Lithium ions lengthen the circadian period of growing cultures of the diatom <i>Skeletonema costatum</i>

Abstract

Turbidity measurements revealed that the circadian rhythm in the growth rate of the marine diatom Skeletonema costatum (Greville) Cleve was insensitive to temperature between 5 and 22°C. Growth of the alga was inhibited by lithium ions at concentrations higher than 2 m M . Lengthening of the circadian period was observed in the presence of 0.5–1.5 m M Li + . The results indicate that the lithium effect generally observed on circadian rhythms should not necessarily be ascribed to changes in an intercellular coupling of cellular oscillators.