They are created by the spunky and tiny pufferfish. The Pufferfish works approximately 24 hrs a week to keep its creation intact and together.
These circular structures are geometrically ordered with a diameter of 2 meters and are created in 7–9 days. Males have to maintain their circles in order to attract a mate.
The white-spotted pufferfish is known for its unique and complex courtship display which involves creating large, geometric circles in the sand.
These spatial circles were first noticed in 1995 by divers. However the reason was only known very recently in 2014, when the species of pufferfish was discovered in Ryukyu Islands by Diver .