The banana shaped objects are the individual cells. Unlike the Pediastrium, however, these cells gather in an informal colonial arrangement. Some of these colonies can get quite large, supporting dozens of cells in one colony. Neither the Pediastrium nor the Selenastrum have a means of locomotion (some colonial protists do), so they depend on water currents for mobility. Like all algae, they convert sunlight, CO2 and nutrients into energy and O2 through photosynthesis. Back To Image Index Page