These underwater “crop circles” were until recently a complete mystery. Japanese underwater photographer Yoji Ookata discovered the intricate 6 foot wide circles on the seafloor off Amami Oshima island in Japan. He returned to the island with an NHK film crew in order to study the circles. Together they discovered the artist behind the circles—a small species of pufferfish. Males of the species create the circles with their fins in order to attract females. They mate in the center and the circle helps keep the eggs from drifting away. The tale is the subject of an NHK documentary and a blog post over at Spoon & Tamago.
via Spoon & Tamago