The empty cells have already divided to produce new daughter colonies, leaving only the colorless remains of the parental cell walls as the "ghost colonies" shown here. The green cells have not yet divided.
Scenedesmus is an example of a coenobium, or a colony where the shape and number of cells are determined genetically in early development and do not change during the life of the organism. Each parent cell can reproduce asexually to form nonflagellate cells that align laterally and develop
into a daughter colony identical to the parent colony. The new autocolonies remain curled tightly
within the parental cell walls until they are eventually released through a break in the cell wall.
This asexual reproduction is similar to that of Hydrodictyon and Pediastrum, although the zoospores of Scenedesmus are not flagellated. Molecular sequence analyses support this relationship.