Fig. 5

Platynereis dumerilii chronobiology. Sun and moon provide different cues for the rhythms that govern the worms’ biology. L-Cry functions as a valence detector, as well as a detector for the full moon phase. r-Ops1 biochemically cannot discriminate between sun or moonlight, but its high sensitivity allows it to precisely determine moonrise. While the ~ 24-h-long clock relies on the “conventional” circadian transcription factor network, the nature of the circalunar (monthly) clock still remains unknown. It also remains to be tested if the annual changes are just direct responses to environmental changes or controlled by an endogenous annual oscillator