Cryptochromes (from the Greek κρυπτό χρώμα, hidden colour) are a class of blue light-sensitive flavoproteins found in plants and animals. Cryptochromes are involved in the circadian rhythms of plants and animals, and in the sensing of magnetic fields in a number of species. The name Cryptochrome was proposed as a pun combining the cryptic nature of the photoreceptor, and the cryptogamic organisms on which many blue light studies were carried out.
https://en.wikipedia.org/wiki/Cryptochrome#In_Drosophila