Confocal image of a squid embryo. All nuclei are stained with DAPI (blue). Phalloidin staining reveals neural structures (red), while cilia on the surface of the embryo are highlighted by acetylated tubulin staining (green).
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 Takifugu rubripes, the poisonous pufferfish eaten by only the bravest sushi connoisseurs.
Yoji found a series of small male fish working tirelessly, day in and night out, to craft these mate-attracting marvels using a single fin.