It's a popular belief that fish can't remember anything for longer than seven seconds. It may seem sad to think that they don't remember what they've eaten or where they've been, and they don't recognize you or any of their friends – every moment in their lives would be like seeing the world for the first time. But don't be so quick to feel sorry for them. A recent study has found that fish have much better memories than we used to think. In fact, certain species(种类) of fish can even remember events from as long as 12 days ago, BBC reported.
In the study, researchers from MacEwan University in Canada trained a kind of fish called African cichlids to go to a certain area of their tank to get food. They then waited for 12 days before putting them back in the tank again. This suggested that they could remember their past experiences. Researchers used computer software to monitor(监视) the fish's movements. They found that after such a long break the fish still went to the same place where they first got food.
In fact, scientists had been thinking for a long time that African cichlids might have a good memory. An earlier study showed that they behaved aggressively in front of certain fish, perhaps because they remembered their past fights.
Just as a good memory can make our lives easier, it also plays an important part when a fish is trying to survive(生存) in the wild. "If fish are able to remember that a certain area contains safe food, they will be able to go back to that area without putting their lives in danger," lead researcher Trevor Hamilton told Live Science.
For a long time, fish were placed far below chimpanzees, dolphins and mice on the list of smart animals. But this study has given scientists a new understanding of their intelligence. So next time you are watching your pet fish from outside the tank, perhaps you should feel closer to them – they may remember who you are.
