Ecological and Morphological Observations on a Population of Cyclotella Pseudostelligera Hustedt

Abstract

Changes in chemical composition and phytoplankton population were studied during the spring and summer of 1963 in a pool 1.3 ha. in area. The numbers of the plankton diatom Cyclotella pseudostelligera were related to the amount of silica in solution, which also had an effect on the pattern of valve ornamentation. Clonal culture confirmed the latter and the silica-deficient forms resembled C. woltereckii Hustedt.