[Tidal and lunar rhythms (author's transl)].

Behavioral and developmental rhythms of some species inhabiting the intertidal zone of sea-coasts as well as some species of tropical lakes and forests have adapted to environmental cycles which are determined by the moon (the semi-diurnal tides, the semi-monthly cycle of springs and neaps, and the changes in moon-light during the night). The underlying timing mechanisms of these tidal and lunar rhythmus are of different kinds. Some of them belong to the oscillating types of physiological clocks (circa-tidal oscillator, circa-semilunar and circa-lunar oscillator), others may represent an hour-glass type (resulting in a single programming), or they are based on a stochastically influenced control of the duration of activity and rest. The combination of a circa-semilunar oscillator with a circadian oscillator enables an intertidal organism to synchronize its rhythms with an environmental situation which reoccurs only every 15 days at the same time of day (1.3., low-water phase of spring tides). The speculations on true lunar rhythms in humans are discussed.