The authors developed a robotic fish that swim with fins that apply flexible oscillating fin technology. The Carp Robot, whose artificial appearance was created through three-dimensional CAD processing of numerical data for the outer shape of living carp sampled through three-dimensional laser digitizing. Although this robotic fish was developed for the amusement field, it is thought to contain key technologies for the development of work robots in the future. For example, "mechatronics" technology involving center-of-gravity shifts, FM radio wave technology for navigation, CCD image data transfer technology for observation, and other technologies were applied to the robotic fish. In this report this robotic fish will be used as examples to explain these development achievements.