by the Center for Biological Diversity

Underwater photographer Yoji Ookata was baffled by what he saw off the coast of Japan some 80 feet below the ocean’s surface: an intricately designed and beautiful “crop circle” nearly 7 feet in diameter. Intrigued, he spent days hanging around the underwater circle waiting to discover the hand of the artist at work.

Turns out it wasn’t the doing of aliens who’d overshot a Nebraska cornfield or out-of-work art students with scuba gear. No, it was a masterwork by an amorous and talented male Fugu rubripes, the poisonous pufferfish eaten by only the bravest sushi connoisseurs.

Recently aired on Japanese television, Ookata’s underwater film shows the fish’s fins forming circular sand patterns, then lining the ridges with tiny, cracked shells. Apparently the intricate circles attract female pufferfish — the more ridges, the more interest — which mate with the males and lay eggs in the centers of their circles.

Check out photos and read more about Ookata’s underwater discovery at the website Spoon & Tamago.