Fish 'Very Capable Of Learning And Remembering'
by ROBERT MATTHEWS
Copyright 2004 The Sunday Telegraph, London
If you thought fish were cold, wet morons who forget everything in three seconds flat, think again. Scientists have found they are fast learners, carry mental maps around in their heads - and can retain memories for months.
Swimming gormlessly around in aquaria, fish have long been dismissed as dunces compared with "higher" animals such as rats, dogs and primates. This view is now being challenged by findings that could re-ignite the debate over the cruelty of angling.
Tests of small fish in aquaria at the University of Oxford has shown that despite their tiny brains, they possess cognitive abilities outstripping those of some small mammals.
Dr Theresa Burt de Perera made the discovery using blind Mexican cave fish, which rely on subtle changes in pressure to detect the presence of objects around them. In the experiments, Dr Burt de Perera found the fish did more than merely avoid bumping into objects in their tank. Tests showed that they set about building a detailed map of their surroundings, memorising the obstacles in it in just a few hours. Once stored in their brain, the fish then used their "mental map" to spot changes in the shape and size of the obstacle course around them - a feat that defeats hamsters.
In one test, involving obstacles arranged in a specific order, the fish proved capable of learning and memorising the order - and quickly spotted when Dr Burt de Perera tried to trick them by swapping obstacles around.
According to Dr Burt de Perera, the findings - which appear in the current issue of the Proceedings of the Royal Society - show that the image of fish is in need of a makeover. "The public perception of them is that they are pea-brained numbskulls that canít remember things for more than a few seconds", she told the Sunday Telegraph. "Weíre now finding that they are very capable of learning and remembering, and possess a range of cognitive skills that would surprise many people".
Laboratory tests on other fish have found that they can store memories for many months, confounding the belief that they forget everything after a few seconds. Dr Culum Brown at the University of Edinburgh has found that Australian crimson spotted rainbowfish who learned to escape from a net put in their tank remembered how they did it 11 months later, which given their much shorter lives, is like humans recalling a lesson learned 40 years ago.
"The take-home message is that in some areas the cognitive abilities of fish can match non-human primates", said Dr Burt de Perera. "Just because they have small brains does not mean they arenít capable of doing interesting things".
Her findings have been welcomed by fish-lovers as scientific proof of their belief that their pets can do more than blow bubbles. "They are totally misunderstood", said Karen Youngs (CORRECT), editor of Practical Fishkeeping. "We know from our readers that fish can recognise their owners, and some will go into a sulk if someone else tries to feed them".
Mrs Youngs added that the research may mean fish-owners have to make their aquaria a bit more interesting for their occupants: "We know that fish such as oscars do enjoy having a table-tennis ball to bash about - they seem to get something out of that".
The mounting evidence for fish intelligence looks likely to re-ignite the controversy over angling, which has so far focused mainly on whether fish can feel pain. "This research moves the debate along, by showing that fish arenít just swimming vegetables", said Dawn Carr, director of People for the Ethical Treatment of Animals (Peta). "The more we find out about fish, the less likely people are to feel comfortable about impaling them on a hook for fun".
Hopes that the new research might lead to a change in heart among angling enthusiasts were quickly dashed by the National Federation of Anglers. "Their intelligence just adds to the interest - it would be awful if people were only catching fish that were stupid", said Rodney Coldron, a spokesman for the NFA. "I think it might attract more people to fishing, by showing itís more of an even contest".
Published here with the permission of the Author. Many thanks to Kyriakos Seitis for getting his permission for MCH.