This mystery has finally been solved! No, aliens are not responsible for the creation of these remarkable underwater circles discovered by a diver named Yoji Ookata near Japan’s Amami-Oshima Island about 20 years ago. While diving almost 80 feet below sea level, he suddenly noticed rippling geometric sand patterns nearly 6.5 feet in diameter.
Scientists say these mysterious circles are actually nests created by male pufferfish, which spend about ten days carefully constructing and decorating the structures to woo females. Observations revealed that the female fish is namely attracted to the hills and valleys within the sand and carefully pass through them.
The male fish, which measures less than 5 inches long, first uses his body to create peaks and valleys in the sandy bottom around a central circle of smooth sand. He accomplished this feat by swimming in toward the center of the circle a straight line and then back around the center in a circular motion.
Before the female fish arrives to inspect his handiwork, the male forms irregular patterns in the fine sand particles of the central circle. He also decorates the peaks of the outer portion with shell and coral fragments. Observations revealed that the female fish is namely attracted to the hills and valleys with the sand and carefully passes through them.
Scientists have also noted that the male and female pufferfish would mate and lay eggs in the center of the circle. When a potential female partner arrives on the scene, the male stirs up the fine sand in the nest’s inner circle. If she deems the nest, and the male who built it, satisfactory, she lays her eggs in the center of the nest and leaves. Once the female leaves, the male remains in the nest until the eggs hatch six days later. Once again, proving that God’s creations are amazing!
Written by: Terri McInnis (PITN Communications Director)