Scientists were long baffled by the appearance of beautiful, intricate underwater artwork that resembled crop circles. These phenomena appeared up to 80 feet below sea level and can be up to six feet in diameter.

The mystery was solved in 2012 when an underwater photographer captured the images of the puffer fish carefully carving the designs in the sand.

Japanese photographer Yoji Ookata discovered the activity and later brought back a film crew and others for further study. What they found was truly breathtaking.

The fish not only uses its body but also takes small shells and uses them to line the inner grooves of the sculpture as decoration. This painstaking attention to detail is for the purpose of attracting a mate. The female puffer fish is drawn to the sand sculpture, and after mating, will lay her eggs in its center.

The fish works with very little rest for almost 24 hours a day, for a full week to complete the design.

See a video of the puffer fish carving a crop circle here.