Evolution is not only a savvy designer, it doesn’t charge anything for the plans:
(The Navy) wants to build robotic bluefin tunas for submarine surveillance missions. The first prototypes, designed by Massachusetts engineers, should be available by the end of the year. Of course, there are many other autonomous underwater vehicles (UAVs) already on the market. But there is a twist: a vast majority of them uses propellers. In fact, they are gliders, not swimmers. And RoboTuna 2.0 will be able to travel three times longer than these gliders with the same batteries.