For years the centifins lived in the deeps hardly changed in their isolated environment. As times went by much more evolved species inhabited the deeps and started competing with them and feeding on them. There the echofin replaced its ancestor the centifin. It is about the same size and in physically quite similar except for one main change: The echofin evolved new senses in order to help it locate itself, run away from predators, and finds it immobile food. It evolved a cone membrane around its neck which absorbs sounds waves. It also evolved a second set of tiny teeth its clicks all the time in order to locate itself and “see” its environments as vibrations using their own echo. They still feed on the pyamus and live in the depth of Sagan 4’s oceans.