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.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. __
