The production of larvae, the formation of statoblasts, and the growth rate of colonies of Plumatella fungosa were investigated in two Polish eutrophic lakes. On the basis of the obtained results and data referring to the seasonal changes in the biomass, origin, and distribution of the bryozoan colonies the author gives a schematic presentation of the life cycle of P. fungosa in the studied lakes.
In the studied eutrophic lakes the freshwater bryozoan Plumatella fungosa produced annually at least 3 generations of colonies. The successive generations differed from each other in their biomass and mode of forming colonies (developed from statoblasts or larvae). The biomass and density of P. fungosa colonies in the littoral zone changed significantly during the season (May-November) and over a period of many years.