UK scientists have created the first convincing robotic fish that shoals will accept as one of their own. The innovation opens up new possibilities for studying fish behaviour and group dynamics, which provides useful information to support freshwater and marine environmental management, to predict fish migration routes and assess the likely impact of human intervention on fish populations.
"We've proven it's possible to use robotic fish to study relationships between individuals and shoal dynamics as well as the behaviour of individual fish," says PhD student Jolyon Faria, from the University of Leeds, who led the experiments. "In the past, we had to watch a shoal and change environmental conditions to see how that affected behaviour. Because the robotic fish is accepted by the shoal, we can use it to control one or several individuals, which allows us to study quite complex situations such as aggressive, cooperative, anti-predator and parental behaviour."
The computer controlled replica dubbed Robofish by its creators John Dyer, Dr Dean Waters and Natalie Holt is a plaster cast model of a three-spined stickleback with an acetate fin, painted to mimic the coloration and markings of a real fish. The scientists needed to prove that Robofish was accepted into the group sufficiently for the fish to respond to the robot like a normal shoal member.
"Although Robofish looked like a stickleback to us, we weren't sure whether the other fish would see it in the same light," explained Jolyon. "We also thought there might be a problem with the smell, as fish use chemical cues in the water to identify other shoal members. In the end, Robofish was accepted straight away though we did trial various models until we found one that worked the best."
Robofish was placed in a tank with either single fish or a group of ten, and then programmed to follow a set path at a slightly faster speed than normal fish. The aim was to see if Robofish cou
|Contact: Jo Kelly|
University of Leeds