The role of bristles in the distribution of a Scenedesmus (Chlorophyceae)

Abstract

In culture, Scenedesmus 614 produces four-celled colonies with spines and bristles. Mean bristle length is 120 μm. Colonies in undisturbed, actively growing, batch cultures remain uniformly distributed in the medium for a period of weeks. Each colony has a fixed position and a finite amount of space.

With its complete bristle complement a colony in the inoculum can remain in suspension until reproduction occurs. Each newly released colony develops its own bristle display, which soon interlaces with other bristles, even those of the discarded parent cell wall. In such an elaborate interlaced net cultures can not, and do not, settle. Suspension is assisted during the light period by convection currents within the culture vessel (e.g. currents produced by the heat from a fluorescent bulb). Colonies began sinking in darkness, at a rate of no more than 2·5 cm in 9 h.