Just because you're feeling paranoid, doesn't mean the fish aren't actually spying on you.
Engineers at the University of Kitakyushu created an underwater survey robot that looks good enough to eat. “Tai-robot-kun,” a 7-kilogram (15.4 lb) robotic sea bream (red snapper) with a silicone body covered in realistically hand-painted scales, features a unique propulsion system that allows it to move its tail and drift silently through the water like a real fish.
The robotic fish can swim for an hour on a full battery charge, and it relies on a ballast system similar to those used in submarines to adjust its buoyancy and depth.
Tai-robot-kun’s creator, professor Ikuo Yamamoto, says the robot can easily be mass-produced, outfitted with various cameras and sensors, and released into the sea to perform a wide range of oceanographic survey tasks. He adds that because the robot swims silently and looks like a real fish, it would be able to gather data without alarming the creatures it encounters.