Scenedesmus morphogenesis. Control of the unicell stage with phosphorus

Abstract

Scenedesmus Meyen is frequently found in freshwater plankton. Many species exhibit extensive morphological variability both in nature and in the laboratory.

The specific control of variation between colonies and unicells in Scenedesmus IUCC 1588 has been investigated. Colony control was achieved with a dilute defined medium containing 3·07 mg 1^-1 total inorganic salts. Additions of phosphate, and no other nutrient, induced unicell formation. These data are correlated with growth in soil extract, concentrated inorganic media and natural waters.