From the Department of Awesome Natural Wonders come these mysterious patterns on the ocean floor off the southern coast of Japan. Japanese scuba diver and photographer Yoji Ookata, who has spent the last 50 years exploring and documenting his underwater discoveries off the coast of Japan, spotted these beautiful and puzzling patterns in the sand, nearly six feet in diameter and 80 feet below sea level, during a dive near Amami Oshima at the southern tip of the country.

So what happened next? Are these rippling geometric patterns the equivalent of crop circles on the seafloor? Not quite, but the answer is still a good one. Colossal explains:

“He soon returned with colleagues and a television crew from the nature program NHK to document the origins what he dubbed the “mystery circle.”

Using underwater cameras the team discovered the artist is a small puffer fish only a few inches in length that swims tirelessly through the day and night to create these vast organic sculptures using the gesture of a single fin. Through careful observation the team found the circles serve a variety of crucial ecological functions, the most important of which is to attract mates. Apparently the female fish are attracted to the hills and valleys within the sand and traverse them carefully to discover the male fish where the pair eventually lay eggs at the circle’s center, the grooves later acting as a natural buffer to ocean currents that protect the delicate offspring. Scientists also learned that the more ridges contained within the sculpture resulted in a much greater likelihood of the fish pairing. 

too cool