Scenedesmus is one of the commonest genera of freshwater algae comprising of hundreds of named species. The cells of Scenedesmus usually are arranged in a row to for 4- or 8-celled colonies. Two to 16-celled colonies can occur and very rarely there are more than 16 cells per colony. Because of the plasticity of shape and form it is doubtful that all of the described species are separate entities.