The polymorphic life history of the marine naked amoeba Flabellula baltica was studied. It can be interpreted in terms of adaptations to an environment that is patchy in time and space and it represents trade-off between longevity during starvation and the ability to initiate multiplication soon after food resource become available. The life history also represents bet hedging in that different cells within a clonal culture may respond in different ways when food is depleted.