Marine worms can distinguish between moonlight and sunlight

Thus, the researchers determined that in the dark, L-Cgu has the form of a dimer of two identical fragments with an unstable bond between them. However, when exposed to bright light, the cryptochrome breaks down into two separate monomers that, even when on their own, can sense light. At higher light intensities, both parts are activated, whereas at low light intensities, only one of them is activated.

Thus, according to the scientists, the worms not only sense light, but can also distinguish between lunar and solar light, and the unique protein even allows them to notice how the phases of the moon change.