This ‘robofish’ is so realistic, it can film fish without frightening them

Most robotic fish are like fish out of water: They’re surprisingly poor swimmers, and they often scare away any other creatures they come in contact with. But a new robot is so realistic that fish in Fiji are falling for it—hook, line, and sinker.

The remote-controlled robofish isn’t the world’s first. But the new version—called SoFi, for Soft Robotic Fish—is a step up from previous generations of robotic fish because it can be maneuvered up and down to depths of up to 18 meters. There’s a fisheye camera where its mouth would be, perfectly positioned to capture any action up ahead. And the robot doesn’t just look like a fish; it also moves like one, undulating its tail to propel itself through the water.

Scientists took SoFi for six test runs in coral reefs around the Pacific island of Fiji. The robot, which is 47 centimeters long, swam at speeds of half a body length per second. That’s a tad slower than most real-life fish, which can swim two to 10 body lengths per second. And it could swim for 40 minutes at a time, controlled by a diver up to 10 meters away, the team reported today in Science Robotics

The Fijian fish didn’t seem to mind SoFi swimming around. So the team hopes that the robot and its camera can be deployed elsewhere to help us peer into the lives of marine animals—to better see how they move, what they’re eating, and who they’re swimming around with.