Study Finds Fish Fear Robotic Predators Unless They Are Drunk

Posted on August 3, 2013

Researchers conducted a series of tests to see if zebrafish would be afraid of robotic versions of predators. Then they got the fish drunk and tested them again. The fish were less afraid of the robotic predator fish (pictured above) and robotic heron (below) when they were drunk.

The research was conducted by Maurizio Porfiri, associate professor of mechanical and aerospace engineering at the Polytechnic Institute of New York University (NYU-Poly) and Simone Macri, a collaborator at the Istituto Superiore di Sanita in Rome, Italy.

The scientists first placed zebrafish and a robotic Indian leaf fish in separate compartments of a three-section tank. The other compartment was left empty. The control group uniformly avoided the robotic predator, showing a preference for the empty section. A robot heron was also used in tests.

The researchers then exposed separate groups of fish to different doses of ethanol in water. Ethanol has been shown to influence anxiety-related responses in humans, rodents and some species of fish. The zebrafish exposed to the highest concentrations of ethanol showed remarkable changes in behavior. The drunk fish failed to avoid the robotic predators.

Porfiri said in a statement, "These results are further evidence that robots may represent an exciting new approach in evaluating and understanding emotional responses and behavior. Robots are ideal replacements as independent variables in tests involving social stimuli-they are fully controllable, stimuli can be reproduced precisely each time, and robots can never be influenced by the behavior of the test subjects."

The research was published PLoS One.

ANIMALS
FISH