Does this look like a Zebra danio?


It seems that it does — if you're a Zebra danio. It's hoped that robots like this could be used to lead real ones away from danger in the future.

This smiley faced 15cm/6" robotic zebrafish was certainly a hit with the real thing, as scientists found that when it was placed in a tank with Zebra danios the fish were drawn to it.

Even though the robotic fish is around five times the size of a real Zebra danio, both single fish and groups mingled happily with it, in preference to spending time in other areas of the tank.

In the research by a team from the Polytechnic Institute of New York, the robot was separated from the live fish by transparent barriers. Although the robot moved its tail, the fish swam in a placid environment and experienced no swimming advantage from the robot. But they still congregated at the barrier near the robot, proving that the appearance of the robotic fish was itself a factor in the attraction.

The robot has features known to attract Zebra danios — a plump shape, similar to that of a fertile female, and it was given the characteristic bright blue stripes. The flexible tail uses a motor to move it back and forth.

Studies showed that motility was attractive to the fish. When the robotic fish was adjacent to a replica whose tail wasn't moving, the danios moved to the side of the tank near the moving robot.

However, when the lights went out, the fish stayed away from the robot — which the researchers say is a sign that they dislike the noise it makes — something that the fish are willing to overlook when they can see its visual cues. For future studies, it's aimed to produce a 'silent' robotic fish.

As well as helping to study fish behaviour, it's hoped that robots like this may have their uses in protecting real fish by luring them away from hazards such as oil spills.

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