The deep sea mystery circle

On the seabed a geometric, circular structure measuring roughly 6.5 ft in diameter had been precisely carved from sand. It consisted of multiple ridges, symmetrically jutting out from the center, and appeared to be the work of an underwater artist, carefully working with tools. For its resemblance to crop circles, Ookata dubbed his new finding a “mystery circle,” and enlisted some colleagues at NHK to help him investigate. The unknown artist was unmasked.

Underwater cameras showed that the artist was a small puffer fish

The artist at work