Earlier this year, off the southern coast of Japan, Yoji Ookata, a deep-sea photographer and diver who has been documenting the deep sea for more than 50 years, saw something he had never observed before. A circular pattern of rippling sand about 80 feet below sea level and 6 feet in diameter was on the ocean floor.
Ookata returned to the same spot with a TV camera crew in tow to capture the discovery and figure out who or what had created its intricate design. Ookata dubbed his new find the “mystery circle” and was shocked to find out that a single puffer fish, no more than a few inches long, had created the circles using just one fin..