Fish Memo

ryThree-second fish memory 'rubbish'

Forget what you know: Fish have a memory that lasts much more than three seconds and are capable of deception and learning, say Australian researchers. Dr Kevin Warbuton, an adjunct researcher at the Institute for Land, Water and Society at Charles Sturt University in Albury, New South Wales has been studying fish for more than three decades and says they're much better at memory than we give them credit for Warbuton's research has been focused on Australian freshwater fish, particularly in southeast Queensland. He says the idea that fish have a short memory is wrong. "It's absolute rubbish," says Warbuton. "There's been a lot of work done over the last 15 years on learning and memory in fish and it has been found that fish are quite sophisticated. "Fish can remember prey types for months; they can learn to avoid predators after being attacked once and they retain this memory for several months." Warbuton believes fish are capable of learning, albeit at a cost. For example, his research on the silver perch revealed something unexpected. "With one type of prey, the fish got more and more efficient at catching their food," he says. "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."

Art of deception

According to Warbuton, fish are also capable of exhibiting human-like behaviours, such as deception. "Fish can recognise other individuals and modify their own behaviour after observing interactions between other individuals. "Siamese fighting fish will attack other members of the same species more aggressively if they've seen them lose contests with other fighters." Warbuton says cleaner fish - reef fish that eat parasites off other larger fish - will also be on the lookout to assess the situation and work out how best to take advantage. "What's fascinating is that they cooperate more with clients when...