Fish robot. Researcher with a robotic tuna fish in a tank of water. This Robotuna forms part of a project to develop better propulsion systems for submarines, and a better understanding of the physics of swimming. The Robotuna is modelled on the bluefin tuna, a fish whose body has evolved over 160 million years to make it a highly- manoeuvrable and efficient swimmer. The Robotuna is propelled by 6 motors, each rated at 1492 watts (2 horsepower), that flex the body by using internal tendons. The fish's skin" is comprised of lycra material. Photograph of David Barrett, the designer and builder of Robotuna, at the Massachusetts Institute of Technology, USA."