I raised some goldfish when I was a child. I love them very much. Many people told me that, “You know what？Goldfish only have 3 second memory. So don’t feed them too much. They will be die because eating too much.” Every time I heard that I feel amazing and puzzled at the same time. I cannot imagine what life will be like if a creature only has 3 second memory and I do not want they die because over eat. I did not try to find answer before, but I decided to figure it out today.

Do goldfish really only has a 3 second memory? The answer is a big NO. Actually according to scientists study, their memory span can last 5 months long, even years. According to Today I found out, scientists have already do a research try to figure out if this myth is right or wrong. One of the experiments they did is that. They put a lever in the fish tank, if they push the lever at certain time during the day. They will got food, otherwise they don’t. Gradually, the fish learned to push the lever during the certain time of the day when they will be feed. During the other time of the day, they just ignore it. Here is vedio about break this myth.

Actually, the study of training fish has great value on fish farming industry. According to Daily mail, scientists trained fish through feed them and play a specific sound at the same time. After training, they release them to the sea. Until they grow up, scientists play the sound in the sea again, and these fish swam back to them. This technique has a lot advantages such as saving feed sources and environment.

Back to the topic, I am very glad to found out that goldfish has a more than 3 second memory. If you raise fish at home, keep changing the spot where fish tank is placed. It helps fish to get rid of bored due to see the same view over and over again. Goldfish even can recognize their own master. Maybe they cannot please you like dog or cat, but they are smarter than you can imagine.

Sources：http://www.dailymail.co.uk/sciencetech/article-1106884/Three-second-memory-myth-Fish-remember-months.html

http://www.todayifoundout.com/index.php/2010/10/goldfish-do-not-have-a-three-second-memory/