As the day when the robots rise up and take over becomes ever closer, one robotic fish has managed to trick some zebrafish into thinking it is real.
It’s only a small step along the path to world domination, but the robotic imitation of the Red Tiger Oscar fish proved to be as fearsome to a smaller fish as a real-life version.
Researchers from New York University created the robotic fish and compared how a zebrafish, prey of the larger fish, responded to being in its presence.
They found the amount of thrashing the smaller fish did increased when it was accompanied by the robot. Along with other factors, they were able to deduce that the fish was scared of the robot.
“Avoidance isn’t the only way we can tell a zebrafish is scared,” said Maurizio Porfiri, a professor at the university.
“When these fish are afraid, they also swim differently, and we were surprised to find that the robotic fish could produce an even stronger fear-related response than the actual live predator.”
The research paper, which published the findings, also said that the response of the Zebrafish was more consistent when it was faced with the robot fish, rather than a live predator.
The researchers also tested how the Zebrafish reacted when projections of its predator were put into the water around it – however, this didn’t have much of an impact on the fish’s behaviour.
The scientists believe that the fact the robotic fish can replicate the effects of intimidation in its prey means that it, and other robotic animals, may be able to be used in future research.
“Besides the replacement of live stimuli with robotic replicas, this study is expected to contribute to the reduction of animals used in experimental research by offering an innovative tool eliciting behavioral reactions characterized by limited inter-individual variation compared with current standards,” the research paper said.
“Reduced inter-individual variation will contribute to animal welfare by increasing the statistical power of experiments.”
However, they said that there are still “substantial” differences between the robot fish and the live predator. These include the robot’s limited movements and the inability to have a sense of smell.
The robot fish was based on the Tiger Oscar Fish down to a level that its tail beat frequency was created to be the same. It was made out of plastic and then spray painted in the correct colours by the team behind the research.
When the robotic fish was placed in a tank, attached to the tank the Zebrafish was in, it was fixed to the top of the tank and suspended in the water.
“The body undulation of the replica was achieved by externally actuating the anal, second dorsal, and caudal fin of the robot through a servomotor placed outside the water tank,” the research paper said.
The full paper was published in the Zebrafish journal and can be found here.
Images courtesy of New York University