Three-second memory myth: Fish show they can remember things for up to five months

Three-second memory myth: Fish show they can remember things for up to five months

By Daily Mail Reporter
Last updated at 10:55 PM on 06th January 2009

Their brain power is at best shallow. Or so we thought. But scientists believe fish may have hidden depths.

The creatures said to have a mere three-second memory span can actually recall information for up to five months.

Scientists found that fish trained to respond to certain sounds in captivity still reacted months later when they heard them in the wild.


New findings suggest that the three-second memory of the fish is in fact a myth

The finding challenges the stereotype of fish being forgetful sorts, an idea reinforced by films such as Finding Nemo, whose characters include an absent-minded fish called Dory.

On a more serious note, it could also prove a boon to fish farmers, cutting the need for expensive cages and feeding regimens.

Researchers from the Technion Institute of Technology in Israel trained young fish to associate a sound played through a loudspeaker with feeding time.

Each time they played a particular sound, the fish would return for food.


Finding Nemo featured a fish called Dory (centre) plagued by memory problems

After a month of training, the fish were released into the sea, where they were left to their own devices.

Four to five months later, when they had become adults and ready for marketing, the sound was played again and the fish returned.

Applied to fish farming, the technique would allow 'trained' fish to be released into the sea, where they would mature naturally until ready for the table.

The cost of cages, staff and feeding would all be cut, as would the impact on the environment, an agricultural conference heard.

Reporting on their findings, the researchers said: 'The new method has many advantages. The fish grow in their natural environment, without the use of cages and without environmental pollution.

'Feeding is more economical and is based mainly on food found naturally.'

Previous studies have shown that goldfish are capable of remembering and learning - and that they outshine trout in the intelligence stakes.

Scientists at St Andrews University in Scotland found minnows to be at least as intelligent as rats.

Researcher Dr Mike Webster said at the time: 'A lot of people have the image of a goldfish with a three-second memory - and that's not the case at all.

'There is a lot of evidence now that fish are no dumber than birds or many mammals - and in many cases they are just as intelligent.

'Many fishes - such as minnows, sticklebacks, and guppies - are capable of the same intellectual feats as, for example, rats or mice.

'They can learn their way around mazes, they can learn to recognise other fish, and they can remember which individuals are better competitors.'

According to research at Plymouth University, goldfish have a memory span of up to three months - and can even tell the time.

The fish were trained to nudge a lever to get food. When the lever was adjusted so it would only work during one hour each day, the goldfish adapted, learning only to press the lever around the right time.

They even clustered around the lever as feeding hour approached, apparently remembering it was nearly lunchtime.

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