Cyst formation in the red tide flagellate Heterosigma akashiwo (Raphidophyceae)

Abstract

A natural population of Heterosigma akashiwo was collected and incubated in the dark with autoclaved marine sediment. A portion of the cells in the population changed into cysts, which were identical to H. akashiwo cysts found in the field. The cysts required at least 2 weeks of mandatory dormancy before germination.