Lunar cycle-mediated behaviours in animals, including humans

Abstract

Abstract The lunar cycle influences the behaviours of life forms across multiple phyla, including humans. Tides are perhaps the most observable effect of the moon. The moon exerts a surprising impact on animals through reflected fluctuations in light levels. Early works on the lunar effect were primarily observations. The interpretation of natural light by animals to adjust their physiology and behaviour has been enigmatic for a long time. In Platynereis, rOpsin1 senses the moonrise. A molecule called L-cryptochrome (L-Cry) can distinguish between moon phases and sun and moonlight. L-Cry distinguishes the proper valence of moonlight and thus entrains the circalunar clock to regulate reproduction. The lunar effects influence animals through hormones such as melatonin, GnRH, and some steroids. Interestingly, several genes have been revealed to constitute the genetic basis of lunar effects. The present communication provides a succinct account of lunar-mediated effects on animals, including our species.