Vincent wrote:
That's a myth I'm afraid.
Well, I stumbled upon the magazine by accident, so here it is:
Icthyologists have known for a long time this isn't true [memory being short], and in 2003 Dr Phil Gee, of the School of Psychology at the University of Plymouth, published research which blew it out of the water. Fish have a memory span of at least three months, and can distinguish between different shapes, colours and sounds. In the Plymouth experiments, goldfish were trained to press a lever to gain a food reward; when the lever was fixed to only work for an hour a day, the fish soon learned to activate it at the correct time. A number of studies has shown that farmed fish can be easily trained to feed at particular times and places, in response to an audible signal.
From the Fortean Times issue 189 (Nov 2004)