Induction of colony formation inOlisthodiscus luteusCarter

Abstract

Olisthodiscus luteus Carter, a marine member of the Chrysophyceae can be grown in two morphological forms: as motile biflagellated unicells in an inorganic seawater medium and as non-coenobic colonies in an enriched seawater medium. The spherical colonies consisted of from two to 22 cells. The transition from unicells to colonies starts 2 days after the transfer of cells from inorganic seawater into enriched seawater medium while the transformation from the colonial to the unicellular habit of growth is almost completed 2 days after the retransfer of the culture into plain seawater medium.