only have 2 or 3 seconds. When these "stupid" fish take a bite of food, will they forget what's in their mouths instantly?
Fortunately, fish, as an early vertebrate species, has a very unique evolutionary position, so there are many scientific studies on fish memory. Although the types of fish used as experimental materials are different, the experimental methods and specific purposes are also different, almost all studies on fish memory show that fish memory is far more than 7 seconds.
For example: paradise fish-also has a strong memory. When the fish meets a strange goldfish in the pool, it will swim around curiously and look at the new strange neighbor until it loses interest. If the paradise fish and goldfish meet for the second time in the water tank, they will soon find that they are old acquaintances and lose interest in exploration. Experiments have found that this memory can last at least 3 months.
Zebrafish-also a very clever animal, can complete various tasks. In 2002, several researchers from the University of Toledo, Ohio, tested the memory ability of zebrafish. During the training, they will give zebra fish a red light as a signal before feeding. After 10 days of training suspension, zebrafish still remembers the red light signal indicating that it is time to eat [5]. In the laboratory, zebrafish can also quickly learn how to walk a maze [6], find food according to sound signals [5], remember the shape of predators, and avoid electric shocks according to tips.