Light micrography of Volvox colonies. - Vídeo de acervo HD

The colonies are composed of hundreds of green algae cells similar to Chlamydomonas, each cell has 2 whip like flagella and a red eye spot. The individual cells are connected by thin strands of cytoplasm and together can swim in a coordinated way. This enables the colony to swim towards a light source, for example, or to rotate, as in the image. Within the colony are daughter colonies that will be released into the surrounding water. The colonies generally range in size from 350 to 500 micrometers but some of the larger species such as Volvox globator can grow up to 6mm across!