First Robot Fish on Display in London

They swim like tuna, accelerate like pike and navigate like eel -- but the new fish in the tanks of the London Aquarium are actually robots.

The world's first ever autonomously controlled fish made a splash at the London Aquarium this week. The three robotic fish, which are about the size of carp, use sensors to navigate round the place and can therefore avoid the other (real) fish they share a tank with.

The scientists at Essex University, who spent three years developing the droids, say that because the robots' undulating movements are so realistic, visitors assume the fish are real. Of course, as the fish have shiny metallic scales and a battery power of five hours, visitors would have to be pretty slow to not realize they are looking at robots. To see if you can tell the difference take a look at this BBC video of the robo-fish swimming in their London tank.