A premature adult Platynereis wormEUREKALERT, CURRENT BIOLOGY, ZHANG ET AL.
Two marine species have internal rhythms driven by the tide and the moon, independent of ordinary circadian rhythms, according to studies published yesterday (September 26) in Current Biology and Cell Reports.
Marine organisms have long been known to exhibit behaviors that cycle with the tides and the phases of the moon. These rhythms coexist alongside the animals’ circadian rhythms—daily patterns driven by an internal molecular clock.
What has been unclear is whether these behavioral fluctuations result from modifications to the creatures’ circadian clocks, or whether they result from an independent molecular rhythm within the animals. The new studies show—at least in the two species researched—that tidal rhythms remain even if the circadian rhythms are disrupted through various molecular and environmental means.
“This is the first ...
