Fishes' three-second memory a myth

Sydney, Jan 15 (IANS) The 'fact' about fishes having a three-second memory is after all a myth, research shows.

Kevin Warburton, adjunct researcher with Charles Sturt University's Institute for Land, Water and Society, who has been studying fish behaviour for many years calls the earlier theory as "absolute rubbish". 	 	
"Fishes have a good enough memory span as they can learn to avoid predators for several months after being attacked once and avoid hooks for at least a year after being caught," says Warburton.	 	
He conducted experiments looking at how Silver Perch (a fish type) learn how to handle different types of prey. "What came out, unexpectedly, was that while they were learning about their prey, their foraging (searching for food) efficiency went down." 	 	
"With one type of prey, the fish got more and more efficient at catching their food, but when we put two different types of prey in together, their overall efficiency dropped. We think it was because they suffered from divided attention. It's a cost of learning," the researcher added.	 	
He said fishes have some behavioural traits that were thought very human, such as deception. "For example, Siamese fighting fish will attack other members of the same species more aggressively if they've seen them lose contests with other fighters," a Charles Sturt release quoting him said.