How This Marine Worm Can Tell Moonglow From Sunbeams

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On a summer night in the Bay of Naples, hordes of worms swam upward from the seagrass toward the water’s surface under the light of a waning moon. Not long before, the creatures began a gruesome sexual metamorphosis: Their digestive systems withered, and their swimming muscles grew, while their bodies filled with eggs or sperm. The finger-length creatures, now little more than muscular bags of sex cells, fluttered to the surface in unison and, over a few hours, circled each other in a frantic nuptial dance. They released countless eggs and sperm into the bay — and then the moonlit waltz ended in the worms’ deaths.


The marine bristle worm Platynereis dumerilii gets only one chance to mate, so its final Phone Number List dance had better not be a solo. To ensure that many worms congregate at the same time, the species synchronizes its reproductive timing with the cycles of the moon. How can an undersea worm tell when the moon is at its brightest? Evolution’s answer is a precise celestial clock wound by a molecule that can sense moonbeams and sync the worms’ reproductive lives to lunar phases. No one had ever seen how one of these moonlight molecules worked.



Recently, however, in a study published in Nature Communications, researchers in Germany determined the different structures that one such protein in bristle worms takes in darkness and in sunlight. They also uncovered biochemical details that help explain how the protein distinguishes between brighter sunbeams and softer moonglow. Abstractions navigates promising ideas in science and mathematics. Journey with us and join the conversation. See all Abstractions blog It’s the first time that scientists have determined the molecular structure of any protein responsible for syncing a biological clock to the phases of the moon.