A clone of Scenedesmus with Chodatella-stages

Abstract

A clonal culture of an organism isolated as Chodatella quadriseta Lemm. developed coenobial stages resembling Scenedesmus quadricauda (Turp.) Bréb. The sequence of these changes was followed, the population being found to consist almost entirely of unicells when young, but with a regular increase in coenobia with increasing age. Definition of the coenobia was attempted by numerical analysis of shape and size. Another clone, from a different habitat, was found to behave similarly. Some of the taxonomic implications of this form of pleomorphism are discussed.