Morphological Variability in Rhizoclonium Riparium (Roth) Harv. (Chlorophyceae: Cladophorales) Under Natural and Experimental Conditions

Résumé du livre

Populations of the filamentous green alga Rhizoclonium riparium (Roth) Harv. (including R. implexum (Dillw.) Kütz.) growing on vertical wooden poles in the intertidal zone, show a morphocline. Filaments with wide, short cells are found high up in the intertidal zone, and filaments with narrow, long cells in the lower parts. Along the gradient these two forms gradually change into one another. By means of culture experiments it could be demonstrated that the morphological characteristics of Rhizoclonium are completely changeable by the action of environmental factors. Each combination of culture conditions (temperature, culture medium, photo-period) modifies both the "wide" and the "narrow" filaments into an ecological form with uniform cell-dimensions, characteristic for those particular conditions.