I wasn’t able to find out too much information about this robotic fish, but it really is a pretty cool bit of engineering.
From what I can tell, Sedensha Co. made this electric fish (link translated from Japanese), which can wriggle its way through the water just like the real deal. Its movements are controlled through electrostatic actuators which replicate the movements of fish muscles. The whole contraption is placed inside a silicon rubber fish, filled with silicone oil. Yum, silicone oil. I guess they were all out of cod liver oil. So without further ado, check out the amazing Japanese Robo-Fish in action:
I like how they even went the extra mile and stuck some googly eyes on it. I don’t know why, but it reminds me of that Dreamcast game Seaman. While the fish definitely has realistic moves, if I were a fish in that tank and saw Robo-Fish coming my way, I’d wet my little fish pants. Of course, I’d be underwater, so nobody would know. Whew.