The robotic carp developed by Ryomei Engineering (a subsidiary of Mitsubishi Heavy Industries) is a curious example of a fish robot. This remote-controlled metal fish resembles to a koi carp, and it’s actually a great catch: 80 cm and 12 Kg. The following video shows the smooth tail movement.
The robotics koi is able to swiming in reverse and rotating in place thanks to its five motors. Additionally, it is equiped with a CCD camera and sensors for analyzing water quality.